WO2018127960A1 - Power conversion device - Google Patents

Power conversion device Download PDF

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Publication number
WO2018127960A1
WO2018127960A1 PCT/JP2017/000176 JP2017000176W WO2018127960A1 WO 2018127960 A1 WO2018127960 A1 WO 2018127960A1 JP 2017000176 W JP2017000176 W JP 2017000176W WO 2018127960 A1 WO2018127960 A1 WO 2018127960A1
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Prior art keywords
voltage
phase
norm
voltage command
threshold value
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PCT/JP2017/000176
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French (fr)
Japanese (ja)
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雄作 小沼
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株式会社日立産機システム
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Priority to JP2018560290A priority Critical patent/JP6731499B2/en
Priority to PCT/JP2017/000176 priority patent/WO2018127960A1/en
Publication of WO2018127960A1 publication Critical patent/WO2018127960A1/en

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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M5/00Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/40Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
    • H02M5/42Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
    • H02M5/44Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
    • H02M5/443Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a thyratron or thyristor type requiring extinguishing means
    • H02M5/45Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only

Definitions

  • the present invention relates to a power conversion device.
  • a power conversion device that creates an AC voltage of a predetermined frequency from the DC voltage is used.
  • an overvoltage is generated due to regenerative energy during deceleration, and an operation occurs when an excessive overvoltage occurs. Will stop.
  • Patent Document 1 Japanese Patent Laid-Open No. 10-66385 (Patent Document 1) is known as background art in this technical field for preventing overvoltage.
  • Patent Document 1 “to provide a control device for an inverter that automatically decelerates while suppressing overvoltage and overcurrent stably without depending on constants such as the resistance of an induction motor and the inertia moment value of a mechanical load”.
  • providing means for detecting the output current and output voltage of the inverter and means for detecting the DC voltage of the smoothing capacitor connected to the DC side of the inverter, the DC voltage of the smoothing capacitor and the output current of the inverter are provided. The speed reduction rate during the deceleration operation of the inverter is calculated and controlled from the detected value of the output voltage. ”Technology is described (see summary).
  • Patent Document 1 describes an inverter control device that suppresses overvoltage.
  • the invention of Patent Document 1 is limited to deceleration operation, and no effect can be obtained during acceleration operation or constant speed operation. Further, during the deceleration operation, the set deceleration rate is automatically corrected, and the vehicle cannot be decelerated at a desired deceleration rate.
  • an object of the present invention is to provide a power converter that can suppress overvoltage even during acceleration operation or constant speed operation, and can decelerate at a desired deceleration rate during deceleration operation.
  • one of the representative inventions is A voltage converter that converts a DC voltage into a voltage based on a voltage command; A voltage detector for detecting the DC voltage; A phase controller for controlling the phase of the voltage command; A power conversion device comprising: The phase controller may change the phase of the voltage command when the detected DC voltage exceeds a first threshold value.
  • the present invention it is possible to provide a power conversion device that can suppress overvoltage even during acceleration operation or constant speed operation and can decelerate at a desired deceleration rate during deceleration operation.
  • FIG. 1 It is a figure which shows an example of the power converter device of Example 1.
  • FIG. It is a figure explaining an example of operation
  • FIG. It is a figure explaining an example of operation
  • FIG. It is a figure which shows an example of the power converter device of Example 2.
  • FIG. It is a figure which shows an example of the power converter device of Example 3.
  • FIG. 1 shows an example of a power conversion apparatus according to Embodiment 1 of the present invention.
  • the power converter 101 that controls the driving of the three-phase AC induction motor 100 includes a rectifier circuit 102, a smoothing circuit 103, a voltage detector 104, a voltage converter 105, a norm controller 107, and a phase controller 106.
  • the three-phase AC voltage output from the three-phase AC power supply 108 is rectified by the rectifier circuit 102 and smoothed by the smoothing circuit 103, thereby generating a DC voltage.
  • a single-phase AC voltage may be input to the rectifier circuit 102 from a single-phase AC power source.
  • the rectifier circuit 102 and the smoothing circuit 103 may be removed and a direct current voltage may be obtained directly from a direct current power source.
  • the voltage detector 104 detects the smoothed DC voltage.
  • the voltage conversion unit 105 that converts a DC voltage into a voltage based on the voltage command 109 includes a switching circuit controller 110 and a switching circuit 111.
  • the switching circuit controller 110 generates a switching circuit control signal 112 so that a voltage based on the voltage command 109 is applied to the three-phase AC induction motor 100. For example, the voltage command and the triangular wave signal are compared to generate the switching circuit control signal 112 including a PWM signal.
  • the switching circuit 111 converts the DC voltage into a voltage based on the voltage command 109 by combining ON / OFF of a plurality of switching elements based on the switching circuit control signal 112.
  • the switching circuit can be configured by connecting in parallel U-phase, V-phase, and W-phase arms each having two switching elements connected in series.
  • the above describes a method of converting a DC voltage into a voltage based on the voltage command 109 by a method called PWM for controlling the width of the voltage pulse, but the DC voltage is converted into a voltage by a method called PAM for changing the amplitude of the voltage pulse.
  • PWM pulse width of the voltage pulse
  • PAM pulse amplitude of the voltage pulse
  • phase controller 106 and norm controller 107 that are the features of this embodiment will be described.
  • the phase controller 106 changes the phase of the voltage command based on the detected DC voltage 113 of the voltage detector 104, and outputs the changed voltage command 109 and the phase controlling signal 115.
  • FIG. 2 shows an example of the operation of the phase controller 106.
  • the example of FIG. 2 is an example in which a first threshold value and a second threshold value are provided to provide a hysteresis effect.
  • f is a frequency
  • t time
  • ⁇ 0 is a phase before being changed by the phase controller 106
  • V0 is a norm (voltage) before being changed by the norm controller 107.
  • the detected DC voltage 113 When the detected DC voltage 113 is between the first threshold and the second threshold as at t2, the voltage command of the phase ⁇ 1 is output without changing the phase ⁇ 1.
  • the detected DC voltage exceeds the second threshold at t4, but the phase is ⁇ 0 and does not change from t3 to t5.
  • the hysteresis effect is eliminated, but the first threshold value and the second threshold value may be set to the same value, that is, one threshold value, and the phase may be changed to ⁇ 0 and ⁇ 1 by one threshold value.
  • the threshold value may be set in advance or externally. Further, the threshold value may be changed according to the driving status of the motor, for example, voltage, current, frequency, and the like. The amount of change in phase may be changed according to the difference between the detected DC voltage 113 and the first threshold value.
  • phase of the three-phase AC voltage created by the switching circuit 111 changes.
  • the direction of the change in the phase ⁇ 1 of the voltage command 109 may be, for example, such that the current flowing through the electric motor is increased.
  • phase control in-progress signal 115 is used for status display and control of phase control in progress.
  • the norm controller 107 changes the norm (voltage) of the voltage command based on the detected DC voltage 113 of the voltage detector 104, and outputs the voltage command 114 before phase control and the norm controlling signal 117 as the changed voltage command. Output.
  • FIG. 3 shows an example of the operation of the norm controller. The example of FIG. 3 is an example in which a third threshold value and a fourth threshold value are provided to provide a hysteresis effect.
  • the norm V0 of the pre-norm control voltage command 116 is increased to V1
  • the pre-phase control voltage command 114 which is a voltage command after the norm increase, and the norm control A medium signal 117 is output.
  • the voltage command of the norm V0 is output as it is as at t4.
  • the fourth threshold value set to a value lower than the third threshold value at t3
  • the norm V1 of the pre-norm control voltage command 116 is returned to V0 before the phase control.
  • a voltage command 114 is output.
  • the detected DC voltage 113 is between the third threshold value and the fourth threshold value as at t2
  • the voltage command of the norm V1 is output without changing the norm V1.
  • the detected DC voltage exceeds the second threshold at t4, but the norm is V0 from t3 to t5 and does not change.
  • the third threshold value and the fourth threshold value may be the same value, that is, the threshold value may be one, and the norm may be changed to V0 and V1 by one threshold value.
  • the threshold value may be set in advance or externally. Further, the threshold value may be changed according to the driving status of the motor, for example, voltage, current, frequency, and the like. The increase amount of the norm may be changed according to the difference between the detected DC voltage 113 and the third threshold value.
  • the norm controller 107 may be removed, and the voltage command 116 before norm control may be directly input to the phase controller 106.
  • the norm control in-progress signal 117 is used for status display and control of the norm control in progress.
  • the present invention can be applied without selecting a motor drive control method such as V / f constant control or vector control.
  • the DC voltage increases depending on the degree.
  • the power converter stops output for the purpose of overvoltage protection, but the power converter sets the first threshold to a value lower than the DC voltage at which output is stopped.
  • the DC voltage can be suppressed before the power converter stops the output, and the driving of the electric motor can be continued.
  • the third threshold value is set to a value lower than the first threshold value, it is possible to further suppress an increase in DC voltage by increasing the norm before changing the phase. Note that even if the third threshold value is set to the same value or a larger value as the first threshold value, and the phase is changed before the norm is increased, an increase in the DC voltage can be suppressed.
  • FIG. 4 shows an example of the power conversion apparatus according to the second embodiment of the present invention.
  • a power converter 201 that controls the driving of the three-phase AC induction motor 100 includes a rectifier circuit 102, a smoothing circuit 103, a voltage converter 105, a norm controller 107, a phase controller 106, a current detector 218, and a power calculator 219. Have.
  • the current detector 218 detects the three-phase alternating current output from the power conversion device 201.
  • the current detector 218 may detect a two-phase current and calculate the remaining one-phase current because the sum of the three-phase alternating currents is zero.
  • a resistor may be provided on the positive electrode side or the negative electrode side of the smoothing circuit 103, and the three-phase alternating current may be estimated from the voltage across the resistor.
  • the power calculator 219 calculates power from the voltage command 116 before norm control and the detected current 220.
  • the power may be calculated by at least one of apparent power, active power, and reactive power. Moreover, what is necessary is just to calculate the electric power of at least one phase among three phases. When calculating two or more phases of electric power, you may calculate those average values.
  • the power may be calculated using the voltage command 109 or the voltage command 114 before phase control instead of the voltage command 116 before norm control.
  • phase controller 106 and the norm controller 107 are the same as those of the first embodiment.
  • the phase controller 106 changes the phase of the voltage command based on the calculated power 221 of the power calculator 219, and outputs the changed voltage command 109 and the phase controlling signal 115.
  • the phase of the pre-phase control voltage command 114 is changed to ⁇ 0 when the calculated power 221 exceeds the first threshold value.
  • the voltage command 109 which is the voltage command after the phase change, and the phase control in-progress signal 115 are output.
  • the voltage command with the phase ⁇ 0 is output as it is.
  • the voltage command 109 is output by returning the phase ⁇ 1 of the pre-phase control voltage command 114 to ⁇ 0. .
  • the voltage command of the phase ⁇ 1 is output without changing the phase ⁇ 1.
  • the hysteresis effect disappears, but the first threshold value and the second threshold value may be the same value, that is, the threshold value may be one, and the phase may be changed to ⁇ 0 and ⁇ 1 by one threshold value.
  • the threshold value may be set in advance or externally. Further, the threshold value may be changed according to the driving status of the motor, for example, voltage, current, frequency, and the like. The amount of change in phase may be changed according to the difference between the detected DC voltage 113 and the first threshold value.
  • a threshold value may be provided for each. Further, the threshold value may be compared with either the absolute value of the calculated power 221, only the positive value of the calculated power 221, or only the absolute value of the negative value of the calculated power 221.
  • the norm controller 107 changes the norm (voltage) of the voltage command based on the calculated power 221 of the power calculator 219, and outputs the pre-phase control voltage command 114 and the norm controlling signal 117, which are the changed voltage commands. To do. For example, in the example in which the third threshold value and the fourth threshold value are provided so as to have a hysteresis effect, when the calculated power 221 exceeds the third threshold value, the norm V0 of the pre-norm control voltage command 116 is set. V1 is increased to output a pre-phase control voltage command 114, which is a voltage command after the norm increase, and a norm controlling signal 117.
  • the norm V0 voltage command is output as it is.
  • the pre-phase control voltage command 114 that returns the norm V1 of the pre-norm control voltage command 116 to V0. Is output.
  • the norm V1 voltage command is output without changing the norm V1. In this way, by setting two thresholds so that the norm does not change unless the threshold is exceeded, malfunction due to noise or the like can be prevented by the hysteresis effect.
  • the third threshold value and the fourth threshold value may be the same value, that is, the threshold value may be one, and the norm may be changed to V0 and V1 by one threshold value.
  • the threshold value may be set in advance or externally. Further, the threshold value may be changed according to the driving status of the motor, for example, voltage, current, frequency, and the like. The increase amount of the norm may be changed according to the difference between the calculated power 221 and the third threshold value. When there are a plurality of calculation powers 221, a threshold value may be provided for each.
  • the threshold value may be compared with either the absolute value of the calculated power 221, only the positive value of the calculated power 221, or only the absolute value of the negative value of the calculated power 221.
  • the norm controller 107 may be removed, and the voltage command 116 before norm control may be directly input to the phase controller 106.
  • the present invention can be applied without selecting a motor drive control method such as V / f constant control or vector control.
  • the DC voltage increases depending on the degree, but the power also changes depending on the increase of the DC voltage.
  • the power converter stops output for the purpose of overvoltage protection, but the first threshold is set to a value lower than the power corresponding to the DC voltage at which the power converter stops output.
  • the third threshold value is set to a value lower than the first threshold value, it is possible to further suppress an increase in DC voltage by increasing the norm before changing the phase. Note that even if the third threshold value is set to the same value or a larger value as the first threshold value, and the phase is changed before the norm is increased, an increase in the DC voltage can be suppressed.
  • FIG. 5 shows an example of the power conversion apparatus according to the third embodiment of the present invention.
  • a power factor calculator 319 is provided instead of the power calculator 219, and the phase of the voltage command is changed based on the calculated power factor.
  • the power factor calculator 319 calculates the power factor from the voltage command 116 before norm control and the detected current 220.
  • the power factor may be calculated using the voltage command 109 or the voltage command 114 before phase control instead of the voltage command 116 before norm control.
  • phase controller 106 and norm controller 107 when the power factor exceeds the threshold is the same as that of the second embodiment.
  • the present invention when the power factor calculated by the power factor calculator exceeds the threshold, the voltage command phase is changed, and the voltage phase applied to the motor is changed, thereby suppressing the DC voltage increase. . Therefore, it is possible to suppress the DC voltage without automatically correcting the acceleration rate or the deceleration rate without depending on the driving conditions such as acceleration, constant speed, and deceleration of the motor. Further, since information on the motor such as resistance and inductance is not required, the present invention can be applied without selecting a motor drive control method such as V / f constant control or vector control.
  • the DC voltage increases depending on the degree, but the power factor also changes depending on the increase of the DC voltage.
  • the power converter stops the output for the purpose of overvoltage protection, but the power converter has a first value lower than the power factor corresponding to the DC voltage at which the power converter stops the output.
  • the threshold value By setting the threshold value, the DC voltage can be suppressed before the power converter stops the output, and the driving of the electric motor can be continued.
  • the third threshold value to a value lower than the first threshold value, it is possible to further suppress an increase in DC voltage by increasing the norm before changing the phase. Note that even if the third threshold value is set to the same value or a larger value as the first threshold value, and the phase is changed before the norm is increased, an increase in the DC voltage can be suppressed.
  • this invention is not limited to the above-mentioned Example, Various modifications are included.
  • the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.
  • a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.
  • each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit.
  • Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor.
  • Information such as programs, tables, and files that realize each function can be stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.
  • control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Ac-Ac Conversion (AREA)
  • Inverter Devices (AREA)
  • Control Of Ac Motors In General (AREA)

Abstract

Provided is a power conversion device with which overvoltage can be prevented during acceleration and during constant-speed operation, and deceleration at a desired deceleration rate is possible during deceleration. The power conversion device is provided with a voltage conversion part for converting direct-current voltage to voltage based on a voltage command, a voltage detector for detecting the direct-current voltage, and a phase controller for controlling the phase of the voltage command. The power conversion device is characterized in that when the detected direct-current voltage exceeds a first threshold, the phase controller causes the phase of the voltage command to change.

Description

電力変換装置Power converter
 本発明は、電力変換装置に関する。 The present invention relates to a power conversion device.
 電動機を可変速運転するために、直流電圧から所定の周波数の交流電圧を作成する電力変換装置が用いられているが、例えば減速時の回生エネルギーにより過電圧が発生し、過大な過電圧が発生すると運転を停止してしまう。 In order to drive the motor at a variable speed, a power conversion device that creates an AC voltage of a predetermined frequency from the DC voltage is used.For example, an overvoltage is generated due to regenerative energy during deceleration, and an operation occurs when an excessive overvoltage occurs. Will stop.
 過電圧を防止する本技術分野の背景技術として、特開平10-66385号公報(特許文献1)がある。この公報には、「誘導電動機の抵抗などの定数や機械負荷の慣性モーメント値に依存しないで安定に過電圧と過電流を抑制しながら自動的に減速するインバータの制御装置を提供すること。」を課題とし、「インバータの出力電流と出力電圧を検出する手段と、前記インバータの直流側に接続された平滑コンデンサの直流電圧を検出する手段とを設け、前記平滑コンデンサの直流電圧とインバータの出力電流、出力電圧の検出値とからインバータの減速運転時の減速率を演算して制御する。」技術が記載されている(要約参照)。 Japanese Patent Laid-Open No. 10-66385 (Patent Document 1) is known as background art in this technical field for preventing overvoltage. In this publication, “to provide a control device for an inverter that automatically decelerates while suppressing overvoltage and overcurrent stably without depending on constants such as the resistance of an induction motor and the inertia moment value of a mechanical load”. As a subject, “providing means for detecting the output current and output voltage of the inverter and means for detecting the DC voltage of the smoothing capacitor connected to the DC side of the inverter, the DC voltage of the smoothing capacitor and the output current of the inverter are provided. The speed reduction rate during the deceleration operation of the inverter is calculated and controlled from the detected value of the output voltage. ”Technology is described (see summary).
特開平10-66385号公報Japanese Patent Laid-Open No. 10-66385
 前記特許文献1には、過電圧を抑制するインバータの制御装置が記載されている。しかし、特許文献1の発明は減速運転時に限定されており、加速運転時や一定速運転時には効果が得られない。また、減速運転時において、設定されている減速率を自動的に修正してしまい、所望の減速率で減速することができない。 Patent Document 1 describes an inverter control device that suppresses overvoltage. However, the invention of Patent Document 1 is limited to deceleration operation, and no effect can be obtained during acceleration operation or constant speed operation. Further, during the deceleration operation, the set deceleration rate is automatically corrected, and the vehicle cannot be decelerated at a desired deceleration rate.
 そこで、本発明は、加速運転時や一定速運転時においても過電圧を抑制でき、減速運転時において、所望の減速率で減速することができる電力変換装置を提供することを目的とする。 Therefore, an object of the present invention is to provide a power converter that can suppress overvoltage even during acceleration operation or constant speed operation, and can decelerate at a desired deceleration rate during deceleration operation.
 上記課題を解決するために、代表的な本発明の一つは、
  直流電圧を電圧指令に基づいた電圧に変換する電圧変換部と、
  前記直流電圧を検出する電圧検出器と、
  前記電圧指令の位相を制御する位相制御器と、
を備えた電力変換装置であって、
  前記位相制御器では、前記検出した直流電圧が第1の閾値を上回った場合に前記電圧指令の位相を変化させることを特徴とする。
In order to solve the above-mentioned problem, one of the representative inventions is
A voltage converter that converts a DC voltage into a voltage based on a voltage command;
A voltage detector for detecting the DC voltage;
A phase controller for controlling the phase of the voltage command;
A power conversion device comprising:
The phase controller may change the phase of the voltage command when the detected DC voltage exceeds a first threshold value.
 本発明によれば、加速運転時や一定速運転時においても過電圧を抑制でき、減速運転時において、所望の減速率で減速することができる電力変換装置を提供することができる。 According to the present invention, it is possible to provide a power conversion device that can suppress overvoltage even during acceleration operation or constant speed operation and can decelerate at a desired deceleration rate during deceleration operation.
実施例1の電力変換装置の一例を示す図である。It is a figure which shows an example of the power converter device of Example 1. FIG. 実施例1の位相制御器の動作の一例を説明する図である。It is a figure explaining an example of operation | movement of the phase controller of Example 1. FIG. 実施例1のノルム制御器の動作の一例を説明する図である。It is a figure explaining an example of operation | movement of the norm controller of Example 1. FIG. 実施例2の電力変換装置の一例を示す図である。It is a figure which shows an example of the power converter device of Example 2. FIG. 実施例3の電力変換装置の一例を示す図である。It is a figure which shows an example of the power converter device of Example 3. FIG.
 以下、本発明の実施例を、図を用いながら説明する。なお、以下の説明において、各図で共通する構成要素には同一の符号を付して、それらについての重複した説明は省略する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are given to components common to the respective drawings, and a duplicate description thereof will be omitted.
 図1に、本発明の実施例1における電力変換装置の一例を示す。 FIG. 1 shows an example of a power conversion apparatus according to Embodiment 1 of the present invention.
 三相交流誘導電動機100の駆動制御を行う電力変換装置101は、整流回路102、平滑回路103、電圧検出器104、電圧変換部105、ノルム制御器107、位相制御器106を有する。 The power converter 101 that controls the driving of the three-phase AC induction motor 100 includes a rectifier circuit 102, a smoothing circuit 103, a voltage detector 104, a voltage converter 105, a norm controller 107, and a phase controller 106.
 三相交流電源108から出力される三相交流電圧は、整流回路102により整流、平滑回路103により平滑されることで、直流電圧が生成される。なお、三相交流電源108に代えて、単相交流電源より単相交流電圧を整流回路102に入力してもよい。また、整流回路102及び平滑回路103を取り外し、直流電源より直接、直流電圧を得てもよい。 The three-phase AC voltage output from the three-phase AC power supply 108 is rectified by the rectifier circuit 102 and smoothed by the smoothing circuit 103, thereby generating a DC voltage. Instead of the three-phase AC power source 108, a single-phase AC voltage may be input to the rectifier circuit 102 from a single-phase AC power source. Alternatively, the rectifier circuit 102 and the smoothing circuit 103 may be removed and a direct current voltage may be obtained directly from a direct current power source.
 電圧検出器104は、平滑された直流電圧を検出する。 The voltage detector 104 detects the smoothed DC voltage.
 直流電圧を電圧指令109に基づいた電圧に変換する電圧変換部105は、スイッチング回路制御器110とスイッチング回路111を有する。 The voltage conversion unit 105 that converts a DC voltage into a voltage based on the voltage command 109 includes a switching circuit controller 110 and a switching circuit 111.
 スイッチング回路制御器110は、電圧指令109に基づいた電圧が三相交流誘導電動機100に印加されるように、スイッチング回路制御信号112を生成する。例えば、電圧指令と三角波信号とを比較して、PWM信号から成るスイッチング回路制御信号112を生成する。 The switching circuit controller 110 generates a switching circuit control signal 112 so that a voltage based on the voltage command 109 is applied to the three-phase AC induction motor 100. For example, the voltage command and the triangular wave signal are compared to generate the switching circuit control signal 112 including a PWM signal.
 スイッチング回路111は、スイッチング回路制御信号112に基づき、複数のスイッチング素子のON/OFFを組み合わせることで、直流電圧を電圧指令109に基づいた電圧に変換する。例えば、スイッチング回路は、それぞれ2個のスイッチング素子を直列接続したU相、V相、W相のアームを並列接続して構成することができる。 The switching circuit 111 converts the DC voltage into a voltage based on the voltage command 109 by combining ON / OFF of a plurality of switching elements based on the switching circuit control signal 112. For example, the switching circuit can be configured by connecting in parallel U-phase, V-phase, and W-phase arms each having two switching elements connected in series.
 上記は、電圧パルスの幅を制御するPWMと呼ばれる方式で直流電圧を電圧指令109に基づいた電圧に変換する方法を説明したが、電圧パルスの振幅を変化させるPAMと呼ばれる方式で直流電圧を電圧指令109に基づいた電圧に変換する方法を用いてもよい。 The above describes a method of converting a DC voltage into a voltage based on the voltage command 109 by a method called PWM for controlling the width of the voltage pulse, but the DC voltage is converted into a voltage by a method called PAM for changing the amplitude of the voltage pulse. A method of converting to a voltage based on the command 109 may be used.
 これまでの構成は、電力変換装置の周知の構成であるので、詳細な説明は省略する。 Since the configuration so far is a well-known configuration of the power conversion device, detailed description is omitted.
 次に、本実施例の特徴である位相制御器106およびノルム制御器107について説明する。 Next, the phase controller 106 and norm controller 107 that are the features of this embodiment will be described.
 位相制御器106は、電圧検出器104の検出直流電圧113に基づいて、電圧指令の位相を変化させ、変化させた電圧指令109と位相制御中信号115を出力する。図2に、位相制御器106の動作の一例を示す。図2の例は、第1の閾値と第2の閾値を設けて、ヒステリシス効果を持たせるようにした例である。
電圧指令vは、例えば、
v=V0・cos(2πft+θ0)
と表すことができる。
ここで、fは周波数、tは時間、θ0は位相制御器106により変化させる前の位相、V0はノルム制御器107により変化させる前のノルム(電圧)である。なお、上式は、一相のみを表しているが、残りの二相は±120°の位相差を持たせればよいため、説明は省略する。また、θ0及びθ1、V0及びV1は、分かりやすく説明するために、それぞれ時間で変化しない場合を説明するが、例えば電動機の駆動状況により、θ0及びθ1、V0及びV1は、それぞれ時間で変化してもよい。
The phase controller 106 changes the phase of the voltage command based on the detected DC voltage 113 of the voltage detector 104, and outputs the changed voltage command 109 and the phase controlling signal 115. FIG. 2 shows an example of the operation of the phase controller 106. The example of FIG. 2 is an example in which a first threshold value and a second threshold value are provided to provide a hysteresis effect.
The voltage command v is, for example,
v = V0 · cos (2πft + θ0)
It can be expressed as.
Here, f is a frequency, t is time, θ0 is a phase before being changed by the phase controller 106, and V0 is a norm (voltage) before being changed by the norm controller 107. Although the above equation represents only one phase, the remaining two phases only need to have a phase difference of ± 120 °, and the description thereof will be omitted. In addition, for the sake of easy understanding, θ0 and θ1, V0 and V1 will be described with respect to the case where they do not change with time. May be.
 図2において、検出直流電圧113がt1で第1の閾値を上回った場合に、位相制御前電圧指令114の位相θ0をθ1に変化させ、位相変化後の電圧指令である電圧指令109と、位相制御中信号115を出力する。なお、検出直流電圧113が第1の閾値以下の場合は、t4のように位相θ0の電圧指令をそのまま出力する。次に、検出直流電圧113が、t3で第1の閾値よりも低い値に設定した第2の閾値を下回った場合には、位相制御前電圧指令114の位相θ1をθ0に戻した電圧指令109を出力する。なお、検出直流電圧113が、t2のように第1の閾値と第2の閾値の間にある場合は位相θ1を変化させることなく、位相θ1の電圧指令を出力する。このように閾値を2つ設定し、閾値を越えないと位相を変化しないようにすることで、ヒステリシス効果によりノイズなどによる誤動作を防ぐことができる。例えば、t4で検出直流電圧は第2の閾値を越えるが、t3~t5で位相はθ0で変化はない。 In FIG. 2, when the detected DC voltage 113 exceeds the first threshold at t1, the phase θ0 of the pre-phase control voltage command 114 is changed to θ1, and the voltage command 109, which is the voltage command after the phase change, The in-control signal 115 is output. When the detected DC voltage 113 is equal to or lower than the first threshold value, the voltage command with the phase θ0 is output as it is, as at t4. Next, when the detected DC voltage 113 falls below the second threshold set to a value lower than the first threshold at t3, the voltage command 109 returns the phase θ1 of the pre-phase control voltage command 114 to θ0. Is output. When the detected DC voltage 113 is between the first threshold and the second threshold as at t2, the voltage command of the phase θ1 is output without changing the phase θ1. By setting two thresholds in this way and preventing the phase from changing unless the threshold is exceeded, malfunction due to noise or the like can be prevented by the hysteresis effect. For example, the detected DC voltage exceeds the second threshold at t4, but the phase is θ0 and does not change from t3 to t5.
 他の例として、ヒステリシス効果は無くなるが、第1の閾値と第2の閾値を同じ値、すなわち閾値を1つとして、1つの閾値により位相をθ0とθ1に変化させるようにしてもよい。なお、閾値は、予め内部に設定、もしくは外部から設定するようにしてもよい。また、閾値は、電動機の駆動状況、例えば電圧や電流、周波数などに応じて変化させてもよい。位相の変化量は、検出直流電圧113と第1の閾値との差に応じて変化させてもよい。 As another example, the hysteresis effect is eliminated, but the first threshold value and the second threshold value may be set to the same value, that is, one threshold value, and the phase may be changed to θ0 and θ1 by one threshold value. Note that the threshold value may be set in advance or externally. Further, the threshold value may be changed according to the driving status of the motor, for example, voltage, current, frequency, and the like. The amount of change in phase may be changed according to the difference between the detected DC voltage 113 and the first threshold value.
 電圧指令109の位相を変化させることにより、スイッチング回路111で作成する三相交流電圧の位相が変化する。電圧指令109の位相θ1の変化の方向は、例えば、電動機に流れる電流が大きくなるようにすればよい。 By changing the phase of the voltage command 109, the phase of the three-phase AC voltage created by the switching circuit 111 changes. The direction of the change in the phase θ1 of the voltage command 109 may be, for example, such that the current flowing through the electric motor is increased.
 なお、位相制御中信号115は、位相制御中であることの状態表示や制御などに用いる。 Note that the phase control in-progress signal 115 is used for status display and control of phase control in progress.
 ノルム制御器107は、電圧検出器104の検出直流電圧113に基づいて、電圧指令のノルム(電圧)を変化させ、変化させた電圧指令である位相制御前電圧指令114とノルム制御中信号117を出力する。図3に、ノルム制御器の動作の一例を示す。図3の例は、第3の閾値と第4の閾値を設けて、ヒステリシス効果を持たせるようにした例である。検出直流電圧113がt1で第3の閾値を上回った場合に、ノルム制御前電圧指令116のノルムV0をV1に増加させ、ノルム増加後の電圧指令である位相制御前電圧指令114と、ノルム制御中信号117を出力する。なお、検出直流電圧113が第3の閾値以下の場合は、t4のようにノルムV0の電圧指令をそのまま出力する。次に、検出直流電圧113が、t3で第3の閾値よりも低い値に設定した第4の閾値を下回った場合には、ノルム制御前電圧指令116のノルムV1をV0に戻した位相制御前電圧指令114を出力する。なお、検出直流電圧113が、t2のように第3の閾値と第4の閾値の間にある場合はノルムV1を変化させることなく、ノルムV1の電圧指令を出力する。このように閾値を2つ設定し、閾値を越えないとノルムを変化しないようにすることで、ヒステリシス効果によりノイズなどによる誤動作を防ぐことができる。例えば、t4で検出直流電圧は第2の閾値を越えるが、t3~t5でノルムはV0で変化はない。 The norm controller 107 changes the norm (voltage) of the voltage command based on the detected DC voltage 113 of the voltage detector 104, and outputs the voltage command 114 before phase control and the norm controlling signal 117 as the changed voltage command. Output. FIG. 3 shows an example of the operation of the norm controller. The example of FIG. 3 is an example in which a third threshold value and a fourth threshold value are provided to provide a hysteresis effect. When the detected DC voltage 113 exceeds the third threshold value at t1, the norm V0 of the pre-norm control voltage command 116 is increased to V1, and the pre-phase control voltage command 114, which is a voltage command after the norm increase, and the norm control A medium signal 117 is output. When the detected DC voltage 113 is equal to or lower than the third threshold value, the voltage command of the norm V0 is output as it is as at t4. Next, when the detected DC voltage 113 falls below the fourth threshold value set to a value lower than the third threshold value at t3, the norm V1 of the pre-norm control voltage command 116 is returned to V0 before the phase control. A voltage command 114 is output. When the detected DC voltage 113 is between the third threshold value and the fourth threshold value as at t2, the voltage command of the norm V1 is output without changing the norm V1. In this way, by setting two thresholds so that the norm does not change unless the threshold is exceeded, malfunction due to noise or the like can be prevented by the hysteresis effect. For example, the detected DC voltage exceeds the second threshold at t4, but the norm is V0 from t3 to t5 and does not change.
 他の例として、ヒステリシス効果は無くなるが、第3の閾値と第4の閾値を同じ値、すなわち閾値を1つとして、1つの閾値によりノルムをV0とV1に変化させるようにしてもよい。なお、閾値は、予め内部に設定、もしくは外部から設定するようにしてもよい。また、閾値は、電動機の駆動状況、例えば電圧や電流、周波数などに応じて変化させてもよい。ノルムの増加量は、検出直流電圧113と第3の閾値との差に応じて変化させてもよい。なお、ノルム制御器107を取り外し、ノルム制御前電圧指令116を直接位相制御器106に入力してもよい。 As another example, the hysteresis effect is eliminated, but the third threshold value and the fourth threshold value may be the same value, that is, the threshold value may be one, and the norm may be changed to V0 and V1 by one threshold value. Note that the threshold value may be set in advance or externally. Further, the threshold value may be changed according to the driving status of the motor, for example, voltage, current, frequency, and the like. The increase amount of the norm may be changed according to the difference between the detected DC voltage 113 and the third threshold value. The norm controller 107 may be removed, and the voltage command 116 before norm control may be directly input to the phase controller 106.
 なお、ノルム制御中信号117は、ノルム制御中であることの状態表示や制御などに用いる。 The norm control in-progress signal 117 is used for status display and control of the norm control in progress.
 上記したように、本実施例では、直流電圧の過電圧を検出した場合、電圧指令の位相を変化させ、電動機に印加する電圧の位相を変化させることで、電動機に流れる電流を増加させ、モータでエネルギーを消費させることにより、直流電圧の上昇を抑制する。従って、電動機の加速、一定速、減速といった駆動状況に依存せず、加速率や減速率を自動的に修正することなく直流電圧の抑制が可能である。また、抵抗やインダクタンスなどの電動機の情報を必要としないので、V/f一定制御やベクトル制御といった電動機の駆動制御方法を選ぶことなく適用できる。 As described above, in this embodiment, when an overvoltage of a DC voltage is detected, the phase of the voltage command is changed, and the phase of the voltage applied to the motor is changed, thereby increasing the current flowing through the motor, By consuming energy, an increase in DC voltage is suppressed. Therefore, it is possible to suppress the DC voltage without automatically correcting the acceleration rate or the deceleration rate without depending on the driving conditions such as acceleration, constant speed, and deceleration of the motor. Further, since information on the motor such as resistance and inductance is not required, the present invention can be applied without selecting a motor drive control method such as V / f constant control or vector control.
 電動機が回生状態になると、その程度に依存して直流電圧が上昇する。電力変換装置は直流電圧が所定の閾値を超えると、過電圧の保護を目的として、出力を停止させるが、電力変換装置が出力を停止させる直流電圧よりも低い値に第1の閾値を設定することで、電力変換装置が出力を停止させる前に直流電圧を抑制でき、電動機の駆動を継続することも可能である。さらに、第1の閾値よりも低い値に第3の閾値を設定することにより、位相を変化させる前にノルムを増加させることで、直流電圧の上昇をより抑制することが可能となる。なお、第3の閾値は第1の閾値と同じ値、もしくは大きい値に設定して、ノルムを増加させる前に位相を変化させるようにしても、直流電圧の上昇を抑制できる。 When the motor is in the regenerative state, the DC voltage increases depending on the degree. When the DC voltage exceeds a predetermined threshold, the power converter stops output for the purpose of overvoltage protection, but the power converter sets the first threshold to a value lower than the DC voltage at which output is stopped. Thus, the DC voltage can be suppressed before the power converter stops the output, and the driving of the electric motor can be continued. Furthermore, by setting the third threshold value to a value lower than the first threshold value, it is possible to further suppress an increase in DC voltage by increasing the norm before changing the phase. Note that even if the third threshold value is set to the same value or a larger value as the first threshold value, and the phase is changed before the norm is increased, an increase in the DC voltage can be suppressed.
 図4に、本発明の実施例2の電力変換装置の一例を示す。 FIG. 4 shows an example of the power conversion apparatus according to the second embodiment of the present invention.
 三相交流誘導電動機100の駆動制御を行う電力変換装置201は、整流回路102、平滑回路103、電圧変換部105、ノルム制御器107、位相制御器106、電流検出器218、電力演算器219を有する。 A power converter 201 that controls the driving of the three-phase AC induction motor 100 includes a rectifier circuit 102, a smoothing circuit 103, a voltage converter 105, a norm controller 107, a phase controller 106, a current detector 218, and a power calculator 219. Have.
 電流検出器218は、電力変換装置201から出力される三相交流電流を検出する。電流検出器218は、二相の電流を検出し、三相交流の総和が零であることから、残りの一相の電流を算出してもよい。また、平滑回路103の正極側または負極側に抵抗を設け、この抵抗の両端の電圧から、三相交流電流を推定してもよい。 The current detector 218 detects the three-phase alternating current output from the power conversion device 201. The current detector 218 may detect a two-phase current and calculate the remaining one-phase current because the sum of the three-phase alternating currents is zero. Further, a resistor may be provided on the positive electrode side or the negative electrode side of the smoothing circuit 103, and the three-phase alternating current may be estimated from the voltage across the resistor.
 電力演算器219は、ノルム制御前電圧指令116と検出電流220から、電力を演算する。電力は、皮相電力、有効電力、無効電力の少なくとも一つ以上演算すればよい。また、三相の内、少なくとも一相以上の電力を演算すればよい。二相以上の電力を演算する場合は、それらの平均値を算出してもよい。なお、ノルム制御前電圧指令116の代わりに、電圧指令109もしくは位相制御前電圧指令114を用いて、電力を演算してもよい。 The power calculator 219 calculates power from the voltage command 116 before norm control and the detected current 220. The power may be calculated by at least one of apparent power, active power, and reactive power. Moreover, what is necessary is just to calculate the electric power of at least one phase among three phases. When calculating two or more phases of electric power, you may calculate those average values. The power may be calculated using the voltage command 109 or the voltage command 114 before phase control instead of the voltage command 116 before norm control.
 位相制御器106およびノルム制御器107の動作は、実施例1の動作と同様である。 The operations of the phase controller 106 and the norm controller 107 are the same as those of the first embodiment.
 位相制御器106は、電力演算器219の演算電力221に基づいて、電圧指令の位相を変化させ、変化させた電圧指令109と位相制御中信号115を出力する。例えば、第1の閾値と第2の閾値を設けて、ヒステリシス効果を持たせるようにした例では、演算電力221が第1の閾値を上回った場合に、位相制御前電圧指令114の位相をθ0からθ1に変化させ、位相変化後の電圧指令である電圧指令109と、位相制御中信号115を出力する。なお、演算電力221が第1の閾値以下の場合は、位相θ0の電圧指令をそのまま出力する。次に、演算電力221が、第1の閾値よりも低い値に設定した第2の閾値を下回った場合には、位相制御前電圧指令114の位相θ1をθ0に戻した電圧指令109を出力する。なお、演算電力221が、第1の閾値と第2の閾値の間にある場合は位相θ1を変化させることなく、位相θ1の電圧指令を出力する。このように閾値を2つ設定し、閾値を越えないと位相を変化しないようにすることで、ヒステリシス効果によりノイズなどによる誤動作を防ぐことができる。 The phase controller 106 changes the phase of the voltage command based on the calculated power 221 of the power calculator 219, and outputs the changed voltage command 109 and the phase controlling signal 115. For example, in the example in which the first threshold value and the second threshold value are provided so as to have a hysteresis effect, the phase of the pre-phase control voltage command 114 is changed to θ0 when the calculated power 221 exceeds the first threshold value. The voltage command 109, which is the voltage command after the phase change, and the phase control in-progress signal 115 are output. When the calculated power 221 is equal to or less than the first threshold, the voltage command with the phase θ0 is output as it is. Next, when the calculated power 221 falls below the second threshold set to a value lower than the first threshold, the voltage command 109 is output by returning the phase θ1 of the pre-phase control voltage command 114 to θ0. . When the calculated power 221 is between the first threshold value and the second threshold value, the voltage command of the phase θ1 is output without changing the phase θ1. By setting two thresholds in this way and preventing the phase from changing unless the threshold is exceeded, malfunction due to noise or the like can be prevented by the hysteresis effect.
 他の例として、ヒステリシス効果は無くなるが、第1の閾値と第2の閾値が同じ値、すなわち閾値を1つとして、1つの閾値により位相をθ0とθ1に変化させるようにしてもよい。なお、閾値は、予め内部に設定、もしくは外部から設定するようにしてもよい。また、閾値は、電動機の駆動状況、例えば電圧や電流、周波数などに応じて変化させてもよい。位相の変化量は、検出直流電圧113と第1の閾値との差に応じて変化させてもよい。演算電力221が複数ある場合には、それぞれに閾値を設けてもよい。また、演算電力221の絶対値、もしくは演算電力221の正の値のみ、もしくは演算電力221の負の値の絶対値のみのいずれかと閾値を比較してもよい。 As another example, the hysteresis effect disappears, but the first threshold value and the second threshold value may be the same value, that is, the threshold value may be one, and the phase may be changed to θ0 and θ1 by one threshold value. Note that the threshold value may be set in advance or externally. Further, the threshold value may be changed according to the driving status of the motor, for example, voltage, current, frequency, and the like. The amount of change in phase may be changed according to the difference between the detected DC voltage 113 and the first threshold value. When there are a plurality of calculation powers 221, a threshold value may be provided for each. Further, the threshold value may be compared with either the absolute value of the calculated power 221, only the positive value of the calculated power 221, or only the absolute value of the negative value of the calculated power 221.
 ノルム制御器107は、電力演算器219の演算電力221に基づいて、電圧指令のノルム(電圧)を変化させ、変化させた電圧指令である位相制御前電圧指令114とノルム制御中信号117を出力する。例えば、第3の閾値と第4の閾値を設けて、ヒステリシス効果を持たせるようにした例では、演算電力221が第3の閾値を上回った場合に、ノルム制御前電圧指令116のノルムV0をV1に増加させ、ノルム増加後の電圧指令である位相制御前電圧指令114と、ノルム制御中信号117を出力する。なお、演算電力221が第3の閾値以下の場合は、ノルムV0の電圧指令をそのまま出力する。次に、演算電力221が、第3の閾値よりも低い値に設定した第4の閾値を下回った場合には、ノルム制御前電圧指令116のノルムV1をV0に戻した位相制御前電圧指令114を出力する。なお、演算電力221が、第3の閾値と第4の閾値の間にある場合はノルムV1を変化させることなく、ノルムV1の電圧指令を出力する。このように閾値を2つ設定し、閾値を越えないとノルムを変化しないようにすることで、ヒステリシス効果によりノイズなどによる誤動作を防ぐことができる。 The norm controller 107 changes the norm (voltage) of the voltage command based on the calculated power 221 of the power calculator 219, and outputs the pre-phase control voltage command 114 and the norm controlling signal 117, which are the changed voltage commands. To do. For example, in the example in which the third threshold value and the fourth threshold value are provided so as to have a hysteresis effect, when the calculated power 221 exceeds the third threshold value, the norm V0 of the pre-norm control voltage command 116 is set. V1 is increased to output a pre-phase control voltage command 114, which is a voltage command after the norm increase, and a norm controlling signal 117. When the calculated power 221 is equal to or smaller than the third threshold value, the norm V0 voltage command is output as it is. Next, when the calculated power 221 falls below the fourth threshold value set to a value lower than the third threshold value, the pre-phase control voltage command 114 that returns the norm V1 of the pre-norm control voltage command 116 to V0. Is output. When the calculated power 221 is between the third threshold and the fourth threshold, the norm V1 voltage command is output without changing the norm V1. In this way, by setting two thresholds so that the norm does not change unless the threshold is exceeded, malfunction due to noise or the like can be prevented by the hysteresis effect.
 他の例として、ヒステリシス効果は無くなるが、第3の閾値と第4の閾値が同じ値、すなわち閾値を1つとして、1つの閾値によりノルムをV0とV1に変化させるようにしてもよい。また、閾値は、予め内部に設定、もしくは外部から設定するようにしてもよい。また、閾値は、電動機の駆動状況、例えば電圧や電流、周波数などに応じて変化させてもよい。ノルムの増加量は、演算電力221と第3の閾値との差に応じて変化させてもよい。演算電力221が複数ある場合には、それぞれに閾値を設けてもよい。また、演算電力221の絶対値、もしくは演算電力221の正の値のみ、もしくは演算電力221の負の値の絶対値のみのいずれかと閾値を比較してもよい。なお、ノルム制御器107を取り外し、ノルム制御前電圧指令116を直接位相制御器106に入力してもよい。 As another example, the hysteresis effect is eliminated, but the third threshold value and the fourth threshold value may be the same value, that is, the threshold value may be one, and the norm may be changed to V0 and V1 by one threshold value. The threshold value may be set in advance or externally. Further, the threshold value may be changed according to the driving status of the motor, for example, voltage, current, frequency, and the like. The increase amount of the norm may be changed according to the difference between the calculated power 221 and the third threshold value. When there are a plurality of calculation powers 221, a threshold value may be provided for each. Further, the threshold value may be compared with either the absolute value of the calculated power 221, only the positive value of the calculated power 221, or only the absolute value of the negative value of the calculated power 221. The norm controller 107 may be removed, and the voltage command 116 before norm control may be directly input to the phase controller 106.
 上記したように、本実施例においても、演算電力が閾値を越えた場合、電圧指令の位相を変化させ、電動機に印加する電圧の位相を変化させることで、直流電圧の上昇を抑制する。従って、電動機の加速、一定速、減速といった駆動状況に依存せず、加速率や減速率を自動的に修正することなく直流電圧の抑制が可能である。また、抵抗やインダクタンスなどの電動機の情報を必要としないので、V/f一定制御やベクトル制御といった電動機の駆動制御方法を選ぶことなく適用できる。 As described above, also in this embodiment, when the calculated power exceeds the threshold value, the phase of the voltage command is changed, and the phase of the voltage applied to the motor is changed, thereby suppressing the increase of the DC voltage. Therefore, it is possible to suppress the DC voltage without automatically correcting the acceleration rate or the deceleration rate without depending on the driving conditions such as acceleration, constant speed, and deceleration of the motor. Further, since information on the motor such as resistance and inductance is not required, the present invention can be applied without selecting a motor drive control method such as V / f constant control or vector control.
 電動機が回生状態になると、その程度に依存して直流電圧が上昇するが、直流電圧の上昇に依存して電力も変化する。電力変換装置は直流電圧が所定の閾値を超えると、過電圧の保護を目的として、出力を停止させるが、電力変換装置が出力を停止させる直流電圧に対応した電力よりも低い値に第1の閾値を設定することで、電力変換装置が出力を停止させる前に直流電圧を抑制でき、電動機の駆動を継続することも可能である。さらに、第1の閾値よりも低い値に第3の閾値を設定することにより、位相を変化させる前にノルムを増加させることで、直流電圧の上昇をより抑制することが可能となる。なお、第3の閾値は第1の閾値と同じ値、もしくは大きい値に設定して、ノルムを増加させる前に位相を変化させるようにしても、直流電圧の上昇を抑制できる。 When the motor is in a regenerative state, the DC voltage increases depending on the degree, but the power also changes depending on the increase of the DC voltage. When the DC voltage exceeds a predetermined threshold, the power converter stops output for the purpose of overvoltage protection, but the first threshold is set to a value lower than the power corresponding to the DC voltage at which the power converter stops output. By setting, the DC voltage can be suppressed before the power conversion device stops the output, and it is possible to continue driving the electric motor. Furthermore, by setting the third threshold value to a value lower than the first threshold value, it is possible to further suppress an increase in DC voltage by increasing the norm before changing the phase. Note that even if the third threshold value is set to the same value or a larger value as the first threshold value, and the phase is changed before the norm is increased, an increase in the DC voltage can be suppressed.
 図5に、本発明の実施例3の電力変換装置の一例を示す。実施例3は、実施例2の電力変換装置において、電力演算器219に代えて力率演算器319を設け、演算した力率に基づいて電圧指令の位相を変えるようにしたものである。 FIG. 5 shows an example of the power conversion apparatus according to the third embodiment of the present invention. In the power conversion apparatus according to the second embodiment, a power factor calculator 319 is provided instead of the power calculator 219, and the phase of the voltage command is changed based on the calculated power factor.
 力率演算器319は、ノルム制御前電圧指令116と検出電流220から、力率を演算する。なお、ノルム制御前電圧指令116の代わりに、電圧指令109もしくは位相制御前電圧指令114を用いて、力率を演算してもよい。 The power factor calculator 319 calculates the power factor from the voltage command 116 before norm control and the detected current 220. The power factor may be calculated using the voltage command 109 or the voltage command 114 before phase control instead of the voltage command 116 before norm control.
 力率が閾値を越えた場合の位相制御器106およびノルム制御器107の動作は、実施例2の動作と同様である。 The operation of the phase controller 106 and norm controller 107 when the power factor exceeds the threshold is the same as that of the second embodiment.
 本実施例においても、力率演算器で演算した力率が閾値を越えた場合、電圧指令の位相を変化させ、電動機に印加する電圧の位相を変化させることで、直流電圧の上昇を抑制する。従って、電動機の加速、一定速、減速といった駆動状況に依存せず、加速率や減速率を自動的に修正することなく直流電圧の抑制が可能である。また、抵抗やインダクタンスなどの電動機の情報を必要としないので、V/f一定制御やベクトル制御といった電動機の駆動制御方法を選ぶことなく適用できる。 Also in the present embodiment, when the power factor calculated by the power factor calculator exceeds the threshold, the voltage command phase is changed, and the voltage phase applied to the motor is changed, thereby suppressing the DC voltage increase. . Therefore, it is possible to suppress the DC voltage without automatically correcting the acceleration rate or the deceleration rate without depending on the driving conditions such as acceleration, constant speed, and deceleration of the motor. Further, since information on the motor such as resistance and inductance is not required, the present invention can be applied without selecting a motor drive control method such as V / f constant control or vector control.
 電動機が回生状態になると、その程度に依存して直流電圧が上昇するが、直流電圧の上昇に依存して力率も変化する。電力変換装置は直流電圧が所定の閾値を超えると、過電圧の保護を目的として、出力を停止させるが、電力変換装置が出力を停止させる直流電圧に対応した力率よりも低い値に第1の閾値を設定することで、電力変換装置が出力を停止させる前に直流電圧を抑制でき、電動機の駆動を継続することも可能である。さらに、第1の閾値よりも低い値に第3の閾値を設定することにより、位相を変化させる前にノルムを増加させることで、直流電圧の上昇をより抑制することが可能となる。なお、第3の閾値は第1の閾値と同じ値、もしくは大きい値に設定して、ノルムを増加させる前に位相を変化させるようにしても、直流電圧の上昇を抑制できる。 When the motor is in a regenerative state, the DC voltage increases depending on the degree, but the power factor also changes depending on the increase of the DC voltage. When the DC voltage exceeds a predetermined threshold, the power converter stops the output for the purpose of overvoltage protection, but the power converter has a first value lower than the power factor corresponding to the DC voltage at which the power converter stops the output. By setting the threshold value, the DC voltage can be suppressed before the power converter stops the output, and the driving of the electric motor can be continued. Furthermore, by setting the third threshold value to a value lower than the first threshold value, it is possible to further suppress an increase in DC voltage by increasing the norm before changing the phase. Note that even if the third threshold value is set to the same value or a larger value as the first threshold value, and the phase is changed before the norm is increased, an increase in the DC voltage can be suppressed.
 上記各実施例では三相交流誘導電動機の場合を説明したが、三相交流同期電動機や三相交流発電機、また、単相や三相以外の多相、さらには直流電動機や直流発電機においても、同様に直流電圧の上昇を抑制することが可能である。 In each of the above embodiments, a case of a three-phase AC induction motor has been described. However, in a three-phase AC synchronous motor or a three-phase AC generator, a multiphase other than a single phase or a three-phase, and a DC motor or a DC generator. Similarly, it is possible to suppress an increase in DC voltage.
 なお、本発明は上記した実施例に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施例は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある実施例の構成の一部を他の実施例の構成に置き換えることが可能であり、また、ある実施例の構成に他の実施例の構成を加えることも可能である。また、各実施例の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 In addition, this invention is not limited to the above-mentioned Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.
 また、上記の各構成、機能、処理部、処理手段等は、それらの一部又は全部を、例えば集積回路で設計する等によりハードウェアで実現してもよい。また、上記の各構成、機能等は、プロセッサがそれぞれの機能を実現するプログラムを解釈し、実行することによりソフトウェアで実現してもよい。各機能を実現するプログラム、テーブル、ファイル等の情報は、メモリや、ハードディスク、SSD(Solid State Drive)等の記録装置、または、ICカード、SDカード、DVD等の記録媒体に置くことができる。 In addition, each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files that realize each function can be stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.
 また、制御線や情報線は説明上必要と考えられるものを示しており、製品上必ずしも全ての制御線や情報線を示しているとは限らない。実際には殆ど全ての構成が相互に接続されていると考えてもよい。 Also, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.
100 三相交流誘導電動機
101 電力変換装置
102 整流回路
103 平滑回路
104 電圧検出器
105 電圧変換部
106 位相制御器
107 ノルム制御器
108 三相交流電源
109 電圧指令
110 スイッチング回路制御器
111 スイッチング回路
112 スイッチング回路制御信号
113 検出直流電圧
114 位相制御前電圧指令
115 位相制御中信号
116 ノルム制御前電圧指令
117 ノルム制御中信号
201 電力変換装置
218 電流検出器
219 電力演算器
220 検出電流
221 演算電力
301 電力変換装置
319 力率演算器
321 力率
100 three-phase AC induction motor 101 power converter 102 rectifier circuit 103 smoothing circuit 104 voltage detector 105 voltage converter 106 phase controller 107 norm controller 108 three-phase AC power supply 109 voltage command 110 switching circuit controller 111 switching circuit 112 switching Circuit control signal 113 Detected DC voltage 114 Pre-phase control voltage command 115 Phase control signal 116 Pre-norm control voltage command 117 Norm control signal 201 Power converter 218 Current detector 219 Power calculator 220 Detected current 221 Calculated power 301 Power conversion Device 319 Power factor calculator 321 Power factor

Claims (14)

  1.  直流電圧を電圧指令に基づいた電圧に変換する電圧変換部と、
     前記直流電圧を検出する電圧検出器と、
     前記電圧指令の位相を制御する位相制御器と、を備えた電力変換装置であって、
     前記位相制御器では、前記検出した直流電圧が第1の閾値を上回った場合に、前記電圧指令の位相を変化させることを特徴とする電力変換装置。
    A voltage converter that converts a DC voltage into a voltage based on a voltage command;
    A voltage detector for detecting the DC voltage;
    A phase converter for controlling the phase of the voltage command, and a power converter comprising:
    The phase controller changes the phase of the voltage command when the detected DC voltage exceeds a first threshold value.
  2.  請求項1に記載の電力変換装置であって、
     前記位相制御器では、前記検出した直流電圧が前記第1の閾値よりも低い第2の閾値を下回った場合に、前記電圧指令の位相を変化させる前の位相に戻すことを特徴とする電力変換装置。
    The power conversion device according to claim 1,
    In the phase controller, when the detected DC voltage falls below a second threshold value that is lower than the first threshold value, the phase conversion unit returns the phase to the phase before changing the phase of the voltage command. apparatus.
  3.  直流電圧を電圧指令に基づいた電圧に変換する電圧変換部と、
     前記電圧変換部の出力電流を検出又は推定する電流検出器と、
     前記電圧指令と前記出力電流から電力を演算する電力演算部と、
     前記電圧指令の位相を制御する位相制御器と、を備えた電力変換装置であって、
     前記位相制御器では、演算した前記電力が第1の閾値を上回った場合に前記電圧指令の位相を変化させることを特徴とする電力変換装置。
    A voltage converter that converts a DC voltage into a voltage based on a voltage command;
    A current detector for detecting or estimating the output current of the voltage converter;
    A power calculator that calculates power from the voltage command and the output current;
    A phase converter for controlling the phase of the voltage command, and a power converter comprising:
    The phase controller changes the phase of the voltage command when the calculated power exceeds a first threshold value.
  4.  請求項3に記載の電力変換装置であって、
     前記位相制御器では、前記演算した電力が前記第1の閾値よりも低い第2の閾値を下回った場合に、前記電圧指令の位相を変化させる前の位相に戻すことを特徴とする電力変換装置。
    The power conversion device according to claim 3,
    In the phase controller, when the calculated power falls below a second threshold value that is lower than the first threshold value, the power converter is configured to return to the phase before the phase of the voltage command is changed. .
  5.  直流電圧を電圧指令に基づいた電圧に変換する電圧変換部と、
     前記電圧変換部の出力電流を検出又は推定する電流検出器と、
     前記電圧指令と前記出力電流から力率を演算する力率演算器と、
     前記電圧指令の位相を制御する位相制御器と、を備えた電力変換装置であって、
     前記位相制御器では、前記演算した力率が第1の閾値を上回った場合に、前記電圧指令の位相を変化させることを特徴とする電力変換装置。
    A voltage converter that converts a DC voltage into a voltage based on a voltage command;
    A current detector for detecting or estimating the output current of the voltage converter;
    A power factor calculator that calculates a power factor from the voltage command and the output current;
    A phase converter for controlling the phase of the voltage command, and a power converter comprising:
    The phase controller changes the phase of the voltage command when the calculated power factor exceeds a first threshold value.
  6.  請求項5に記載の電力変換装置であって、
     前記位相制御器では、前記演算した力率が前記第1の閾値よりも低い第2の閾値を下回った場合に、前記電圧指令の位相を変化させる前の位相に戻すことを特徴とする電力変換装置。
    The power conversion device according to claim 5,
    In the phase controller, when the calculated power factor falls below a second threshold value that is lower than the first threshold value, the phase conversion unit returns the phase to the phase before changing the phase of the voltage command. apparatus.
  7.  請求項1または2に記載の電力変換装置であって、
     さらに、前記電圧指令のノルムを制御するノルム制御器を備え、
     前記ノルム制御器では、前記検出した直流電圧が第3の閾値を上回った場合に、前記電圧指令のノルムを増加させることを特徴とする電力変換装置。
    The power converter according to claim 1 or 2,
    Furthermore, a norm controller for controlling the norm of the voltage command is provided,
    The norm controller increases the norm of the voltage command when the detected DC voltage exceeds a third threshold value.
  8.  請求項7に記載の電力変換装置であって、
     前記ノルム制御器では、前記検出した直流電圧が前記第3の閾値よりも低い第4の閾値を下回った場合に、前記電圧指令のノルムを変化させる前のノルムに戻すことを特徴とする電力変換装置。
    The power conversion device according to claim 7,
    In the norm controller, when the detected DC voltage falls below a fourth threshold value that is lower than the third threshold value, the norm of the voltage command is returned to the norm before changing the norm. apparatus.
  9.  請求項3または4に記載の電力変換装置であって、
     さらに、前記電圧指令のノルムを制御するノルム制御器を備え、
     前記ノルム制御器では、前記演算した電力が第3の閾値を上回った場合に、前記電圧指令のノルムを増加させることを特徴とする電力変換装置。
    The power conversion device according to claim 3 or 4,
    Furthermore, a norm controller for controlling the norm of the voltage command is provided,
    The norm controller increases the norm of the voltage command when the calculated power exceeds a third threshold value.
  10.  請求項9に記載の電力変換装置であって、
     前記ノルム制御器では、前記演算した電力が前記第3の閾値よりも低い第4の閾値を下回った場合に、前記電圧指令のノルムを変化させる前のノルムに戻すことを特徴とする電力変換装置。
    The power conversion device according to claim 9,
    In the norm controller, when the calculated power falls below a fourth threshold lower than the third threshold, the norm of the voltage command is returned to the norm before changing the norm of the voltage command. .
  11.  請求項5または6に記載の電力変換装置であって、
     さらに、前記電圧指令のノルムを制御するノルム制御器を備え、
     前記ノルム制御器では、前記演算した力率が第3の閾値を上回った場合に、前記電圧指令のノルムを増加させることを特徴とする電力変換装置。
    The power conversion device according to claim 5 or 6,
    Furthermore, a norm controller for controlling the norm of the voltage command is provided,
    The norm controller increases the norm of the voltage command when the calculated power factor exceeds a third threshold value.
  12.  請求項11に記載の電力変換装置であって、
     前記ノルム制御器では、前記演算した力率が前記第3の閾値よりも低い第4の閾値を下回った場合に、前記電圧指令のノルムを変化させる前のノルムに戻すことを特徴とする電力変換装置。
    The power conversion device according to claim 11,
    In the norm controller, when the calculated power factor falls below a fourth threshold value lower than the third threshold value, the norm of the voltage command is returned to a norm before changing the norm of the voltage command. apparatus.
  13.  請求項1乃至12の何れか1項に記載の電力変換装置であって、
     前記位相制御器では、前記電圧指令の位相を変化させた際に位相制御中信号を出力することを特徴とする電力変換装置。
    The power conversion device according to any one of claims 1 to 12,
    The phase controller outputs a signal during phase control when the phase of the voltage command is changed.
  14.  請求項7乃至12の何れか1項に記載の電力変換装置であって、
     前記ノルム制御器では、前記電圧指令のノルムを増加させた際にノルム制御中信号を出力することを特徴とする電力変換装置。
    The power conversion device according to any one of claims 7 to 12,
    The norm controller outputs a signal during norm control when the norm of the voltage command is increased.
PCT/JP2017/000176 2017-01-05 2017-01-05 Power conversion device WO2018127960A1 (en)

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JP2013039026A (en) * 2011-07-29 2013-02-21 General Electric Co <Ge> Power conversion system with transient event ride-through capability and method thereof
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JP2013039026A (en) * 2011-07-29 2013-02-21 General Electric Co <Ge> Power conversion system with transient event ride-through capability and method thereof
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