JP2004201439A - Voltage conversion system, residual charge consumption method, and computer-readable recording medium storing program for making computer consume residual charge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voltage conversion system capable of consuming a residual charge without depending on a discharge resistance. <P>SOLUTION: A controller 30 generates a signal PWMB1 and outputs it to a stepup converter 12. The stepup converter 12 charges back the electric power accumulated in a capacitor C2 to a DC power supply B according to the signal PWMB1. When a DC current BCRT from an electric current sensor 18 falls below a prescribed value, system relays SR1 and SR2 are turned off, and the controller 30 generates a signal PWDCH1 and outputs it to the stepup converter 12. NPN transistors Q1 and Q2 are turned on/off according to the signal PWDCH1. So the residual charge of the capacitor C1 is consumed by a stepup operation of the stepup converter 12 while that of the capacitor C2 is consumed by a stepdown operation of the stepup converter 12. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a voltage conversion system capable of consuming a residual charge of a capacitor, a method of consuming a residual charge, and a computer-readable recording medium storing a program for causing a computer to execute the consumption of the residual charge.
[0002]
[Prior art]
Recently, hybrid vehicles and electric vehicles have attracted much attention as environmentally friendly vehicles. Some hybrid vehicles have been put to practical use.
[0003]
This hybrid vehicle is a vehicle that uses, in addition to a conventional engine, a DC power source, an inverter, and a motor driven by the inverter as power sources. That is, a power source is obtained by driving the engine, a DC voltage from a DC power supply is converted into an AC voltage by an inverter, and a motor is rotated by the converted AC voltage to obtain a power source. An electric vehicle is a vehicle that uses a DC power supply, an inverter, and a motor driven by the inverter as power sources.
[0004]
Such a hybrid vehicle or an electric vehicle includes, for example, a motor drive device 300 as shown in FIG. Referring to FIG. 25, motor driving device 300 includes DC power supply B, system relay SR, capacitors 309 and 320, boost converter 310, and inverter 330.
[0005]
Boost converter 310 includes a reactor 311, NPN transistors 312 and 313, and diodes 314 and 315.
[0006]
NPN transistors 312 and 313 are connected in series between the power supply line of inverter 330 and the ground line. The NPN transistor 312 has a collector connected to the power supply line and an emitter connected to the collector of the NPN transistor 313. The emitter of NPN transistor 313 is connected to the ground line.
[0007]
Diodes 314 and 315 are connected in parallel to NPN transistors 312 and 313, respectively, so that current flows from the emitter side to the collector side of the NPN transistors.
[0008]
Reactor 311 has one end connected to the power supply line of DC power supply B, and the other end connected to an intermediate point between NPN transistor 312 and NPN transistor 313.
[0009]
DC power supply B outputs a DC voltage. When turned on by a control signal from a control device (not shown), system relay SR supplies the DC voltage output from DC power supply B to boost converter 12. Capacitor 309 smoothes the DC voltage output from DC power supply B. Boost converter 310 has NPN transistors 312 and 313 turned on / off by a control device (not shown), boosts a DC voltage supplied from DC power supply B, and supplies an output voltage to inverter 330. In addition, boost converter 310 generates electric power by AC motor M1 and reduces the DC voltage converted by inverter 330 during regenerative braking of a hybrid vehicle or an electric vehicle equipped with motor drive device 300, and supplies the DC voltage to DC power source B. . Capacitor 320 smoothes the DC voltage supplied from boost converter 310.
[0010]
When DC voltage is supplied from boost converter 310, inverter 330 converts the DC voltage into an AC voltage based on control from a control device (not shown) and drives AC motor M1. As a result, AC motor M1 is driven to generate a torque specified by the torque command value. In addition, inverter 330 converts an AC voltage generated by AC motor M1 into a DC voltage based on control from a control device (not shown) during regenerative braking of a hybrid vehicle or an electric vehicle equipped with motor drive device 300. Then, the converted DC voltage is supplied to boost converter 310 via capacitor 320.
[0011]
As described above, motor drive device 300 drives AC motor M1 by boosting the DC voltage output from DC power supply B, and charges DC power supply B with the power generated by AC motor M1.
[0012]
In Japanese Patent No. 3097482, when the motor driving device 300 is stopped, the residual charge of the capacitor 320 is charged back to the DC power supply B.
[0013]
[Patent Document 1]
Japanese Patent No. 3097482
[0014]
[Patent Document 2]
JP-A-11-332248
[0015]
[Problems to be solved by the invention]
However, in the conventional motor drive device, when the residual charge of the capacitor arranged on the input side of the inverter is charged back to the DC power supply, if the voltage across the capacitor becomes equal to or less than the voltage of the DC power supply, the charge cannot be charged back. The remaining charge cannot be consumed.
[0016]
In this case, it is supposed that the residual charge of the capacitor is consumed by the discharge resistor. However, if the discharge resistor is provided, there is a problem that the cost increases. It is also conceivable to discharge to other auxiliary equipment, etc., but when discharging to auxiliary equipment, it is necessary to give the auxiliary equipment withstand voltage performance equivalent to discharge resistance, which raises the problem of increased cost. Occurs.
[0017]
Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a voltage conversion system capable of consuming residual charges without passing through a discharge resistor.
[0018]
Another object of the present invention is to provide a residual charge consuming method for consuming residual charges without passing through a discharge resistor.
[0019]
Still another object of the present invention is to provide a computer-readable recording medium on which a program for causing a computer to consume a residual charge without passing through a discharge resistor is recorded.
[0020]
Means for Solving the Problems and Effects of the Invention
According to the present invention, a voltage conversion system includes a power supply, an inverter, a voltage converter, first and second capacitors, and control means. The voltage converter is connected between the power supply and the inverter. The first capacitor is inserted on the power supply side of the voltage converter. The second capacitor is inserted on the inverter side of the voltage converter. The control means controls the voltage converter to consume the residual charge of the first capacitor and the residual charge of the second capacitor in response to the stop signal.
[0021]
Preferably, the control means controls the voltage converter such that residual charge of the first capacitor is consumed by a boosting operation by the voltage converter and residual charge of the second capacitor is consumed by a step-down operation by the voltage converter. I do.
[0022]
Preferably, the control means controls the voltage converter such that the step-up operation and the step-down operation are alternately repeated for a predetermined time.
[0023]
Preferably, the control means consumes a residual charge of the first and second capacitors when the first voltage of the first capacitor or the second voltage of the second capacitor is lower than or equal to the voltage of the power supply. To control the voltage converter.
[0024]
Preferably, the voltage converter includes first and second arms and a reactor. The first arm is arranged on the first capacitor side and includes first and second switching elements. The second arm is disposed on the second capacitor side and includes third and fourth switching elements. One end of the reactor is connected to an intermediate point between the first switching element and the second switching element, and the other end is connected to an intermediate point between the third switching element and the fourth switching element. Then, the control means controls the switching of the first to fourth switching elements so as to alternately perform the step-up operation and the step-down operation.
[0025]
Preferably, the control means lowers the carrier frequency and controls the switching of the first and fourth switching elements with a decrease in the first voltage of the first capacitor or the second voltage of the second capacitor. .
[0026]
Preferably, the control means controls the switching of the first and fourth switching elements by a carrier frequency corresponding to the first voltage or the second voltage.
[0027]
Preferably, the voltage conversion system further includes first and second voltage sensors. The first voltage sensor detects a first voltage of the first capacitor. The second voltage sensor detects a second voltage of the second capacitor. The control means holds the relationship between the first voltage or the second voltage and the carrier frequency as a map, and receives the first voltage received from the first voltage sensor or the voltage received from the second voltage sensor. A carrier frequency corresponding to the extracted second voltage is extracted with reference to a map, and the first and fourth switching elements are switching-controlled by the extracted carrier frequency.
[0028]
Preferably, the control means performs switching control of the first to fourth switching elements using a drive voltage lower than a drive voltage in a normal operation.
[0029]
Preferably, the control means controls the switching of the first and fourth switching elements at a carrier frequency lower than the carrier frequency during normal operation.
[0030]
Preferably, the voltage conversion system further includes an inductance changing unit. The inductance changing unit reduces the inductance of the reactor as the first voltage of the first capacitor or the second voltage of the second capacitor decreases.
[0031]
Preferably, the inductance changing means reduces the number of turns of the coil of the reactor as the first voltage or the second voltage decreases.
[0032]
Preferably, the inductance changing unit changes the number of turns of the coil to a number of turns corresponding to the first voltage or the second voltage.
[0033]
Preferably, the control means controls the switching of the first to fourth switching elements by increasing the carrier frequency.
[0034]
Preferably, the voltage converter includes an arm and a reactor. The arm is disposed on a second capacitor side and includes first and second switching elements. The reactor has one end connected to the positive electrode of the first capacitor and the other end connected to an intermediate point between the first switching element and the second switching element. Then, the control means controls the first and second switching elements such that the step-up operation and the step-down operation are performed alternately.
[0035]
Preferably, the control means controls the switching of the first and second switching elements by lowering the carrier frequency with a decrease in the first voltage of the first capacitor or the second voltage of the second capacitor. .
[0036]
Preferably, the control means controls the switching of the first and second switching elements by a carrier frequency corresponding to the first voltage or the second voltage.
[0037]
Preferably, the voltage conversion system further includes first and second voltage sensors. The first voltage sensor detects a first voltage of the first capacitor. The second voltage sensor detects a second voltage of the second capacitor. The control means holds the relationship between the first voltage or the second voltage and the carrier frequency as a map, and receives the first voltage received from the first voltage sensor or the voltage received from the second voltage sensor. A carrier frequency corresponding to the extracted second voltage is extracted with reference to a map, and the switching of the first and second switching elements is controlled by the extracted carrier frequency.
[0038]
Preferably, the control unit controls the first and second switching elements using a drive voltage lower than a drive voltage during normal operation.
[0039]
Preferably, the control means controls the switching of the first and second switching elements at a carrier frequency lower than the carrier frequency during normal operation.
[0040]
Preferably, the voltage converter is a bidirectional buck-boost converter.
Preferably, the control means controls the voltage converter to alternately perform the step-up operation and the step-down operation when the electric path to the power supply is cut off.
[0041]
Preferably, the control means controls the voltage converter so as to consume the residual charge of the first capacitor and the residual charge of the second capacitor after disconnecting the power supply.
[0042]
Further, according to the present invention, the residual charge consuming method is a method of consuming residual charge of a first capacitor provided on an input side of a voltage converter and a second capacitor provided on an output side of the voltage converter. A charge consuming method, comprising: a first step of consuming a residual charge of a first capacitor by a step-up operation by a voltage converter; and a second step of consuming a residual charge of a second capacitor by a step-down operation by a voltage converter. And a third step of alternately repeating the step-up operation and the step-down operation for a predetermined time.
[0043]
Preferably, the voltage converter includes first and second arms and a reactor. The first arm is disposed on the first capacitor side and includes first and second switching elements. The second arm is disposed on the second capacitor side and includes third and fourth switching elements. One end of the reactor is connected to an intermediate point between the first switching element and the second switching element, and the other end is connected to an intermediate point between the third switching element and the fourth switching element. Then, in the first step, the second and third switching elements are turned off, and the first and fourth switching elements are turned on. In the second step, the first and fourth switching elements are turned off, and the second and third switching elements are turned on.
[0044]
Preferably, the first to fourth switching elements are controlled to be switched by lowering the carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases.
[0045]
Preferably, the first to fourth switching elements are switching-controlled by a drive voltage lower than a drive voltage during normal operation.
[0046]
Preferably, the first to fourth switching elements are controlled to be switched by lowering the carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases.
[0047]
Preferably, in the first and second steps, the inductance of the reactor is reduced as the first voltage of the first capacitor or the second voltage of the second capacitor decreases.
[0048]
Preferably, the first to fourth switching elements are switching-controlled by increasing the carrier frequency.
[0049]
Preferably, the voltage converter includes an arm and a reactor. The arm is arranged on the side of the second capacitor and includes first and second switching elements. The reactor has one end connected to the positive electrode of the first capacitor and the other end connected to an intermediate point between the first switching element and the second switching element. Then, in the first step, the first switching element is turned off, and the second switching element is turned on. Further, in the second step, the first switching element is turned on and the second switching element is turned off.
[0050]
Preferably, the first and second switching elements are switching-controlled by lowering the carrier frequency with a decrease in the first voltage of the first capacitor or the second voltage of the second capacitor.
[0051]
Preferably, the switching of the first and second switching elements is controlled by a drive voltage lower than the drive voltage during normal operation.
[0052]
Preferably, the first and second switching elements are switching-controlled by further lowering the carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. .
[0053]
Preferably, in the first and second steps, the inductance of the reactor is reduced as the first voltage of the first capacitor or the second voltage of the second capacitor decreases.
[0054]
Preferably, the first and second switching elements are switching-controlled by increasing the carrier frequency.
[0055]
Preferably, the residual charge consuming method includes the step of disconnecting a power supply for supplying a DC voltage to the voltage converter via the first capacitor before the first, second, and third steps are performed. Further included.
[0056]
Further, according to the present invention, there is provided a program for causing a computer to execute the consumption of residual charges of a first capacitor provided on an input side of a voltage converter and a second capacitor provided on an output side of the voltage converter. A computer-readable recording medium on which the remaining electric charge of the first capacitor is consumed by the boosting operation by the voltage converter and the residual electric charge of the second capacitor is consumed by the step-down operation by the voltage converter And a third step of alternately repeating a step-up operation and a step-down operation for a predetermined time for a predetermined time.
[0057]
Preferably, the voltage converter includes first and second arms and a reactor. The first arm is arranged on the first capacitor side and includes first and second switching elements. The second arm is disposed on the second capacitor side and includes third and fourth switching elements. One end of the reactor is connected to an intermediate point between the first switching element and the second switching element, and the other end is connected to an intermediate point between the third switching element and the fourth switching element. Then, in the first step, the second and third switching elements are turned off, and the first and fourth switching elements are turned on. In the second step, the first and fourth switching elements are turned off, and the second and third switching elements are turned on.
[0058]
Preferably, the first to fourth switching elements are controlled to be switched by lowering the carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases.
[0059]
Preferably, the first to fourth switching elements are switching-controlled by a drive voltage lower than a drive voltage during normal operation.
[0060]
Preferably, the first to fourth switching elements are switching-controlled by further lowering the carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. .
[0061]
Preferably, in the first and second steps, the inductance of the reactor is reduced as the first voltage of the first capacitor or the second voltage of the second capacitor decreases.
[0062]
Preferably, the first to fourth switching elements are switching-controlled by increasing the carrier frequency.
[0063]
Preferably, the voltage converter includes an arm and a reactor. The arm is arranged on the side of the second capacitor and includes first and second switching elements. The reactor has one end connected to the positive electrode of the first capacitor and the other end connected to an intermediate point between the first switching element and the second switching element. Then, in the first step, the first switching element is turned off, and the second switching element is turned on. Further, in the second step, the first switching element is turned on and the second switching element is turned off.
[0064]
Preferably, the first and second switching elements are switching-controlled by lowering the carrier frequency with a decrease in the first voltage of the first capacitor or the second voltage of the second capacitor.
[0065]
Preferably, the switching of the first and second switching elements is controlled by a drive voltage lower than the drive voltage during normal operation.
[0066]
Preferably, the first and second switching elements are switching-controlled by further lowering the carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. .
[0067]
Preferably, in the first and second steps, the inductance of the reactor is reduced as the first voltage of the first capacitor or the second voltage of the second capacitor decreases.
[0068]
Preferably, the first and second switching elements are switching-controlled by increasing the carrier frequency.
[0069]
Preferably, the program further includes, in the computer, before performing the first, second, and third steps, a fourth step of disconnecting a power supply for supplying a DC voltage to the voltage converter via the first capacitor. Let it run.
[0070]
In the present invention, the residual charges of the two capacitors provided on the input side and the output side of the voltage converter are consumed by alternately repeating the step-up operation and the step-down operation by the voltage converter.
[0071]
Therefore, according to the present invention, the residual charge of the capacitor can be consumed without providing a new component.
[0072]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.
[0073]
[Embodiment 1]
Referring to FIG. 1, voltage conversion system 100 according to Embodiment 1 of the present invention includes a DC power supply B, voltage sensors 10A, 11, and 13, temperature sensors 10B, system relays SR1 and SR2, and capacitors C1 and C1. C2, boost converter 12, inverter 14, current sensors 18, 24, and control device 30.
[0074]
AC motor M1 is a drive motor for generating torque for driving drive wheels of a hybrid vehicle or an electric vehicle. Alternatively, the motor has the function of a generator driven by the engine, and operates as an electric motor for the engine, for example, to be incorporated into a hybrid vehicle so that the engine can be started. Is also good.
[0075]
Boost converter 12 includes a reactor L1, NPN transistors Q1 and Q2, and diodes D1 and D2. NPN transistors Q1 and Q2 are connected in series between a power supply line of inverter 14 and a ground line. The NPN transistor Q1 has a collector connected to the power supply line and an emitter connected to the collector of the NPN transistor Q2. The emitter of NPN transistor Q2 is connected to the ground line.
[0076]
Diodes D1 and D2 are connected between the emitter and collector of each of the NPN transistors Q1 and Q2, respectively, so that current flows from the emitter side to the collector side.
[0077]
Reactor L1 has one end connected to the power supply line of DC power supply B and the other end connected to an intermediate point between NPN transistor Q1 and NPN transistor Q2, that is, between the emitter of NPN transistor Q1 and the collector of NPN transistor Q2. Is done.
[0078]
Inverter 14 includes a U-phase arm 15, a V-phase arm 16, and a W-phase arm 17. U-phase arm 15, V-phase arm 16, and W-phase arm 17 are provided in parallel between the power supply line of inverter 14 and the ground line.
[0079]
U-phase arm 15 includes NPN transistors Q3 and Q4 connected in series, V-phase arm 16 includes NPN transistors Q5 and Q6 connected in series, and W-phase arm 17 includes NPN transistors Q7 and Q7 connected in series. Q8. Diodes D3 to D8 are connected between the emitters and collectors of the NPN transistors Q3 to Q8, respectively, to flow current from the emitter side to the collector side.
[0080]
An intermediate point of each phase arm is connected to each phase end of each phase coil of AC motor M1. That is, the AC motor M1 is a three-phase permanent magnet motor, in which one end of three coils of U, V, and W phases is commonly connected to a middle point, and the other end of the U-phase coil is an NPN transistor Q3. At the midpoint of Q4, the other end of the V-phase coil is connected to the midpoint of NPN transistors Q5 and Q6, and the other end of the W-phase coil is connected to the midpoint of NPN transistors Q7 and Q8.
[0081]
The DC power supply B is composed of a secondary battery such as a nickel hydrogen battery or a lithium ion battery. Voltage sensor 10A detects DC voltage Vb output from DC power supply B, and outputs the detected DC voltage Vb to control device 30. Temperature sensor 10B detects temperature Tb of DC power supply B and outputs the detected temperature Tb to control device 30. System relays SR1 and SR2 are turned on / off by signal SE from control device 30. More specifically, system relays SR1 and SR2 are turned on by H (logic high) signal SE from control device 30 and turned off by L (logic low) signal SE from control device 30.
[0082]
Capacitor C1 absorbs a ripple voltage at the time of switching of NPN transistors Q1 and Q2. Voltage sensor 11 detects voltage Vc1 across capacitor C1 and outputs the detected voltage Vc1 to control device 30.
[0083]
Boost converter 12 boosts DC voltage Vb supplied from DC power supply B and supplies the same to inverter 14. More specifically, when boosting converter 12 receives signal PWMU1 from control device 30, boosting converter 12 boosts the DC voltage in accordance with the period in which NPN transistor Q2 is turned on by signal PWMU1, and supplies the boosted DC voltage to inverter 14. In this case, the NPN transistor Q1 is turned off by the signal PWMU1.
[0084]
Further, upon receiving signal PWMD1 from control device 30, boost converter 12 steps down the DC voltage supplied from inverter 14 via capacitor C2 and charges DC power supply B.
[0085]
Further, upon receiving signal PWMB1 from control device 30, boost converter 12 charges back the electric power stored in capacitor C2 to DC power supply B.
[0086]
Further, upon receiving signal PWDCH1 from control device 30, boost converter 12 consumes residual charge in capacitor C1 in accordance with the period during which NPN transistor Q2 is turned on by signal PWDCH1, and NPN transistor Q1 is turned on by signal PWDCH1. The residual charge of the capacitor C2 is consumed according to the period.
[0087]
Capacitor C2 absorbs a ripple voltage generated at the time of switching in boost converter 12 and inverter 14.
[0088]
Voltage sensor 13 detects voltage Vc2 across capacitor C2, that is, the output voltage of boost converter 12 (corresponding to the input voltage of inverter 14), and outputs the detected voltage Vc2 to control device 30.
[0089]
When DC voltage is supplied from boost converter 12, inverter 14 converts the DC voltage into an AC voltage based on signal PWMI from control device 30, and drives AC motor M1. Thus, AC motor M1 is driven to generate a torque specified by torque command value TR. Further, the inverter 14 converts the AC voltage generated by the AC motor M1 into a DC voltage based on the signal PWMC from the control device 30 during regenerative braking of the hybrid vehicle or the electric vehicle equipped with the voltage conversion system 100, The converted DC voltage is supplied to boost converter 12 via capacitor C2. Note that the regenerative braking referred to here is braking with regenerative power generation when a driver driving a hybrid vehicle or an electric vehicle performs a foot brake operation, and does not operate the foot brake, but turns off the accelerator pedal during traveling. This includes decelerating the vehicle (or stopping acceleration) while generating regenerative power.
[0090]
Current sensor 18 detects current BCRT when DC power supply B is charged, and outputs the detected current BCRT to control device 30. Current sensor 24 detects motor current MCRT flowing through AC motor M <b> 1 and outputs the detected motor current MCRT to control device 30.
[0091]
Control device 30 includes torque command value TR and motor rotation speed MRN input from an externally provided ECU (Electrical Control Unit), DC voltage Vb from voltage sensor 10A, output voltage Vc2 from voltage sensor 13, and current. Based on the motor current MCRT from the sensor 24, a signal PWMU1 for driving the boost converter 12 and a signal PWMI for driving the inverter 14 are generated by a method described later, and the generated signals PWMU1 and PWMI are respectively Output to boost converter 12 and inverter 14.
[0092]
Signal PWMU1 is a signal for driving boost converter 12 when converting DC voltage Vb from DC power supply B to output voltage Vc2. Then, when boost converter 12 converts DC voltage Vb to output voltage Vc2, control device 30 performs feedback control on output voltage Vc2, and controls boost converter 12 so that output voltage Vc2 becomes a commanded voltage command Vdccom. A signal PWMU1 for driving is generated. A method for generating the signal PWMU1 will be described later.
[0093]
Further, when control device 30 receives a signal RGE indicating that the hybrid vehicle or the electric vehicle has entered the regenerative braking mode from the external ECU, signal PWMC for converting the AC voltage generated by AC motor M1 to a DC voltage is output. Is generated and output to the inverter 14. In this case, the switching of NPN transistors Q3 to Q8 of inverter 14 is controlled by signal PWMC. Thereby, inverter 14 converts the AC voltage generated by AC motor M <b> 1 into a DC voltage and supplies the DC voltage to boost converter 12.
[0094]
Further, when receiving a signal RGE indicating that the hybrid vehicle or the electric vehicle has entered the regenerative braking mode from the external ECU, the control device 30 generates a signal PWMD1 for lowering the DC voltage supplied from the inverter 14, The generated signal PWMD1 is output to boost converter 12. Thus, the AC voltage generated by the AC motor M1 is converted into a DC voltage, stepped down, and supplied to the DC power supply B.
[0095]
Further, when the hybrid vehicle or the electric vehicle equipped with voltage conversion system 100 is stopped, control device 30 receives from external ECU a signal IGOFF indicating that the ignition key has been turned off. Then, when receiving the signal IGOFF, the control device 30 sets a capacitor when the voltage Vc2 satisfies a predetermined relationship between the voltage Vb and the voltage Vb based on the voltage Vb from the voltage sensor 10A and the voltage Vc2 from the voltage sensor 13. The boost converter 12 is controlled so that the electric power stored in C2 is charged back to the DC power supply B.
[0096]
When charging back the power stored in capacitor C2 to DC power supply B, control device 30 outputs signal PWMB1 for boost converter 12 to step down voltage Vc2 across capacitor C2 and supply the same to DC power supply B. It is generated and output to boost converter 12. Conditions and detailed operations for charging back the power stored in the capacitor C2 will be described later.
[0097]
Further, the controller 30 generates an L level signal SE when the DC current BCRT from the current sensor 18 becomes smaller than the predetermined value α while the power stored in the capacitor C2 is being charged back to the DC power source B. Output to relays SR1 and SR2, and also generates signal PWDCH1 and outputs it to boost converter 12.
[0098]
Further, after generating signal PWDCH1 and outputting it to boost converter 12, control device 30 sets NPN transistors Q1, Q2 when voltage Vc1 from voltage sensor 11 and voltage Vc2 from voltage sensor 13 become smaller than predetermined value β. Is generated and output to boost converter 12.
[0099]
Further, control device 30 generates signal SE for turning on / off system relays SR1 and SR2, and outputs the signal to system relays SR1 and SR2.
[0100]
FIG. 2 is a functional block diagram of the control device 30. Referring to FIG. 2, control device 30 includes a motor torque control unit 301 and a voltage conversion control unit 302.
[0101]
The motor torque control means 301 is obtained by calculating a torque command value TR (a torque command to be given to the motor in consideration of the degree of depression of an accelerator pedal in a vehicle, and in a hybrid vehicle, an operation state of an engine), Based on DC voltage Vb, motor current MCRT, motor rotation speed MRN and output voltage Vc2 output from power supply B, when AC motor M1 is driven, NPN transistors Q1 and Q2 of boost converter 12 are turned on / off by a method described later. And a signal PWMI for turning on / off the NPN transistors Q3 to Q8 of the inverter 14, and outputs the generated signal PWMU1 and signal PWMI to the boost converter 12 and the inverter 14, respectively.
[0102]
Voltage conversion control means 302 receives a signal RGE indicating that the hybrid vehicle or the electric vehicle has entered the regenerative braking mode from the external ECU during regenerative braking, and converts the AC voltage generated by AC motor M1 into a DC voltage. Is generated and output to the inverter 14.
[0103]
When the signal RGE is received from the external ECU during regenerative braking, the voltage conversion control means 302 generates a signal PWMD1 for stepping down the DC voltage supplied from the inverter 14, and converts the generated signal PWMD1 to the voltage of the step-up converter 12 Output to As described above, boost converter 12 can also decrease the voltage by signal PWMD1 for decreasing the DC voltage, and thus has the function of a bidirectional converter.
[0104]
Further, upon receiving a signal IGOFF indicating that the ignition key has been turned off from the external ECU, the voltage conversion control means 302 determines the voltage based on the integrated value of the current BCRT from the current sensor 18 and the temperature Tb from the temperature sensor 10B. The remaining capacity of the DC power supply B is obtained. The voltage conversion control means 302 converts the DC voltage stored in the capacitor C2 into a DC power based on the signal IGOFF, the remaining capacity of the DC power supply B, the voltage Vc2 from the voltage sensor 13 and the voltage Vb from the voltage sensor 10A. It is determined whether or not a charge-back condition for charging back to B is satisfied. When the charge-back condition is satisfied, a signal PWMB1 for charging back the DC voltage accumulated in the capacitor C2 to the DC power supply B is generated. Output to boost converter 12. The chargeback condition will be described later.
[0105]
Further, the voltage conversion control means 302 generates an L level signal SE when the DC current BCRT from the current sensor 18 becomes smaller than the predetermined value α during the charge back of the DC voltage accumulated in the capacitor C2. Output to relays SR1 and SR2, and also generates signal PWDCH1 and outputs it to boost converter 12.
[0106]
Further, after voltage conversion control means 302 generates signal PWDCH1 and outputs it to boost converter 12, when voltage Vc1 from voltage sensor 11 and voltage Vc2 from voltage sensor 13 become smaller than predetermined value β, NPN transistor Q1 , Q2 to stop and generate a signal STP and output it to boost converter 12.
[0107]
FIG. 3 is a functional block diagram of the motor torque control means 301. Referring to FIG. 3, motor torque control means 301 includes motor control phase voltage calculator 40, inverter PWM signal converter 42, inverter input voltage command calculator 50, and converter duty ratio calculator 52. And a converter PWM signal conversion unit 54.
[0108]
Motor control phase voltage calculator 40 receives output voltage Vc2 of boost converter 12, that is, the input voltage to inverter 14, from voltage sensor 13, and receives motor current MCRT flowing through each phase of AC motor M1 from current sensor 24. And a torque command value TR from an external ECU. Then, motor control phase voltage calculation section 40 calculates a voltage to be applied to each phase coil of AC motor M1 based on these input signals, and outputs the calculated result to inverter PWM signal conversion section 42. Supply to
[0109]
The inverter PWM signal conversion unit 42 generates a signal PWMI for actually turning on / off each of the NPN transistors Q3 to Q8 of the inverter 14 based on the calculation result received from the motor control phase voltage calculation unit 40, The generated signal PWMI is output to each of the NPN transistors Q3 to Q8 of the inverter 14.
[0110]
As a result, the switching of NPN transistors Q3 to Q8 is controlled, and the current flowing to each phase of AC motor M1 is controlled so that AC motor M1 outputs a commanded torque. In this way, the motor drive current is controlled, and a motor torque corresponding to the torque command value TR is output.
[0111]
On the other hand, inverter input voltage command calculation unit 50 calculates an optimum value (target value) of the inverter input voltage based on torque command value TR and motor rotation speed MRN, and calculates the calculated optimum value as converter duty ratio calculation unit 52. Output to
[0112]
Converter duty ratio calculation unit 52 converts input voltage Vc2 from voltage sensor 13 into inverter input voltage command calculation unit 50 based on DC voltage Vb (also referred to as “battery voltage Vb”) output from voltage sensor 10A. Calculate the duty ratio for setting to the optimal value output from.
[0113]
Converter PWM signal converter 54 generates a signal PWMU1 for turning on / off NPN transistors Q1 and Q2 of boost converter 12 based on the duty ratio from converter duty ratio calculator 52, and generates generated signal PWMU1. Is output to the boost converter 12.
[0114]
By increasing the on-duty of NPN transistor Q2 on the lower side of boost converter 12, power storage in reactor L1 increases, so that a higher voltage output can be obtained. On the other hand, by increasing the on-duty of the upper NPN transistor Q1, the voltage of the power supply line decreases. Therefore, by controlling the duty ratio of the NPN transistors Q1 and Q2, the voltage of the power supply line can be controlled to an arbitrary voltage equal to or higher than the output voltage of the DC power supply B.
[0115]
The charge-back condition when charging the power stored in the capacitor C2 to the DC power supply B will be described. Chargeback conditions are:
(1) The ignition key is turned off
(2) The remaining capacity of the DC power supply B is equal to or less than a predetermined amount.
(3) The voltage difference Vc2−Vb between the voltage Vc2 across the capacitor C2 and the output voltage Vb of the DC power supply B is equal to or more than a predetermined value γ.
Is satisfied.
[0116]
One condition for chargeback, “the ignition key is turned off” is satisfied when the control device 30 receives the signal IGOFF from the external ECU.
[0117]
One condition in the case of chargeback, “the remaining capacity of the DC power supply B is equal to or less than a predetermined amount” is determined by the integrated value obtained by integrating the current BCRT from the current sensor 18 and the DC power supply from the temperature sensor 10B. The determination is made by obtaining the current capacity SOC (State Of Charge) of the DC power supply B based on the temperature Tb of B.
[0118]
More specifically, voltage conversion control means 302 integrates current BCRT from current sensor 18 and estimates the current capacity SOC of DC power supply B based on the integrated value. Then, voltage conversion control means 302 detects the remaining capacity of DC power supply B by correcting the integrated value with temperature Tb from temperature sensor 10B, and determines whether the remaining capacity is equal to or less than a predetermined amount. .
[0119]
The integrated value obtained by integrating the current BCRT from the current sensor 18 is corrected based on the temperature for the following reason. The output voltage Vb and the capacity SOC of the DC power supply B satisfy the relationship shown in FIG. That is, the relationship between the output voltage Vb and the capacity SOC changes according to the temperature Tb of the DC power supply B as shown by the curves k1 to k3. In particular, the relationship between the voltage Vb and the capacity SOC when the capacity SOC becomes 20 to 80% of the full charge greatly changes depending on the temperature Tb of the DC power supply B. Therefore, the integrated value obtained by integrating the current BCRT means the capacity discharged from the DC power supply B when the current BCRT flows out of the DC power supply B, and the DC power supply B is charged when the current BCRT is supplied to the DC power supply B. When the current capacity SOC estimated from the integrated value falls within the range of 20 to 80% of the full charge amount, which of the curves k1 to k3 is on the curve k1 to k3. Must be corrected by the temperature Tb. In this case, correcting the current capacity SOC estimated from the integrated value by the temperature Tb is equivalent to correcting the integrated value because the integrated value means the capacity charged and discharged to the DC power supply B.
[0120]
The voltage conversion control means 302 holds the curves k1 to k3 indicating the relationship between the voltage Vb and the capacity SOC shown in FIG. 4, integrates the current BCRT from the current sensor 18, and uses the integrated value as the temperature Tb To obtain the remaining capacity of the DC power supply B. Then, voltage conversion control means 302 determines whether or not the obtained remaining capacity is equal to or less than a predetermined amount.
[0121]
The voltage conversion control unit 302 determines whether the difference between the voltage Vc2 from the voltage sensor 13 and the voltage Vb from the voltage sensor 10A is equal to or greater than a predetermined value γ. The predetermined value γ is stored in the capacitor C2. Is determined to such an extent that the used power cannot be used effectively. Further, predetermined value γ may be determined so as to correspond to an error between voltage sensor 10A and voltage sensor 13.
[0122]
When the voltage conversion control means 302 determines that the voltage Vc2 across the capacitor C2 is higher than the output voltage Vb of the DC power supply B by a predetermined value γ or more, the power stored in the capacitor C2 is charged to the DC power supply B. The reason for the back-up is to charge back the DC power supply B with the power that can be effectively used.
[0123]
The voltage conversion control means 302 generates an L level signal SE when the DC current BCRT from the current sensor 18 becomes smaller than the predetermined value α during the charge back of the power stored in the capacitor C2 to the DC power supply B. Output to system relays SR1 and SR2, and also generates signal PWDCH1 to output to boost converter 12.
[0124]
Signal PWDCH1 is a signal for alternately turning on / off (ie, switching control) NPN transistor Q1 and NPN transistor Q2 of boost converter 12.
[0125]
Therefore, when DC current BCRT charged back to DC power supply B becomes smaller than predetermined value α, system relays SR1 and SR2 are turned off, and boost converter 12 responds to a period during which NPN transistor Q2 is turned on by signal PWDCH1. The residual charge of the capacitor C1 is consumed, and the residual charge of the capacitor C2 is consumed according to a period during which the NPN transistor Q1 is turned on by the signal PWDCH1. That is, when the NPN transistor Q1 is turned off and the NPN transistor Q2 is turned on by the signal PWDCH1, the electric charge accumulated in the capacitor C1 during the period when the NPN transistor Q2 is turned on is grounded via the reactor L1 and the NPN transistor Q2. Flow on the line. Then, the residual charge of the capacitor C1 is consumed by the loss in the reactor L1 and the loss in the NPN transistor Q2. Further, when the NPN transistor Q2 is turned off and the NPN transistor Q1 is turned on by the signal PWDCH1, while the NPN transistor Q1 is turned on, the electric charge accumulated in the capacitor C2 is supplied to the DC through the NPN transistor Q1 and the reactor L1. It flows to the power supply line of the power supply B. The residual charge of the capacitor C2 is consumed by the loss in the NPN transistor Q1 and the loss in the reactor L1.
[0126]
The operation performed by boost converter 12 when NPN transistor Q1 is turned off by signal PWDCH1 and NPN transistor Q2 is turned on is the same as the boosting operation when boosting DC voltage Vb from DC power supply B to output voltage Vc2. Therefore, the operation of consuming the residual charge of the capacitor C1 by the signal PWDCH1 is referred to as “consumption of the residual charge by the boosting operation”. Further, the operation performed by boost converter 12 when NPN transistor Q1 is turned on by signal PWDCH1 and NPN transistor Q2 is turned off is the same as the step-down operation when stepping down the DC voltage supplied from inverter 14, so that The operation of consuming the residual charge of the capacitor C2 by the signal PWDCH1 is called "consumption of the residual charge by the step-down operation".
[0127]
As described above, according to the present invention, after charging back the power accumulated in the capacitor C2 to the DC power supply B, the system relays SR1 and SR2 are turned off, the residual charge of the capacitor C1 is consumed by the boosting operation, and the capacitor is reduced by the step-down operation. It is characterized in that the residual charge of C2 is consumed.
[0128]
As a result, the residual charges of the capacitors C1 and C2 can be consumed by using the boost converter 12 without newly providing a discharge resistor.
[0129]
When the residual charge of capacitors C1 and C2 is consumed using reactor L1 and NPN transistors Q1 and Q2 constituting boost converter 12, preferably, carrier frequency fc1 when switching control of NPN transistors Q1 and Q2 is: It can be changed according to the voltages Vc1 and Vc2.
[0130]
The voltage Vc1, Vc2 between both ends of the capacitors C1, C2 when the residual charges of the capacitors C1, C2 are consumed, that is, between the residual voltage of the capacitors C1, C2 and the carrier frequency fc1, a straight line k4 in FIG. The relationship represented by is established. That is, the remaining voltages (Vc1, Vc2) of the capacitors C1, C2 have a proportional relationship with the carrier frequency fc1.
[0131]
The voltage conversion control unit 302 holds the relationship represented by the straight line k4 in FIG. 5 as a map, and when receiving the voltage Vc1 from the voltage sensor 11 or the voltage Vc2 from the voltage sensor 13, the voltage conversion control unit 302 corresponds to the voltage Vc1 or Vc2. The carrier frequency fc1 is extracted with reference to a map, and a signal PWDCH1 having the extracted carrier frequency fc1 is generated and output to the boost converter 12.
[0132]
Therefore, as the voltage Vc1 or the voltage Vc2 decreases, the carrier frequency fc1 for controlling the switching of the NPN transistors Q1 and Q2 when consuming the residual charges of the capacitors C1 and C2 decreases.
[0133]
As described above, the reason why the carrier frequency fc1 is lowered together with the voltage Vc1 or the voltage Vc2 is that the current flowing through the reactor L1 and the NPN transistor Q2 or the NPN transistor Q1 and the reactor L1 when the residual voltage of the capacitor C1 or C2 decreases. In order to increase the loss in the reactor L1 and the NPN transistors Q1 and Q2 by controlling the carrier frequency fc1 to be low and increasing the current flowing through the reactor L1 and the NPN transistor Q2 or the NPN transistor Q1 and the reactor L1. It is.
[0134]
As described above, the present invention is characterized in that the residual charge of capacitors C1 and C2 is consumed by the loss in reactor L1 and NPN transistors Q1 and Q2. Therefore, in the present invention, NPN transistors Q1 and Q2 are preferably turned on by a drive voltage lower than the drive voltage during normal operation. That is, when the NPN transistors Q1 and Q2 are turned on, the voltage applied to the bases of the NPN transistors Q1 and Q2 is made lower than in the normal operation to increase the on-resistance of the NPN transistors Q1 and Q2. Thereby, the loss in NPN transistors Q1 and Q2 can be further increased, and the residual charges in capacitors C1 and C2 can be consumed more quickly.
[0135]
In this case, the voltage conversion control means 302 generates the signal PWDCH1 by lowering the amplitude of the signal PWMD1 from the amplitude of the signals PWMU1 and PWMD1. As a result, the NPN transistors Q1 and Q2 flow the current from the capacitors C1 and C2 by increasing the on-resistance as compared with the normal operation.
[0136]
When the NPN transistors Q1 and Q2 are driven by a drive voltage lower than the drive voltage in the normal operation, the carrier frequency fc1 corresponding to the voltages Vc1 and Vc2 is further determined using the relationship represented by the straight line k4 in FIG. The extracted NPN transistors Q1 and Q2 are subjected to switching control. In this case, the reason for lowering the carrier frequency fc1 with the lowering of the voltage Vc1 or Vc2 is for the same reason as described above.
[0137]
With reference to FIGS. 6 and 7, an operation of consuming the residual charges according to the first embodiment will be described. When a series of operations is started, voltage conversion control means 302 receives signal IGOFF from an external ECU (step S1). Then, voltage conversion control means 302 determines, in accordance with signal IGOFF, whether or not the above-described charge-back condition is satisfied. When charge-back condition is satisfied, generates voltage PWMB1 to boost converter 12 Output. Thus, the power stored in the capacitor C2 is charged back to the DC power supply B (Step S2).
[0138]
Thereafter, the voltage conversion control means 302 determines whether or not the DC voltage BCRT (also referred to as “charge-back current”; the same applies hereinafter) from the current sensor 18 is smaller than a predetermined value α (step S3). When the charge-back current BCRT is equal to or more than the predetermined value α in step S3, steps S2 and S3 are repeatedly executed.
[0139]
If it is determined in step S3 that the charge back current BCRT is smaller than the predetermined value α, the voltage conversion control means 302 controls the boost converter 12 to stop the charge back (step S4). That is, voltage conversion control means 302 generates signal STP for stopping NPN transistors Q1 and Q2, and outputs the signal to boost converter 12. Thereby, boost converter 12 is stopped, and the charge back of DC power supply B to the power stored in capacitor C2 is stopped.
[0140]
Then, voltage conversion control means 302 generates L-level signal SE and outputs it to system relays SR1 and SR2. Thereby, system relays SR1 and SR2 are turned off (step S5). Then, the DC power supply B is disconnected.
[0141]
Thereafter, the residual charges of capacitors C1 and C2 are consumed by switching of boost converter 12 (step S6). The detailed operation of step S6 in FIG. 6 will be described with reference to FIG. After step S5 shown in FIG. 6, voltage conversion control means 302 generates signal PWDCH1 and outputs it to boost converter 12. As a result, the NPN transistor Q1 is turned off, and the NPN transistor Q2 is turned on. Then, the residual charge of the capacitor C1 is consumed by the loss in the reactor L1 and the NPN transistor Q2 (Step S61).
[0142]
Thereafter, the NPN transistor Q1 is turned on and the NPN transistor Q2 is turned off. Then, the residual charge of the capacitor C2 is consumed by the loss in the NPN transistor Q1 and the reactor L1 (Step S62). Thus, the operation in step S6 shown in FIG. 6 ends.
[0143]
Referring again to FIG. 6, after step S6, voltage conversion control means 302 determines whether remaining voltages Vc1, Vc2 of capacitors C1, C2 are smaller than predetermined value β (step S7). When the remaining voltages Vc1 and Vc2 are equal to or greater than the predetermined value β, steps S6 and S7 are repeatedly executed.
[0144]
When step S6 is repeatedly performed, as described above, the carrier frequency fc1 for controlling the switching of the NPN transistors Q1 and Q2 may be reduced as the remaining voltages Vc1 and Vc2 decrease. When step S6 is repeatedly performed, as described above, NPN transistors Q1 and Q2 may be driven by a drive voltage lower than the drive voltage during normal operation.
[0145]
When it is determined in step S7 that the remaining voltages Vc1 and Vc2 of the capacitors C1 and C2 are smaller than the predetermined value β, the voltage conversion control means 302 generates a signal STP for turning off the NPN transistors Q1 and Q2. Output to boost converter 12. Thereby, NPN transistors Q1 and Q2 are turned off, and boost converter 12 stops (step S8). Thereafter, the system is turned off (step S9), and a series of operations ends.
[0146]
Note that the residual charge consuming method according to the present invention is a residual charge consuming method for consuming the residual charges of the capacitors C1 and C2 according to the flowcharts shown in FIGS.
[0147]
In addition, the control of the operation of consuming the residual charges of the capacitors C1 and C2 in the first embodiment is actually executed by a CPU (Central Processing Unit), and the CPU performs each step of the flowcharts shown in FIGS. Is read from a ROM (Read Only Memory), and the read program is executed to consume the residual charges of the capacitors C1 and C2 in accordance with the flowcharts shown in FIGS.
[0148]
Therefore, the ROM corresponds to a computer (CPU) readable recording medium on which a program including the steps of the flowcharts shown in FIGS. 6 and 7 is recorded.
[0149]
Referring again to FIG. 1, the overall operation in voltage conversion system 100 will be described. When the entire operation is started, control device 30 generates an H-level signal SE and outputs it to system relays SR1 and SR2, and system relays SR1 and SR2 are turned on. DC power supply B outputs DC voltage Vb to boost converter 12 via system relays SR1 and SR2.
[0150]
Voltage sensor 10A detects DC voltage Vb output from DC power supply B, and outputs the detected DC voltage Vb to control device 30. The voltage sensor 11 detects the voltage Vc1 across the capacitor C1 and outputs the detected voltage Vc1 to the control device 30. Voltage sensor 13 detects voltage Vc2 across capacitor C2 and outputs the detected voltage Vc2 to control device 30. Further, current sensor 18 detects current BCRT flowing out or inflowing from DC power supply B and outputs it to control device 30, and temperature sensor 10B detects temperature Tb of DC power supply B and outputs it to control device 30. Further, current sensor 24 detects motor current MCRT flowing through AC motor M <b> 1 and outputs it to control device 30. Control device 30 receives torque command value TR and motor rotation speed MRN from the external ECU.
[0151]
Then, control device 30 generates signal PWMI by the above-described method based on DC voltage Vb, voltage Vc2, motor current MCRT, torque command value TR, and motor rotation speed MRN, and outputs generated signal PWMI to inverter 14. Output. Control device 30 controls switching of NPN transistors Q1 and Q2 of boost converter 12 based on DC voltage Vb, voltage Vc2, motor current MCRT, torque command value TR, and motor speed MRN by the above-described method. The signal PWMU1 is generated, and the generated signal PWMU1 is output to the boost converter 12.
[0152]
Then, boost converter 12 boosts DC voltage Vb from DC power supply B in accordance with signal PWMU 1 and supplies the boosted DC voltage to inverter 14. Then, inverter 14 converts the DC voltage supplied from boost converter 12 into an AC voltage by signal PWMI from control device 30, and drives AC motor M1. Thereby, AC motor M1 generates a torque specified by torque command value TR.
[0153]
At the time of regenerative braking of a hybrid vehicle or an electric vehicle equipped with voltage conversion system 100, control device 30 receives signal RGE from the external ECU, generates signal PWMC in accordance with the received signal RGE, and generates inverter PWM 14. To generate a signal PWMD1 and output it to the boost converter 12.
[0154]
Then, inverter 14 converts the AC voltage generated by AC motor M1 into a DC voltage according to signal PWMC, and supplies the converted DC voltage to boost converter 12 via capacitor C2. Then, boost converter 12 receives the DC voltage from inverter 14, reduces the received DC voltage by signal PWMD <b> 1, and supplies the reduced DC voltage to DC power supply B. Thus, the power generated by AC motor M1 is charged to DC power supply B.
[0155]
Further, when the hybrid vehicle or the electric vehicle equipped with voltage conversion system 100 is stopped, control device 30 receives signal IGOFF from the external ECU, and in accordance with the received signal IGOFF, performs charge-back by the above-described method. It is determined whether the condition is satisfied.
[0156]
When determining that the charge-back condition is satisfied, control device 30 stops inverter 14, generates signal PWMB1, outputs signal PWMC1 to boost converter 12, and charges power stored in capacitor C2 to DC power source B. Back.
[0157]
When the DC current BCRT from the current sensor 18, that is, the charge back current BCRT to the DC power supply B becomes smaller than the predetermined value α, the control device 30 generates a signal STP and outputs the signal STP to the boost converter 12, An L-level signal SE is generated and output to system relays SR1 and SR2.
[0158]
Thereafter, control device 30 generates signal PWDCH1 and outputs the signal to boost converter 12. As a result, the residual charge of the capacitor C1 is consumed by the above-described step-up operation, and the residual charge of the capacitor C2 is consumed by the above-described step-down operation. Then, when remaining voltages Vc1 and Vc2 of capacitors C1 and C2 become lower than predetermined value β, control device 30 generates signal STP and outputs it to boost converter 12. Then, the voltage conversion system 100 is stopped.
[0159]
As described above, in the present invention, when the charge back of the power stored in capacitor C2 to DC power supply B is completed, the residual charge of capacitors C1 and C2 is consumed by the step-up operation and step-down operation by step-up converter 12, respectively.
[0160]
Therefore, the residual charges of the capacitors C1 and C2 can be consumed without newly providing a discharge resistor.
[0161]
According to the first embodiment, the voltage conversion system includes a boost converter, a capacitor C1 provided on the input side of the boost converter, a capacitor C2 provided on the output side of the boost converter, and a boost operation and a step-down operation. Since there is provided a control device for controlling the boost converter so as to perform the alternation, the residual charges of the capacitors C1 and C2 can be consumed without providing new components.
[0162]
[Embodiment 2]
Referring to FIG. 8, voltage conversion system 100A according to the second embodiment has a configuration in which boost converter 12 of voltage conversion system 100 is replaced with boost converter 12A, and control device 30 is replaced with control device 30A. It is the same as the voltage conversion system 100.
[0163]
Boost converter 12A is the same as boost converter 12 except that reactor L1 of boost converter 12 is replaced with reactor L2. Reactor L2 is a reactor whose inductance can be changed.
[0164]
Control device 30A generates signal EXC and outputs it to reactor L2 of boost converter 12A when the operation of consuming the residual charges of capacitors C1 and C2 is started in addition to the function of control device 30. Signal EXC is a signal for reducing the number of turns of the coil of reactor L2 according to the remaining voltage of capacitors C1 and C2.
[0165]
Referring to FIG. 9, control device 30A is the same as control device 30 except that voltage conversion control means 302 of control device 30 is replaced with voltage conversion control means 302A. Voltage conversion control means 302A, in addition to the function of voltage conversion control means 302, generates signal EXC and outputs it to reactor L2 of boost converter 12A. That is, voltage conversion control means 302A generates signal PWDCH1 and outputs it to boost converter 12A, and controls boost converter 12A to consume the residual charges of capacitors C1 and C2 by the boost operation and the step-down operation. A signal EXC for reducing the number of turns of the coil of the reactor L2 is generated in accordance with the remaining voltage of the capacitors C1 and C2, and is output to the reactor L2.
[0166]
When the residual voltage (Vc1, Vc2) of the capacitors C1 and C2 decreases, it becomes difficult for DC current to flow through the reactor L2. Therefore, as the residual voltage of the capacitors C1 and C2 decreases, the inductance of the reactor L2 decreases. As a result, even if the residual voltage of the capacitors C1 and C2 decreases, the DC current easily flows to the reactor L2, and the residual charges of the capacitors C1 and C2 can be consumed more quickly.
[0167]
Therefore, in the second embodiment, when the residual charges of capacitors C1 and C2 are consumed by the step-up operation and step-down operation of boost converter 12A, the inductance of reactor L2 included in boost converter 12A is reduced by the residual voltage of capacitors C1 and C2. It is characterized in that it is made smaller with a decrease in.
[0168]
A relationship represented by a straight line k5 in FIG. 10 is established between the inductance of the reactor L2 and the remaining voltages (Vc1, Vc2) of the capacitors C1, C2. Further, a relationship represented by a curve k6 in FIG. 11 is established between the number of turns n of the coil of the reactor L2 and the inductance.
[0169]
Therefore, the voltage conversion control means 302A holds the relationship of the straight line k5 shown in FIG. 10 and the relationship of the curve k6 shown in FIG. 11 as maps, respectively, and stores the voltage Vc1 from the voltage sensor 11 or the voltage from the voltage sensor 13. The inductance corresponding to Vc2 is extracted from the straight line k5, and the number of turns n corresponding to the extracted inductance is extracted from the curve k6. Then, voltage conversion control means 302A generates signal EXC for changing the number of turns of the coil of reactor L2 to the extracted number of turns n, and outputs the signal to reactor L2.
[0170]
When the residual charge of the capacitors C1 and C2 is consumed by reducing the inductance, preferably, the carrier frequency for switching control of the NPN transistors Q1 and Q2 is increased according to the residual voltage of the capacitors C1 and C2.
[0171]
In this case, a straight line k7 shown in FIG. 12 is established between the residual voltages of the capacitors C1 and C2 and the carrier frequency. Referring to FIG. 12, carrier frequency fc2 decreases as the residual voltage of capacitors C1 and C2 increases, and increases as the residual voltage of capacitors C1 and C2 decreases. When the residual charge of the capacitors C1 and C2 is consumed by decreasing the inductance, the switching control of the NPN transistors Q1 and Q2 by increasing the carrier frequency fc2 with the decrease of the residual voltage of the capacitors C1 and C2 is performed by reducing the inductance. By reducing the current, the current flowing through the reactor L2 is increased to increase the loss in the reactor L2, and the carrier frequency fc2 for controlling the switching of the NPN transistors Q1, Q2 is increased to increase the switching loss of the NPN transistors Q1, Q2. This is because the residual charges of the capacitors C1 and C2 are consumed more quickly.
[0172]
Therefore, the voltage conversion control means 302A holds the relationship of the straight line k7 shown in FIG. 12 as a map, and holds the carrier frequency fc2 corresponding to the voltage Vc1 from the voltage sensor 11 or the voltage Vc2 from the voltage sensor 13. Extract by referring to the map. Then, voltage conversion control means 302A generates signal PWDCH1 using extracted carrier frequency fc2 and outputs the signal to boost converter 12A.
[0173]
Referring to FIG. 13, reactor L2 includes a core 2, coils 3A and 3B, and a number-of-turns switching unit 4. The core 2 includes straight portions 23A and 23B and curved portions 23C and 23D. The straight portions 23A and 23B and the curved portions 23C and 23D are arranged in an annular shape so as to partially form the gaps 21 and 22. The gaps 21 and 22 are made of, for example, a glass epoxy material.
[0174]
The coil 3A is manufactured by winding a copper wire around one straight portion 23A of the core 2, and the coil 3B is manufactured by winding a copper wire around the other straight portion 23B of the core 2. Coil 3A is connected to coil 3B by wiring 3C. Thereby, the coils 3A and 3B are connected in series.
[0175]
The number-of-turns switching unit 4 has a contact switching unit 4A. The contact switching unit 4A switches the contacts according to the signal EXC from the control device 30A such that the number of turns of the coils 3A and 3B becomes the number of turns corresponding to the remaining voltage of the capacitors C1 and C2. Then, the number-of-turns switching unit 4 is connected to the terminal 6B by the wiring 5.
[0176]
Referring to FIG. 14, contact switching unit 4 </ b> A includes contacts 411 to 41 m (m is a natural number) and a switch 420. The contact 411 is connected to a terminal (not shown) in which the number of turns of the coils 3A and 3B is n1. The contact 412 is connected to a terminal (not shown) in which the number of turns of the coils 3A and 3B is n2 (<n1). In the same manner, the contacts 413,..., 41m are connected to terminals (not shown) having n3 (<n2),. The switch 420 is switched to a contact (one of the contacts 411 to 41m) in which the number of turns of the coil becomes the number of turns corresponding to the remaining voltage of the capacitors C1 and C2 according to the signal EXC from the control device 30A. Then, the switch 420 is connected to the wiring 5.
[0177]
Referring again to FIG. 13, coil 3A is wound so that current flows in the direction of arrow 13A, and coil 3B is wound so that current flows in the direction of arrow 14A. When a current flows from the terminal 6A to the terminal 6B, a current flows through the coil 3A in a direction indicated by an arrow 13A, and a current flows through the coil 3B in a direction indicated by an arrow 14A.
[0178]
Then, the magnetic flux generated by the current flowing through coils 3A and 3B passes through gap 21 in the direction of arrow 15A and passes through gap 22 in the direction of arrow 16A. That is, the generated magnetic flux moves in a direction that makes a round in the annular core 2. Reactor L2 has an inductance corresponding to the number of turns switched by turn number switching unit 4.
[0179]
The operation of consuming the residual charges of capacitors C1 and C2 in voltage conversion control means 302A is performed according to the flowcharts shown in FIGS. The flowchart shown in FIG. 15 is different from the flowchart shown in FIG. 6 in that step S6 of the flowchart shown in FIG. 6 is replaced with step S6A.
[0180]
FIG. 16 is a flowchart for explaining the operation of step S6A in the flowchart shown in FIG. Referring to FIG. 16, after step S5 shown in FIG. 15, voltage conversion control means 302A winds coils 3A and 3B of reactor L2 corresponding to voltage Vc1 from voltage sensor 11 or voltage Vc2 from voltage sensor 13. The number is extracted with reference to the held map (step S59).
[0181]
Then, voltage conversion control means 302A generates signal EXC for changing the number of turns of coils 3A and 3B to the extracted number of turns, and outputs the signal to reactor L2.
[0182]
Then, in reactor L2, winding number switching section 4A switches switch 420 to any of contact points 411 to 41m in response to signal EXC from voltage conversion control means 302A, and changes the winding number of coils 3A, 3B to capacitors C1, C2. Is set to the number of windings corresponding to the remaining voltage (step S60). Thereafter, steps S61 and S62 described above are executed, and the residual charges of the capacitors C1 and C2 are consumed.
[0183]
When step S6A is repeatedly performed, as described above, the carrier frequency fc2 for controlling the switching of NPN transistors Q1 and Q2 may be increased as the remaining voltages Vc1 and Vc2 decrease.
[0184]
Others are as described above.
The residual charge consuming method according to the present invention is a residual charge consuming method for consuming the residual charges of the capacitors C1 and C2 according to the flowcharts shown in FIGS.
[0185]
In addition, the control of the operation of consuming the residual charges of the capacitors C1 and C2 in the second embodiment is actually executed by the CPU, and the CPU executes the program including the steps of the flowcharts shown in FIGS. , And executes the read program to consume the residual charges of the capacitors C1 and C2 in accordance with the flowcharts shown in FIGS.
[0186]
Therefore, the ROM corresponds to a computer (CPU) readable recording medium on which a program including the steps of the flowcharts shown in FIGS. 15 and 16 is recorded.
[0187]
The overall operation of the voltage conversion system 100A is such that the operation of consuming the residual charges of the capacitors C1 and C2 in the voltage conversion system 100 is replaced with the operation of consuming the residual charges of the capacitors C1 and C2 in the second embodiment. The rest is the same as the operation of the voltage conversion system 100.
[0188]
In the above description, the inductance is changed by changing the number of turns of coils 3A and 3B of reactor L2. However, the present invention is not limited to this, and other than changing the number of turns of coils 3A and 3B. Depending on the method, the inductance of reactor L2 may be changed. The present invention is generally applied to an apparatus in which the inductance of the reactor L2 is set to an inductance corresponding to the residual voltage of the capacitors C1 and C2, and the residual charges of the capacitors C1 and C2 are consumed.
[0189]
Further, voltage conversion control means 302A for generating signal EXC and outputting it to reactor L2 and winding number switching section 4 constitute "inductance changing means".
[0190]
The rest is the same as the first embodiment.
According to the second embodiment, the voltage conversion system reduces the inductance of the boost converter, the capacitor C1 provided on the input side of the boost converter, the capacitor C2 provided on the output side of the boost converter, and the reactor. Since the control device for controlling the boost converter so as to alternately perform the boosting operation and the step-down operation is provided, the residual charges of the capacitors C1 and C2 can be consumed more quickly without providing new components.
[0191]
[Embodiment 3]
Referring to FIG. 17, voltage conversion system 100B according to the third embodiment has a configuration in which boost converter 12 of voltage conversion system 100 is replaced with converter 12B, and control device 30 is replaced with control device 30B. It is the same as the conversion system 100.
[0192]
Converter 12B includes a reactor L1, NPN transistors Q01 to Q04, and diodes D01 to D04.
[0193]
NPN transistors Q01 and Q02 are connected in series between power supply line 25 of DC power supply B and ground line 26. NPN transistor Q01 has a collector connected to power supply line 25 and an emitter connected to the collector of NPN transistor Q02. The emitter of NPN transistor Q02 is connected to ground line 26.
[0194]
NPN transistors Q03 and Q04 are connected in series between power supply line 27 of inverter 14 and ground line 28. NPN transistor Q03 has a collector connected to power supply line 27 and an emitter connected to the collector of NPN transistor Q04. Further, the emitter of NPN transistor Q04 is connected to earth line 28.
[0195]
Diodes D01 to D04 are connected to NPN transistors Q01 to Q04, respectively, so that current flows from the emitter side to the collector side.
[0196]
Reactor L1 has one end connected to the emitter of NPN transistor Q01 and the collector of NPN transistor Q02, and the other end connected to the emitter of NPN transistor Q03 and the collector of NPN transistor Q04.
[0197]
In converter 12B, NPN transistor Q01 is turned on / off simultaneously with NPN transistor Q04, and NPN transistor Q02 is turned on / off simultaneously with NPN transistor Q03.
[0198]
Converter 12B changes the voltage level of DC voltage Vb supplied from DC power supply B and supplies the changed voltage level to inverter 14. More specifically, when converter 12B receives signal PWMU2 from control device 30B, converter 12B changes the voltage level of the DC voltage according to the period in which NPN transistors Q01 and Q04 are turned on by signal PWMU2 and supplies the changed voltage to inverter 14. .
[0199]
When converter 12B receives signal PWMD2 from control device 30B, converter 12B changes the voltage level of the DC voltage supplied from inverter 14 and charges DC power supply B.
[0200]
Control device 30B is based on torque command value TR and motor speed MRN input from external ECU, DC voltage Vb from voltage sensor 10A, output voltage Vc2 from voltage sensor 13, and motor current MCRT from current sensor 24. Then, signal PWMU2 for driving converter 12B and signal PWMI for driving inverter 14 are generated by a method described later, and the generated signal PWMU2 and signal PWMI are output to converter 12B and inverter 14, respectively.
[0201]
Signal PWMU2 is a signal for driving converter 12B when converting DC voltage Vb from DC power supply B to output voltage Vc2. Then, when converter 12B converts DC voltage Vb to output voltage Vc2, control device 30B performs feedback control on output voltage Vc2 and drives converter 12B such that output voltage Vc2 becomes a commanded voltage command Vdccom. Signal PWMU2 is generated. The method for generating the signal PWMU2 is the same as the method for generating the signal PWMU1 described above.
[0202]
Further, when control device 30B receives a signal RGE indicating that the hybrid vehicle or the electric vehicle has entered the regenerative braking mode from the external ECU, signal PWMC for converting the AC voltage generated by AC motor M1 to a DC voltage is output. Is generated and output to the inverter 14. In this case, the switching of NPN transistors Q3 to Q8 of inverter 14 is controlled by signal PWMC. Thereby, inverter 14 converts the AC voltage generated by AC motor M1 into a DC voltage and supplies the DC voltage to converter 12B.
[0203]
Further, when receiving a signal RGE indicating that the hybrid vehicle or the electric vehicle has entered the regenerative braking mode from the external ECU, the control device 30B generates a signal PWMD2 for lowering the DC voltage supplied from the inverter 14, The generated signal PWMD2 is output to converter 12B. As a result, the AC voltage generated by the AC motor M1 is converted to a DC voltage, and the voltage level is changed and supplied to the DC power supply B.
[0204]
Further, when the hybrid vehicle or the electric vehicle equipped with voltage conversion system 100B is stopped, control device 30B receives from external ECU a signal IGOFF indicating that the ignition key has been turned off. Then, when receiving the signal IGOFF, the control device 30B sets the capacitor when the voltage Vc2 satisfies a predetermined relationship between the voltage Vb and the voltage Vb from the voltage sensor 10A based on the voltage Vb from the voltage sensor 10A and the voltage Vc2 from the voltage sensor 13. A signal PWMB2 for charging back the power stored in C2 to DC power supply B is generated and output to converter 12B.
[0205]
Further, when the DC current BCRT from the current sensor 18 becomes smaller than the predetermined value α while the power stored in the capacitor C2 is being charged back to the DC power supply B, the control device 30B generates an L-level signal SE to generate a system signal. While outputting to relays SR1 and SR2, signal PWDCH2 is generated and output to converter 12B.
[0206]
Further, after generating signal PWDCH2 and outputting it to converter 12B, control device 30B switches NPN transistors Q01-Q04 when voltage Vc1 from voltage sensor 11 and voltage Vc2 from voltage sensor 13 become smaller than predetermined value β. A signal STP for stopping is generated and output to converter 12B.
[0207]
Further, control device 30B generates signal SE for turning on / off system relays SR1 and SR2, and outputs the signal to system relays SR1 and SR2.
[0208]
Signal PWDCH2 is a signal for alternately turning on / off (ie, switching control) NPN transistors Q01 and Q04 and NPN transistors Q02 and Q03 of converter 12B.
[0209]
Therefore, when DC current BCRT charged back to DC power supply B becomes smaller than predetermined value α, system relays SR1 and SR2 are turned off, and converter 12B operates according to a period during which NPN transistors Q01 and Q04 are turned on by signal PWDCH2. Thus, the residual charge of the capacitor C1 is consumed, and the residual charge of the capacitor C2 is consumed according to a period during which the NPN transistors Q02 and Q03 are turned on by the signal PWDCH2. That is, when the NPN transistors Q02 and Q03 are turned off and the NPN transistors Q01 and Q04 are turned on by the signal PWDCH2, while the NPN transistors Q01 and Q04 are turned on, the electric charge accumulated in the capacitor C1 is changed to the NPN transistor Q01, It flows to ground lines 26 and 28 via reactor L1 and NPN transistor Q04. The residual charge of capacitor C1 is consumed by the loss in reactor L1 and the loss in NPN transistors Q01 and Q04. When signal PWDCH2 turns off NPN transistors Q01 and Q04 and turns on NPN transistors Q02 and Q03, while NPN transistors Q02 and Q03 are turned on, the electric charge accumulated in capacitor C2 is reduced by NPN transistors Q03 and Q03. It flows to power supply line 25 via reactor L1 and NPN transistor Q02. The residual charge of capacitor C2 is consumed by the loss in NPN transistors Q02 and Q03 and the loss in reactor L1.
[0210]
The operation performed by converter 12B when NPN transistors Q02 and Q03 are turned off by signal PWDCH2 and NPN transistors Q01 and Q04 are turned on is a step-up operation when stepping up DC voltage Vb from DC power supply B to output voltage Vc2. Since the operation is the same as the operation, the operation of consuming the residual charge of the capacitor C1 by the signal PWDCH2 is referred to as “consumption of the residual charge by the boosting operation”. The operation performed by converter 12B when NPN transistors Q02 and Q03 are turned on and NPN transistors Q01 and Q04 are turned off by signal PWDCH2 is the same as the step-down operation when stepping down the DC voltage supplied from inverter 14. Therefore, the operation of consuming the residual charge of the capacitor C2 by the signal PWDCH2 is referred to as "consumption of the residual charge by the step-down operation".
[0211]
The operation of consuming the residual charges in the third embodiment is performed according to the flowcharts shown in FIGS. The flowchart shown in FIG. 18 is the same as the flowchart shown in FIG. 6 except that step S6 of the flowchart shown in FIG. 6 is replaced with step S6B.
[0212]
FIG. 19 is a flowchart for explaining the operation of step S6B of the flowchart shown in FIG. Referring to FIG. 19, after step S5 in the flowchart shown in FIG. 18, control device 30B generates signal PWDCH2 and outputs it to converter 12B.
[0213]
Then, NPN transistors Q01 and Q04 are turned on, and NPN transistors Q02 and Q03 are turned off. Then, the residual charge of the capacitor C1 is consumed by the loss in the reactor L1 and the NPN transistors Q01 and Q04 (step S71).
[0214]
Thereafter, NPN transistors Q02 and Q03 are turned on, and NPN transistors Q01 and Q04 are turned off. Then, the residual charge of the capacitor C2 is consumed by the loss in the NPN transistors Q02, Q03 and the reactor L1 (step S72). Thus, the operation in step S6B shown in FIG. 18 ends.
[0215]
When step S6B is repeatedly performed, as described above, the carrier frequency fc1 for controlling the switching of the NPN transistors Q01 to Q04 may be reduced as the remaining voltages Vc1 and Vc2 of the capacitors C1 and C2 decrease. When step S6B is repeatedly performed, as described above, NPN transistors Q01 to Q04 may be driven by a drive voltage lower than the drive voltage during normal operation.
[0216]
The residual charge consuming method according to the present invention is a residual charge consuming method for consuming the residual charges of the capacitors C1 and C2 according to the flowcharts shown in FIGS.
[0219]
In addition, the control of the operation of consuming the residual charges of the capacitors C1 and C2 in the third embodiment is actually executed by the CPU, and the CPU executes the program including each step of the flowcharts shown in FIGS. , And executes the read program to consume the residual charges of the capacitors C1 and C2 in accordance with the flowcharts shown in FIGS.
[0218]
Therefore, the ROM corresponds to a computer (CPU) readable recording medium on which a program including the steps of the flowcharts shown in FIGS. 18 and 19 is recorded.
[0219]
Referring again to FIG. 17, the overall operation of voltage conversion system 100B will be described. When a series of operations is started, control device 30B generates H-level signal SE and outputs it to system relays SR1 and SR2, and AC motor M1 generates a torque specified by torque command value TR. To generate a signal PWMU2 and a signal PWMI for controlling the converter 12B and the inverter 14, respectively, and output them to the converter 12B and the inverter 14, respectively.
[0220]
DC power supply B outputs DC voltage Vb, and system relays SR1 and SR2 supply DC voltage Vb to converter 12B.
[0221]
Then, NPN transistors Q01 to Q04 of converter 12B are turned on / off in response to signal PWMU2 from control device 30B, and a DC current corresponding to the on-duty of NPN transistors Q01 and Q04 flows through reactor L1. Then, converter 12B converts DC voltage Vb from DC power supply B into output voltage Vc2, and supplies the converted output voltage Vc2 to inverter 14.
[0222]
NPN transistors Q3 to Q8 of inverter 14 are turned on / off in accordance with signal PWMI from control device 30B. Inverter 14 converts a DC voltage into an AC voltage, and AC motor M1 applies a torque specified by torque command value TR to torque. A predetermined alternating current is applied to each of the U, V, and W phases of the AC motor M1 so as to output. Thereby, AC motor M1 outputs the torque specified by torque command value TR.
[0223]
When the hybrid vehicle or the electric vehicle equipped with voltage conversion system 100B is in the regenerative braking mode, control device 30B receives signal RGE indicating that the vehicle has been in the regenerative braking mode from an external ECU, and receives signal PWMC and signal PWMD2. It is generated and output to the inverter 14 and the converter 12B, respectively.
[0224]
AC motor M <b> 1 generates an AC voltage and supplies the generated AC voltage to inverter 14. Then, inverter 14 converts the AC voltage into a DC voltage according to signal PWMC from control device 30B, and supplies the converted DC voltage to converter 12B.
[0225]
Converter 12B changes the voltage level of the DC voltage in accordance with signal PWMD2 from control device 30B, supplies the changed DC voltage to DC power supply B, and charges DC power supply B.
[0226]
When the DC current BCRT from the current sensor 18, that is, the charge back current BCRT to the DC power supply B becomes smaller than the predetermined value α, the control device 30B generates a signal STP and outputs the signal STP to the converter 12B. A level signal SE is generated and output to system relays SR1 and SR2.
[0227]
Thereafter, control device 30B generates signal PWDCH2 and outputs it to converter 12B. As a result, the residual charge of the capacitor C1 is consumed by the above-described step-up operation, and the residual charge of the capacitor C2 is consumed by the above-described step-down operation. When remaining voltages Vc1 and Vc2 of capacitors C1 and C2 become lower than predetermined value β, control device 30B generates signal STP and outputs it to converter 12B. Then, the voltage conversion system 100B is stopped.
[0228]
The rest is the same as the first embodiment.
According to the third embodiment, the voltage conversion system includes a boost converter, a capacitor C1 provided on the input side of the boost converter, a capacitor C2 provided on the output side of the boost converter, and a boost operation and a step-down operation. And a control device for controlling the boost converter so as to alternately perform the boosting operation and the step-down operation using two NPN transistors and a reactor. Charges can be consumed faster.
[0229]
[Embodiment 4]
Referring to FIG. 20, a voltage conversion system 100C according to the fourth embodiment has a configuration in which converter 12B of voltage conversion system 100B is replaced with converter 12C, and control device 30B is replaced with control device 30C. Same as system 100B.
[0230]
Converter 12C is the same as converter 12B except that reactor L1 of converter 12B is replaced with reactor L2. In other words, converter 12C is obtained by changing the inductance of the reactor in converter 12B.
[0231]
Control device 30C has a function in which a function of generating signal EXC of control device 30A and outputting it to converter 12C is added to the function of control device 30B.
[0232]
That is, the fourth embodiment is equivalent to the third embodiment obtained by applying the second embodiment.
[0233]
The operation of consuming the residual charges of capacitors C1 and C2 in the fourth embodiment is performed according to the flowcharts shown in FIGS. The flowchart shown in FIG. 21 is the same as the flowchart shown in FIG. 18 except that step S6C in the flowchart shown in FIG. 18 is replaced with step S6C.
[0234]
FIG. 22 is a flowchart for explaining the operation of step S6C in the flowchart shown in FIG. The flowchart shown in FIG. 22 is a flowchart in which, after executing steps S59 and S60 in the flowchart shown in FIG. 16 above, steps S71 and S72 in the flowchart shown in FIG. 19 are executed. Therefore, detailed description is omitted.
[0235]
When step S6C is repeatedly performed, as described above, the carrier frequency fc2 for controlling the switching of the NPN transistors Q1 and Q2 may be increased with the decrease in the remaining voltages Vc1 and Vc2.
[0236]
Others are as described above.
The residual charge consuming method according to the present invention is a residual charge consuming method for consuming the residual charges of the capacitors C1 and C2 according to the flowcharts shown in FIGS.
[0237]
In addition, the control of the operation of consuming the residual charges of the capacitors C1 and C2 in the fourth embodiment is actually executed by the CPU, and the CPU executes the program including the steps of the flowcharts shown in FIGS. , And executes the read program to consume the residual charges of the capacitors C1 and C2 in accordance with the flowcharts shown in FIGS. 21 and 22.
[0238]
Therefore, the ROM corresponds to a computer (CPU) readable recording medium on which a program including the steps of the flowcharts shown in FIGS. 21 and 22 is recorded.
[0239]
The overall operation of voltage conversion system 100C is such that the operation of consuming the residual charges of capacitors C1 and C2 in voltage conversion system 100B is replaced with the operation of consuming the residual charges of capacitors C1 and C2 in the fourth embodiment. Others are the same as the operation of the voltage conversion system 100B.
[0240]
Others are the same as the second and third embodiments.
According to the fourth embodiment, the voltage conversion system reduces the inductance of the boost converter, the capacitor C1 provided on the input side of the boost converter, the capacitor C2 provided on the output side of the boost converter, and the reactor. A control device for controlling the boost converter so as to alternately perform the step-up operation and the step-down operation. Since the step-up operation and the step-down operation are performed using two NPN transistors and a reactor, no new parts are required. Can also consume the residual charges of the capacitors C1 and C2 more quickly.
[0241]
The voltage conversion system according to the present invention may be a voltage conversion system 100D shown in FIG. Referring to FIG. 23, voltage conversion system 100D is obtained by adding coil 60, rectifier circuit 61 and auxiliary battery 62 to voltage conversion system 100, and replacing control device 30 of voltage conversion system 100 with control device 30D. Yes, the rest is the same as the voltage conversion system 100.
[0242]
The coil 60 is provided to face the coil of the reactor L1. The rectifier circuit 61 receives the voltage generated at both ends of the coil 60, rectifies the received voltage, and charges the auxiliary battery 62. The auxiliary battery 62 is a battery for driving auxiliary equipment such as lights mounted on a hybrid vehicle or an electric vehicle.
[0243]
Control device 30D replaces the function of control device 30 of generating signal PWDCH1 and outputting it to boost converter 12 with the function of generating signal PWDCH3 and outputting it to boost converter 12. Is the same as
[0244]
When the DC current BCRT from the current sensor 18 becomes smaller than the predetermined value α while the power stored in the capacitor C2 is being charged back to the DC power supply B, the control device 30D stops the charge back and outputs the L-level signal SE. After the signal is generated and output to system relays SR1 and SR2, signal PWDCH3 is generated and output to boost converter 12.
[0245]
Signal PWDCH3 is a signal for turning on NPN transistor Q1 of boost converter 12 and turning off NPN transistor Q2. Therefore, upon receiving signal PWDCH3 from control device 30D, boost converter 12 accumulates the residual charge of capacitor C2 in reactor L1. Then, a voltage is generated at both ends of reactor L1, and the generated voltage is converted by the coil of reactor L1 and coil 60. Then, the rectifier circuit 61 rectifies the voltage generated at both ends of the coil 60 to charge the auxiliary battery 62.
[0246]
By converting the voltage generated at both ends of the reactor L1 by the coil of the reactor L1 and the coil 60, the residual charge of the capacitor C2 is reduced, and the voltage Vc2 across the capacitor C2 is reduced to the voltage Vc1 across the capacitor C1. Then, the residual charges of the capacitors C1 and C2 are accumulated in the reactor L1, and the voltage is converted to the coil 60. Then, the residual charges of the capacitors C1 and C2 are voltage-converted to the coil 60 to charge the auxiliary battery 62 until the voltage across the capacitors C1 and C2 becomes lower than a predetermined value β.
[0247]
As described above, voltage conversion system 100D consumes the residual charges of capacitors C1 and C2 by converting the voltage stored in reactor L1 to the secondary side of coil 60, rectifier circuit 61 and auxiliary battery 62.
[0248]
Others are as described above.
Further, the voltage conversion system according to the present invention may be the voltage conversion system shown in FIG. Referring to FIG. 24, voltage conversion system 100E is obtained by adding coil 60, rectifier circuit 61 and auxiliary battery 62 to voltage conversion system 100B, and replacing control device 30B of voltage conversion system 100B with control device 30E. Yes, the rest is the same as the voltage conversion system 100B.
[0249]
The coil 60, the rectifier circuit 61 and the auxiliary battery 62 are as described above.
[0250]
Control device 30E replaces the function of control device 30B of generating signal PWDCH2 and outputting it to converter 12B with the function of generating signal PWDCH4 and outputting it to converter 12B, and is otherwise the same as control device 30B. It is.
[0251]
Signal PWDCH4 is a signal for turning on NPN transistors Q01 and Q03 and turning off NPN transistors Q02 and Q04 of converter 12B. Therefore, upon receiving signal PWDCH4 from control device 30E, converter 12B accumulates the residual charges of capacitors C1 and C2 in reactor L1 by the same operation as voltage conversion system 100D, and converts the voltage generated across reactor L1 into a coil. By converting the voltage to the secondary side of the rectifier circuit 61 and the auxiliary battery 62, the residual charges of the capacitors C1 and C2 are consumed.
[0252]
Others are as described above.
In motor drive devices 100D and 100E, reactor L1 may be replaced with reactor L2. In that case, control devices 30D and 30E generate signal EXC for changing the number of turns of coils 3A and 3B of reactor L2, and output the signal to reactor L2.
[0253]
In the above description, the case where the number of AC motors is one has been described. However, the present invention is not limited to this, and can be applied to a voltage conversion system that drives a plurality of AC motors. In that case, a plurality of inverters provided corresponding to the plurality of AC motors are connected in parallel to both ends of the capacitor C2. Each of the plurality of inverters converts the output voltage Vc2 received from boost converters 12 and 12A or converters 12B and 12C via capacitor C2 to an AC voltage and drives a corresponding AC motor.
[0254]
Further, the switching elements forming boost converters 12 and 12A, converters 12B and 12C, and inverter 14 are not limited to NPN transistors, but may be MOS transistors.
[0255]
The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description of the embodiments, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram of a voltage conversion system according to a first embodiment.
FIG. 2 is a functional block diagram of the control device shown in FIG.
FIG. 3 is a functional block diagram for explaining a function of a motor torque control unit shown in FIG. 2;
FIG. 4 is a relationship diagram between an output voltage of the DC power supply shown in FIG. 1 and a battery capacity.
FIG. 5 is a diagram showing a relationship between a residual voltage of the capacitor shown in FIG. 1 and a carrier frequency.
FIG. 6 is a flowchart for describing an operation of consuming the residual charge of the capacitor according to the first embodiment.
FIG. 7 is a flowchart for explaining the operation of step S6 in the flowchart shown in FIG. 6;
FIG. 8 is a schematic block diagram of a voltage conversion system according to a second embodiment.
9 is a functional block diagram of the control device shown in FIG.
FIG. 10 is a diagram showing a relationship between the inductance of the reactor shown in FIG. 8 and the residual voltage of a capacitor.
11 is a diagram showing a relationship between the inductance and the number of turns in the reactor shown in FIG.
FIG. 12 is a diagram illustrating a relationship between a carrier frequency and a residual voltage of a capacitor.
FIG. 13 is a perspective view of the reactor shown in FIG.
FIG. 14 is an enlarged view of a winding number switching unit shown in FIG.
FIG. 15 is a flowchart for illustrating an operation of consuming residual charge of a capacitor according to the second embodiment.
16 is a flowchart for explaining the operation of step S6A in the flowchart shown in FIG.
FIG. 17 is a schematic block diagram of a voltage conversion system according to a third embodiment.
FIG. 18 is a flowchart illustrating an operation of consuming the residual charge of the capacitor according to the third embodiment.
FIG. 19 is a flowchart for explaining the operation of step S6B in the flowchart shown in FIG. 18;
FIG. 20 is a schematic block diagram of a voltage conversion system according to a fourth embodiment.
FIG. 21 is a flowchart illustrating an operation of consuming the residual charge of the capacitor according to the fourth embodiment.
FIG. 22 is a flowchart for explaining the operation of step S6C in the flowchart shown in FIG. 21;
FIG. 23 is another schematic block diagram of a voltage conversion system according to the present invention.
FIG. 24 is still another schematic block diagram of the voltage conversion system according to the present invention.
FIG. 25 is a schematic block diagram of a conventional motor drive device.
[Explanation of symbols]
2 cores, 3A, 3B, 60 coils, 3C, 5 wiring, 4 turns switching section, 4A contact switching section, 6A, 6B terminals, 10A, 11, 13 voltage sensor, 10B temperature sensor, 12, 12A, 310 boost converter, 12B, 12C converter, 13A, 14A, 15A, 16A arrow, 14,330 inverter, 15 U-phase arm, 16 V-phase arm, 17 W-phase arm, 18, 24 current sensor, 21, 22 gap, 23A, 23B linear part , 23C, 23D bending section, 25, 27 power line, 26, 28 ground line, 30, 30A, 30B, 30C, 30D, 30E control device, 40 motor control phase voltage calculation section, 42 inverter PWM signal conversion section, 50 Inverter input voltage command calculator, 52 Converter duty ratio calculator, 54 converter PWM signal converter, 61 rectifier circuit, 62 auxiliary battery, 100, 100A, 100B, 100C, 100D, 100E voltage conversion system, 300 motor drive device, 312, 313, Q1 to Q8, Q01 to Q04 NPN transistor, 314, 315, D1 to D8, D01 to D04 Diode, 301 Motor torque control means, 302, 302A Voltage conversion control means, 411 to 41m contacts, 420 switch, B DC power supply, SR1, SR2 system relay, C1, C2, 309 , 320 capacitors, L1, L2, 311 reactors, M1 AC motor.

Claims (55)

Power and
An inverter,
A voltage converter connected between the power supply and the inverter;
A first capacitor inserted on the power supply side of the voltage converter;
A second capacitor inserted on the inverter side of the voltage converter;
Control means for controlling the voltage converter so as to consume the residual charge of the first capacitor and the residual charge of the second capacitor in response to a stop signal. The control means is configured to consume the residual charge of the first capacitor by the boosting operation by the voltage converter and to consume the residual charge of the second capacitor by the step-down operation by the voltage converter. The voltage conversion system according to claim 1, wherein the voltage conversion system controls a transformer. 3. The voltage conversion system according to claim 2, wherein the control unit controls the voltage converter so that the step-up operation and the step-down operation are alternately repeated for a predetermined time. 4. When the first voltage of the first capacitor or the second voltage of the second capacitor is equal to or lower than the voltage of the power supply, the control means consumes residual charges of the first and second capacitors. The voltage conversion system according to any one of claims 1 to 3, wherein the voltage converter is controlled to perform the voltage conversion. The voltage converter,
A first arm disposed on the first capacitor side and including first and second switching elements;
A second arm disposed on the second capacitor side and including third and fourth switching elements;
A reactor having one end connected to an intermediate point between the first switching element and the second switching element and the other end connected to an intermediate point between the third switching element and the fourth switching element; Including
4. The voltage conversion system according to claim 2, wherein the control unit performs switching control of the first to fourth switching elements so as to alternately perform the step-up operation and the step-down operation. 5. The controller controls the first and fourth switching elements by lowering a carrier frequency with a decrease in a first voltage of the first capacitor or a second voltage of the second capacitor. The voltage conversion system according to claim 5, wherein 7. The voltage conversion system according to claim 6, wherein the control unit controls switching of the first and fourth switching elements based on a carrier frequency corresponding to the first voltage or the second voltage. 8. A first voltage sensor for detecting the first voltage;
A second voltage sensor that detects the second voltage,
The control unit holds a relationship between the first voltage or the second voltage and the carrier frequency as a map, and stores the relationship between the first voltage received from the first voltage sensor and the second voltage. 8. The method according to claim 7, wherein a carrier frequency corresponding to a second voltage received from the voltage sensor is extracted with reference to the map, and the first and fourth switching elements are switching-controlled by the extracted carrier frequency. 9. Voltage conversion system. 6. The voltage conversion system according to claim 5, wherein the control unit performs switching control of the first to fourth switching elements using a drive voltage lower than a drive voltage in a normal operation. 7. The voltage conversion system according to claim 9, wherein the control unit performs switching control of the first and fourth switching elements at a carrier frequency lower than a carrier frequency during normal operation. The voltage conversion system according to claim 5, further comprising: an inductance changing unit configured to reduce inductance of the reactor as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. . The voltage conversion system according to claim 11, wherein the inductance changing unit decreases the number of turns of the coil of the reactor as the first voltage or the second voltage decreases. The voltage conversion system according to claim 12, wherein the inductance changing unit changes the number of turns of the coil to a number of turns corresponding to the first voltage or the second voltage. 14. The voltage conversion system according to claim 13, wherein the control unit performs switching control of the first to fourth switching elements by increasing a carrier frequency. The voltage converter,
An arm disposed on the second capacitor side and including first and second switching elements;
One end is connected to a positive electrode of the first capacitor, and the other end includes a reactor connected to an intermediate point between the first switching element and the second switching element,
4. The voltage conversion system according to claim 2, wherein the control unit controls the first and second switching elements such that the step-up operation and the step-down operation are performed alternately. 5. The controller controls the first and second switching elements by lowering a carrier frequency with a decrease in a first voltage of the first capacitor or a second voltage of the second capacitor. The voltage conversion system according to claim 15, wherein: 17. The voltage conversion system according to claim 16, wherein said control means controls switching of said first and second switching elements by a carrier frequency corresponding to said first voltage or said second voltage. A first voltage sensor for detecting the first voltage;
A second voltage sensor that detects the second voltage,
The control unit holds a relationship between the first voltage or the second voltage and the carrier frequency as a map, and stores the relationship between the first voltage received from the first voltage sensor and the second voltage. The method according to claim 17, wherein a carrier frequency corresponding to a second voltage received from a voltage sensor is extracted with reference to the map, and switching of the first and second switching elements is controlled by the extracted carrier frequency. Voltage conversion system. 16. The voltage conversion system according to claim 15, wherein the control unit controls the first and second switching elements using a drive voltage lower than a drive voltage in a normal operation. 20. The voltage conversion system according to claim 19, wherein said control means performs switching control of said first and second switching elements at a carrier frequency lower than a carrier frequency during normal operation. The voltage conversion system according to claim 15, further comprising an inductance changing unit configured to reduce an inductance of the reactor as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. . 22. The voltage conversion system according to claim 21, wherein the inductance changing unit decreases the number of turns of a coil of the reactor as the first voltage or the second voltage decreases. 23. The voltage conversion system according to claim 22, wherein the inductance changing unit changes the number of turns of the coil to a number of turns corresponding to the first voltage or the second voltage. 24. The voltage conversion system according to claim 23, wherein the control unit performs switching control of the first and second switching elements by increasing a carrier frequency. The voltage conversion system according to claim 2, wherein the voltage converter is a bidirectional buck-boost converter. 5. The voltage converter according to claim 2, wherein the control unit controls the voltage converter to alternately perform the step-up operation and the step-down operation when an electric path to the power supply is cut off. system. The method according to claim 1, wherein, after disconnecting the power supply, the control unit controls the voltage converter so as to consume the residual charge of the first capacitor and the residual charge of the second capacitor. 4. The voltage conversion system as described. A residual charge consuming method for consuming residual charge of a first capacitor provided on an input side of a voltage converter and a second capacitor provided on an output side of the voltage converter,
A first step of consuming a residual charge of the first capacitor by a boosting operation by the voltage converter;
A second step of consuming the residual charge of the second capacitor by the step-down operation by the voltage converter;
A third step of alternately repeating the step-up operation and the step-down operation for a predetermined period of time; The voltage converter,
A first arm disposed on the first capacitor side and including first and second switching elements;
A second arm disposed on the second capacitor side and including third and fourth switching elements;
A reactor having one end connected to an intermediate point between the first switching element and the second switching element and the other end connected to an intermediate point between the third switching element and the fourth switching element; Including
In the first step, the second and third switching elements are turned off, the first and fourth switching elements are turned on,
29. The residual charge consuming method according to claim 28, wherein in the second step, the first and fourth switching elements are turned off, and the second and third switching elements are turned on. The switching control of the first to fourth switching elements is performed by lowering a carrier frequency with a decrease in a first voltage of the first capacitor or a second voltage of the second capacitor. Item 30. The residual charge consuming method according to Item 29. 30. The residual charge consuming method according to claim 29, wherein the first to fourth switching elements are switching-controlled by a drive voltage lower than a drive voltage in a normal operation. The switching control of the first to fourth switching elements is performed by lowering a carrier frequency with a decrease in a first voltage of the first capacitor or a second voltage of the second capacitor. Item 32. The method for consuming residual charges according to Item 31. 30. The reactor according to claim 29, wherein, in the first and second steps, the inductance of the reactor is reduced as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. Residual charge consumption method as described. 34. The residual charge consuming method according to claim 33, wherein the first to fourth switching elements are switching-controlled by increasing a carrier frequency. The voltage converter,
An arm disposed on the second capacitor side and including first and second switching elements;
One end is connected to a positive electrode of the first capacitor, and the other end includes a reactor connected to an intermediate point between the first switching element and the second switching element,
In the first step, the first switching element is turned off, the second switching element is turned on,
29. The method according to claim 28, wherein in the second step, the first switching element is turned on and the second switching element is turned off. The switching control of the first and second switching elements is performed by lowering a carrier frequency with a decrease in a first voltage of the first capacitor or a second voltage of the second capacitor. Item 36. The residual charge consuming method according to Item 35. 36. The residual charge consuming method according to claim 35, wherein the switching of the first and second switching elements is controlled by a driving voltage lower than a driving voltage in a normal operation. The first and second switching elements are switching-controlled by further lowering the carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. The method for consuming residual charges according to claim 37. 36. The method according to claim 35, wherein, in the first and second steps, the inductance of the reactor is reduced with a decrease in a first voltage of the first capacitor or a second voltage of the second capacitor. Residual charge consumption method as described. The residual charge consuming method according to claim 39, wherein the first and second switching elements are switching-controlled by increasing a carrier frequency. 4. The method according to claim 1, further comprising: before performing the first, second, and third steps, disconnecting a power supply that supplies a DC voltage to the voltage converter via the first capacitor. 29. The method for consuming residual charges according to 28. Computer readable recording a program for causing a computer to execute the consumption of the residual charge of the first capacitor provided on the input side of the voltage converter and the second capacitor provided on the output side of the voltage converter A recording medium,
A first step of consuming a residual charge of the first capacitor by a boosting operation by the voltage converter;
A second step of consuming the residual charge of the second capacitor by the step-down operation by the voltage converter;
A computer-readable recording medium storing a program for causing a computer to execute a third step of alternately repeating the step-up operation and the step-down operation for a predetermined time. The voltage converter,
A first arm disposed on the first capacitor side and including first and second switching elements;
A second arm disposed on the second capacitor side and including third and fourth switching elements;
A reactor having one end connected to an intermediate point between the first switching element and the second switching element and the other end connected to an intermediate point between the third switching element and the fourth switching element; Including
In the first step, the second and third switching elements are turned off, the first and fourth switching elements are turned on,
43. The program according to claim 42, wherein the first and fourth switching elements are turned off and the second and third switching elements are turned on in the second step. Computer readable recording medium. The switching control of the first to fourth switching elements is performed by lowering a carrier frequency with a decrease in a first voltage of the first capacitor or a second voltage of the second capacitor. Item 44. A computer-readable recording medium recording a program to be executed by a computer according to Item 43. 44. The computer-readable recording medium storing a program for causing a computer to execute according to claim 43, wherein the first to fourth switching elements are switching-controlled by a drive voltage lower than a drive voltage in a normal operation. . The first to fourth switching elements are switching-controlled by further lowering the carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. A computer-readable recording medium on which a program for causing a computer to execute according to claim 45 is recorded. 44. The method according to claim 43, wherein, in the first and second steps, the inductance of the reactor is reduced with a decrease in a first voltage of the first capacitor or a second voltage of the second capacitor. A computer-readable recording medium on which a program to be executed by a computer according to the present invention is recorded. 48. The computer-readable recording medium according to claim 47, wherein the first to fourth switching elements are switching-controlled by increasing a carrier frequency. The voltage converter,
An arm disposed on the second capacitor side and including first and second switching elements;
One end is connected to a positive electrode of the first capacitor, and the other end includes a reactor connected to an intermediate point between the first switching element and the second switching element,
In the first step, the first switching element is turned off, the second switching element is turned on,
43. The computer-readable recording medium storing a program for causing a computer to execute according to claim 42, wherein in the second step, the first switching element is turned on and the second switching element is turned off. . The switching control of the first and second switching elements is performed by lowering a carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. 50. A computer-readable recording medium recording a program to be executed by a computer according to item 49. 50. The computer-readable recording medium according to claim 49, wherein the first and second switching elements are switching-controlled by a drive voltage lower than a drive voltage in a normal operation. . The first and second switching elements are switching-controlled by further lowering the carrier frequency as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. A computer-readable recording medium on which a program for causing a computer to execute according to claim 51 is recorded. 50. The reactor according to claim 49, wherein, in the first and second steps, the inductance of the reactor is reduced as the first voltage of the first capacitor or the second voltage of the second capacitor decreases. A computer-readable recording medium on which a program to be executed by a computer according to the present invention is recorded. 54. The computer-readable recording medium according to claim 53, wherein the first and second switching elements are switching-controlled by increasing a carrier frequency. And causing the computer to further execute a fourth step of disconnecting a power supply for supplying a DC voltage to the voltage converter via the first capacitor before performing the first, second, and third steps. A computer-readable recording medium on which a program for causing a computer according to claim 42 to execute is recorded.

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