JP5205420B2 - Electric motor system, power converter, and method for controlling power converter - Google Patents

Description

  The present invention relates to an electric motor system, an electric power converter, and a control method for the electric power converter, and more particularly, to an electric motor system, an electric power converter, and a control method for the electric power converter that are suitable for suppressing fluctuations in DC voltage in an inverter. .

  In electric motor driving using a power converter, AC power supplied from a commercial power source is rectified by a diode inside the power converter and smoothed by a smoothing capacitor to be converted to a DC voltage. The converted DC voltage is further converted into an arbitrary AC voltage by an inverter and output to the electric motor to perform variable speed control of the electric motor.

  This DC voltage is affected by the status of the commercial power supply and the operation status of the inverter. When the commercial power supply fluctuates, problems such as torque shortage and overcurrent abnormality relating to the inverter output occur. For example, JP-A-6-311787 Japanese Laid-Open Patent Publication No. 2007-228959 discloses a technique for providing a voltage detector for detecting a DC voltage and controlling an output frequency so as to achieve a rated V / F ratio.

JP-A-6-311787

  On the other hand, when the electric motor performs a deceleration operation, mechanical energy stored in the electric motor is regenerated in the inverter. In this regenerative operation, if the regenerative operation continues, excessive regenerative power flows from the motor to the inverter, the smoothing capacitor is charged, the DC voltage becomes excessive, and the inverter circuit is affected.

  In the prior art described in the above-mentioned JP-A-6-311787, a direct current voltage is directly detected. Therefore, if an excessive DC voltage is suppressed on the extension line of the above-described prior art, installation of a detection circuit and maintenance after installation are required. In addition, the increase in the number of parts complicates the apparatus, and the reliability of the apparatus decreases. In particular, in a multiplex type power conversion device, the number of detection circuits increases and the device becomes more complicated.

  In the first place, the above conventional technology is not aware that regenerative power flows from the motor to the inverter during regenerative operation, and excessive DC voltage caused by charging the smoothing capacitor affects the inverter circuit. It is not conscious about giving.

  An object of the present invention is to provide a power conversion system, a power conversion device, and a control method for the power conversion device that can suppress a DC voltage overvoltage during regenerative operation by omitting a DC voltage detection means. is there. Further, it is possible to suppress the influence on the inverter circuit due to the regenerative power flowing from the electric motor to the inverter.

  In order to achieve the above object, the present invention calculates a command value for controlling the power converter, detects the output voltage of the power converter, and uses the detected output voltage value and output voltage command value to perform DC A voltage value or a fluctuation value is estimated, and a rise in DC voltage is suppressed during deceleration operation according to the estimated value.

  Alternatively, a speed command that commands the speed of the power converter is calculated, an output voltage command value that is a command of the output voltage output from the power converter is calculated based on the speed command, and a DC voltage is detected, or a DC voltage Alternatively, the fluctuation value is estimated, and the speed command value is corrected so as to suppress the increase of the DC voltage when the detected value or the estimated value becomes larger than a predetermined value during the deceleration operation.

  More specifically, the DC voltage value or fluctuation value is estimated from the ratio of the detected output voltage value and the output voltage command value, and the speed command value is corrected if the DC voltage value or fluctuation value is equal to or greater than a predetermined value. The configuration.

  According to the present invention, for example, even when the DC voltage is steep and greatly fluctuates during driving of the electric motor, it is possible to obtain an effect that the smoothing capacitor DC overvoltage in the inverter can be suppressed at low cost and with high accuracy.

It is a block diagram of the power converter device of Example 1. FIG. It is a figure explaining the structure of the controller of Example 1. FIG. It is a flowchart explaining the speed command correction according to the first embodiment. FIG. 5 is a schematic diagram of speed command correction operation according to the first embodiment. It is a simulation waveform which shows the effect of this invention. FIG. 10 is a schematic diagram of speed command correction operation according to the second embodiment. FIG. 10 is a schematic diagram of speed command correction operation according to the third embodiment. It is a figure explaining the structure of the controller of Example 4. FIG. FIG. 10 is a configuration diagram illustrating a configuration of an operation according to a fifth embodiment. It is a block diagram of the power converter device of Example 6. FIG. It is a flowchart explaining the speed command correction according to the seventh embodiment.

  Embodiments for carrying out the present invention will be described below with reference to the drawings.

A first embodiment of the present invention is shown in FIG. In FIG. 1, an AC voltage supplied from a three-phase AC power source 101 is rectified by a rectifier diode (diode unit) 102 and smoothed by a smoothing capacitor 103 to obtain a DC voltage. Hereinafter, for example, a converter using an IGBT instead of a rectifier diode may be used. The DC voltage is converted into AC having an arbitrary frequency and phase by an inverter (inverter unit) 104 and supplied to the AC motor 105 to control the AC motor at a variable speed. The output current detector 106 detects U-phase, V-phase, and W-phase output currents in the AC motor 105, and calculates a torque current detection value I _q ^FB by output current detection value coordinate conversion 108. The output voltage detector 107 detects U-phase, V-phase, and W-phase output voltages in the AC motor 105, and outputs the detected d-axis output voltage V _d ^FB and q-axis by the output voltage detection value coordinate conversion 109. Calculate the output voltage detection value V _q ^FB .

FIG. 2 is a diagram specifically showing the configuration of the output voltage command value calculation unit 111, the gate pulse generation unit 112, the output voltage command value correction unit 113, the DC voltage fluctuation estimation unit 114, and the speed command correction unit 115 in FIG. It is. These output voltage command value calculation means 111, gate pulse generation unit 112, output voltage command value correction means 113, DC voltage fluctuation estimation means 114, and speed command correction means 115 are described functionally, but one in total. Alternatively, it may be configured by a plurality of computers, and each function may be realized by software, or each function may be realized by a dedicated control logic. Speed command value obtained by correcting the speed command value ω _r ^* with the speed command correction value Δω _r ^* by the speed command correction means 115 with respect to the speed command correction value ω _r ^* by the speed command generation unit 116 (after correction) ω _r1 ^** (Ω _r1 ^** = ω _r ^* + Δω _r ^* ) is calculated. The output voltage command value calculation means 111 calculates the calculated speed command value (after correction) ω _r1 ^** and the torque current detection value I _q. ^FB , excitation current command value I _d ^* by the excitation current command generator 110, and primary resistance r ₁ , secondary resistance r ₂ , primary self-inductance L ₁ , secondary self-inductance L ₂ , primary conversion leakage inductance, AC motor 105 Based on L _σ , excitation inductance M, secondary time constant T ₂ , and d-axis magnetic flux command Φ _2d ^* , d-axis output voltage command value V _d ^* and q-axis output voltage command value V _q ^* are as follows: It calculates and outputs with the formula (1) and the formula (2) shown. Further, the primary conversion leakage inductance L _σ , the secondary time constant T ₂ , and the d-axis magnetic flux command Φ _2d ^{* in the} formulas (1) and (2) are expressed by formulas (3), (4), And (5) to calculate and output.

In the output voltage command value correcting means 113, the d-axis output voltage command value V _d ^* , the q-axis output voltage command value V _q ^* , the d-axis output voltage detection value V _d ^FB , and the q-axis output voltage detection value V _q ^{Based on the} DC voltage value or the fluctuation estimation result α in the DC voltage fluctuation estimating means 114 with the ^FB as an input, the d-axis divider is used for the d-axis output voltage command value V _d ^* and the q-axis output voltage command value V _q ^* . 118 and q-axis divider 119, d-axis output voltage command value (after correction) V _d ^** and q-axis output voltage command value (after correction) according to the following equations (6) and (7) Calculate V _q ^** .

In the DC voltage fluctuation estimation means 114, the output voltage command correction value magnitude calculation means 120 detects the d-axis output voltage command value (after correction) V _d ^** and the q-axis output voltage command value (after correction) V _q ^**. From the output voltage value (after correction) magnitude V ^** calculated by the following equation (8), the output voltage detection value magnitude calculation means 121 uses the d-axis output voltage detection value V _d ^FB and q Using the magnitude V ^FB calculated by the following equation (9) from the detected shaft output voltage value V _q ^FB , the DC voltage fluctuation estimation calculation unit 122 uses the following equation (10) to calculate the DC voltage value or fluctuation. The estimation result α is calculated, and the DC voltage value or fluctuation value is estimated.

Next, the output voltage command value correction means 113 converts the d-axis output voltage command value (after correction) V _d ^** and the q-axis output voltage command value (after correction) V _q ^** into output voltage command correction value coordinate conversion. 117 converts to U phase output voltage command value (after correction) V _U ^** , V phase output voltage command value (after correction) V _V ^** , and W phase output voltage command value (after correction) V _W ^** To do. Further, in the gate pulse generator 112, for example, the U-phase output voltage command value (after correction) V _U ^** , the V-phase output voltage command value (after correction) V _V ^** , and the W-phase output voltage command value (after correction) ) A PWM-modulated gate pulse is generated by comparing V _W ^** with the carrier waveform, and the switching element of the inverter (inverter unit) 104 is controlled to be turned on / off.

In the speed command correction means 115, the speed command correction value calculation means 123 outputs the speed command correction value Δω _r ^* to perform speed command value correction. Specific processing of the speed command correction unit 115 will be described with reference to the flowchart of FIG. In the step shown as each operation in the flow of FIG. 3, the process is started in step 200, and then in step 201, the speed command value ω _r ^* (t) at time t is set, and the normal deceleration rate is set. drive. For example, it is set to linearly decelerate from omega _r ^* is set at t ₁ corresponds in Fig. 4 to omega _r ^* is set at t ₃ corresponds. Next, the DC voltage value or fluctuation value α estimated in step 202 is calculated. Next, it is determined whether the DC voltage value or the fluctuation value α estimated in step 203 is greater or smaller than the limit value α ₁ . The α ₁ is a value corresponding to the maximum DC voltage allowable value determined by the characteristics of the smoothing capacitor. If α exceeds α ₁ , the speed command correction value Δω _r ^* is output as 0 in step 204. On the other hand, if α is less than α ₁ in step 203, a speed command correction value Δω _r ^* is calculated in step 205. Here, the speed command correction value Δω _r ^* may be a predetermined value that is determined in advance, or may be set so as to increase as the fluctuation value α increases. Depending on the fluctuation value α, the speed command value (after correction) ω _r1 ^** may be selected to be constant speed, switching between acceleration operation, deceleration, or changing the rate. Next, in step 206, the speed command value (after correction) ω _r ^* and the speed command correction value Δω _r ^* are added, and the corrected speed command value (after correction) ω _r1 ^** (ω _r1 ^** = ω _r ^* + _{Δω r} ^*) newly set up. Next, at step 207, the time t + Δt seconds advanced by the sampling time Δt seconds is set. With the sampling time t + Δt seconds set in step 207, the flow returns to step 201, and the speed command value ω _r ^* (t) after time t + Δt seconds advanced by the sampling time Δt seconds is set. As a result, the speed pattern is automatically corrected to suppress the increase of the DC voltage.

Next, the manner in which the DC voltage value is suppressed according to the flowchart described above will be described with reference to the operation waveform diagram of FIG. The speed command value (after correction) ω _r1 ^* is held at a constant speed during the time t ₁ to t ₂ during which the speed command value correction is performed (the speed command value ω _r ^* between t _{1 and} t ₂₎ ^{. ) And} the integrated value of the speed command correction value Δω _r ^* between t ₁ and t ₂ are set to the same value), but the mechanical angular frequency ω _r1 of the AC motor 105 is the speed command value. can not follow the change at the same time, even between t ₁ ~t _a, a determination of the estimated DC voltage value or variation value alpha ≦ limit value alpha ₁ outputs a speed command correction value [Delta] [omega _r ^* However, in order to continue the deceleration motion, regenerative power flows from the AC motor 105 to the inverter (inverter unit) 104, and the DC voltage value increases by about several percent. Thereafter, between t _{a and} t ₂ , the mechanical angular frequency ω _r1 is accelerated and the DC voltage value decreases. Thereafter, between t _{2 and} t _b , when the DC voltage value falls below the limit value α ₁ , the speed command value restarts the deceleration operation at the normal deceleration rate (speed command correction between t _{2 and} t _b). Value Δω _r ^* = 0), but the mechanical angular frequency ω _r1 cannot follow simultaneously with the change of the speed command value, and continues the acceleration motion or constant speed operation between t ₂ and t _b Therefore, the DC voltage value decreases by about several percent. Thereafter, between t _{b and} t ₃ , the mechanical angular frequency ω _r1 is decelerated and the DC voltage value increases. t ₃ or later to repeat the same operation.

  In order to show the effect of this invention in FIG. 5, the result of having performed simulation about the fluctuation | variation of the DC voltage value at the time of regenerative operation is shown. Compared with the case where the speed command correction means is not implemented (FIG. 5 (i)), the DC voltage value can be kept below a certain value by using the embodiment of the present invention (FIG. 5 (ii)).

  With the above configuration, when the DC voltage value exceeds a predetermined value, the speed command value is corrected, and an increase in the DC voltage of the smoothing capacitor 103 can be accurately suppressed without using a detection circuit. It becomes possible.

Next, a difference between the second embodiment of the present invention and the first embodiment will be described. That is, it is the same as that of the 1st Example of another part. In the first embodiment, when the estimated DC voltage value or fluctuation value exceeds the limit value, the speed command value is set to a constant speed to suppress the increase of the DC voltage value. As shown in the figure, when the DC voltage value or fluctuation value estimated by the DC voltage fluctuation estimating means 114 exceeds the limit value, the speed command value is temporarily set to the acceleration operation to suppress the increase of the DC voltage value. Also good. In this embodiment, compared with the first embodiment, it takes time to reach the target attainment speed command value ω _r ^* _goal , but the same effect can be obtained with respect to the suppression of the DC voltage value.

Next, a difference between the third embodiment of the present invention and the first embodiment will be described. In the third embodiment, as shown in the operation waveform diagram of FIG. 7, when the DC voltage value or fluctuation value estimated by the DC voltage fluctuation estimation means 114 exceeds the limit value, the deceleration rate of the speed command value is normally set. By making it smaller than this value, the rise of the DC voltage value is suppressed. When the speed command value is between t ₁ and t ₂ and between t ₃ and t ₄ , the DC voltage increases after several percent and then decreases immediately after the change, as in the first and second embodiments. . During low-speed rotation operation as between t _{5 and} t ₆ , the deceleration operation is continued with the deceleration rate being reduced, so the DC voltage rises above the limit value. In this embodiment, the DC voltage value is several percent larger than in the first and second embodiments, but it is possible to reach the target attainment speed command value ω _r ^* _goal earliest.

Next, a difference between the fourth embodiment of the present invention and the first embodiment will be described. This embodiment can be realized by replacing the speed command correction means 115 of the first embodiment with the speed command correction combination means 124A in FIG. In the first embodiment, when the estimated DC voltage value or fluctuation value exceeds the limit value, the speed command correction value calculation means 123 calculates the speed command correction value Δω _r ^* to suppress the increase of the DC voltage value. However, as shown in FIG. 8, in addition to calculating the speed command correction value Δω _r ^* _Vdc by the speed command correction value calculation means 123, when the detected torque current value I _q ^FB falls below a predetermined value, Then, the speed command correction value calculating means 125 calculates the speed command correction value Δω _r ^* _IqFB , and the speed command correction combination means 124A calculates the speed command correction value Δω _r2 ^* _obtained by adding Δω _r ^* _Vdc and Δω _r ^* _IqFB. By using this to calculate the speed command correction value ω _r2 ^** , it is possible to suppress the DC voltage value more accurately.

Next, a difference of the fifth embodiment of the present invention from the fourth embodiment will be described. This embodiment can be realized by changing the speed command correction combination means 124A of the fourth embodiment to the speed command correction ratio change combination means 124B of FIG. In the fourth embodiment, speed command value correction is performed when the estimated DC voltage value or fluctuation value exceeds the limit value, and when the torque current detection value I _q ^FB falls below a predetermined value. As shown in FIG. 9, the speed command correction ratio change combination means 124B has gains K ₁ , K ₂ (K ₁ > 0, K) in each speed command correction value. ₂ > 0) and each value is changed to suppress an increase in the DC voltage value. By changing K ₁ and K ₂ to arbitrary values, it is possible to suppress the vibration of the DC voltage value and the detected torque current value and to suppress the increase of the DC voltage value.

  Next, a difference of the sixth embodiment of the present invention from the first embodiment will be described. FIG. 10 shows an example in which the present invention shown in the first embodiment is applied to a serial multiplex power converter. 127U, 128V, and 129W are U-phase, V-phase, and W-phase converters, respectively. 130U to 132U are a part of the inverter units in the U-phase converter, and a plurality of similar inverter units are connected. 133V to 134V are inverter units in the V-phase converter, 135W to 136W are inverter units in the W-phase converter, and a plurality of connection units are connected to the inverter units 130U to 132U in the U-phase converter. Inverter unit is connected. For each of the inverter units 130U to 136W, a PWM-modulated gate pulse signal is output from each of a plurality of controllers having the same configuration as the controller 137, and on / off of the switching element of the single-phase inverter of each inverter unit is controlled. To do.

  Also in this configuration, as in the first embodiment, during the regenerative operation, the speed command value is corrected according to the estimated DC voltage value or fluctuation value, and the DC of the smoothing capacitor in each inverter unit is corrected. It is possible to suppress an increase in voltage. As described above, the effect of the present invention is shown in the configuration of the two-level inverter having the three-phase output in the first embodiment. However, the same effect as that of the first embodiment can be achieved in the serial multiplex power converter as in the present embodiment. It is possible to obtain

  In addition to this, the same effect can be obtained with an inverter using a smoothing capacitor.

Next, a difference of the seventh embodiment of the present invention from the first embodiment will be described. In the present embodiment, as shown in FIG. 11, in the case where Δω _r3 ^* shown in the equation (11) is larger than 0 in step 208, the speed command correction value Δω _r ^{* is} determined in step 204 ^. Is output as 0. On the other hand, in the case of deceleration operation where Δω _r3 ^* is smaller than 0, a DC voltage value or fluctuation estimated value α is calculated. If α exceeds α ₁ , the speed command correction value Δω _r ^* is calculated in step 204 ^. Is output as 0. On the other hand, if α is less than α ₁ in step 203, a speed command correction value Δω _r ^* is calculated in step 205. Next, in step 206, the speed command value ω _r ^* and the speed command correction value Δω _r ^* are added, and a corrected speed command value ω _r1 ^** is newly set. Next, in step 207, the speed command value ω _r ^* (t) after time t + Δt seconds advanced by the sampling time Δt seconds is set. As a result, the speed command correction means is implemented only during deceleration operation, and during acceleration operation or constant speed operation, it is determined that the overvoltage has occurred due to a DC voltage value increase due to system power supply voltage rise, and the speed command correction means is implemented. The effect which prevents that can be acquired.

101 Three-phase AC power supply 102 Rectifier diode 103 Smoothing capacitor 104 Inverter (inverter part)
105 AC Motor 106 Output Current Detector 107 Output Voltage Detector 108 Output Current Detection Value Coordinate Conversion 109 Output Voltage Detection Value Coordinate Conversion 110 Excitation Current Command Generation Unit 111 Output Voltage Command Value Calculation Unit 112 Gate Pulse Generation Unit 113 Output Voltage Command Value Correction means 114 DC voltage fluctuation estimation means 115 Speed command correction means 116 Speed command generation unit 117 Output voltage command correction value coordinate conversion 118 d-axis divider 119 q-axis divider 120 Output voltage command correction value magnitude calculation means 121 Output voltage detection Value magnitude calculation means 122 DC voltage fluctuation estimation calculation section 123 Speed command correction value calculation means 123A based on DC voltage value or fluctuation value estimation result Specific speed command correction value calculation means based on DC voltage value or fluctuation value estimation result Calculation method 124A Speed command correction combination means 124B Speed command compensation Positive ratio change combination means 125 Speed command correction value calculation means 125A based on torque current value Specific calculation method 126 of speed command correction calculation means based on torque current value Multiple winding transformer 127U to 129W U-phase to W-phase converters 130U to 132U U-phase inverter unit 133V to 134V V-phase inverter unit 135W to 136W W-phase inverter unit 137 Controller 200 Speed command value correction processing start 201 Normal deceleration rate operation 202 DC voltage fluctuation estimation calculation unit 203 DC overvoltage determination means 204 Speed command correction value Output unit 205 Speed command correction value calculation unit 206 Speed command correction value adder 207 Calculation time calculation unit 208 Deceleration operation determination unit I _q ^FB torque current detection value V _d ^FB d-axis output voltage detection value V _q ^FB q-axis output voltage detection Value ω _r ^* Speed command value ω _r1 ^** Speed command value (after correction)
I _d ^* Excitation current command value r ₁ primary resistance r ₂ secondary resistance L ₁ primary self inductance L ₂ secondary self inductance L _σ primary conversion leakage inductance M excitation inductance T ₂ secondary time constant Φ _2d d-axis magnetic flux V _d ^* d-axis output voltage command value V _q ^* q-axis output voltage command value V _d ^** d-axis output voltage command value (after correction)
V _q ^** q-axis output voltage command value (after correction)
V ^** Output voltage command value (after correction) V ^FB output voltage detection value size α DC voltage value or fluctuation estimation result V _U ^** U-phase output voltage command value (after correction)
V _V ^** V-phase output voltage command value (after correction)
V _W ^** W-phase output voltage command value (after correction)
Δω _r ^* Speed command correction value ω _r ^* _goal target speed command value ω _r1 Mechanical angular frequency Δω _r ^* _Vdc , Δω _r ^* _IqFB Speed command correction value Δω _r2 ^* Δω _r ^* _Vdc plus Δω _r ^* _IqFB Command correction value ω _r2 ^** Speed command value ω _r ^* (t) corrected by speed command correction combination means 124A in the fourth embodiment Speed command value Δt at time t Sampling speed command value during sampling time Δω _r3 ^* Δt Change

Claims (6)

A power converter that converts an AC voltage supplied from a commercial power source into a DC voltage and converts the DC voltage into an arbitrary frequency, an electric motor driven by the power converter, and a control device that controls the power converter The control device controls the power converter so that the power converter operates according to the command value, and the command value is set to the command value. Includes an output voltage command value that is an output voltage command output from the power converter and a speed command value, and at least the speed command value is a speed correction value so as to suppress an increase in the DC voltage during deceleration operation. Is corrected by Δω _r2 ^** _s , the output current detection means for detecting the output current of the electric motor, the output voltage detection means for detecting the output voltage of the power converter, and the detected output voltage value The output voltage The DC voltage estimation unit that estimates the value or variation value of the DC voltage provided with a decree value, the estimated value-using the speed command correction value calculation means for outputting a speed command correction value [Delta] [omega _r ^* _Vdc in accordance with the estimated values Current-use speed command correction value calculation means for outputting a speed command correction value Δω _r ^* _IqFB in relation to the output current, and the speed correction value Δω _r2 ^** _s is the speed command correction value Δω motor system, characterized in that the correction value obtained by adding the _r ^* _Vdc said speed command correction value Δω _r ^* _IqFB.
According to claim 1, wherein the current-using the speed command correction value calculation means, an electric motor, characterized in that the output current value the detected outputs said speed command correction value [Delta] [omega _r ^* _IqFB if it becomes less than a predetermined value system.
2. The estimated value utilization type speed command correction value computing means outputs the speed command correction value Δω _r ^* _Vdc when the estimated DC voltage value or DC voltage fluctuation value becomes a predetermined value or more. motor system, and the current-using the speed command correction value calculation means, characterized in that the output current value the detected outputs said speed command correction value [Delta] [omega _r ^* _IqFB if it becomes less than a predetermined value.
4. The value of the speed command correction value Δω _r ^* _Vdc and the value of the speed command correction value Δω _r ^* _IqFB in accordance with the estimated DC voltage value or fluctuation value or the detected output current value. An electric motor system characterized by changing each.
  A command calculation unit that converts a DC voltage supplied from a commercial power source into a DC voltage, converts the DC voltage into an arbitrary frequency, and a control device that controls the power converter, and calculates a command value The control device controls the power converter so that the power converter operates according to the command value, and the command value includes an output voltage output from the power converter. Output voltage command value and speed command value, and at least the speed command value is set to a speed correction value Δω so as to suppress an increase in the DC voltage during deceleration operation. _r2 ^** _s The output current detecting means for detecting the output current of the electric motor, the output voltage detecting means for detecting the output voltage of the power converter, the detected output voltage value and the output voltage command value Is used to estimate a value or fluctuation value of the DC voltage, and a speed command correction value Δω according to the estimated value. _r ^* _Vdc Speed command correction value calculation means for outputting estimated value and speed command correction value Δω in relation to the output current _r ^* _IqFB Current-use speed command correction value calculation means for outputting the speed correction value Δω _r2 ^** _s Is the speed command correction value Δω _r ^* _Vdc And the speed command correction value Δω _r ^* _IqFB A power converter characterized by being a correction value obtained by adding
  A method for controlling a power converter that converts an AC voltage supplied from a commercial power source into a DC voltage and controls a power converter that converts the DC voltage into an arbitrary frequency, the method for controlling the power converter A command value is calculated, and the command value includes an output voltage command value that is a command of an output voltage output from the power converter and a speed command value, and suppresses an increase in the DC voltage during deceleration operation. At least the speed command value is a speed correction value Δω _r2 ^** _s The output voltage of the electric motor is detected, the output voltage of the power converter is detected, and the DC voltage value or fluctuation is detected using the detected output voltage value and the output voltage command value. Value is estimated as a DC voltage estimate, and the speed command correction value Δω according to the estimated value _r ^* _Vdc Is calculated as an estimated value-based speed command correction value calculation, and the speed command correction value Δω is related to the output current. _r ^* _IqFB Is calculated as a current-based speed command correction value calculation, and the speed correction value Δω _r2 ^** _s Is the speed command correction value Δω _r ^* _Vdc And the speed command correction value Δω _r ^* _IqFB The control method of the power converter device which is the correction value which added.

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