JPWO2017163312A1 - Elevator control device and elevator control method - Google Patents

Abstract

A converter and a controller that supplies a DC power source corresponding to a target value to a motor of the hoisting machine by switching the converter while controlling the power factor by separating the AC current component into an active current and a reactive current. When generating the reactive current command value, the controller sets a power running setting value that makes the reactive current less likely to flow during regenerative operation than the regenerative operation when the elevator is in regenerative operation. Sets as a threshold a set value for regenerative operation that makes reactive current flow more easily than during power running, and generates a reactive current command value.

Description

  The present invention relates to an elevator control device and an elevator control method for improving control performance in elevator-specific travel control in which power running operation and regenerative operation are frequently switched.

  With the advent of high-speed switching devices represented by SiC (silicon carbide), the switching frequency of inverters and converters has been increased. By increasing the switching frequency of the inverter and the converter, it is possible to reduce the capacity of the inductance that rectifies the switched current. As a result, there is an advantage that the apparatus can be miniaturized in an elevator control apparatus to which such high-speed switching control is applied.

  On the other hand, in such an elevator control apparatus, a short circuit prevention time Td for preventing a short circuit between devices is provided. The short-circuit prevention time Td cannot be shortened in proportion to the higher switching frequency in relation to the stable drive of the inverter and converter.

  When the short-circuit prevention time Td cannot be reduced, there is a problem that in the converter, a surplus output is generated on the power running side and an output shortage occurs on the regeneration side. For such a problem, there is a conventional technique having a configuration in which a power running operation / regenerative operation is determined based on a command value of an active current component, and a threshold value at which a reactive current for power factor control starts to flow is changed (for example, Patent Document 1).

  By providing such a configuration, Patent Literature 1 realizes an operation of suppressing an increase in the overhead line voltage in the case of regeneration and suppressing a decrease in the overhead line voltage in the case of powering.

JP-A-4-285472

However, the prior art has the following problems.
The configuration as disclosed in Patent Document 1 is not appropriate from the following viewpoint to be applied to a converter that frequently switches between power running / regenerative operation, such as an elevator. That is, in an elevator control device, if the following characteristics of switching are poor, the desired output improvement performance cannot be obtained, and if the switching is not smooth, the running characteristics of the car are impaired, and the control performance is further improved. is necessary.

  The present invention has been made to solve the above-described problems, and an elevator control device and an elevator control capable of improving the tracking characteristics of switching between power running / regenerative operation and the traveling characteristics of the elevator. The purpose is to obtain a method.

  An elevator control device according to the present invention includes a converter that converts an AC power supplied via a reactor into a DC power and supplies the DC power to a motor of a hoist that drives the elevator, and an AC current of the AC power An elevator control device comprising: a controller that supplies a DC power source corresponding to a target value to a motor by performing switching of a converter while controlling a power factor by separating components into an active current and a reactive current. When the controller determines whether the elevator is in power running or regenerative operation and generates a reactive current command value for controlling reactive current, it is more ineffective during power running than during regenerative operation A reactive current command value is generated by setting a first threshold so that current does not flow easily, and a second threshold is set so that the reactive current flows more easily during regenerative operation than during powering operation. And it generates a reactive current command value by setting.

  Further, an elevator control method according to the present invention includes a converter that converts an alternating current power supplied via a reactor into a direct current power and supplies the direct current power to a motor of a hoist that drives the elevator, and an alternating current power supply An elevator control device comprising a controller that supplies a DC power source corresponding to a target value to a motor by switching a converter while controlling a power factor by separating an AC current component into an active current and a reactive current. An elevator control method that is applied and executed by a controller, comprising: a first step for determining whether the elevator is in a power running operation or a regenerative operation; and a reactive current command value for controlling the reactive current When generating, the reactive current command value is generated by setting the first threshold so that the reactive current is less likely to flow during powering operation than during regenerative operation. During regenerative operation in which a second step of generating a reactive current command value by setting the second threshold to facilitate the flow of reactive current than during a power running operation.

  According to the present invention, the timing at which the power running operation state and the regenerative operation state are switched during one run from the start to the stop is determined, and an appropriate reactive current command is generated according to each operation state. It has a configuration that can. As a result, it is possible to obtain an elevator control device and an elevator control method capable of improving the follow-up characteristics of switching between power running / regenerative operation and the traveling characteristics of the elevator.

It is a circuit block diagram including the control apparatus of the PWM converter in Embodiment 1 of this invention. It is the figure which showed the internal structure of the reactive current reference circuit in Embodiment 1 of this invention. 1 is an overall configuration diagram of an elevator system including an elevator control device according to Embodiment 1 of the present invention. It is the figure which showed the time change of the effective electric current command _IP ^* during the traveling control by the control apparatus of the elevator which concerns on Embodiment 1 of this invention. It is the figure which showed the threshold value change process performed with the reactive current control circuit contained in the controller of the control apparatus of the elevator which concerns on Embodiment 1 of this invention. It is the figure which showed the threshold value change process different from previous FIG. 5 performed with the reactive current control circuit contained in the controller of the control apparatus of the elevator which concerns on Embodiment 1 of this invention.

  Hereinafter, preferred embodiments of an elevator control device and an elevator control method of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a circuit configuration diagram including a control device for a PWM converter according to Embodiment 1 of the present invention. Although not shown in detail, the PWM converter 1 is composed of a diode bridge circuit connected in reverse parallel with the self-extinguishing switch element, and an AC power source V _AC is connected to the AC input side via an AC reactor 2. Has been. A filter capacitor 4 and a load 5 are connected in parallel on the DC output side of the PWM converter 1.

The current detection circuit 6 detects the DC voltage V of the PWM converter 1. The voltage control circuit 7 compares the voltage command V ^* and the DC voltage V, and outputs an effective current command I _P ^* so as to reduce the deviation.

Phase detection circuit 9, the voltage of the AC power source, and outputs a phase signal theta _PS. Current detecting circuit 17, a current detector 12R, alternating current IR detected by 12S, IS and, from the phase signal theta _PS supply voltage V _AC detected by the phase detection circuit 9, the effective current I is the active component of the alternating current It calculates the _P and reactive current I _Q is a reactive component, and outputs the separated.

  Although FIG. 1 illustrates the case where the current detector detects R-phase and S-phase currents of the three phases, the present invention is not limited to such a configuration. The same effect can be obtained by adopting a configuration that detects the current of any two phases or all three phases of the three phases.

Active current control circuit 14, the active current command I _P ^* outputted from the voltage control circuit 7, based on a deviation between the active current I _P computed by the current detection circuit 17, the effective voltage command e of PWM converter 1 Calculate _P ^* . On the other hand, reactive current control circuit 15, a reactive current command I _Q ^* calculated by the reactive current reference circuit 18 to be described later, based on a deviation between the reactive current I _Q computed by the current detection circuit 17, PWM converter 1 The reactive voltage command e _Q ^* is calculated.

PWM control circuit 16, an active voltage instruction e _P ^*, a reactive voltage command e _Q ^*, and a power supply voltage V _AC phase signal theta _PS, outputs a switching command SW of the PWM converter 1 to the self-extinguishing type switching elements To do.

  In FIG. 1, the voltage control circuit 7, the active current control circuit 14, the reactive current control circuit 15, the PWM control circuit 16, and the reactive current reference circuit 18 send the switching command SW based on the detection results of the detection circuits. This corresponds to the internal configuration of the controller 30 that outputs.

In the elevator control apparatus configured as described above, the technique for calculating the reactive current command I _Q ^* by the reactive current reference circuit 18 has the technical feature of the present invention, and will be described in detail with reference to FIG. .

  FIG. 2 is a diagram showing an internal configuration of the reactive current reference circuit 18 according to the first embodiment of the present invention. The reactive current reference circuit 18 in the first embodiment includes a threshold determination circuit 18a, a square sum component calculation circuit 18b, and a power factor control circuit 18c.

When the active current command I _P ^* is equal to or greater than 0, that is, during powering operation in which the PWM converter 1 forward-converts AC power to DC power, the threshold determination circuit 18a uses the following equation (1) to calculate the effective current command I _P ^{When *} is negative, that is, during regenerative operation in which the PWM converter 1 reversely converts DC power into AC power, the threshold value used for power factor control in the subsequent stage is calculated by using the following equation (2).
When I _P ^* ≧ 0, threshold = Vlim (1)
When I _P ^* <0, threshold = Vlim−ΔVd (2)

Here, Vlim is a component determined by a voltage limit value that can be output by the PWM converter 1. ΔVd is a correction voltage component of the vertical short circuit prevention time Td, and is calculated, for example, as the following expression (3).
ΔVd = DC bus voltage [V] × upper and lower short-circuit prevention time [sec]
× Switching frequency [Hz] (3)

The square sum component calculation circuit 18b calculates the square sum of the effective voltage command e _P ^* and the reactive voltage command e _Q ^* . Then, the power factor control circuit 18c generates the reactive current command Iq * based on the deviation between the threshold calculated by the threshold determination circuit 18a and the square sum calculated by the square sum component calculation circuit 18b.

  As described above, in the case of comparison using the square sum component, the threshold is calculated so that Vlim and ΔVd have the same dimension as the square sum component. Further, in the case of comparison using the square root signal of the sum of squares, the threshold is calculated so that Vlim and ΔVd have the same dimensions as the square root signal.

  Generally, the Td correction in the PWM converter 1 turns into a surplus output on the power running side and acts as an output shortage on the regeneration side. Further, in order to improve the voltage utilization rate of the PWM converter 1, an operation corresponding to field weakening control referred to by a motor is performed by passing a reactive current.

  Here, when the PWM converter 1 has a high switching frequency, the ratio of the Td correction voltage increases, leading to a decrease in the voltage utilization rate. Therefore, in the present invention, it is determined whether the PWM converter 1 is in the power running operation or the regenerative operation based on the active current command value or the like, and the threshold for power factor control that takes into account the Td correction voltage is dynamically determined according to the determination result. It is changed and set.

  By providing such a configuration, it is possible to make the reactive current difficult to flow on the power running side, and to make the reactive current easy to flow on the regeneration side. As a result, the reactive current command Ip * can be generated in accordance with the power running operation / regenerative operation with better tracking accuracy than in the past, and the voltage utilization factor of the converter can be improved.

  In other words, by adopting the reactive current reference circuit 18 described with reference to FIGS. 1 and 2, the AC reactor 2 can be reduced in size when the PWM converter is operated at a high switching frequency using a high-speed switching device such as SiC. In addition, it is possible to perform power conversion without deteriorating the voltage utilization rate more than necessary.

  Next, the case where the PWM converter control apparatus according to the first embodiment as shown in FIG. 1 is applied to elevator control will be described in detail below.

  FIG. 3 is an overall configuration diagram of an elevator system including the elevator control device according to Embodiment 1 of the present invention. Here, the controller 30 in FIG. 3 corresponds to the controller 30 that controls the PWM converter 1 shown in FIG. Further, the load 5 in FIG. 1 corresponds to the motor of the hoisting machine 31. In the following, the motor of the hoisting machine 31 will be described simply as the hoisting machine 31.

  The car 35 is connected by a main rope 33, and the main rope 33 is wound around a hoisting machine 31 and connected to a weight 34 via a deflecting wheel 32. The hoisting machine 31 obtains a drive command 39 from the controller 30 and moves the car 35 up and down.

  The drive command 39 travels so that the car 35 is directed to the target landing when the passenger operates each of the landing operation panels 38a to 38c in the landings 40a to 40c or the in-car operation panel 36 in the car 35. The direction is set and commanded from the controller 30.

  Further, the scale device 37 installed in the car or the like detects the load in the car 35 so that it can be determined whether the movement of the car is power running or regenerative. Then, the controller 30 can determine whether the elevator is started in the power running operation or the regenerative operation based on the traveling direction and the load in the car 35.

  Then, the controller 30 transmits the power running / regeneration determination result to the threshold determination circuit 18a in the reactive current reference circuit 18 shown in FIG. That is, the reactive current reference circuit 18 can know whether the power running operation or the regenerative operation is activated from the determination result based on the traveling direction and the load in the car 35 at the time of activation.

  Here, as an operation peculiar to the elevator, a timing at which the power running operation and the regenerative operation are switched within one travel occurs. Therefore, when such switching is performed, the reactive current reference circuit 18 appropriately changes the threshold for power factor control as described above, so that elevator control is executed at a high switching frequency. The reduction of the voltage utilization rate can be suppressed.

FIG. 4 is a diagram showing a time change of the effective current command I _P ^* during the traveling control of the elevator according to Embodiment 1 of the present invention. More specifically, FIG. 4 shows the time transition of the converter current command value in the following two operation patterns A and B.
Driving pattern A: Driving pattern starting from powering operation from the first floor to the second floor by powering operation, and switching from powering operation to regenerative operation when arriving at the second floor driving pattern B : Starting from regenerative operation from the second floor to the third floor, starting operation by regenerative operation, and driving pattern that switches from regenerative operation to power running operation when arriving at the third floor

The control by the controller 30 when executing such an operation pattern A or operation pattern B will be described below, divided into STEP1 to STEP3.
<STEP 1>: Processing at Start-up The controller 30 is started as a power running operation or a regenerative operation depending on the combination of the load in the car 35 detected by the scale device 37 and the traveling direction of the car 35. It can be judged. Specifically, the controller 30 can determine whether the operation is a power running operation or a regenerative operation in the following cases 1 to 4.

Case 1: When the load in the car is greater than or equal to the weight of the weight 34 and the traveling direction is the upward direction, it is determined as power running. Case 2: The load in the car is less than the weight of the weight 34, and When the traveling direction is the upward direction, it is determined as regenerative operation. Case 3: When the load in the car is heavier than the weight 34 and the traveling direction is the downward direction, it is determined as regenerative operation. Case 4: Car When the internal load is equal to or less than the weight of the weight 34 and the traveling direction is the descending direction, it is determined that the power running operation is performed.

<STEP 2> Travel Control Until Start of Deceleration The controller 30 uses the threshold value corresponding to the power running operation or the regenerative operation determined in STEP 1 until the deceleration to stop at the target floor is started after the start. The reactive current command I _Q ^* is generated and the elevator traveling control is executed.

<STEP 3> The travel control after the start of deceleration The controller 30 switches from the acceleration or constant speed state to the deceleration state, thereby switching from the power running operation to the regenerative operation as shown in FIG. Estimate when to switch to driving. It should be noted that the controller 30 can estimate the timing at which the operating state is switched from the information of the operating pattern, and detect it from the positive and negative values of the active current command I _P ^* as described above with reference to FIG. Is also possible.

  Then, the controller 30 uses the above equation (1) during the power running operation, and uses the above equation (2) during the regenerative operation, and switches the threshold according to the operation state, and then the appropriate reactive current. Generate directives.

  FIG. 5 is a diagram illustrating a threshold value changing process executed by the reactive current control circuit 18 included in the controller 30 of the elevator control device according to the first embodiment of the present invention. Specifically, the result of the threshold value changing process corresponding to the operation patterns A and B shown in FIG. 4 is shown.

  As shown in FIG. 5, the controller 30 according to the first embodiment adds ΔVd corresponding to the correction voltage component of the vertical short circuit prevention time Td to Vlim according to the above equation (1) during the power running operation. The threshold is dynamically changed and set. On the other hand, during the regenerative operation, the controller 30 dynamically changes and sets the threshold value by subtracting ΔVd from Vlim according to the above equation (2).

  As a result, even in an elevator-specific control environment where the polarity of electric power exchange occurs at the start of deceleration during one run, appropriate reactive current control can be executed according to the operating state, and switching between power running / regenerative operation Even in this case, good tracking characteristics can be realized.

  FIG. 6 is a diagram showing a threshold value changing process different from FIG. 5 executed by the reactive current control circuit 18 included in the controller 30 of the elevator control apparatus according to Embodiment 1 of the present invention. It is. Specifically, in the threshold value changing process shown in FIG. 6, in addition to the process in FIG. 5, the threshold value is changed to a ramp function or a low-pass filter at the time of switching to further improve the control characteristics. I am trying.

  In this way, by performing processing using a ramp function or a low-pass filter, it is possible to prevent the threshold value from switching in a staircase at a stretch, and to limit the amount of change in the threshold value per unit time within an allowable value. As a result, since the threshold value is switched smoothly, it is possible to suppress the occurrence of unpleasant vibrations in the car 35 and realize a smooth movement of the car.

  As described above, according to the first embodiment, it is possible to provide a reactive current control circuit that realizes control performance with higher accuracy than in the conventional control of an elevator in which power running operation and regenerative operation are frequently switched. That is, a configuration is realized in which the switching timing between the power running / regenerative operation is predicted during the elevator traveling, and an appropriate reactive current command can be generated according to the driving state.

  Specifically, at the time of start-up, the power running operation or the regenerative operation is specified by the load in the car and the traveling direction. Further, at the time of deceleration, the switching timing is predicted from the operation pattern information or the value of the active current command. In addition, when setting the power factor control threshold value for generating the reactive current command at the switching timing, the correction amount addition / subtraction is switched according to the value corresponding to the correction voltage component of the upper / lower short-circuit prevention time. .

  As a result, it is possible to dynamically generate an appropriate reactive current command according to the driving state and execute the driving control, and to improve the tracking characteristics of switching between power running / regenerative driving and the driving characteristics of the elevator. An elevator control device and an elevator control method can be obtained.

  In the above-described embodiment, SiC is cited as an example of a high-speed switching device. However, as a wide band gap semiconductor having a larger band gap than silicon, other than SiC, for example, a gallium nitride material or diamond is used. is there.

  A bridge circuit composed of a self-extinguishing switch element and a diode formed of such a wide band gap semiconductor has high voltage resistance and high allowable current density. For this reason, it is possible to reduce the size of the bridge circuit. By using the reduced size of the bridge circuit, it is possible to reduce the size of the semiconductor module incorporating the bridge circuit.

  In addition, since the heat resistance is high, the heat dissipating fins of the heat sink can be downsized and the water cooling section can be air cooled, so that the semiconductor module can be further downsized.

  In addition, since the power loss is low, the self-extinguishing switch element and the diode can be highly efficient, and the semiconductor module can be highly efficient.

  Furthermore, since the switching frequency can be increased, the inductance capacity can also be reduced, and the size of the AC reactor can be further reduced as an elevator control device.

  It is desirable that both the self-extinguishing switch element and the diode be formed of a wide band gap semiconductor, but either the self-extinguishing switch element or the diode is formed of a wide band gap semiconductor. May be. Even in this case, the above-described effects can be obtained.

Claims (7)

A converter that converts AC power supplied through a reactor into DC power and supplies the DC power to a motor of a hoisting machine that drives an elevator;
A controller for supplying the DC power source corresponding to a target value to the motor by switching the converter while controlling the power factor by separating the AC current component of the AC power source into an active current and a reactive current. An elevator control device comprising:
The controller determines whether the elevator is in a power running operation or a regenerative operation, and generates a reactive current command value for controlling the reactive current, during the power running operation, the regenerative operation The reactive current command value is generated by setting a first threshold so that the reactive current is less likely to flow than during the regenerative operation, and the reactive current is more easily flowed during the regenerative operation than during the power running operation. An elevator control device that sets two threshold values and generates the reactive current command value. The controller, when switching the threshold for generating the reactive current command value from the first threshold to the second threshold, or when switching from the second threshold to the first threshold, The elevator control device according to claim 1, wherein the threshold value changing process is executed by limiting the amount of change so as to be within an allowable value. 3. The elevator control device according to claim 1, wherein the controller sets the first threshold value and the second threshold value in consideration of an upper and lower short-circuit prevention time of a switching element in the converter in which the switching is performed. . The controller sets a voltage limit value that can be output by the converter to Vlim, and sets a correction voltage component ΔVd for the upper and lower short-circuit prevention time,
ΔVd = DC bus voltage [V] × upper and lower short-circuit prevention time [sec]
× Switching frequency [Hz]
When the first threshold value and the second threshold value are
1st threshold = Vlim
Second threshold = Vlim−ΔVd
The elevator control apparatus according to claim 3, wherein the reactive current command value is generated. The elevator control device according to claim 3, wherein the switching element in the converter is formed of a wide band gap semiconductor. The elevator control device according to claim 5, wherein the wide band gap semiconductor is silicon carbide, a gallium nitride-based material, or diamond. A converter that converts AC power supplied through a reactor into DC power and supplies the DC power to a motor of a hoisting machine that drives an elevator;
A controller for supplying the DC power source corresponding to a target value to the motor by switching the converter while controlling the power factor by separating the AC current component of the AC power source into an active current and a reactive current. An elevator control method that is applied to an elevator control device and that is executed by the controller,
A first step of determining whether the elevator is in a power running operation or a regenerative operation;
When generating the reactive current command value for controlling the reactive current, the reactive current command is set by setting a first threshold so that the reactive current is less likely to flow during the power running operation than during the regenerative operation. And a second step of generating a reactive current command value by setting a second threshold so that the reactive current flows more easily during the regenerative operation than during the power running operation. Method.

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