CN107979297B - AC/DC converter based on multiplexing inductance - Google Patents
AC/DC converter based on multiplexing inductance Download PDFInfo
- Publication number
- CN107979297B CN107979297B CN201711277551.2A CN201711277551A CN107979297B CN 107979297 B CN107979297 B CN 107979297B CN 201711277551 A CN201711277551 A CN 201711277551A CN 107979297 B CN107979297 B CN 107979297B
- Authority
- CN
- China
- Prior art keywords
- power switch
- diode
- power
- voltage
- converter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/12—Arrangements for reducing harmonics from ac input or output
Abstract
The invention relates to an AC/DC converter based on a multiplexing inductor, belonging to the field of power electronics. The novel AC/DC converter based on the multiplexing inductor mainly comprises: the device comprises a current transformation circuit, a control circuit and a detection circuit; the current transformation circuit comprises a first power switch, a second power switch, a third power switch, a first diode, a second diode, a fifth diode, a first inductor, a filter capacitor and a smoothing capacitor. The control circuit controls the on and off of the first power switch to the third power switch according to the direct-current voltage output by the converter circuit and the power grid voltage of the power grid alternating-current power supply, which are acquired by the detection circuit, so as to control the converter circuit to work in the working modes of voltage boosting, voltage reducing and voltage boosting. According to the invention, a combined grounding structure is adopted between the AC side and the DC side, only three power switches are needed, and the three-phase DC power supply has the advantages of high utilization rate of an inductor, low cost, small voltage stabilizing capacitor at the DC side, small ripple of output DC voltage and the like.
Description
Technical Field
The invention relates to an AC/DC converter, in particular to an AC/DC converter based on multiplexing inductors.
Background
The AC/DC converter is mainly used for converting alternating current output by an alternating current power grid or alternating current generated by a distributed power generation system into direct current required by a direct current micro grid. In the prior art, the grounding method of the AC/DC converter applied to the DC micro grid may be generally divided into a joint grounding structure, a single-side grounding structure, a virtual isolation grounding structure, and the like.
Fig. 1 shows a joint grounding structure of an AC/DC converter in a DC microgrid. In this configuration, the AC high voltage first passes through a split phase transformer T1And reducing the voltage to 110V alternating current low voltage, then connecting the alternating current low voltage into an AC/DC converter to perform alternating current/direct current conversion, and finally providing power for the direct current micro-grid. The alternating-current low-voltage system and the direct-current micro-grid share the ground wire. The combined grounding structure has the advantage that the direct-current microgrid can be easily installed in an original alternating-current low-voltage power grid, so that a hybrid power system is formed. In a hybrid power system, a safe and reliable ground line is required for low-voltage electric devices. However, most low voltage AC systems are not suitable for this configuration without a dedicated or complex AC/DC converter providing ground. At the same time, DC current is required to be smallThe net must be suitable for a three-port bipolar voltage transformation architecture.
In the prior art, the direct current microgrid and the low-voltage alternating current system are difficult to share the ground wire due to the limitation of low-voltage equipment. So many scholars consider a single-side grounding structure. Fig. 2 shows a single-side grounding structure with a double dc bus bar in a dc microgrid. In this configuration, the AC high voltage is passed through a step-down transformer T2The alternating current is converted into low alternating current suitable for the input of the AC/DC converter, and then the power is provided for the direct current micro grid through the AC/DC converter. Step-down transformer T here2Similar to an isolation transformer and which provides an ac voltage for the dc microgrid which is typically lower than the standard ac voltage. For example, a three-phase step-down transformer may output a 200V line voltage instead of a standard 380V line voltage. In addition, the AC/DC converter can convert AC power to DC power of different requirements depending on the DC voltage output power and the power rating requirements. For example, the dc microgrid may be a single dc bus system or a dual dc bus system. The advantage of this single-side grounding structure is that the AC/DC converter can be a simple structure, such as a two-level three-phase converter, or a three-level three-phase converter, or other converters. The disadvantage is that the output of the step-down transformer cannot be directly connected with other low-voltage alternating-current civil loads, so the adaptability of the direct-current microgrid is limited.
In the prior art, it is not easy to realize a common ground for a hybrid ac and dc power grid system because of the presence of low voltage devices. Therefore, a virtual isolation ground structure has been proposed by scholars. As shown in fig. 3a-3b, virtual isolated ground structures can be generally classified into two categories depending on the type of transformer.
FIG. 3a shows a transformer T based on industrial frequency3The virtual isolated ground structure of (1). This configuration is similar to the single-sided grounding configuration, but here the transformer is connected to a low voltage ac power system, rather than a high voltage ac system. FIG. 3b shows a high frequency transformer T4The virtual isolated ground structure of (1). In contrast to the method shown in fig. 3a, a high frequency transformer T is used in fig. 3b4And two current transformers. The high-frequency transformer based on the method has more advantages compared with a power frequency transformer system because the converter has higher conversion efficiency.
Although the virtual isolation grounding mode can be very flexibly adapted to the requirements of the direct current microgrid structure, the transformer and the plurality of converters used in the virtual isolation grounding mode have additional power loss, and the conversion efficiency of the whole system is reduced.
In the dc microgrid, if an ac power system is connected by using a virtual isolated ground structure, the conversion efficiency of the system is reduced. The adaptability of the dc microgrid may be limited if a single-sided grounding structure is utilized. Therefore, in the prior art, an AC/DC converter of a combined ground structure is provided, as shown in fig. 4. The AC/DC converter has the advantages of high efficiency, low cost, safety and reliability. However, the AC/DC converter also has drawbacks. For example, only the first converter circuit or the second converter circuit operates in the positive half cycle or the negative half cycle of the power frequency, so that a smoothing capacitor with a large capacity needs to be connected in parallel to the output direct current side to keep the output direct current voltage substantially stable. Meanwhile, since the first output power is equal to the second output power, if the power absorbed by the two dc loads connected to the dc output terminal is different, the first output dc voltage E is obtained1And a second output DC voltage E2It is difficult to maintain balance, and thus the requirement of the input voltage stability of the dc load cannot be satisfied. Please refer to fig. 5 and fig. 6, which are a BUCK operating state diagram and a BOOST operating state diagram of the AC/DC converter with the joint grounding structure, respectively. If the above problem is to be solved, a dc voltage balance adjustment circuit must be added to the circuit shown in fig. 4, thereby increasing the cost.
In view of the disadvantages of the AC/DC converter shown in fig. 4 in the prior art, it is necessary to provide a new AC/DC converter.
Disclosure of Invention
The invention aims to provide a safe, reliable and low-cost AC/DC converter.
The invention provides an AC/DC converter based on multiplexing inductance, which comprises: the device comprises a current transformation circuit, a control circuit and a detection circuit;
the current transformation circuit at least comprises a first power switch, a second power switch, a third power switch, a first diode, a second diode, a fifth diode, a first inductor, a filter capacitor and a smoothing capacitor; the fifth diode and the third power switch are connected in series and then connected between the alternating current input end of the current transformation circuit and the second end of the first inductor; the first diode and the first power switch are connected in series and then connected between the alternating current input end and the first end of the first inductor; the first end of the fourth diode is connected with the second end of the first inductor and is grounded through the third diode and the second power switch which are connected in series; the fourth diode is connected between the second end of the first inductor and the direct current output end; the first end of the first inductor is grounded through the second diode; the alternating current input end of the converter circuit is connected to an alternating current power supply of a power grid, and the filter capacitor is connected to two ends of the alternating current power supply of the power grid in parallel and used for filtering alternating current input into the converter circuit;
the detection circuit is used for detecting the direct current voltage output by the converter circuit and the power grid voltage of the power grid alternating current power supply and feeding back the direct current voltage and the power grid voltage to the control circuit;
the control circuit is used for sending a switch control signal to the controlled ends of the first power switch to the third power switch according to the detected direct-current voltage and the detected power grid voltage so as to control the converter circuit to work in a working mode of boosting, reducing voltage and boosting and reducing voltage.
In the AC/DC converter based on the multiplexed inductors according to the present invention, preferably, the control circuit:
controlling the converter circuit to work in a boosting mode when the power frequency is in a positive half cycle and the direct current voltage is higher than the absolute value of the instantaneous value of the power grid voltage, controlling the converter circuit to work in a voltage reduction mode when the power frequency is in the positive half cycle and the direct current voltage is lower than the absolute value of the instantaneous value of the power grid voltage, and controlling the converter circuit to work in a voltage reduction mode when the power frequency is in a negative half cycle; or
And controlling the converter circuit to work in a boosting mode when the power frequency is in a negative half cycle and the direct current voltage is higher than the absolute value of the instantaneous value of the power grid voltage, controlling the converter circuit to work in a voltage reduction mode when the power frequency is in the negative half cycle and the direct current voltage is lower than the absolute value of the instantaneous value of the power grid voltage, and controlling the converter circuit to work in a voltage reduction mode when the power frequency is in a positive half cycle.
In the AC/DC converter based on the multiplexed inductor according to the present invention, preferably, an anode of the first diode is connected to the AC input terminal, and a cathode thereof is connected to the first power switch; the cathode of the second diode is connected with the first end of the first inductor, and the anode of the second diode is grounded; the anode of the third diode is connected with the second power switch, and the cathode of the third diode is grounded; the cathode of the fourth diode is connected with the direct current output end, and the anode of the fourth diode is connected with the second end of the first inductor; and the cathode of the fifth diode is connected with the alternating current input end, and the anode of the fifth diode is connected with the third power switch. Thus, when determining that the dc voltage is higher than the absolute value of the instantaneous value of the grid voltage: in the positive half cycle of the power frequency, the first power switch is closed, the second power switch works at high frequency, and the third power switch is opened; in the negative half cycle of the power frequency, the third power switch works at high frequency, and the first power switch and the second power switch are disconnected; when the control circuit determines that the direct current voltage is lower than the absolute value of the instantaneous value of the power grid voltage: in the positive half cycle of the power frequency, the first power switch works at high frequency, and the second power switch and the third power switch are disconnected; and in the negative half cycle of the power frequency, the third power switch works at high frequency, and the first power switch and the second power switch are disconnected.
In the AC/DC converter based on the multiplexed inductor according to the present invention, preferably, the cathode of the first diode is connected to the AC input terminal, and the anode is connected to the first power switch; the anode of the second diode is connected with the first end of the first inductor, and the cathode of the second diode is grounded; the cathode of the third diode is connected with the second power switch, and the anode of the third diode is grounded; the anode of the fourth diode is connected with the direct current output end, and the cathode of the fourth diode is connected with the second end of the first inductor; and the anode of the fifth diode is connected with the alternating current input end, and the cathode of the fifth diode is connected with the third power switch. Thus, when determining that the dc voltage is higher than the absolute value of the instantaneous value of the grid voltage: in the negative half cycle of the power frequency, the first power switch is closed, the second power switch works at high frequency, and the third power switch is opened; in the positive half cycle of the power frequency, the third power switch works at high frequency, and the first power switch and the second power switch are disconnected; when the control circuit determines that the direct current voltage is lower than the absolute value of the instantaneous value of the power grid voltage: in the negative half cycle of the power frequency, the first power switch works at high frequency, and the second power switch and the third power switch are disconnected; and in the positive half cycle of the power frequency, the third power switch works at high frequency, and the first power switch and the second power switch are disconnected.
In the AC/DC converter based on the multiplexed inductor according to the present invention, preferably, the AC/DC converter based on the multiplexed inductor further includes a second inductor connected between the grid AC power source and the AC input terminal.
In the AC/DC converter based on the multiplexing inductor according to the present invention, preferably, the first to third power switches are MOS field effect transistors, insulated gate bipolar transistors or integrated gate commutated thyristors.
In the AC/DC converter based on the multiplexed inductor according to the present invention, preferably, the first diode, the third diode and the fifth diode are replaced by a MOS field effect transistor, an insulated gate bipolar transistor or an integrated gate commutated thyristor.
In the AC/DC converter based on the multiplexed inductor according to the present invention, preferably, the whole of the first diode and the first power switch, the whole of the third diode and the second power switch, and the whole of the fifth diode and the third power switch are replaced by a reverse-blocking type insulated gate bipolar transistor.
According to the AC/DC converter based on the multiplexing inductor, the first inductor is used for storing and releasing energy in any working state of the converter, and the control circuit controls the states of the first power switch, the second power switch, the third power switch and the fourth power switch according to the direct current output voltage and the power grid voltage, so that the direct current voltage output by the converter circuit is kept stable; meanwhile, the AC/DC converter only uses a single inductor, so that the cost of the system is reduced.
Drawings
The features and advantages of the present invention will become more readily appreciated from the detailed description section provided below with reference to the drawings, in which:
FIG. 1 is a combined ground structure of a prior art AC/DC converter;
FIG. 2 is a single side grounding configuration of a prior art AC/DC converter;
FIG. 3a is a virtual isolation grounding structure based on a power frequency transformer of a prior art AC/DC converter;
FIG. 3b is a high frequency transformer based virtual isolated ground structure of a prior art AC/DC converter;
FIG. 4 is a prior art AC/DC converter in a combined ground configuration;
FIG. 5 is a diagram of a BUCK operation of an AC/DC converter in a combined ground configuration according to the prior art;
FIG. 6 is a state diagram of BOOST operation of an AC/DC converter in a combined ground configuration according to the prior art;
FIG. 7 is a schematic diagram of a current transformation circuit of a multiplexing inductance based AC/DC converter according to a first embodiment of the present invention;
FIG. 8 is a schematic diagram of a control circuit and a detection circuit of a multiplexing inductance based AC/DC converter according to a first embodiment of the present invention;
FIG. 9 is a schematic diagram of a current transformation circuit of a multiplexing inductance based AC/DC converter according to a second embodiment of the present invention;
100. a current transformation circuit; 200. a detection circuit; 300. a control circuit; s1A first power switch; s2A second power switch; s3A third power switch; d1A first diode; d2A second diode; d3A third diode; d4A fourth diode; d5A fifth diode; C. a smoothing capacitor; r, equivalent direct current load; l, a first inductor; l isgA second inductor; cfAnd a filter capacitor.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
Aiming at the defects of the grounding structure of the AC/DC converter applied to the direct-current microgrid in the prior art, in particular to the defects of the AC/DC converter of the combined grounding structure shown in fig. 4, the invention provides a novel AC/DC converter based on the multiplexing inductor. The main idea of the invention is that the first inductor is used for storing and releasing energy in any working state of the converter. And then the control circuit controls the states of the first to third power switches according to the direct-current voltage and the power grid voltage which are obtained by the detection of the detection circuit, so that the output direct-current voltage is stable and reliable.
Embodiments of the present invention will be described in detail below with reference to fig. 7-8. Fig. 7 and 8 are schematic diagrams of a current transformation circuit and a control part of a multiplexing inductance based AC/DC converter according to a first embodiment of the present invention. An AC/DC converter of a first embodiment of the present invention includes: the converter circuit 100, the detection circuit 200 and the control circuit 300;
the inverter circuit 100 includes first to third power switches S1-S3First to fifth diodes D1-D5A first inductor L and a filter capacitor CfAnd a smoothing capacitor C. In fig. 8, R is the equivalent dc load.
In the present invention, the fifth diode D5And a third power switch S3Connected in series between the ac input terminal of the inverter circuit 100 and the second terminal of the first inductor L. First diode D1And a first power switch S1After being connected in series, the alternating current transformer is connected between the alternating current input end of the current transformation circuit and the first end of the first inductor. Fourth diode D4Is connected to the second terminal of the first inductor L and via a third diode D connected in series3And a second power switch S2And (4) grounding. Fourth diode D4Is connected between the second end of the first inductor L and the dc output terminal. The first end of the first inductor L is also connected to the second diode D2And (4) grounding. The AC input terminal of the converter circuit 100 is connected to the AC power supply of the power grid, and the filter capacitor CfAnd the filter is connected in parallel at two ends of the alternating current power supply of the power grid and is used for filtering alternating current input into the current transformation circuit. Preferably, the AC/DC converter further comprises a second inductor L connected between the grid AC power source and the AC input terminalg. Two ends of the smoothing capacitor C are respectively connected to the dc output end of the inverter circuit 100 and ground.
Referring to fig. 7, a first embodiment of the inverter circuit 100 of the present invention is shown, wherein the polarities of the diodes are set such that the polarity of the dc output terminal of the inverter circuit is positive. Wherein the first diode D1Is connected with the AC input terminal, a first diode D1And the first power switch S1And (4) connecting. Second diode D2Is connected to a first end of a first inductor L, a second diode D2The anode of (2) is grounded. Third diode D3Anode and second power switch S2Connected, a third diode D3The cathode of (2) is grounded. Fourth diode D4Is connected to the second terminal of the first inductor L, a fourth diode D4The cathode of the anode is connected with the direct current output end. Fifth diode D5Anode and third power switch S3Connected, a fifth diode D5Is connected to the ac input terminal.
The detection circuit 200 is used for detecting the dc voltage output by the inverter circuit 100 and the grid voltage of the grid ac power supply, and detecting the dc voltage E and the grid voltage VgTo the control circuit 300.
The control circuit 300 is used for receiving the sampling signal of the detection circuit according to the DC voltage E and the grid voltage VgAnd judging the current working mode, and sending a switch control signal for controlling the on and off of the first to third power switches to the controlled ends of the first to third power switches so as to control the converter circuit 100 to work in the working modes of voltage boosting, voltage reducing and voltage boosting. Preferably, the detection circuit 200 further comprisesPower grid output current i for detecting power grid alternating current power supplygAnd sent to the control circuit 300. The control circuit 300 is further configured to determine a duty cycle of the switching control signal according to the circuit parameter when transmitting the switching control signal. Specifically, the control circuit 300 is used for controlling the DC output according to the DC voltage E output by the DC output terminal and the reference DC voltage ErefComparing, and sending the error to a direct-current voltage outer loop controller; multiplying the output result of the DC voltage outer loop controller by a sine signal and feeding back the sine signal and the grid output current igComparing, and sending the error to an alternating current inner loop controller; finally, the control circuit 300 determines the duty ratio of the switching control signal according to the output result of the alternating current inner loop controller.
In the first embodiment, the control circuit 300 is in the positive half cycle of power frequency and the dc voltage E is higher than (including equal to) the grid voltage VgWhen the absolute value of the instantaneous value is controlled, the converter circuit 100 is controlled to work in a boosting mode, and in the positive half cycle of power frequency, the direct-current voltage E is lower than the voltage V of the power gridgAnd controlling the converter circuit 100 to work in a voltage reduction mode when the absolute value of the instantaneous value is positive, and controlling the converter circuit 100 to work in a voltage reduction mode when the power frequency is negative for a half cycle.
Specifically, the control circuit 300 determines that the DC voltage E is higher than (including equal to) the grid voltage VgIs carried out in the following manner: in the power frequency positive half cycle, the converter circuit 100 is operated in the boost mode, which specifically includes: make the first power switch S1Closed, second power switch S2High frequency operation, third power switch S3And (5) disconnecting. In power frequency negative half cycle, make converter circuit work in the buck-boost mode, specifically include: make the third power switch S3Operating at high frequency, first power switch S1And a second power switch S2And (5) disconnecting.
When the control circuit 300 determines that the direct voltage E is lower than the grid voltage VgIs carried out in the following manner: in the power frequency positive half cycle, the converter circuit 100 is operated in the step-down mode, which specifically includes: make the first power switch S1Operating at high frequency, second power switch S2And a third power switch S3And (5) disconnecting. At power frequencyIn the negative half cycle, make converter circuit work in the buck-boost mode, specifically include: make the third power switch S3Operating at high frequency, first power switch S1And a second power switch S2And (5) disconnecting.
In the embodiment of the invention, the first power switch S is used in the negative half cycle of power frequency1And a second power switch S2And (5) disconnecting. By closing the third power switch S3Therefore, the alternating current network power supply and the first inductor L form a closed loop to store energy for the first inductor L. By opening the third power switch S3The energy stored in the first inductor L is enabled to be supplied to the equivalent dc load R. Through the control, the stability of the voltage at two ends of the direct-current load of the AC/DC converter is guaranteed. Meanwhile, the utilization rate of the first inductor L is improved.
In the embodiment of the invention, the first inductor L is used for storing and releasing energy in any working state of the converter. The detection circuit 200 detects and obtains the direct-current voltage output by the converter circuit 100, and then the control circuit 300 controls the states of the first to third power switches, so that the normal operation of the AC/DC converter can be guaranteed under various working conditions. Compared with the prior art, the novel AC/DC converter only needs one inductor, needs a small number of power switching devices, and adopts a combined grounding structure, thereby not only reducing the cost and the ripple rate of direct-current voltage, but also improving the safety of the AC/DC converter.
In the embodiment of the present invention, the first to third power switches may be implemented by using a MOS field effect transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), or an Integrated Gate Commutated Thyristor (IGCT). Preferably, the first power switch S1To the third power switch S3N-channel MOS field effect transistors (MOSFETs) are used. By adopting the MOS type field effect transistor as the switching device, the conduction loss can be further reduced.
In this embodiment, the first diode D1And a first power switch S1May be interchanged. Third diode D3And a second power switch S2May be interchanged. Fifth diode D5And a third power switchOff S3May be interchanged. First diode D1And a first power switch S1Instead of this, a reverse blocking type igbt may be used. Third diode D3And a second power switch S2Instead of this, a reverse blocking type igbt may be used. Fifth diode D5And a third power switch S3Instead of this, a reverse blocking type igbt may be used. Thus, the number of devices can be further reduced. First diode D1A third diode D3And a fifth diode D5Corresponding MOS field effect transistors (MOSFET), Insulated Gate Bipolar Transistors (IGBT) or Integrated Gate Commutated Thyristors (IGCT) may be used instead, for example N-channel MOS field effect transistors, to reduce the turn-on voltage drop.
Fig. 9 is a schematic diagram of a converter circuit in an AC/DC converter based on a multiplexed inductor according to a second embodiment of the present invention. This second embodiment provides another topology. Compared with fig. 7, the operation principle and the operation mode are the same as those of fig. 7 except that the voltage polarity is different. Specifically, the polarity of each diode is set so that the polarity of the direct current output end of the current transformation circuit is negative. Wherein the first diode D1Is connected to the AC input terminal, a first diode D1Anode and first power switch S1And (4) connecting. Second diode D2Is connected to a first end of a first inductor L, a second diode D2The cathode of (2) is grounded. Third diode D3And a second power switch S2Connected, a third diode D3The anode of (2) is grounded. Fourth diode D4Is connected to the second end of the first inductor L, a fourth diode D4The anode of the anode is connected with the direct current output end. Fifth diode D5And the third power switch S3Connected, a fifth diode D5Is connected with the alternating current input end.
In this second embodiment, the control circuit 300 is accordingly operated at the negative half cycle of the power frequency and the dc voltage E is higher than (including equal to) the grid voltage VgOf instantaneous valueWhen the absolute value is controlled, the converter circuit 100 works in a boosting mode, and the direct-current voltage is lower than the voltage V of a power grid in the negative half cycle of power frequencygAnd controlling the converter circuit 100 to work in a voltage reduction mode when the absolute value of the instantaneous value is positive, and controlling the converter circuit 100 to work in a voltage increase and decrease mode when the power frequency is positive.
Specifically, the control circuit 300 determines that the DC voltage E is higher than (including equal to) the grid voltage VgIs carried out in the following manner: in the negative half cycle of power frequency, make converter circuit 100 work in the boost mode, specifically include: make the first power switch S1Closed, second power switch S2High frequency operation, third power switch S3And (5) disconnecting. In the positive half cycle of power frequency, make converter circuit work in the buck-boost mode, specifically include: make the third power switch S3Operating at high frequency, first power switch S1And a second power switch S2And (5) disconnecting.
When the control circuit 300 determines that the direct voltage E is lower than the grid voltage VgThe absolute value of the instantaneous value is: in the negative half cycle of power frequency, the converter circuit 100 is operated in the step-down mode, which specifically includes: make the first power switch S1Operating at high frequency, second power switch S2And a third power switch S3And (5) disconnecting. In the positive half cycle of power frequency, make converter circuit work in the buck-boost mode, specifically include: make the third power switch S3Operating at high frequency, first power switch S1And a second power switch S2And (5) disconnecting.
In summary, the ac side and the dc side of the present invention adopt a joint grounding structure, and only three power switches are needed, so that the present invention has the advantages of high utilization rate of inductors, low cost, small voltage-stabilizing capacitance at the dc side, small ripple of output dc voltage, etc.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (9)
1. A multiplexed inductance based AC/DC converter, comprising: the device comprises a current transformation circuit, a control circuit and a detection circuit;
the converter circuit at least comprises a first power switch, a second power switch, a third power switch, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a first inductor, a filter capacitor and a smoothing capacitor;
the fifth diode and the third power switch are connected in series and then connected between the alternating current input end of the current transformation circuit and the second end of the first inductor; the first diode and the first power switch are connected in series and then connected between the alternating current input end and the first end of the first inductor; the first end of the fourth diode is connected with the second end of the first inductor and is grounded through the third diode and the second power switch which are connected in series; the fourth diode is connected between the second end of the first inductor and the direct current output end; the first end of the first inductor is grounded through the second diode; the alternating current input end of the converter circuit is connected to an alternating current power supply of a power grid, and the filter capacitor is connected to two ends of the alternating current power supply of the power grid in parallel and used for filtering alternating current input into the converter circuit;
the detection circuit is used for detecting the direct current voltage output by the converter circuit and the power grid voltage of the power grid alternating current power supply and feeding back the direct current voltage and the power grid voltage to the control circuit;
the control circuit is used for sending a switch control signal to the controlled ends of the first power switch to the third power switch according to the detected direct-current voltage and the detected power grid voltage so as to control the converter circuit to work in a working mode of boosting, reducing voltage and boosting and reducing voltage;
the control circuit controls the converter circuit to work in a boosting mode when the power frequency is in a positive half cycle and the direct current voltage is higher than the absolute value of the instantaneous value of the power grid voltage, controls the converter circuit to work in a voltage reduction mode when the power frequency is in the positive half cycle and the direct current voltage is lower than the absolute value of the instantaneous value of the power grid voltage, and controls the converter circuit to work in a voltage reduction mode when the power frequency is in a negative half cycle; or
The control circuit controls the converter circuit to work in a boosting mode when the power frequency is in a negative half cycle and the direct current voltage is higher than the absolute value of the instantaneous value of the power grid voltage, controls the converter circuit to work in a voltage reduction mode when the power frequency is in the negative half cycle and the direct current voltage is lower than the absolute value of the instantaneous value of the power grid voltage, and controls the converter circuit to work in a voltage reduction mode when the power frequency is in a positive half cycle.
2. The multiplexed inductor based AC/DC converter of claim 1 wherein the first diode has an anode connected to the AC input and a cathode connected to the first power switch; the cathode of the second diode is connected with the first end of the first inductor, and the anode of the second diode is grounded; the anode of the third diode is connected with the second power switch, and the cathode of the third diode is grounded; the cathode of the fourth diode is connected with the direct current output end, and the anode of the fourth diode is connected with the second end of the first inductor; and the cathode of the fifth diode is connected with the alternating current input end, and the anode of the fifth diode is connected with the third power switch.
3. The multiplexed inductance based AC/DC converter of claim 2, wherein:
when the control circuit determines that the direct voltage is higher than the absolute value of the instantaneous value of the network voltage: in the positive half cycle of the power frequency, the first power switch is closed, the second power switch works at high frequency, and the third power switch is opened; in the negative half cycle of the power frequency, the third power switch works at high frequency, and the first power switch and the second power switch are disconnected;
when the control circuit determines that the direct current voltage is lower than the absolute value of the instantaneous value of the power grid voltage: in the positive half cycle of the power frequency, the first power switch works at high frequency, and the second power switch and the third power switch are disconnected; and in the negative half cycle of the power frequency, the third power switch works at high frequency, and the first power switch and the second power switch are disconnected.
4. The multiplexed inductor based AC/DC converter of claim 1 wherein the first diode has a cathode connected to the AC input terminal and an anode connected to the first power switch; the anode of the second diode is connected with the first end of the first inductor, and the cathode of the second diode is grounded; the cathode of the third diode is connected with the second power switch, and the anode of the third diode is grounded; the anode of the fourth diode is connected with the direct current output end, and the cathode of the fourth diode is connected with the second end of the first inductor; and the anode of the fifth diode is connected with the alternating current input end, and the cathode of the fifth diode is connected with the third power switch.
5. The multiplexed inductance based AC/DC converter of claim 4, wherein:
when the control circuit determines that the direct voltage is higher than the absolute value of the instantaneous value of the network voltage: in the negative half cycle of the power frequency, the first power switch is closed, the second power switch works at high frequency, and the third power switch is opened; in the positive half cycle of the power frequency, the third power switch works at high frequency, and the first power switch and the second power switch are disconnected;
when the control circuit determines that the direct current voltage is lower than the absolute value of the instantaneous value of the power grid voltage: in the negative half cycle of the power frequency, the first power switch works at high frequency, and the second power switch and the third power switch are disconnected; and in the positive half cycle of the power frequency, the third power switch works at high frequency, and the first power switch and the second power switch are disconnected.
6. The multiplexed inductance based AC/DC converter according to any one of claims 1 to 5, further comprising a second inductance connected between the grid AC power source and the AC input.
7. The multiplexing inductance based AC/DC converter according to any one of claims 1 to 5, wherein the first to third power switches are MOS type field effect transistors, insulated gate bipolar transistors or integrated gate commutated thyristors.
8. The multiplexed inductance based AC/DC converter according to any one of claims 1 to 5, wherein the first diode, the third diode and the fifth diode are replaced by MOS type field effect transistors, insulated gate bipolar transistors or integrated gate commutated thyristors.
9. The multiplexed inductance based AC/DC converter according to any one of claims 1 to 5, wherein the whole of the first diode and the first power switch, the whole of the third diode and the second power switch, and the whole of the fifth diode and the third power switch are replaced by reverse-blocking type insulated gate bipolar transistors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711277551.2A CN107979297B (en) | 2017-12-06 | 2017-12-06 | AC/DC converter based on multiplexing inductance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711277551.2A CN107979297B (en) | 2017-12-06 | 2017-12-06 | AC/DC converter based on multiplexing inductance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107979297A CN107979297A (en) | 2018-05-01 |
| CN107979297B true CN107979297B (en) | 2020-03-10 |
Family
ID=62009307
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711277551.2A Active CN107979297B (en) | 2017-12-06 | 2017-12-06 | AC/DC converter based on multiplexing inductance |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107979297B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102018116486A1 (en) | 2018-07-06 | 2020-01-09 | HELLA GmbH & Co. KGaA | coupling device |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI463778B (en) * | 2011-04-29 | 2014-12-01 | Energy Pass Inc | Current mode buck-boost converter and direct current voltage converting method thereof |
| CN103326599A (en) * | 2013-06-19 | 2013-09-25 | 华南理工大学 | BUCK-BUCK-BOOST bridgeless converter |
| CN103337973B (en) * | 2013-06-19 | 2016-01-06 | 华南理工大学 | A kind of BOOST-BUCK-BOOST is without bridging parallel operation |
| CN106374770A (en) * | 2016-10-28 | 2017-02-01 | 燕山大学 | Input and output common-ground boost-buck photovoltaic grid-connected inverter and control method thereof |
-
2017
- 2017-12-06 CN CN201711277551.2A patent/CN107979297B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN107979297A (en) | 2018-05-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8476859B2 (en) | DC power for SGCT devices using a high frequency current loop with multiple current transformers | |
| US9431917B2 (en) | Switching power supply including a rectifier circuit having switching elements, and electric power converter | |
| US11652408B2 (en) | Power converter used in a renewable energy device such as a photo-voltaic device or a wind energy device | |
| US9203323B2 (en) | Very high efficiency uninterruptible power supply | |
| US20140001856A1 (en) | Multilevel power converter | |
| US20140049998A1 (en) | DC to AC Power Converter | |
| JP2014079145A (en) | Bidirectional DC/DC converter | |
| US9859808B2 (en) | Power converter topology for use in an energy storage system | |
| CN111342693B (en) | Boost-buck photovoltaic grid-connected inverter | |
| Kosenko et al. | Full soft-switching high step-up current-fed DC-DC converters with reduced conduction losses | |
| CN107769592B (en) | A kind of both ends shape of the mouth as one speaks AC/DC current transformer based on coupling inductance | |
| CN105356784A (en) | Grid connected inverter with DC bus voltage balance function | |
| US6999325B2 (en) | Current/voltage converter arrangement | |
| CN114175481A (en) | DC-DC converter of power conversion system | |
| Nguyen et al. | Voltage swell/sag compensation with single-phase Z-source AC/AC converter | |
| CN107979297B (en) | AC/DC converter based on multiplexing inductance | |
| KR20190115364A (en) | Single and three phase combined charger | |
| TWI794329B (en) | Dc-to-ac power converter and isolated dc-to-dc converter suitable to be used in the dc-to-ac power converter | |
| KR20170064076A (en) | Shared flux type of power supply device | |
| US9325273B2 (en) | Method and system for driving electric machines | |
| Sun et al. | A novel topology of high voltage and high power bidirectional ZCS DC-DC converter based on serial capacitors | |
| US10812014B1 (en) | Modular photovoltaic string inverter system adapted for SiC MOSFETs | |
| EP3100346B1 (en) | Unidirectional matrix converter with regeneration system | |
| CN112997396A (en) | Adapter device for bidirectional operation | |
| CN117652085A (en) | Control method of PFC circuit and PFC circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |