JP2007189814A - Controller of power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method of a power converter in which switching loss is reduced at low cost and short circuit can be prevented easily. <P>SOLUTION: A power converter receiving a three-phase AC voltage and outputting a two-phase voltage comprises a switch 30 for connecting/opening each phase of the three-phase AC voltage and the two-phase output voltage, an input voltage synchronous signal generator generating input synchronous pulse signals (i1-6) for determining the direction of a current flowing from each phase to the output phase based on the period of the input AC voltage (Vr, Vs, Vt) of each phase, an open command generator outputting a command value for opening the input phase at least once during one period based on the I/O state of the power converter, and a synthesizer for generating a synthetic signal from the input voltage synchronous signal and the open command wherein each switch of the power converter is driven with the synthetic signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power converter having a three-phase AC voltage as an input and an output as a two-phase, and more particularly to a method for controlling a power converter including a matrix converter.

Conventionally, various methods are known as control methods for a rectifier, a power converter in which a rectifier and an inverter are connected, and a matrix converter (see, for example, Non-Patent Document 1).
2004, IEEJ National Convention Transaction D, Vol. 124, No. 5, 457-463, “Controlling Matrix Converter by Virtual AC / DC / AC Conversion Method Using Carrier Comparison Method”

  FIG. 13 is a diagram showing the configuration of the control block of the rectifier by the above-described method (hereinafter referred to as carrier comparison method). In the carrier comparison method, a pulse for determining switching of the rectifier is calculated from the voltage-type rectifier control block 21, the PWM control unit 22, and the block 23 that performs relative calculation. The voltage type rectifier control block 21 first generates a command value for controlling the voltage type rectifier from the output voltage command, the input current command, the input line voltage, and the input phase current. Next, the PWM control unit 22 generates a pulse train by comparing the command value generated by the voltage type rectifier control block 21 with the carrier signal. Next, in a block 23 for performing a relative operation, a relative pulse train is obtained from a pulse train generated by the PWM control unit 22 by a logical operation, thereby controlling the rectifier.

However, in the voltage type rectifier control block 21, it is necessary to newly design control of a virtual voltage type rectifier, and the control structure becomes complicated. For this reason, in order to realize this control, it is necessary to use an expensive microcomputer, which increases the cost. Further, since PWM control is performed, the number of times of switching per unit time increases, and the switching loss increases, so the efficiency deteriorates. Furthermore, although the relative calculation 23 is based on the following non-patent document 2, according to this paper, there is a problem in optimizing the short-circuit pattern after the relative calculation, and the optimization method is shown. It has not been.
1996, IEEJ Transaction D, Vol.116, No.1, “Triangle Wave Comparison Type PWM Control of Current Type Three-Phase Inverter / Converter”

  An object of the present invention is to solve the above-mentioned problems, and to provide a method for controlling a power converter that can realize low-cost, low switching loss, and easily prevent short circuit.

  According to a first aspect of the present invention, there is provided a power converter control method including a three-phase AC voltage as an input and an output having a two-phase output. Input synchronization pulse signal (i1 ~ 6) that determines the direction of current flowing from each phase to the output phase based on the switch of connecting / opening between them and the cycle of input AC voltage (Vr, Vs, Vt) of each phase An input voltage synchronization signal generator for generating a command, an open command generator for outputting a command value for opening an input phase at least once in one cycle based on an input / output state of the power converter, and the input voltage synchronization And a combiner that generates a combined signal from the signal and the opening command, and drives each switch of the power converter by the combined signal.

  The power converter control method according to the second aspect of the present invention is controlled by a matrix converter as a power converter that receives a multi-phase AC voltage and outputs a multi-phase AC voltage, and an output voltage of the matrix converter. Input synchronization pulse signals (i1 to 6) that determine the direction of current flowing from each phase to the output phase based on the period of the input AC voltage (Vr, Vs, Vt) of each phase. An input voltage synchronization signal generator to be generated, an open command generator for outputting a command value for opening the input phase at least once in one cycle based on an input / output state of the power converter, and the input voltage synchronization signal And a combiner that generates a combined signal from the opening command, an inverter controller that generates an inverter control signal that determines the direction of the current flowing to the motor based on the output voltage command of the motor, and the combination And a pulse generator for generating a switching pulse from the signal and the inverter control signals, and is characterized in that to drive the matrix converter based on the switching pulse.

  According to the first aspect of the method for controlling a power converter of the present invention, the amount of calculation required for control can be reduced by driving the rectifier based on a pulse synchronized with the input voltage. As a result, since the rectifier can be controlled without using an expensive microcomputer, there is a cost reduction effect. In addition, PWM-based control has a large switching loss due to a large number of switching operations. However, by using a pulse synchronized with the input voltage as a base, the output voltage and input current can be adjusted with a very small number of switching operations. Therefore, there is a loss reduction effect. In general, control of a rectifier using a voltage source as an input is difficult to control because it must be controlled while considering a short circuit between phases. However, according to this method, a short circuit can be prevented with a simple configuration.

  According to the second invention of the power converter control method of the present invention, the matrix converter control can be simply configured by applying to the control of the matrix converter, so that the cost of the control device of the control system for driving the matrix converter is reduced. Can be reduced. Moreover, the inverter control unit can be realized with a simple structure by using the synchronization signal generation logic used in the control of the rectifier in the inverter control unit. Therefore, since both the rectifier control unit and the inverter control unit have a simple structure, the control device of the matrix converter can be configured simply, and the cost of the control device can be reduced.

  In the power converter control method of the present invention, the input voltage synchronization signal generator can be configured to generate the input voltage synchronization signal based on positive or negative of the input voltage. With this configuration, since the pulse is determined by the positive or negative of the input voltage, it can be realized with a small amount of calculation.

  In the method for controlling a power converter according to the present invention, the open command generator may include a voltage controller, and the voltage controller may be configured to output an open command based on the magnitude relationship of the input voltage. With this configuration, since the output voltage can be controlled simply by giving an open signal, the control configuration is simplified. This can be realized with a small amount of calculation.

  Furthermore, in the method for controlling a power converter according to the present invention, the open command generator includes a current controller, and the current controller can be configured to output an open command based on the magnitude relationship of the input current. With this configuration, the input current can be controlled simply by giving an open signal, so that the control configuration is simplified. This can be realized with a small amount of calculation.

  Furthermore, in the method for controlling a power converter according to the present invention, the open command generator is configured to input the output voltage command value and the input current command value and switch the operation of the voltage control unit and the current control unit based on the map. be able to. By configuring in this way, voltage control and current control can be switched according to the map, so that appropriate control according to the state of the command value can be performed, which is efficient.

  In the method for controlling a power converter according to the present invention, the combiner can be configured to obtain a combined signal from logic combination. With this configuration, pulses can be generated by logic synthesis, so that the structure is simple and can be realized with a small amount of calculation.

  Furthermore, in the power converter control method of the present invention, the motor output voltage command can be obtained based on the motor rotation speed. With this configuration, the control of the inverter unit that determines the control of the matrix converter can be made simple, so the overall control configuration is also simplified, and the control device for the matrix converter can be configured at low cost.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In the following example, a power converter is an example of a rectifier as Example 1, and an example of a power converter is a matrix converter (AC power conversion system) as Example 2.

<Rectifier (Example 1)>
FIGS. 1-9 is a figure for demonstrating the example which applied the control method of the power converter of this invention to the rectifier, respectively. Hereinafter, the first embodiment will be described with reference to FIGS.

1. Configuration 1.1 Circuit Configuration FIG. 1 shows a circuit configuration of a rectifier in the present embodiment. The rectifier 30 is composed of switches S1 to S6, and is a power converter wired as shown in the figure. Reference numerals 41 to 43 denote current detectors, and R, S, and T phases are input phases. Ir, Is, It are input currents, Vrs, Vst, Vtr are input phase voltages. For example, Vrs is an R-phase voltage based on the S-phase voltage. Vout is an output voltage.

1.2 Control Configuration FIG. 2 shows the control configuration of the rectifier in this embodiment. The rectifier control unit 10 includes an open signal generation unit 11, a logic operation unit 12, and an input voltage synchronization signal generation unit 13. The rectifier controller 10 receives the current command values Irref, Isref, Itref, the output voltage command Voutref, the input currents Ir, Is, It, and the input interphase voltages Vrs, Vst, Vtr for each input phase, and the rectifier control pulse. i1 to i6 are output. i1 to i6 are open / close signals of the switches S1 to S6, respectively. The features of this configuration are: (1) switching pulse is determined in synchronization with the cycle of the input voltage, switching so that at least one ON and at least one open state occur in one cycle, and (2) By appropriately arranging the open state, the output voltage and the input current are controlled. Hereinafter, the operation of each block will be described.

1.2.1 Input voltage synchronization signal generator 13
The input voltage synchronization signal generator 13 in FIG. 2 receives the input line voltages Vrs, Vst, Vtr and outputs the input voltage synchronization signals i1 ′ to i6 ′. The method of determining the input voltage synchronization signals i1 ′ to i6 ′ is shown in FIG. 3 and equations (1) to (6).
i1 '= 1 i4' = 0 (Vr> = 0) (1)
i1 '= 0 i4' = 1 (Vr <0) (2)
i2 '= 1 i5' = 0 (Vs> = 0) (3)
i2 '= 0 i5' = 1 (Vs <0) (4)
i3 '= 1 i6' = 0 (Vt> = 0) (5)
i3 '= 0 i6' = 1 (Vt <0) (6)

In FIG. 3, the horizontal axis represents time, and the vertical axis represents R-phase input voltage, S-phase input voltage, T-phase input voltage, R-phase input voltage synchronization signals i1 ', i4', and S-phase input voltage synchronization signals i2 ', i5. ', T-phase input voltage synchronization signals i3', i6 'are shown. The input voltage synchronization signals i1 'to i6' in the figure are 0 or 1 pulse trains. Since there are six combinations of the synchronization signals as shown in FIG. 3, for convenience, the six combinations are divided into six modes and referred to as mode a to mode f.
Vr, Vs, and Vt are obtained from the equations (7) to (9) from the input line voltages Vrs, Vst, and Vtr.
Vr = (Vrs-Vtr) / 2√3 (7)
Vs = (Vst-Vrs) / 2√3 (8)
Vt = (Vtr-Vst) / 2√3 (9)
Through the above calculation, input voltage synchronization signals i1 ′ to i6 ′ as shown in FIG. 3 synchronized with the input voltages Vr, Vs, and Vt are generated.

1.2.2 Logical operation unit 12
Next, the configuration of the logical operation unit 12 in FIG. 2 will be described. The logical operation unit 12 is represented by a circuit as shown in FIG. The logical operation block 12 inputs the input voltage synchronization signals i1 ′ to i6 ′, the S1S2 open signal, the S2S3 open signal, the S3S1 open signal, the S4S5 open signal, the S5S6 open signal, and the S6S4 open signal, and the rectifier switches S1 to S6. The pulses i1 to i6 for driving are output. i1 to i6 are determined by the logical operation unit 12 including the upper arm logical operation block 121 and the lower arm logical operation block 122.

  A signal is output as shown in FIG. 5 by the above-described logical operation. For example, in the case of mode a, i1 and i2 are output as shown in the figure by logical synthesis of the S1S2 release signal and i1 'and i2'. That is, when the S1S2 release signal is 0, i1 = 1 and i2 = 0, and when the S1S2 release signal is 1, i1 = 0 and i2 = 1. The other modes are also configured to perform the same operation as mode a by combining the release signal and the synchronization signal.

1.2.3 Open signal generator 11
Returning to FIG. 2, the open signal generation unit 11 inputs line voltages Vrs, Vst, Vtr, input currents It, Ir, Is, output voltage command Voutref, input current commands Irref, Isref, Itref, and outputs S1S2 The release signal, S2S3 release signal, S3S1 release signal, S4S5 release signal, S5S6 release signal, and S6S4 release signal are output. The inside of the open signal generation unit 11 is configured as shown in FIG. 6 and is roughly divided into a voltage control unit 111, a current control unit 112, and a control determination unit 113. Hereinafter, the operation of each block will be described.

1.2.3.1 Voltage control unit 111
The voltage controller 111 includes an S1S2 open signal generator 1111, an S2S3 open signal generator 1112, an S3S1 open signal generator 1113, an S4S5 open signal generator 1114, an S5S6 open signal generator 1115, and an S6S4 open signal generator 1116. The line voltages Vrs, Vst, and Vtr are input, and the S1S2 open signal, S2S3 open signal, S3S1 open signal, S4S5 open signal, S5S6 open signal, and S6S4 open signal are output. The S1S2 release signal generation unit 1111 receives Vst and Vtr, and generates an S1S2 release signal based on the magnitude relationship between Vst and Vtr. For example, in mode a, as shown in FIG. 7, the S1S2 release signal is set to 0 when Vst> = Vtr, and the S1S2 release signal is set to 1 when Vst <Vtr. Similarly, the S2S3 release signal generation unit 1112 generates the S2S3 release signal based on the magnitude relationship between Vrs and Vtr. The S3S1 release signal generator 1113 generates the S2S3 release signal based on the magnitude relationship between Vrs and Vst. The S4S5 release signal generation unit 1114 generates an S4S5 release signal based on the magnitude relationship between Vst and Vtr. The S5S6 release signal generation unit 1115 generates an S5S6 release signal based on the magnitude relationship between Vrs and Vtr. The S6S4 release signal generator 1116 generates the S6S4 release signal based on the magnitude relationship between Vrs and Vst.

1.2.3.2 Current control unit 112
The current controller 112 includes an S1S2 open signal generator 1121, an S2S3 open signal generator 1122, an S3S1 open signal generator 1123, an S4S5 open signal generator 1124, an S5S6 open signal generator 1125, and an S6S4 open signal generator 1126. The phase currents Ir, Is, It are input, and the S1S2 open signal, S2S3 open signal, S3S1 open signal, S4S5 open signal, S5S6 open signal, and S6S4 open signal are output. The S1S2 release signal generation unit 1121 receives Ir and Is, and generates an S1S2 release signal based on the magnitude relationship between Ir and Is. For example, in the case of mode a, the S1S2 release signal is set to 0 when Ir> = Is, and the S1S2 release signal is set to 1 when Ir <Is, as shown in FIG. Similarly, the S2S3 release signal generator 1122 generates an S2S3 release signal based on the magnitude relationship between Is and It. The S3S1 release signal generation unit 1123 generates an S2S3 release signal based on the magnitude relationship between It and Is. The S4S5 release signal generation unit 1124 generates an S4S5 release signal based on the magnitude relationship between Ir and Is. The S5S6 release signal generation unit 1125 generates an S5S6 release signal based on the magnitude relationship between Is and It. The S6S4 release signal generation unit 1126 generates an S6S4 release signal based on the magnitude relationship between It and Ir.

1.2.3.3 Control determination unit 113
The control determination unit 113 receives the output voltage command value Voutref and the input current commands Irref, Isref, Itref, and determines whether to obtain an open signal from the current control unit 111 or an open signal from the current control unit 112. The determination is made from a map as shown in FIG. 9 in which Voutref and the amplitude Iref of Irref, Isref and Itref are input.

2. Advantages of Embodiment 1 2.1 Effects of Pulse Generation Synchronized with Input Voltage By driving a rectifier based on a pulse synchronized with an input voltage, the amount of calculation required for control can be reduced. As a result, since the rectifier can be controlled without using an expensive microcomputer, there is a cost reduction effect. In addition, PWM-based control has a large switching loss due to a large number of switching operations. However, by using a pulse synchronized with the input voltage as a base, the output voltage and input current can be adjusted with a very small number of switching operations. Therefore, there is a loss reduction effect. In general, control of a rectifier using a voltage source as an input is difficult to control because it must be controlled while considering a short circuit between phases. However, according to this method, a short circuit can be prevented with a simple configuration.

2.2 Effect of providing an open state for each phase by generating an open signal The output voltage or input current can be controlled by a simple logic that provides an open state for switching of each phase. Adjustment of the output voltage and adjustment of the input current can be realized without damage. As a result, the amount of calculation required for the control can be kept small, and even an inexpensive microcomputer can be sufficiently controlled, so that there is a cost reduction effect.

<Matrix converter system (Example 2)>
10 to 12 are diagrams for explaining examples in which the power converter control method of the present invention is applied to a matrix converter. Hereinafter, Example 2 will be described with reference to FIGS.

1. Configuration 1.1 Circuit Configuration FIG. 10 shows a circuit configuration in this embodiment. Sa1 to Sa9 are switches, 400 is a power converter including switches Sa1 to Sa9, 200 and 201 are permanent magnet synchronous motors, 202 is an engine, 300 to 302 are capacitors, 51 is a rotational angular velocity ω of the permanent magnet synchronous motor 201 This is a rotational angular velocity detector.

1.2 Control Configuration The control of Sa1 to Sa9 in FIG. 10 is performed by the control configuration in FIG. That is, matrix converter control pulses ia1 to ia9 for driving Sa1 to Sa9 by synthesizing the rectifier control pulses ib1 to ib6 generated from the equivalent power converter control unit 500 and the inverter control pulses ib7 to ib12 in the logic synthesis block 70. obtain. Hereinafter, each block of FIG. 11 will be described.

1.2.1 Equivalent power converter controller 500
The equivalent power converter control unit 500 of FIG. 11 determines control for the circuit configuration of FIG. Therefore, first, the configuration of FIG. 12 will be described.

1.2.1.1 Circuit Configuration of Equivalent Power Converter 401 The system configuration in FIG. 12 has a structure in which the power converter 400 is replaced with an equivalent power converter 401 in the system configuration in FIG. Further, the equivalent power converter 401 includes a rectifier 402 and an inverter 403. Sb1 to Sb12 are switches, power converter 401 is a power converter including switches Sb1 to Sb12, 200 and 201 are permanent magnet synchronous motors, 202 is an engine, 300 to 302 are capacitors, and 51 is a rotational angular velocity of permanent magnet synchronous motor 201. Is a rotational angular velocity detector for detecting

1.2.1.2 Control Configuration of Equivalent Power Converter 401 The equivalent power converter 401 is controlled by the equivalent power converter controller 500 of FIG. The equivalent power converter controller 500 is roughly divided into a rectifier controller 10 that controls the rectifier 402 and an inverter controller 60 that controls the inverter 403. Hereinafter, the operation of each unit will be described.

1.2.1.2.1 Rectifier control unit 10
The rectifier control unit 10 has the same configuration as the rectifier control unit 10 of the first embodiment, and outputs rectifier control pulses ib1 to ib6 as outputs.

1.2.1.2.2 Inverter control unit 60
The inverter control unit 60 includes a motor rotation synchronization signal generation unit 14 and an output voltage command calculation unit 15. In the output voltage command calculation unit 15, the rotation angular velocity ω detected from the rotation angular velocity detector 51 is input, and the output voltage commands Vuref, Vvref, Vwref to the output phases of the inverter of FIG. Generate based on (12).
Vuref = cos (Pω) (10)
Vvref = cos (Pω-3 / 2 * π) (11)
Vwref = cos (Pω + 3/2 * π) (12)
However, P is the number of pole pairs of the permanent magnet synchronous motor 201.

The motor rotation synchronization signal generation unit 14 receives the output voltage commands Vuref, Vvref, Vwref calculated by the output voltage command calculation unit and inputs inverter control pulses ib7 to ib12 based on the following equations (13) to (18). Decide.
ib7 = 1 ib10 = 0 (Vuref> = 0) (13)
ib7 = 0 ib10 = 1 (Vuref <0) (14)
ib8 = 1 ib11 = 0 (Vvref> = 0) (15)
ib8 = 0 ib11 = 1 (Vvref <0) (16)
ib9 = 1 ib12 = 0 (Vwref> = 0) (17)
ib9 = 0 ib12 = 1 (Vwref <0) (18)

1.2.2 Logic synthesis block 70
The logic synthesis block 70 receives the rectifier control pulses ib1 to ib6 and the inverter control pulses ib7 to ib12, and generates MtoM control pulses ia1 to ia9 by the following logic synthesis formula.
ia1 = ib1 * ib7 + ib4 * ib10 (19)
ia2 = ib2 * ib7 + ib5 * ib10 (20)
ia3 = ib3 * ib7 + ib6 * ib10 (21)
ia4 = ib1 * ib8 + ib4 * ib11 (22)
ia5 = ib2 * ib8 + ib5 * ib11 (23)
ia6 = ib3 * ib8 + ib6 * ib11 (24)
ia7 = ib1 * ib9 + ib4 * ib12 (25)
ia8 = ib2 * ib9 + ib4 * ib12 (26)
ia9 = ib3 * ib9 + ib4 * ib12 (27)
With the above control configuration, the matrix converter is driven.

1.3 Effects of Embodiment 2 By applying the control of the rectifier of Embodiment 1 to the control of the matrix converter, the control of the matrix converter can be configured simply, so that the cost of the control device of the control system that drives the matrix converter can be reduced. Can be reduced. Further, the inverter control unit 60 can also be realized with a simple structure by using the synchronization signal generation logic used in the control of the rectifier. Therefore, since both the rectifier control unit and the inverter control unit have a simple structure, the control device of the matrix converter can be configured simply, and the cost of the control device can be reduced.

  According to the power converter control method of the present invention, the output voltage can be adjusted and the input current can be adjusted with a very small number of switching operations by using a pulse synchronized with the input voltage as a base, thereby reducing loss. In addition to being effective, by performing pulse control on both the generator side and the driving side, a short-circuit prevention step can be easily incorporated. Therefore, the power converter control method of the present invention can be suitably used for a rectifier, a matrix converter, and the like.

It is a figure for demonstrating an example of the example which applied the control method of the power converter of this invention to the rectifier. It is a figure for demonstrating the other example of the example which applied the control method of the power converter of this invention to the rectifier. It is a graph which shows the principle of the input voltage synchronous signal generation | occurrence | production in the example which applied the control method of the power converter of this invention to the rectifier. It is a figure for demonstrating the structure of the logic calculating part in the example which applied the control method of the power converter of this invention to the rectifier. It is a graph which shows the logic synthesis | combining method of the pulse in the example which applied the control method of the power converter of this invention to the rectifier. It is a figure for demonstrating the structure of the open signal production | generation part in the example which applied the control method of the power converter of this invention to the rectifier. It is a graph which shows the principle which produces | generates an open signal by the voltage control part in the example which applied the control method of the power converter of this invention to the rectifier. It is a graph which shows the principle which produces | generates an open signal by the current control part in the example which applied the control method of the power converter of this invention to the rectifier. It is a figure for demonstrating the structure of the map which switches the voltage control and electric current control in the example which applied the control method of the power converter of this invention to the rectifier. It is a figure for demonstrating an example of the example which applied the control method of the power converter of this invention to the matrix converter. It is a figure for demonstrating the other example of the example which applied the control method of the power converter of this invention to the matrix converter. It is a figure for demonstrating the power converter equivalent to a matrix converter in this invention, and a system structure. It is a figure for demonstrating the control method of the conventional power converter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rectifier control part 11 Opening signal generation part 12 Logic operation part 13 Input voltage synchronous signal generation part 30 Rectifier 200, 201 Permanent magnet synchronous motor 202 Engine 400 Power converter 401 Equivalent power converter 402 Rectifier 403 Inverter

Claims (8)

  In a power converter with a three-phase AC voltage as input and an output as two-phase, each phase of the three-phase AC voltage, a switch for connecting / opening the two phases of the output, and the input AC voltage ( The input voltage synchronization signal generator that generates the input synchronization pulse signal (i1 to 6) that determines the direction of the current flowing from each phase to the output phase based on the period of Vr, Vs, Vt), and the input of the power converter An open command generator that outputs a command value that opens the input phase at least once during one cycle based on the output state, and a combiner that generates a composite signal from the input voltage synchronization signal and the open command A method of controlling a power converter, wherein each switch of the power converter is driven by the combined signal.   The input AC voltage (Vr, Vs) for each phase in a configuration consisting of a matrix converter as a power converter that outputs multiphase AC voltage as input, and a motor controlled by the output voltage of the matrix converter. , Vt), the input voltage synchronization signal generator for generating the input synchronization pulse signal (i1 to 6) for determining the direction of the current flowing from each phase to the output phase, and the input / output state of the power converter An open command generator that outputs a command value for releasing the input phase at least once during one cycle, a combiner that generates a combined signal from the input voltage synchronization signal and the open command, and an output voltage of the motor Based on the command, an inverter controller that generates an inverter control signal that determines the direction of current flowing to the motor, and generates a switching pulse from the combined signal and the inverter control signal. Control method for a power converter characterized by a pulse generator, to drive the matrix converter based on the switching pulse.   The method of controlling a power converter according to claim 1, wherein the input voltage synchronization signal generator generates an input voltage synchronization signal based on positive or negative of the input voltage.   The method for controlling a power converter according to claim 1 or 2, wherein the open command generator includes a voltage controller, and the voltage controller outputs an open command based on a magnitude relationship between input voltages.   The method for controlling a power converter according to claim 1 or 2, wherein the open command generator includes a current controller, and the current controller outputs an open command based on a magnitude relationship between input currents.   The open command generator receives the output voltage command value and the input current command value, and switches the operation of the voltage control unit and the current control unit based on the map. The method for controlling the power converter according to Item 1.   The method for controlling a power converter according to claim 1, wherein the combiner obtains a combined signal from logic combination.   3. The method of controlling a power converter according to claim 2, wherein the motor output voltage command is obtained based on the motor speed.

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