WO2021200209A1 - Motor control device, motor system, and motor control method - Google Patents

Motor control device, motor system, and motor control method Download PDF

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WO2021200209A1
WO2021200209A1 PCT/JP2021/011058 JP2021011058W WO2021200209A1 WO 2021200209 A1 WO2021200209 A1 WO 2021200209A1 JP 2021011058 W JP2021011058 W JP 2021011058W WO 2021200209 A1 WO2021200209 A1 WO 2021200209A1
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phase
current
rotor
motor
pwm signal
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French (fr)
Japanese (ja)
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隆志 大場
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ミネベアミツミ株式会社
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/22—Current control, e.g. using a current control loop
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
    • H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
    • H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
    • H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/14—Electronic commutators
    • H02P6/15—Controlling commutation time
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/28—Arrangements for controlling current

Definitions

  • the PWM signal V is a PWM signal for driving two switching elements constituting the upper and lower arms of the V phase.
  • the switching element of the lower arm of the V phase is on (the switching element of the upper arm of the V phase is off), and when the PWM signal V is at a high level, it is below the V phase.
  • the switching element of the arm is turned off (the switching element of the upper arm of the V phase is turned on).
  • the two switching elements constituting the upper and lower arms of the V phase complementarily operate on and off in response to a change in the level of the PWM signal V.
  • the illustration of the dead time for preventing a short circuit between the upper and lower arms is omitted.
  • the upper arm of the phase corresponding to the PWM signal when the PWM signal is at a high level, the upper arm of the phase corresponding to the PWM signal is defined as on, and when the PWM signal is at a low level, the lower arm of the phase corresponding to the PWM signal is defined as on.
  • the relationship between the logic level of the PWM signal and the on / off of each arm may be defined in the opposite manner in consideration of the circuit configuration and the like.
  • Each one cycle Tpwm of the plurality of PWM signals U, V, W corresponds to the cycle of the carrier C (the reciprocal of the carrier frequency).
  • the change points (t1 to t6) represent the timing at which the logic level of the PWM signal changes.
  • the voltage value of the voltage generated at both ends of the current detector 24 at the energization time T22 is the current value of the negative W-phase current “ ⁇ Iw” flowing from the W-phase terminal of the motor 4.
  • the energizing time T22 is a time from t5 to t6.
  • the energizing time T22 corresponds to a period in which the lower arm Un, Vn and the upper arm Wp are on and the remaining three arms are off.
  • the phase current of each phase cannot be detected unless an energization section (energization time) is provided.
  • an energization section energization time
  • only one phase current can be detected in one energization time. Therefore, at least two energization times are provided during one cycle of the PWM signal (see FIG. 2), and the equation (iu + iv + iv) is provided.
  • an energizing time is provided to distinguish and detect the phase currents of each phase, the current flowing through the current detector 24 is amplified, so that the current detecting unit 27 has zero current flowing through the current detector 24. Sometimes it is not possible to measure the detection error included in the detected value of the phase current of each phase.
  • FIG. 11 is a diagram showing a first example of the waveform of the PWM signal when detecting the current value of the current flowing through the current detector before the inverter rotates the rotor.
  • the inverter 23 energizes the motor 4 having a rotor by turning on some of all the arms that are different for each energization pattern.
  • the PWM signal generation unit 32 has a first period in which all the arms are turned off during the idling of the rotor, a second period in which some arms are turned on in the first energization pattern during the idling of the rotor, and some arms are idling in the rotor.
  • a PWM signal of each phase including a third period to be turned on by the second energization pattern is generated in one cycle. As a result, the switching state of each arm as shown in FIG. 11 can be obtained.
  • the first reference current flowing through the current detector 24 in the second period and the second reference current flowing through the current detector 24 in the third period Can be treated as a two-phase reference current such as the offset current described above.
  • the current detection unit 27 detects the current at least twice in the same energization pattern as in FIG. 11 for each cycle of the PWM signal, so that each of the three-phase phase currents Detect the current value.
  • the current detection unit 27 subtracts the three-phase reference current value stored in advance in the memory from each of the three-phase phase currents detected in each cycle of the PWM signal for each cycle of the PWM signal. Therefore, the current detection values of the three-phase phase currents Iu, Iv, and Iw are calculated. As a result, the current detection unit 27 corrects the phase current of each phase flowing through the current detector 24 when the inverter 23 is rotating the rotor, according to the reference current of each phase.
  • FIG. 13 is a diagram showing a second example of the waveform of the PWM signal when detecting the current value of the current flowing through the current detector 24 before the inverter rotates the rotor.
  • the inverter 23 energizes the motor 4 having a rotor by turning on some of all the arms that are different for each energization pattern.
  • the PWM signal generation unit 32 includes a first section in which some arms are turned on in the first energization pattern while the rotor is idling, and a second section in which some arms are turned on in the second energization pattern while the rotor is idling.
  • the first period section includes a first section Q1 including the timing of the first detection, a second section Q2 including the timing of the second detection, and a third section Q3 in which all the upper arms are turned on.
  • the current detector 27 is half the sum of the first current value of the first phase flowing through the current detector 24 in the first section Q1 and the second current value of the first phase flowing through the current detector 24 in the second section Q2. Is subtracted from the first current value or the second current value. In this example, the current detection unit 27 calculates the offset current value of the first phase by subtracting it from the second current value.
  • FIG. 18 illustrates the case where the first phase is the U phase.
  • FIG. 19 illustrates a case where the PWM signal generation unit 32 generates PWM signals of each phase having a second period section at a duty ratio of 50%.
  • the PWM signal generation unit 32 has a fourth section Q4 in which some arms are turned on in the fourth energization pattern while the rotor is idling, and a fifth section Q5 in which some arms are turned on in the fifth energization pattern while the rotor is idling.
  • FIG. 19 illustrates a case where the PWM signal generation unit 32 generates PWM signals of each phase having a second period section at a duty ratio of 50%.
  • the PWM signal generation unit 32 has a fourth section Q4 in which some arms are turned on in the fourth energization pattern while the rotor is idling, and
  • the second period section includes a fourth section Q4 including the timing of the first detection, a fifth section Q5 including the timing of the second detection, and a sixth section Q6 in which all the upper arms are turned on.
  • the current detector 27 is half the sum of the third current value of the second phase flowing through the current detector 24 in the fourth section Q4 and the fourth current value of the second phase flowing through the current detector 24 in the fifth section Q5. Is subtracted from the third current value or the fourth current value.
  • the current detection unit 27 calculates the offset current value of the second phase by subtracting it from the fourth current value.
  • FIG. 19 illustrates a case where the second phase is the W phase.
  • the second cycle section may be a section adjacent to the first cycle section, a section having one or more cycle sections sandwiched between the first cycle section, or the same section as the first cycle section. good.
  • the current detection unit 27 may correct the current value of the phase current of the first phase flowing through the current detector 24 when the inverter 23 is rotating the rotor according to the offset current value of the first phase. .. Similarly, the current detection unit 27 may correct the current value of the phase current of the second phase flowing through the current detector 24 when the inverter 23 is rotating the rotor according to the offset current value of the second phase. good.
  • the first phase is the U phase and the second phase is the W phase, but other combinations may be used.
  • the functions of the current detection unit 27, the energization pattern generation unit 35, the current detection timing adjustment unit 34, and the initial position estimation unit 38 are CPU (Central Processing Unit) by a program readable and stored in a storage device (not shown). Is realized by the operation of. For example, each of these functions is realized by the collaboration of hardware and software in a microcomputer including a CPU.
  • CPU Central Processing Unit

Abstract

A motor control method carried out by a motor control device, in which a portion of all of the arms of an inverter, said portion differing for each energization pattern, is turned on, thereby energizing a motor having a rotor, wherein there is generated a PWM signal for each phase including, in a single cycle, a first period in which all of the arms are turned off while the rotor is racing, a second period in which the portion of the arms is turned on with a first energization pattern while the rotor is racing, and a third period in which the portion of the arms is turned on with a second energization pattern while the rotor is racing, and a first reference current flowing in a current detector during the second period and a second reference current flowing in the current detector during the third period are detected.

Description

モータ制御装置、モータシステム及びモータ制御方法Motor control device, motor system and motor control method
　本開示は、モータ制御装置、モータシステム及びモータ制御方法に関する。 The present disclosure relates to a motor control device, a motor system, and a motor control method.
　従来、インバータ回路の直流母線に接続される１つのシャント抵抗を用いて、モータを制御するための各相の相電流を検出する１シャント電流検出方式が知られている（例えば、特許文献１参照）。 Conventionally, a one-shunt current detection method for detecting the phase current of each phase for controlling a motor by using one shunt resistor connected to the DC bus of an inverter circuit is known (see, for example, Patent Document 1). ).
特開２０１５－２０８０７１号公報Japanese Unexamined Patent Publication No. 2015-208071
　１シャント電流検出方式でモータを制御する場合、インバータがロータを回転させる前（モータの起動前）に１シャントの電流検出器に流れる電流を検出する場合がある。モータの起動前に検出される電流は、例えば、モータの起動前の故障検出に利用されたり、モータがインバータにより起動しインバータがロータを回転させている時の電流検出や故障検出の精度向上に利用されたりする。 When the motor is controlled by the 1-shunt current detection method, the current flowing through the 1-shunt current detector may be detected before the inverter rotates the rotor (before the motor starts). The current detected before the motor starts is used, for example, for failure detection before the motor starts, or for improving the accuracy of current detection and failure detection when the motor is started by the inverter and the inverter is rotating the rotor. It is used.
　しかしながら、インバータがロータを回転させる前にロータが空転しているときに、１シャントの電流検出器に流れる電流を検出すると、空転中のロータに発生する回生ブレーキによってロータの回転が阻害されることがある。空転中のロータの回転が阻害されると、例えば、モータの減速や異音などの意図しない挙動が発生するおそれがある。 However, if the current flowing through the current detector of one shunt is detected when the rotor is idling before the inverter rotates the rotor, the regenerative brake generated in the idling rotor hinders the rotation of the rotor. There is. If the rotation of the rotor during idling is hindered, unintended behavior such as deceleration of the motor or abnormal noise may occur.
　本開示は、電流検出器に流れる電流を検出することによりロータの空転が阻害されることを軽減可能なモータ制御装置、モータシステム及びモータ制御方法を提供する。 The present disclosure provides a motor control device, a motor system, and a motor control method capable of reducing the hindrance of idling of the rotor by detecting the current flowing through the current detector.
　本開示の一実施の形態に係るモータ制御装置は、
　全アームのうち通電パターン毎に異なる一部のアームをオンすることで、ロータを有するモータを通電させるインバータと、
　前記インバータの直流側に接続される電流検出器と、
　前記全アームを前記ロータの空転中にオフさせる第１期間と前記一部のアームを前記空転中に第１通電パターンでオンさせる第２期間と前記一部のアームを前記空転中に第２通電パターンでオンさせる第３期間とを１周期に含む各相のＰＷＭ信号を生成するＰＷＭ信号生成部と、
　前記第２期間に前記電流検出器に流れる第１基準電流と前記第３期間に前記電流検出器に流れる第２基準電流とを検出する電流検出部と、を備える。 The motor control device according to the embodiment of the present disclosure is
An inverter that energizes a motor with a rotor by turning on some of the arms that are different for each energization pattern,
A current detector connected to the DC side of the inverter and
The first period in which all the arms are turned off during the idling of the rotor, the second period in which some of the arms are turned on in the first energization pattern during the idling, and the second energization of the part of the arms during the idling. A PWM signal generator that generates a PWM signal for each phase that includes a third period that is turned on in a pattern in one cycle.
A current detection unit for detecting a first reference current flowing through the current detector in the second period and a second reference current flowing through the current detector in the third period is provided.
　本開示によれば、電流検出器に流れる電流を検出することによりロータの空転が阻害されることを軽減できる。 According to the present disclosure, it is possible to reduce the hindrance of idling of the rotor by detecting the current flowing through the current detector.
本開示の実施の形態１に係るモータシステムの構成例を示す図である。It is a figure which shows the structural example of the motor system which concerns on Embodiment 1 of this disclosure. 複数のＰＷＭ信号の波形と、これらのＰＷＭ信号の一周期当たりのキャリアの波形と、各相の相電圧指令の波形とを例示する図である。It is a figure which illustrates the waveform of a plurality of PWM signals, the waveform of a carrier per one cycle of these PWM signals, and the waveform of the phase voltage command of each phase. 通電時の各アームのスイッチング状態の一例を示す図である。It is a figure which shows an example of the switching state of each arm at the time of energization. 非通電時の各アームのスイッチング状態の一例を示す図である。It is a figure which shows an example of the switching state of each arm at the time of de-energization. いずれもデューティ比が５０％の各相のＰＷＭ信号に従ってインバータの全アームのうち一部のアームをオンさせることで電流検出器に流れる各相のオフセット電流を例示するタイミングチャートである。Each is a timing chart illustrating the offset current of each phase flowing through the current detector by turning on a part of all the arms of the inverter according to the PWM signal of each phase having a duty ratio of 50%. いずれかのデューティ比が５０％とは異なる各相のＰＷＭ信号に従ってインバータがロータを回転させている時に図５と同じ一部のアームをオンさせることで電流検出器に流れる各相の相電流を例示するタイミングチャートである。When the inverter is rotating the rotor according to the PWM signal of each phase whose duty ratio is different from 50%, by turning on some of the same arms as in FIG. 5, the phase current of each phase flowing through the current detector is changed. It is an example timing chart. インバータがロータを回転させる前に電流検出器に流れる電流の電流値を検出するときのＰＷＭ信号の波形の一比較例を示す図である。It is a figure which shows a comparative example of the waveform of the PWM signal at the time of detecting the current value of the current flowing through the current detector before the inverter rotates a rotor. 非通電区間で下アームが全てオン状態の場合を示す図である。It is a figure which shows the case where all the lower arms are turned on in a non-energized section. 非通電区間で上アームが全てオン状態の場合を示す図である。It is a figure which shows the case where all the upper arms are turned on in a non-energized section. 非通電区間で上下アームが全てオフ状態の場合を示す図である。It is a figure which shows the case where all the upper and lower arms are off state in a non-energized section. インバータがロータを回転させる前に電流検出器に流れる電流の電流値を検出するときのＰＷＭ信号の波形の第１例を示す図である。It is a figure which shows the 1st example of the waveform of the PWM signal at the time of detecting the current value of the current flowing through the current detector before the inverter rotates a rotor. いずれもデューティ比が５０％の各相のＰＷＭ信号に従ってインバータの全アームのうち一部のアームをオンさせることで電流検出器に流れるＵ相電流の電流波形の一例を示す拡大図である。Each is an enlarged view showing an example of the current waveform of the U-phase current flowing through the current detector by turning on a part of all the arms of the inverter according to the PWM signal of each phase having a duty ratio of 50%. インバータがロータを回転させる前に電流検出器に流れる電流の電流値を検出するときのＰＷＭ信号の波形の第２例を示す図である。It is a figure which shows the 2nd example of the waveform of the PWM signal at the time of detecting the current value of the current flowing through the current detector before the inverter rotates a rotor. 負のＵ相電流“－Ｉｕ”が電流検出器に流れるスイッチング状態を示す図である。It is a figure which shows the switching state in which a negative U-phase current "-Iu" flows through a current detector. 正のＵ相電流“＋Ｉｕ”が電流検出器に流れるスイッチング状態を示す図である。It is a figure which shows the switching state in which a positive U-phase current "+ Iu" flows through a current detector. ロータの空転時のＰＷＭ信号の１０周期におけるＵ相オフセット電流値を演算する処理の一例を示す波形図である。It is a waveform diagram which shows an example of the process of calculating the U-phase offset current value in 10 cycles of the PWM signal at the time of idling of a rotor. 図１６に示す点線枠で囲まれた部分の拡大図である。It is an enlarged view of the part surrounded by the dotted line frame shown in FIG. Ｕ相オフセット電流値を演算する処理の一例を示す波形図である。It is a waveform diagram which shows an example of the process of calculating the U-phase offset current value. Ｗ相オフセット電流値を演算する処理の一例を示す波形図である。It is a waveform diagram which shows an example of the process of calculating the W phase offset current value.
　以下、図面を参照して、本開示の実施の形態に係るモータ制御装置、モータシステム及びモータ制御方法について詳細に説明する。 Hereinafter, the motor control device, the motor system, and the motor control method according to the embodiment of the present disclosure will be described in detail with reference to the drawings.
　図１は、本開示の実施の形態１に係るモータシステム１－１の構成例を示す図である。図１に示されるモータシステム１－１は、モータ４の回転動作を制御する。モータシステム１－１が搭載される機器は、例えば、コピー機、パーソナルコンピュータ、冷蔵庫、ポンプ等であるが、当該機器は、これらに限られない。モータシステム１－１は、モータ４と、モータ制御装置１００－１とを少なくとも備える。 FIG. 1 is a diagram showing a configuration example of the motor system 1-1 according to the first embodiment of the present disclosure. The motor system 1-1 shown in FIG. 1 controls the rotational operation of the motor 4. The equipment on which the motor system 1-1 is mounted is, for example, a copier, a personal computer, a refrigerator, a pump, and the like, but the equipment is not limited thereto. The motor system 1-1 includes at least a motor 4 and a motor control device 100-1.
　モータ４は、複数のコイルを有する永久磁石同期モータである。モータ４は、例えば、Ｕ相コイルとＶ相コイルとＷ相コイルとを含む３相コイルを有する。モータ４の具体例として、３相のブラシレス直流モータなどが挙げられる。モータ４は、少なくとも一つの永久磁石が配置されるロータと、そのロータの軸回りに配置されるステータとを有する。モータ４は、ロータの磁石の角度位置（磁極位置）を検出する位置センサを使用しないセンサレス型のモータである。モータ４は、例えば、送風用のファンを回すファンモータである。 Motor 4 is a permanent magnet synchronous motor having a plurality of coils. The motor 4 has, for example, a three-phase coil including a U-phase coil, a V-phase coil, and a W-phase coil. Specific examples of the motor 4 include a three-phase brushless DC motor. The motor 4 has a rotor in which at least one permanent magnet is arranged and a stator arranged around the axis of the rotor. The motor 4 is a sensorless type motor that does not use a position sensor that detects the angular position (pole position) of the magnet of the rotor. The motor 4 is, for example, a fan motor that rotates a fan for blowing air.
　モータ制御装置１００－１は、３相ブリッジ接続された複数のスイッチング素子を３相のＰＷＭ信号を含む通電パターンに従いオンオフ（ＯＮ、ＯＦＦ）制御することで、直流を３相交流に変換するインバータを介してモータを駆動する。モータ制御装置１００－１は、インバータ２３、電流検出部２７、電流検出タイミング調整部３４、駆動回路３３、通電パターン生成部３５、キャリア発生部３７、及びクロック発生部３６を備える。 The motor control device 100-1 controls an inverter that converts direct current into three-phase alternating current by controlling on / off (ON / OFF) of a plurality of switching elements connected by a three-phase bridge according to an energization pattern including a three-phase PWM signal. Drive the motor through. The motor control device 100-1 includes an inverter 23, a current detection unit 27, a current detection timing adjustment unit 34, a drive circuit 33, an energization pattern generation unit 35, a carrier generation unit 37, and a clock generation unit 36.
　インバータ２３は、直流電源２１から供給される直流を複数のスイッチング素子のスイッチングによって３相交流に変換し、３相交流の駆動電流をモータ４に流すことによって、モータ４のロータを回転させる回路である。インバータ２３は、通電パターン生成部３５によって生成される複数の通電パターン（より具体的には、通電パターン生成部３５内のＰＷＭ信号生成部３２によって生成される３相のＰＷＭ信号）に基づいて、モータ４を駆動する。ＰＷＭとは、Pulse Width Modulation（パルス幅変調）を意味する。 The inverter 23 is a circuit that rotates the rotor of the motor 4 by converting the direct current supplied from the DC power supply 21 into a three-phase alternating current by switching a plurality of switching elements and passing a driving current of the three-phase alternating current through the motor 4. be. The inverter 23 is based on a plurality of energization patterns generated by the energization pattern generation unit 35 (more specifically, a three-phase PWM signal generated by the PWM signal generation unit 32 in the energization pattern generation unit 35). Drives the motor 4. PWM means Pulse Width Modulation.
　インバータ２３は、３相ブリッジ接続された複数のアームＵｐ，Ｖｐ，Ｗｐ，Ｕｎ，Ｖｎ，Ｗｎを有する。上アームＵｐ，Ｖｐ，Ｗｐは、それぞれ、直流電源２１の正極側に正側母線２２ａを介して接続されるハイサイドスイッチング素子である。下アームＵｎ，Ｖｎ，Ｗｎは、それぞれ、直流電源２１の負極側（具体的には、グランド側）に接続されるローサイドスイッチング素子である。複数のアームＵｐ，Ｖｐ，Ｗｐ，Ｕｎ，Ｖｎ，Ｗｎは、それぞれ、上述の通電パターンに含まれるＰＷＭ信号に基づいて駆動回路３３から供給される複数の駆動信号のうち、対応する駆動信号に従って、オン又はオフとなる。以下では、複数のアームＵｐ，Ｖｐ，Ｗｐ，Ｕｎ，Ｖｎ，Ｗｎを、特に区別しない場合には、単にアームと称する場合がある。 The inverter 23 has a plurality of arms Up, Vp, Wp, Un, Vn, Wn connected by a three-phase bridge. The upper arms Up, Vp, and Wp are high-side switching elements connected to the positive electrode side of the DC power supply 21 via the positive bus 22a, respectively. The lower arms Un, Vn, and Wn are low-side switching elements connected to the negative electrode side (specifically, the ground side) of the DC power supply 21, respectively. The plurality of arms Up, Vp, Wp, Un, Vn, and Wn each follow the corresponding drive signal among the plurality of drive signals supplied from the drive circuit 33 based on the PWM signal included in the above-mentioned energization pattern. Turns on or off. In the following, a plurality of arms Up, Vp, Wp, Un, Vn, and Wn may be simply referred to as arms unless otherwise specified.
　Ｕ相上アームＵｐとＵ相下アームＵｎとの接続点は、モータ４のＵ相コイルの一端に接続される。Ｖ相上アームＶｐとＶ相下アームＶｎとの接続点は、モータ４のＶ相コイルの一端に接続される。Ｗ相上アームＷｐとＷ相下アームＷｎとの接続点は、モータ４のＷ相コイルの一端に接続される。Ｕ相コイルとＶ相コイルとＷ相コイルとのそれぞれの他端は、互いに接続されている。 The connection point between the U-phase upper arm Up and the U-phase lower arm Un is connected to one end of the U-phase coil of the motor 4. The connection point between the V-phase upper arm Vp and the V-phase lower arm Vn is connected to one end of the V-phase coil of the motor 4. The connection point between the W-phase upper arm Wp and the W-phase lower arm Wn is connected to one end of the W-phase coil of the motor 4. The other ends of the U-phase coil, the V-phase coil, and the W-phase coil are connected to each other.
　アームの具体例として、Ｎチャネル型のＭＯＳＦＥＴ（Metal Oxide Semiconductor Field Effect Transistor）やＩＧＢＴ（Insulated Gate Bipolar Transistor）などが挙げられる。しかしながら、アームは、これらに限られない。 Specific examples of the arm include an N-channel MOSFET (Metal Oxide Semiconductor Field Effect Transistor) and an IGBT (Insulated Gate Bipolar Transistor). However, the arm is not limited to these.
　電流検出器２４は、インバータ２３の直流側に接続され、インバータ２３の直流側に流れる電流の電流値に対応する検出信号Ｓｄを出力する。図１に示される電流検出器２４は、負側母線２２ｂに流れる電流の電流値に対応する検出信号Ｓｄを発生させる。電流検出器２４は、例えば、負側母線２２ｂに配置される電流検出素子であり、より具体的には、負側母線２２ｂに挿入されるシャント抵抗である。シャント抵抗等の電流検出素子は、自身に流れる電流の電流値に対応する電圧信号を検出信号Ｓｄとして発生する。 The current detector 24 is connected to the DC side of the inverter 23 and outputs a detection signal Sd corresponding to the current value of the current flowing on the DC side of the inverter 23. The current detector 24 shown in FIG. 1 generates a detection signal Sd corresponding to the current value of the current flowing through the negative bus 22b. The current detector 24 is, for example, a current detection element arranged on the negative bus 22b, and more specifically, a shunt resistor inserted in the negative bus 22b. A current detection element such as a shunt resistor generates a voltage signal corresponding to the current value of the current flowing through it as a detection signal Sd.
　電流検出部２７は、通電パターン生成部３５によって生成される複数の通電パターン（より具体的には、３相のＰＷＭ信号）に基づいて、検出信号Ｓｄを取得することによって、モータ４に流れるＵ，Ｖ，Ｗ各相の相電流Ｉｕ，Ｉｖ，Ｉｗを検出する。より詳細には、電流検出部２７は、複数の通電パターン（より具体的には、３相のＰＷＭ信号）に同期する取得タイミングで検出信号Ｓｄを取得することによって、モータ４に流れるＵ，Ｖ，Ｗ各相の相電流Ｉｕ，Ｉｖ，Ｉｗを検出する。検出信号Ｓｄの取得タイミングは、電流検出タイミング調整部３４により設定される。 The current detection unit 27 acquires the detection signal Sd based on a plurality of energization patterns (more specifically, three-phase PWM signals) generated by the energization pattern generation unit 35, so that the U flows through the motor 4. , V, W Phase currents Iu, Iv, Iw of each phase are detected. More specifically, the current detection unit 27 acquires the detection signal Sd at the acquisition timing synchronized with the plurality of energization patterns (more specifically, the three-phase PWM signals), so that the U, V flowing through the motor 4 , W The phase currents Iu, Iv, and Iw of each phase are detected. The acquisition timing of the detection signal Sd is set by the current detection timing adjusting unit 34.
　例えば、電流検出部２７は、電流検出器２４で発生するアナログ電圧の検出信号Ｓｄを、電流検出タイミング調整部３４により設定される取得タイミングでＡＤ（Analog to Digital）変換器に取り込む。当該ＡＤ変換器は、電流検出部２７に設けられている。そして、電流検出部２７は、取り込んだアナログの検出信号Ｓｄをデジタルの検出信号ＳｄにＡＤ変換し、ＡＤ変換後のデジタルの検出信号Ｓｄをデジタル処理することによって、モータ４のＵ，Ｖ，Ｗ各相の相電流Ｉｕ，Ｉｖ，Ｉｗを検出する。電流検出部２７により検出された各相の相電流Ｉｕ，Ｉｖ，Ｉｗの検出値は、通電パターン生成部３５に供給される。 For example, the current detection unit 27 captures the analog voltage detection signal Sd generated by the current detector 24 into the AD (Analog to Digital) converter at the acquisition timing set by the current detection timing adjustment unit 34. The AD converter is provided in the current detection unit 27. Then, the current detection unit 27 AD-converts the captured analog detection signal Sd into a digital detection signal Sd, and digitally processes the digital detection signal Sd after the AD conversion, thereby U, V, W of the motor 4. The phase currents Iu, Iv, and Iw of each phase are detected. The detected values of the phase currents Iu, Iv, and Iw of each phase detected by the current detection unit 27 are supplied to the energization pattern generation unit 35.
　クロック発生部３６は、内蔵する発振回路により所定周波数のクロックを生成し、生成したクロックをキャリア発生部３７へ出力する回路である。なお、クロック発生部３６は、例えば、モータ制御装置１００－１の電源が投入されると同時に、動作を開始する。 The clock generation unit 36 is a circuit that generates a clock having a predetermined frequency by a built-in oscillation circuit and outputs the generated clock to the carrier generation unit 37. The clock generation unit 36 starts operation at the same time when the power of the motor control device 100-1 is turned on, for example.
　キャリア発生部３７は、クロック発生部３６により生成されるクロックに基づいて、キャリアＣを生成する。キャリアＣは、レベルが周期的に増減する搬送波信号である。 The carrier generation unit 37 generates the carrier C based on the clock generated by the clock generation unit 36. Carrier C is a carrier signal whose level increases and decreases periodically.
　通電パターン生成部３５は、インバータ２３を通電させるパターン（インバータ２３の通電パターン）を生成する。インバータ２３の通電パターンは、モータ４を通電させるパターン（モータ４の通電パターン）と言い換えてもよい。インバータ２３の通電パターンには、インバータ２３を通電させる３相のＰＷＭ信号が含まれる。通電パターン生成部３５は、電流検出部２７により検出されるモータ４の相電流Ｉｕ，Ｉｖ，Ｉｗの検出値に基づいて、モータ４が回転するようにインバータ２３を通電させる３相のＰＷＭ信号を生成するＰＷＭ信号生成部３２を有する。 The energization pattern generation unit 35 generates a pattern for energizing the inverter 23 (the energization pattern of the inverter 23). The energization pattern of the inverter 23 may be rephrased as a pattern for energizing the motor 4 (energization pattern of the motor 4). The energization pattern of the inverter 23 includes a three-phase PWM signal for energizing the inverter 23. The energization pattern generation unit 35 generates a three-phase PWM signal for energizing the inverter 23 so that the motor 4 rotates based on the detected values of the phase currents Iu, Iv, and Iw of the motor 4 detected by the current detection unit 27. It has a PWM signal generation unit 32 to generate.
　通電パターン生成部３５は、インバータ２３の通電パターンをベクトル制御により生成する場合、ベクトル制御部３０を更に有する。なお、本実施の形態においてはベクトル制御によってインバータの通電パターンを生成しているが、これに限らず、ｖｆ制御等を用いて各相の相電圧を求めてもよい。 The energization pattern generation unit 35 further includes a vector control unit 30 when the energization pattern of the inverter 23 is generated by vector control. In the present embodiment, the energization pattern of the inverter is generated by vector control, but the present invention is not limited to this, and the phase voltage of each phase may be obtained by using vf control or the like.
　ベクトル制御部３０は、外部からモータ４の回転速度指令ωｒｅｆが与えられると、モータ４の回転速度の測定値又は推定値と、回転速度指令ωｒｅｆとの差分に基づいて、トルク電流指令Ｉｑｒｅｆと励磁電流指令Ｉｄｒｅｆを生成する。ベクトル制御部３０は、モータ４のＵ，Ｖ，Ｗ各相の相電流Ｉｕ，Ｉｖ，Ｉｗに基づいて、ロータ位置θを用いたベクトル制御演算により、トルク電流Ｉｑ及び励磁電流Ｉｄを算出する。ベクトル制御部３０は、トルク電流指令Ｉｑｒｅｆとトルク電流Ｉｑとの差分に対して例えばＰＩ制御演算を行い、電圧指令Ｖｑを生成する。ベクトル制御部３０は、励磁電流指令Ｉｄｒｅｆと励磁電流Ｉｄとの差分に対して例えばＰＩ制御演算を行い、電圧指令Ｖｄを生成する。ベクトル制御部３０は、電圧指令Ｖｑ，Ｖｄを上記のロータ位置θを用いてＵ，Ｖ，Ｗ各相の相電圧指令Ｖｕ*，Ｖｖ*，Ｖｗ*に変換する。ロータ位置θは、モータ４のロータの磁極位置を表す。 When the rotation speed command ωref of the motor 4 is given from the outside, the vector control unit 30 excites the torque current command Iqref and the excitation based on the difference between the measured value or the estimated value of the rotation speed of the motor 4 and the rotation speed command ωref. Generates the current command Idref. The vector control unit 30 calculates the torque current Iq and the exciting current Id by the vector control calculation using the rotor position θ based on the phase currents Iu, Iv, and Iw of the U, V, and W phases of the motor 4. The vector control unit 30 performs, for example, a PI control calculation on the difference between the torque current command Iqref and the torque current Iq, and generates the voltage command Vq. The vector control unit 30 performs, for example, a PI control calculation on the difference between the exciting current command Idref and the exciting current Id, and generates the voltage command Vd. The vector control unit 30 converts the voltage commands Vq and Vd into phase voltage commands Vu *, Vv * and Vw * for each of the U, V and W phases using the rotor position θ. The rotor position θ represents the magnetic pole position of the rotor of the motor 4.
　ＰＷＭ信号生成部３２は、ベクトル制御部３０により生成される相電圧指令Ｖｕ*，Ｖｖ*，Ｖｗ*を、キャリア発生部３７により生成されるキャリアＣのレベルと比較することによって、３相のＰＷＭ信号を含む通電パターンを生成する。ＰＷＭ信号生成部３２は、上アーム駆動用の３相のＰＷＭ信号を反転させた下アーム駆動用のＰＷＭ信号も生成し、必要に応じてデッドタイムを付加した後、生成したＰＷＭ信号を含む通電パターンを駆動回路３３に出力する。 The PWM signal generation unit 32 compares the phase voltage commands Vu *, Vv *, Vw * generated by the vector control unit 30 with the level of the carrier C generated by the carrier generation unit 37, thereby performing a three-phase PWM. Generate an energization pattern that includes a signal. The PWM signal generation unit 32 also generates a PWM signal for driving the lower arm by inverting the PWM signal of the three phases for driving the upper arm, adds a dead time as necessary, and then energizes the generated PWM signal. The pattern is output to the drive circuit 33.
　駆動回路３３は、与えられたＰＷＭ信号を含む通電パターンに従い、インバータ２３に含まれる６つのアームＵｐ，Ｖｐ，Ｗｐ，Ｕｎ，Ｖｎ，Ｗｎをスイッチングさせる駆動信号を出力する。これにより、３相交流の駆動電流がモータ４に供給され、モータ４のロータが回転する。 The drive circuit 33 outputs a drive signal for switching the six arms Up, Vp, Wp, Un, Vn, and Wn included in the inverter 23 according to the energization pattern including the given PWM signal. As a result, a three-phase alternating current drive current is supplied to the motor 4, and the rotor of the motor 4 rotates.
　電流検出タイミング調整部３４は、キャリア発生部３７から供給されるキャリアＣと、ＰＷＭ信号生成部３２により生成されるＰＷＭ信号を含む通電パターンとに基づいて、電流検出部２７がキャリアＣの１周期内で３つ相の相電流のうちのいずれかの相の相電流を検出するための取得タイミングを決定する。 In the current detection timing adjustment unit 34, the current detection unit 27 performs one cycle of the carrier C based on the carrier C supplied from the carrier generation unit 37 and the energization pattern including the PWM signal generated by the PWM signal generation unit 32. The acquisition timing for detecting the phase current of any one of the three phases is determined.
　電流検出部２７は、電流検出タイミング調整部３４により決定される複数の取得タイミングで検出信号Ｓｄを取得することによって、相電流Ｉｕ，Ｉｖ，Ｉｗを検出する。電流検出部２７は、一つの電流検出器２４から複数の相電流を検出する方式（いわゆる、１シャント電流検出方式）で、相電流Ｉｕ，Ｉｖ，Ｉｗを検出する。 The current detection unit 27 detects the phase currents Iu, Iv, and Iw by acquiring the detection signals Sd at a plurality of acquisition timings determined by the current detection timing adjustment unit 34. The current detection unit 27 detects phase currents Iu, Iv, and Iw by a method of detecting a plurality of phase currents from one current detector 24 (so-called one-shunt current detection method).
　ところで、センサレス型の永久磁石同期電動機が停止しているときにロータの磁極位置（初期位置）を推定する方法として、インダクティブセンシングと呼ばれる手法がある。インダクティブセンシングとは、永久磁石同期モータのロータ磁石の磁極位置をインダクタンスのロータ位置依存性を利用して検出する手法である。この位置検出手法は、モータの誘起電圧を使用しないため、モータのロータが停止又は極低速の状態でもロータ磁石の磁極位置を検出できる。ロータが極低速の状態とは、モータ制御装置が誘起電圧を検出できない程度にロータが低速で回転している状態をいう。本明細書では、説明の便宜上、“ロータが停止又は極低速の状態”を、単に、“ロータの停止状態”という。 By the way, there is a method called inductive sensing as a method of estimating the magnetic pole position (initial position) of the rotor when the sensorless permanent magnet synchronous motor is stopped. Inductive sensing is a method of detecting the magnetic pole position of the rotor magnet of a permanent magnet synchronous motor by utilizing the rotor position dependence of inductance. Since this position detection method does not use the induced voltage of the motor, the magnetic pole position of the rotor magnet can be detected even when the rotor of the motor is stopped or at an extremely low speed. The state in which the rotor is extremely low speed means a state in which the rotor is rotating at such a low speed that the motor control device cannot detect the induced voltage. In the present specification, for convenience of explanation, "a state in which the rotor is stopped or extremely low speed" is simply referred to as "a state in which the rotor is stopped".
　本実施の形態１に係るモータ制御装置１００－１は、インダクティブセンシングによって、モータのロータの停止状態での磁極位置である初期位置θｓを推定する初期位置推定部３８を備える。通電パターン生成部３５は、初期位置推定部３８により推定された初期位置θｓを用いて、モータ４のロータを回転させるＰＷＭ信号を含む通電パターンを駆動回路３３に出力する。ベクトル制御部３０は、初期位置推定部３８により推定された初期位置θｓをロータ位置θの初期値として用いて、電圧指令Ｖｑ，Ｖｄを相電圧指令Ｖｕ*，Ｖｖ*，Ｖｗ*に変換する。なお、本開示において、初期位置θｓは一例として３０度の幅を持った値となる。このような場合、初期位置θｓに基づき定めた所定の値を用いて、モータ４の制御が行われる。 The motor control device 100-1 according to the first embodiment includes an initial position estimation unit 38 that estimates the initial position θs, which is the magnetic pole position of the motor in the stopped state, by inductive sensing. The energization pattern generation unit 35 outputs an energization pattern including a PWM signal for rotating the rotor of the motor 4 to the drive circuit 33 using the initial position θs estimated by the initial position estimation unit 38. The vector control unit 30 uses the initial position θs estimated by the initial position estimation unit 38 as the initial value of the rotor position θ, and converts the voltage commands Vq and Vd into the phase voltage commands Vu *, Vv * and Vw *. In the present disclosure, the initial position θs is a value having a width of 30 degrees as an example. In such a case, the motor 4 is controlled by using a predetermined value determined based on the initial position θs.
　図２は、複数のＰＷＭ信号Ｕ，Ｖ，Ｗの波形と、これらのＰＷＭ信号の一周期当たりのキャリアＣの波形と、各相の相電圧指令Ｖｕ*，Ｖｖ*，Ｖｗ*の波形とを例示する図である。 FIG. 2 shows the waveforms of a plurality of PWM signals U, V, W, the waveform of the carrier C per cycle of these PWM signals, and the waveforms of the phase voltage commands Vu *, Vv *, Vw * of each phase. It is a figure which exemplifies.
　ＰＷＭ信号生成部３２は、各相の相電圧指令Ｖｕ*，Ｖｖ*，Ｖｗ*とキャリアＣのレベルとの大小関係に基づいて、複数のＰＷＭ信号Ｕ，Ｖ，Ｗを生成する。 The PWM signal generation unit 32 generates a plurality of PWM signals U, V, W based on the magnitude relationship between the phase voltage commands Vu *, Vv *, Vw * of each phase and the level of the carrier C.
　ＰＷＭ信号Ｕは、Ｕ相の上下アームを構成する２つのスイッチング素子を駆動するためのＰＷＭ信号である。この例では、ＰＷＭ信号Ｕがローレベルのとき、Ｕ相の下アームのスイッチング素子がオン（Ｕ相の上アームのスイッチング素子がオフ）となり、ＰＷＭ信号Ｕがハイレベルのとき、Ｕ相の下アームのスイッチング素子がオフ（Ｕ相の上アームのスイッチング素子がオン）となる。ＰＷＭ信号Ｕのレベルの変化に対して、Ｕ相の上下アームを構成する２つのスイッチング素子は相補的にオンオフ動作する。 The PWM signal U is a PWM signal for driving two switching elements constituting the upper and lower arms of the U phase. In this example, when the PWM signal U is at a low level, the switching element of the lower arm of the U phase is on (the switching element of the upper arm of the U phase is off), and when the PWM signal U is at a high level, it is below the U phase. The switching element of the arm is turned off (the switching element of the upper arm of the U phase is turned on). The two switching elements constituting the upper and lower arms of the U phase complementarily operate on and off in response to a change in the level of the PWM signal U.
　ＰＷＭ信号Ｖは、Ｖ相の上下アームを構成する２つのスイッチング素子を駆動するためのＰＷＭ信号である。この例では、ＰＷＭ信号Ｖがローレベルのとき、Ｖ相の下アームのスイッチング素子がオン（Ｖ相の上アームのスイッチング素子がオフ）となり、ＰＷＭ信号Ｖがハイレベルのとき、Ｖ相の下アームのスイッチング素子がオフ（Ｖ相の上アームのスイッチング素子がオン）となる。ＰＷＭ信号Ｖのレベルの変化に対して、Ｖ相の上下アームを構成する２つのスイッチング素子は相補的にオンオフ動作する。 The PWM signal V is a PWM signal for driving two switching elements constituting the upper and lower arms of the V phase. In this example, when the PWM signal V is at a low level, the switching element of the lower arm of the V phase is on (the switching element of the upper arm of the V phase is off), and when the PWM signal V is at a high level, it is below the V phase. The switching element of the arm is turned off (the switching element of the upper arm of the V phase is turned on). The two switching elements constituting the upper and lower arms of the V phase complementarily operate on and off in response to a change in the level of the PWM signal V.
　ＰＷＭ信号Ｗは、Ｗ相の上下アームを構成する２つのスイッチング素子を駆動するためのＰＷＭ信号である。この例では、ＰＷＭ信号Ｗがローレベルのとき、Ｗ相の下アームのスイッチング素子がオン（Ｗ相の上アームのスイッチング素子がオフ）となり、ＰＷＭ信号Ｗがハイレベルのとき、Ｗ相の下アームのスイッチング素子がオフ（Ｗ相の上アームのスイッチング素子がオン）となる。ＰＷＭ信号Ｗのレベルの変化に対して、Ｗ相の上下アームを構成する２つのスイッチング素子は相補的にオンオフ動作する。 The PWM signal W is a PWM signal for driving two switching elements constituting the upper and lower arms of the W phase. In this example, when the PWM signal W is at a low level, the switching element of the lower arm of the W phase is on (the switching element of the upper arm of the W phase is off), and when the PWM signal W is at a high level, it is below the W phase. The switching element of the arm is turned off (the switching element of the upper arm of the W phase is turned on). The two switching elements constituting the upper and lower arms of the W phase complementarily operate on and off in response to a change in the level of the PWM signal W.
　なお、図２では、上下アームの短絡防止のためのデッドタイムの図示が省略されている。また、図２では、ＰＷＭ信号がハイレベルのとき、そのＰＷＭ信号に対応する相の上アームがオン、ＰＷＭ信号がローレベルのとき、そのＰＷＭ信号に対応する相の下アームがオンと定義している。しかしながら、ＰＷＭ信号の論理レベルと各アームのオンオフとの関係は、回路構成等を考慮して、反対に定義されてもよい。 Note that in FIG. 2, the illustration of the dead time for preventing a short circuit between the upper and lower arms is omitted. Further, in FIG. 2, when the PWM signal is at a high level, the upper arm of the phase corresponding to the PWM signal is defined as on, and when the PWM signal is at a low level, the lower arm of the phase corresponding to the PWM signal is defined as on. ing. However, the relationship between the logic level of the PWM signal and the on / off of each arm may be defined in the opposite manner in consideration of the circuit configuration and the like.
　複数のＰＷＭ信号Ｕ，Ｖ，Ｗのそれぞれの１周期Ｔｐｗｍは、キャリアＣの周期（キャリア周波数の逆数）に相当する。変化点（ｔ１～ｔ６）は、ＰＷＭ信号の論理レベルが遷移するタイミングを表す。 Each one cycle Tpwm of the plurality of PWM signals U, V, W corresponds to the cycle of the carrier C (the reciprocal of the carrier frequency). The change points (t1 to t6) represent the timing at which the logic level of the PWM signal changes.
　ＰＷＭ信号生成部３２は、図２に示すように、各相で共通の一つのキャリアＣを用いて、各相のＰＷＭ信号を生成してもよい。位相ｔｂを中心とする左右対称の三角波をキャリアＣとしているため、各相のＰＷＭ信号の波形生成の回路構成を簡素化できる。キャリアＣのカウンタは、位相ｔａまでダウンカウント中であり、位相ｔａから位相ｔｂまでアップカウント中であり、位相ｔｂからダウンカウント中である。このように、カウントアップ期間とカウントダウン期間とが繰り返される。なお、ＰＷＭ信号生成部３２は、各相のそれぞれに対応する複数のキャリアＣを用いて各相のＰＷＭ信号を生成してもよいし、他の公知の方法で、各相のＰＷＭ信号を生成してもよい。 As shown in FIG. 2, the PWM signal generation unit 32 may generate a PWM signal for each phase using one carrier C common to each phase. Since the carrier C is a symmetrical triangular wave centered on the phase tb, the circuit configuration for generating the waveform of the PWM signal of each phase can be simplified. The counter of the carrier C is down-counting from phase ta, up-counting from phase ta to phase tb, and down-counting from phase tb. In this way, the count-up period and the count-down period are repeated. The PWM signal generation unit 32 may generate the PWM signal of each phase by using a plurality of carriers C corresponding to each of the phases, or generate the PWM signal of each phase by another known method. You may.
　図２は、第１電流検出タイミングＴｍ１が通電期間Ｔ２１に設定され、第２電流検出タイミングＴｍ２が通電期間Ｔ２２に設定される場合を例示する。なお、第１電流検出タイミングＴｍ１及び第２電流検出タイミングＴｍ２が設定される通電期間は、これらの期間に限られない。 FIG. 2 illustrates a case where the first current detection timing Tm1 is set to the energization period T21 and the second current detection timing Tm2 is set to the energization period T22. The energization period in which the first current detection timing Tm1 and the second current detection timing Tm2 are set is not limited to these periods.
　インバータ２３がＰＷＭ変調された３相交流を出力している状態では、電流検出部２７は、上アームＵｐ，Ｖｐ，Ｗｐに対する通電パターンに応じて、特定の相の電流を検出できる。あるいは、インバータ２３がＰＷＭ変調された３相交流を出力している状態では、電流検出部２７は、下アームＵｎ，Ｖｎ，Ｗｎに対する通電パターンに応じて、特定の相の電流を検出してもよい。 In the state where the inverter 23 outputs PWM-modulated three-phase alternating current, the current detection unit 27 can detect the current of a specific phase according to the energization pattern for the upper arms Up, Vp, and Wp. Alternatively, in a state where the inverter 23 outputs PWM-modulated three-phase alternating current, the current detection unit 27 may detect the current of a specific phase according to the energization pattern for the lower arms Un, Vn, and Wn. good.
　例えば図２のように、通電時間Ｔ２１において、電流検出器２４の両端に発生する電圧の電圧値は、モータ４のＵ相端子から流出する正のＵ相電流“＋Ｉｕ”の電流値に対応する。通電時間Ｔ２１は、ｔ４からｔ５までの時間である。通電時間Ｔ２１は、下アームＵｎ及び上アームＶｐ，Ｗｐがオン且つ残りの３つのアームがオフの状態の期間に相当する。したがって、電流検出部２７は、通電時間Ｔ２１内の第１電流検出タイミングＴｍ１で検出信号Ｓｄを取得することによって、モータ４のＵ相端子から流出する正のＵ相電流“＋Ｉｕ”の電流値を検出できる。 For example, as shown in FIG. 2, the voltage value of the voltage generated across the current detector 24 at the energization time T21 corresponds to the current value of the positive U-phase current “+ Iu” flowing out from the U-phase terminal of the motor 4. .. The energizing time T21 is a time from t4 to t5. The energizing time T21 corresponds to a period in which the lower arm Un and the upper arms Vp and Wp are on and the remaining three arms are off. Therefore, the current detection unit 27 acquires the detection signal Sd at the first current detection timing Tm1 within the energization time T21 to obtain the current value of the positive U-phase current “+ Iu” flowing out from the U-phase terminal of the motor 4. Can be detected.
　電流検出タイミング調整部３４は、ＰＷＭ信号の内の１相が他の２相と異なる論理レベルに遷移する時（例えば、Ｕ相のＰＷＭ信号がＶ相及びＷ相と同じハイレベルから、Ｖ相及びＷ相と異なるローレベルに遷移するタイミング：ｔ４）から所定の遅延時間ｔｄ経過時に第１電流検出タイミングＴｍ１を設定する。このとき、電流検出タイミング調整部３４は、通電時間Ｔ２１内に、第１電流検出タイミングＴｍ１を設定する。 When one phase of the PWM signal transitions to a logic level different from that of the other two phases (for example, the PWM signal of the U phase changes from the same high level as the V phase and the W phase to the V phase, the current detection timing adjusting unit 34 is used. The first current detection timing Tm1 is set when a predetermined delay time td elapses from the timing of transitioning to a low level different from that of the W phase: t4). At this time, the current detection timing adjusting unit 34 sets the first current detection timing Tm1 within the energization time T21.
　また、例えば図２のように、通電時間Ｔ２２において、電流検出器２４の両端に発生する電圧の電圧値は、モータ４のＷ相端子から流入する負のＷ相電流“－Ｉｗ”の電流値に対応する。通電時間Ｔ２２は、ｔ５からｔ６までの時間である。通電時間Ｔ２２は、下アームＵｎ，Ｖｎ及び上アームＷｐがオン且つ残りの３つのアームがオフの状態の期間に相当する。したがって、電流検出部２７は、通電時間Ｔ２２内の第２電流検出タイミングＴｍ２で検出信号Ｓｄを取得することによって、モータ４のＷ相端子から流入する負のＷ相電流“－Ｉｗ”の電流値を検出できる。 Further, for example, as shown in FIG. 2, the voltage value of the voltage generated at both ends of the current detector 24 at the energization time T22 is the current value of the negative W-phase current “−Iw” flowing from the W-phase terminal of the motor 4. Corresponds to. The energizing time T22 is a time from t5 to t6. The energizing time T22 corresponds to a period in which the lower arm Un, Vn and the upper arm Wp are on and the remaining three arms are off. Therefore, the current detection unit 27 acquires the detection signal Sd at the second current detection timing Tm2 within the energization time T22, so that the current value of the negative W-phase current “−Iw” flowing in from the W-phase terminal of the motor 4 Can be detected.
　電流検出タイミング調整部３４は、ＰＷＭ信号の内の１相が他の２相と異なる論理レベルに遷移する時（例えば、Ｖ相のＰＷＭ信号がＷ相と同じハイレベルから、Ｕ相と同じローレベルに遷移したことで、Ｗ相がＵ相及びＶ相と異なる論理レベルとなるタイミング：ｔ５）から、所定の遅延時間ｔｄ経過時に、第２電流検出タイミングＴｍ２を設定する。このとき、電流検出タイミング調整部３４は、通電時間Ｔ２２内に、第２電流検出タイミングＴｍ２を設定する。 When one phase of the PWM signal transitions to a logic level different from that of the other two phases (for example, the PWM signal of the V phase changes from the same high level as the W phase to the same low level as the U phase). The second current detection timing Tm2 is set when the predetermined delay time td elapses from the timing when the W phase becomes a logical level different from the U phase and the V phase due to the transition to the level: t5). At this time, the current detection timing adjusting unit 34 sets the second current detection timing Tm2 within the energization time T22.
　同様に、電流検出部２７は、他の相電流の電流値も検出できる。 Similarly, the current detection unit 27 can also detect current values of other phase currents.
　このように、３相のＰＷＭ信号を含む通電パターンに応じて相電流Ｉｕ，Ｉｖ，Ｉｗのうち、２相の相電流を順次検出して記憶すれば、３相分の電流を時分割で検出することが可能となる。３相の相電流の総和が零であることから（ｉｕ＋ｉｖ＋ｉｗ＝０）、電流検出部２７は、３相の相電流うち２相の相電流を検出できれば、残り１相の相電流も検出できる。 In this way, if the two-phase phase currents of the two-phase currents Iu, Iv, and Iw are sequentially detected and stored according to the energization pattern including the three-phase PWM signals, the currents for the three phases are detected in time division. It becomes possible to do. Since the total of the three-phase phase currents is zero (iu + iv + iwa = 0), the current detection unit 27 can detect the phase currents of the remaining one phase if it can detect the phase currents of two of the three phase currents.
　図３は、通電時の各アームのスイッチング状態の一例を示す図である。図４は、非通電時の各アームのスイッチング状態の一例を示す図である。図３に示すように、上アームＵｐ及び下アームＶｎ，Ｗｎがオン且つ残りの３つのアームがオフの状態の通電期間では、電流検出部２７は、モータ４のＵ相端子から流入する負のＵ相電流“－Ｉｕ”の電流値を検出できる。一方、図４に示すように、全ての上アームＵｐ，Ｖｐ，Ｗｐがオン且つ全ての下アームＵｎ，Ｖｎ，Ｗｎがオフの状態では、電流が電流検出器２４に流れないため、電流検出部２７は、各相の相電流を検出できない。全ての上アームＵｐ，Ｖｐ，Ｗｐがオフ且つ全ての下アームＵｎ，Ｖｎ，Ｗｎがオンの状態でも、電流が電流検出器２４に流れないため、電流検出部２７は、各相の相電流を検出できない。 FIG. 3 is a diagram showing an example of a switching state of each arm when energized. FIG. 4 is a diagram showing an example of a switching state of each arm when the power is off. As shown in FIG. 3, during the energization period in which the upper arm Up and the lower arms Vn and Wn are on and the remaining three arms are off, the current detection unit 27 receives a negative current from the U-phase terminal of the motor 4. The current value of the U-phase current "-Iu" can be detected. On the other hand, as shown in FIG. 4, when all the upper arms Up, Vp, Wp are on and all the lower arms Un, Vn, Wn are off, no current flows through the current detector 24, so that the current detection unit 27 cannot detect the phase current of each phase. Even when all the upper arms Up, Vp, and Wp are off and all the lower arms Un, Vn, and Wn are on, no current flows through the current detector 24, so the current detector 27 determines the phase current of each phase. Cannot be detected.
　このように、１シャント電流検出方式では、通電区間（通電時間）を設けなければ、各相の相電流を検出できない。１シャント電流検出方式では、一つの通電時間で検出できる相電流は１相分だけであるので、ＰＷＭ信号の１周期の間に少なくとも２つの通電時間を設けて（図２参照）、式（ｉｕ＋ｉｖ＋ｉｗ＝０）に基づいて３相の相電流を区別して検出する。しかしながら、各相の相電流を区別して検出するために通電時間を設けると、電流検出器２４に流れる電流は増幅されてしまうので、電流検出部２７は、電流検出器２４に流れる電流が零のときに各相の相電流の検出値に含まれる検出誤差をそれぞれ測定できない。 As described above, in the one-shunt current detection method, the phase current of each phase cannot be detected unless an energization section (energization time) is provided. In the one-shunt current detection method, only one phase current can be detected in one energization time. Therefore, at least two energization times are provided during one cycle of the PWM signal (see FIG. 2), and the equation (iu + iv + iv) is provided. The three-phase phase currents are detected separately based on = 0). However, if an energizing time is provided to distinguish and detect the phase currents of each phase, the current flowing through the current detector 24 is amplified, so that the current detecting unit 27 has zero current flowing through the current detector 24. Sometimes it is not possible to measure the detection error included in the detected value of the phase current of each phase.
　そこで、モータが停止中の時、いずれもデューティ比が同一値の各相のＰＷＭ信号に従ってインバータ２３の全アームのうち一部のアームをオンさせることで電流検出器２４に流れる各相の電流をオフセット電流と定義する場合がある。この場合、電流検出部２７は、いずれもデューティ比が同一値の各相のＰＷＭ信号に従ってインバータ２３の全アームのうち一部のアームをオンさせることで電流検出器２４に流れる各相のオフセット電流の電流値をオフセット電流値（検出誤差）として検出する。 Therefore, when the motor is stopped, the current of each phase flowing through the current detector 24 is reduced by turning on some of all the arms of the inverter 23 according to the PWM signals of the phases having the same duty ratio. Sometimes defined as offset current. In this case, the current detection unit 27 turns on some of all the arms of the inverter 23 according to the PWM signals of the phases having the same duty ratio, so that the offset current of each phase flowing through the current detector 24 The current value of is detected as an offset current value (detection error).
　図５は、一例としていずれもデューティ比が５０％の場合の各相のＰＷＭ信号に従ってインバータ２３の全アームのうち一部のアームをオンさせることで電流検出器２４に流れる各相のオフセット電流を例示するタイミングチャートである。図６は、いずれかのデューティ比が５０％とは異なる各相のＰＷＭ信号に従ってインバータ２３がロータを回転させている時に図５と同じ一部のアームをオンさせることで電流検出器２４に流れる各相の相電流を例示するタイミングチャートである。 As an example, FIG. 5 shows the offset current of each phase flowing through the current detector 24 by turning on some of all the arms of the inverter 23 according to the PWM signal of each phase when the duty ratio is 50%. It is an example timing chart. FIG. 6 shows the current flow to the current detector 24 by turning on some of the same arms as in FIG. 5 when the inverter 23 is rotating the rotor according to the PWM signal of each phase whose duty ratio is different from 50%. It is a timing chart which illustrates the phase current of each phase.
　図５において、電流検出部２７は、インバータ２３がロータを回転させる前（モータ４の起動前）に、ＰＷＭ信号の１周期ごとに少なくとも２回の電流検出を行うことで、３相のオフセット電流の各々の電流値を検出する。電流検出部２７は、検出した各々の電流値を３相のオフセット電流値としてメモリに記憶する。図５は、電流検出部２７が正のＵ相電流“Ｉｕ”と負のＷ相電流“－Ｉｗ”の各々のオフセット電流値を検出し、それらの検出結果から残りのＶ相電流のオフセット電流値を検出（演算）し、検出した３相のオフセット電流値をメモリに記憶する場合を例示する。３相のオフセット電流値がメモリに記憶された後、モータ４がインバータ２３により起動し、インバータ２３がロータを回転させる。 In FIG. 5, the current detection unit 27 detects the current at least twice for each cycle of the PWM signal before the inverter 23 rotates the rotor (before the motor 4 is started), so that the three-phase offset current is generated. Each current value of is detected. The current detection unit 27 stores each detected current value in the memory as a three-phase offset current value. In FIG. 5, the current detection unit 27 detects the offset current values of the positive U-phase current “Iu” and the negative W-phase current “−Iw”, and the offset current of the remaining V-phase current is obtained from the detection results. An example shows a case where a value is detected (calculated) and the detected three-phase offset current value is stored in a memory. After the three-phase offset current values are stored in the memory, the motor 4 is started by the inverter 23, and the inverter 23 rotates the rotor.
　図６において、電流検出部２７は、いずれかのデューティ比が５０％とは異なる各相のＰＷＭ信号に従ってインバータ２３がロータを回転させている時に、ＰＷＭ信号の１周期ごとに図５と同じ通電パターンで少なくとも２回の電流検出を行うことで、３相の相電流の各々の電流値を検出する。電流検出部２７は、ＰＷＭ信号の１周期ごとに検出される３相の相電流の各々の電流値から、メモリに事前に記憶した３相のオフセット電流値を、ＰＷＭ信号の１周期ごとに差し引くことで、３相の相電流Ｉｕ，Ｉｖ，Ｉｗのそれぞれの電流検出値を演算する。これにより、３相の相電流Ｉｕ，Ｉｖ，Ｉｗの各々の電流検出値から検出誤差が除去される。ＰＷＭ信号生成部３２は、検出誤差が除去された３相の相電流Ｉｕ，Ｉｖ，Ｉｗの各々の電流検出値に基づいて、インバータ２３がロータを回転させている時の３相のＰＷＭ信号を生成することで、モータ４の回転をインバータ２３により高精度に制御できる。 In FIG. 6, the current detection unit 27 energizes the same as in FIG. 5 for each cycle of the PWM signal when the inverter 23 rotates the rotor according to the PWM signal of each phase whose duty ratio is different from 50%. By performing current detection at least twice in the pattern, the current value of each of the three-phase phase currents is detected. The current detection unit 27 subtracts the three-phase offset current value stored in advance in the memory from each of the three-phase phase currents detected in each cycle of the PWM signal for each cycle of the PWM signal. Therefore, the current detection values of the three-phase phase currents Iu, Iv, and Iw are calculated. As a result, the detection error is removed from the current detection values of the three-phase phase currents Iu, Iv, and Iw. The PWM signal generation unit 32 generates a three-phase PWM signal when the inverter 23 is rotating the rotor based on the current detection values of the three-phase phase currents Iu, Iv, and Iw from which the detection error has been removed. By generating it, the rotation of the motor 4 can be controlled with high accuracy by the inverter 23.
　ところが、インバータ２３がロータを３相の交流電流で回転させていない状態でも、ロータは、風などの外乱により空転していることがある。特に、摩擦抵抗が比較的小さいファンなどの回転体を回転させるロータは、空転しやすい。インバータ２３がロータを３相の交流電流で回転させる前にロータが空転しているときに、電流検出器２４に流れる電流を検出すると、空転中のロータに発生する回生ブレーキによってロータの回転が阻害されることがある。空転中のロータの回転が阻害されると、例えば、モータ４の減速や異音などの意図しない挙動が発生するおそれがある。 However, even in a state where the inverter 23 does not rotate the rotor with a three-phase alternating current, the rotor may idle due to disturbance such as wind. In particular, a rotor that rotates a rotating body such as a fan having a relatively small frictional resistance tends to slip. When the rotor is idling before the inverter 23 rotates the rotor with three-phase alternating current, if the current flowing through the current detector 24 is detected, the regenerative brake generated in the idling rotor hinders the rotation of the rotor. May be done. If the rotation of the rotor during idling is hindered, unintended behavior such as deceleration of the motor 4 or abnormal noise may occur.
　図７は、インバータがロータを回転させる前に電流検出器に流れる電流の電流値を検出するときのＰＷＭ信号の波形の一比較例を示し、各相のＰＷＭ信号のデューティ比がいずれも５０％の場合を例示する。各相のＰＷＭ信号の波形によって、回生電流が流れる期間（回生区間）と回生電流が流れない期間（非回生区間）が発生する。図７に示す非通電区間が、回生区間に相当する。回生区間（非通電区間）では、上下どちらかのアームが全てオン状態になっている。 FIG. 7 shows a comparative example of the PWM signal waveform when detecting the current value of the current flowing through the current detector before the inverter rotates the rotor, and the duty ratio of the PWM signal of each phase is 50%. The case of is illustrated. Depending on the waveform of the PWM signal of each phase, a period in which the regenerative current flows (regenerative section) and a period in which the regenerative current does not flow (non-regenerative section) occur. The non-energized section shown in FIG. 7 corresponds to the regenerative section. In the regeneration section (non-energized section), either the upper or lower arm is in the on state.
　図８は、非通電区間で下アームが全てオン状態の場合を示す図であり、図７の両側の非通電区間におけるスイッチング状態を示す。図９は、非通電区間で上アームが全てオン状態の場合を示す図であり、図７の両側の非通電区間に挟まれる中間の非通電区間におけるスイッチング状態を示す。風などの外力によりモータ４のロータが空転すると、ロータの空転によってモータ４の各相のコイルに誘起電圧が発生する。これらの誘起電圧によって、図８，９に示すように、図７に示す非通電区間では、モータ４からインバータ２３への回生電流が発生し、空転中のロータに回生ブレーキがかかる。空転中のロータの回転が回生ブレーキによって阻害されると、例えば、モータの減速や異音などの意図しない挙動が発生するおそれがある。 FIG. 8 is a diagram showing a case where all the lower arms are in the non-energized section in the non-energized section, and shows a switching state in the non-energized section on both sides of FIG. 7. FIG. 9 is a diagram showing a case where all the upper arms are in the non-energized section in the non-energized section, and shows a switching state in the intermediate non-energized section sandwiched between the non-energized sections on both sides of FIG. When the rotor of the motor 4 idles due to an external force such as wind, an induced voltage is generated in the coils of each phase of the motor 4 due to the idling of the rotor. As shown in FIGS. 8 and 9, these induced voltages generate a regenerative current from the motor 4 to the inverter 23 in the non-energized section shown in FIG. 7, and regenerative braking is applied to the idling rotor. If the rotation of the rotor during idling is hindered by the regenerative brake, unintended behavior such as deceleration of the motor or abnormal noise may occur.
　＜ロータの空転時の電流検出方法１＞
　本開示における“ロータの空転時の電流検出方法１”では、ＰＷＭ信号生成部３２は、非通電区間で回生電流が流れないように、図１０に示すように、インバータ２３の全アームをオフ状態に設定する各相のＰＷＭ信号を生成する。これにより、ロータが空転していても、非通電区間ではインバータ２３の全アームがオフ状態になっているので、モータ４からインバータ２３に流れる回生電流が理論的には発生しない。したがって、空転中のロータに発生する回生ブレーキによってロータの回転が阻害されることが軽減され、例えば、モータ４の減速や異音などの意図しない挙動が発生する可能性を低減できる。 <Current detection method 1 when the rotor is idling>
In the "current detection method 1 when the rotor is idling" in the present disclosure, the PWM signal generation unit 32 turns off all the arms of the inverter 23 as shown in FIG. 10 so that the regenerative current does not flow in the non-energized section. Generates a PWM signal for each phase set to. As a result, even if the rotor is idling, all the arms of the inverter 23 are off in the non-energized section, so that the regenerative current flowing from the motor 4 to the inverter 23 is theoretically not generated. Therefore, it is possible to reduce the possibility that the rotation of the rotor is hindered by the regenerative brake generated in the rotor during idling, and to reduce the possibility of unintended behavior such as deceleration of the motor 4 and abnormal noise.
　図１１は、インバータがロータを回転させる前に電流検出器に流れる電流の電流値を検出するときのＰＷＭ信号の波形の第１例を示す図である。インバータ２３は、全アームのうち通電パターン毎に異なる一部のアームをオンすることで、ロータを有するモータ４を通電させる。ＰＷＭ信号生成部３２は、全アームをロータの空転中にオフさせる第１期間と一部のアームをロータの空転中に第１通電パターンでオンさせる第２期間と一部のアームをロータの空転中に第２通電パターンでオンさせる第３期間とを１周期に含む各相のＰＷＭ信号を生成する。これにより、図１１に示すような各アームのスイッチング状態が得られる。 FIG. 11 is a diagram showing a first example of the waveform of the PWM signal when detecting the current value of the current flowing through the current detector before the inverter rotates the rotor. The inverter 23 energizes the motor 4 having a rotor by turning on some of all the arms that are different for each energization pattern. The PWM signal generation unit 32 has a first period in which all the arms are turned off during the idling of the rotor, a second period in which some arms are turned on in the first energization pattern during the idling of the rotor, and some arms are idling in the rotor. A PWM signal of each phase including a third period to be turned on by the second energization pattern is generated in one cycle. As a result, the switching state of each arm as shown in FIG. 11 can be obtained.
　図１１に示す例において、全アームがオフ状態になっている非通電区間Ｔ１は、第１期間の一例であり、一部のアームが第１通電パターンでオン状態になっている電流検出区間の前半区間Ｔ２は、第２期間の一例であり、一部のアームが第２通電パターンでオン状態になっている電流検出区間の後半区間Ｔ３は、第３期間の一例である。 In the example shown in FIG. 11, the non-energized section T1 in which all the arms are in the off state is an example of the first period, and is a current detection section in which some arms are in the on state in the first energization pattern. The first half section T2 is an example of the second period, and the second half section T3 of the current detection section in which some arms are turned on in the second energization pattern is an example of the third period.
　電流検出区間の前半区間Ｔ２（第２期間の一例）では、下アームＵｎ及び上アームＶｐ，Ｗｐが第１通電パターンでオン状態になっているので、モータ４のＵ相端子から流出する正のＵ相電流“＋Ｉｕ”が電流検出器２４に流れる。電流検出区間の後半区間Ｔ３（第３期間の一例）では、下アームＵｎ，Ｖｎ及び上アームＷｐが第２通電パターンでオン状態になっているので、モータ４のＷ相端子から流入する負のＷ相電流“－Ｉｗ”が電流検出器２４に流れる。電流検出部２７は、前半区間Ｔ２に電流検出器２４に流れる第１基準電流（この例では、正のＵ相電流“＋Ｉｕ”）と後半区間Ｔ３に電流検出器２４に流れる第２基準電流（この例では、負のＷ相電流“－Ｉｗ”）とを検出する。 In the first half section T2 of the current detection section (an example of the second period), the lower arm Un and the upper arms Vp and Wp are turned on in the first energization pattern, so that the positive flows out from the U-phase terminal of the motor 4. A U-phase current "+ Iu" flows through the current detector 24. In the latter half section T3 of the current detection section (an example of the third period), the lower arms Un, Vn and the upper arm Wp are turned on in the second energization pattern, so that the negative current flows from the W phase terminal of the motor 4. A W-phase current "-Iw" flows through the current detector 24. The current detection unit 27 includes a first reference current (in this example, a positive U-phase current “+ Iu”) flowing through the current detector 24 in the first half section T2 and a second reference current (in this example) flowing through the current detector 24 in the second half section T3. In this example, a negative W-phase current “−Iw”) is detected.
　このように、電流検出方法１によれば、非通電区間Ｔ１では、全アームがオフ状態になっているので、回生ブレーキを発生させる不要なトルクの発生が抑制される。よって、インバータ２３がロータを３相の交流電流で回転させる前にロータが空転しているときに、電流検出部２７が電流検出器２４に流れる電流を電流検出区間に検出しても、全アームがオフ状態の非通電区間Ｔ１が存在するので、ロータの空転が阻害されにくい。 As described above, according to the current detection method 1, since all the arms are in the off state in the non-energized section T1, the generation of unnecessary torque that generates the regenerative brake is suppressed. Therefore, even if the current detector 27 detects the current flowing through the current detector 24 in the current detection section when the rotor is idling before the inverter 23 rotates the rotor with the three-phase alternating current, all arms Since there is a non-energized section T1 in the off state, the idling of the rotor is less likely to be hindered.
　図１１に示す例では、第２期間と第３期間との合計期間の一例である電流検出区間は、第１期間の一例である非通電区間よりも短く設定されている。非通電区間では、回生ブレーキ状態は遮断されていることから、回生ブレーキを発生させる不要なトルクの発生が抑制される。一方、電流検出区間は非通電区間よりも短いので、電流検出区間内の通電時間には微小な電流しか流れない。よって、インバータ２３がロータを３相の交流電流で回転させる前にロータが空転しているときに、電流検出部２７が電流検出器２４に流れる電流を電流検出区間に検出しても、空転中のロータの回転が阻害されることが軽減される。その結果、例えば、モータ４の減速や異音などの意図しない挙動の発生を抑制できる。 In the example shown in FIG. 11, the current detection section, which is an example of the total period of the second period and the third period, is set shorter than the non-energized section, which is an example of the first period. In the non-energized section, since the regenerative braking state is cut off, the generation of unnecessary torque that generates the regenerative braking is suppressed. On the other hand, since the current detection section is shorter than the non-energized section, only a minute current flows during the energization time in the current detection section. Therefore, even if the current detection unit 27 detects the current flowing through the current detector 24 in the current detection section when the rotor is idling before the inverter 23 rotates the rotor with the three-phase alternating current, it is still idling. The impediment to the rotation of the rotor is reduced. As a result, for example, it is possible to suppress the occurrence of unintended behavior such as deceleration of the motor 4 and abnormal noise.
　例えば、電流検出部２７は、インバータ２３がロータを回転させている時に電流検出器２４に流れる第１相の相電流を、第２期間に検出された第１相の第１基準電流に応じて補正してもよい。同様に、電流検出部２７は、インバータ２３がロータを回転させている時に電流検出器２４に流れる第２相の相電流を、第２期間に検出された第２相の第２基準電流に応じて補正してもよい。例えば、第１相はＵ相、第２相はＷ相であるが、他の組み合わせでもよい。１周期のうちの第１期間では電流検出器２４に電流が流れないので、第２期間に電流検出器２４に流れる第１基準電流と第３期間に電流検出器２４に流れる第２基準電流とを、上述のオフセット電流のような２相の基準電流として扱うことができる。 For example, the current detection unit 27 sets the phase current of the first phase flowing through the current detector 24 when the inverter 23 is rotating the rotor according to the first reference current of the first phase detected in the second period. It may be corrected. Similarly, the current detection unit 27 makes the phase current of the second phase flowing through the current detector 24 when the inverter 23 is rotating the rotor correspond to the second reference current of the second phase detected in the second period. May be corrected. For example, the first phase is the U phase and the second phase is the W phase, but other combinations may be used. Since no current flows through the current detector 24 in the first period of one cycle, the first reference current flowing through the current detector 24 in the second period and the second reference current flowing through the current detector 24 in the third period Can be treated as a two-phase reference current such as the offset current described above.
　電流検出部２７は、例えば、第２期間に検出された第１相の第１基準電流と第３期間に検出された第２相の第２基準電流から、３相の相電流の総和が零であることを利用して、ロータの空転中に電流検出器２４に流れる第３相の第３基準電流を検出（演算）してもよい。第３相の第３電基準流も、上述のオフセット電流のような１相の基準電流として扱うことができる。第３相は、例えばＶ相である。電流検出部２７は、インバータ２３がロータを回転させている時に電流検出器２４に流れる第３相の相電流を、検出（演算）された第３相の第３基準電流に応じて補正してもよい。 In the current detection unit 27, for example, the sum of the phase currents of the three phases is zero from the first reference current of the first phase detected in the second period and the second reference current of the second phase detected in the third period. Therefore, the third reference current of the third phase flowing through the current detector 24 during idling of the rotor may be detected (calculated). The third electric reference current of the third phase can also be treated as a one-phase reference current such as the offset current described above. The third phase is, for example, the V phase. The current detection unit 27 corrects the phase current of the third phase flowing through the current detector 24 when the inverter 23 is rotating the rotor according to the detected (calculated) third reference current of the third phase. May be good.
　例えば、第１相の第１基準電流の値を第１基準電流値とし、第２相の第２基準電流の値を第２基準電流値とし、第３相の第３基準電流の値を第３基準電流値とする。電流検出部２７は、第２期間に第１基準電流値を検出し、第３期間に第２基準電流値を検出し、それらの検出結果から残りの第３基準電流値を検出（演算）し、検出した３相の基準電流値をメモリに記憶する。３相の基準電流値がメモリに記憶された後、モータ４がインバータ２３により起動し、インバータ２３がロータを回転させる。 For example, the value of the first reference current of the first phase is set as the first reference current value, the value of the second reference current of the second phase is set as the second reference current value, and the value of the third reference current of the third phase is the third. 3 Use the reference current value. The current detection unit 27 detects the first reference current value in the second period, detects the second reference current value in the third period, and detects (calculates) the remaining third reference current value from those detection results. , The detected reference current value of the three phases is stored in the memory. After the three-phase reference current values are stored in the memory, the motor 4 is started by the inverter 23, and the inverter 23 rotates the rotor.
　電流検出部２７は、インバータ２３がロータを回転させている時に、ＰＷＭ信号の１周期ごとに図１１と同じ通電パターンで少なくとも２回の電流検出を行うことで、３相の相電流の各々の電流値を検出する。電流検出部２７は、ＰＷＭ信号の１周期ごとに検出される３相の相電流の各々の電流値から、メモリに事前に記憶した３相の基準電流値を、ＰＷＭ信号の１周期ごとに差し引くことで、３相の相電流Ｉｕ，Ｉｖ，Ｉｗのそれぞれの電流検出値を演算する。これにより、電流検出部２７は、インバータ２３がロータを回転させている時に電流検出器２４に流れる各相の相電流を、各相の基準電流に応じて補正することになるので、３相の相電流Ｉｕ，Ｉｖ，Ｉｗの各々の電流検出値から検出誤差が除去される。ＰＷＭ信号生成部３２は、検出誤差が除去された補正後の３相の相電流Ｉｕ，Ｉｖ，Ｉｗの各々の電流検出値を用いて、インバータ２３がロータを回転させている時の３相のＰＷＭ信号を生成することで、モータ４の回転をインバータ２３により高精度に制御できる。 When the inverter 23 is rotating the rotor, the current detection unit 27 detects the current at least twice in the same energization pattern as in FIG. 11 for each cycle of the PWM signal, so that each of the three-phase phase currents Detect the current value. The current detection unit 27 subtracts the three-phase reference current value stored in advance in the memory from each of the three-phase phase currents detected in each cycle of the PWM signal for each cycle of the PWM signal. Therefore, the current detection values of the three-phase phase currents Iu, Iv, and Iw are calculated. As a result, the current detection unit 27 corrects the phase current of each phase flowing through the current detector 24 when the inverter 23 is rotating the rotor, according to the reference current of each phase. The detection error is removed from each of the current detection values of the phase currents Iu, Iv, and Iw. The PWM signal generation unit 32 uses the current detection values of the corrected three-phase currents Iu, Iv, and Iw from which the detection error has been removed, and uses the current detection values of the three-phase when the inverter 23 is rotating the rotor. By generating the PWM signal, the rotation of the motor 4 can be controlled with high accuracy by the inverter 23.
　なお、上記以外の方法として、例えば、ＰＷＭ機能を用いず、汎用ポート機能を使用して、ポートからオン／オフ信号を出力するだけで、図１０の状態を作り出してもよい。 As a method other than the above, for example, the state shown in FIG. 10 may be created only by outputting an on / off signal from the port by using the general-purpose port function without using the PWM function.
　＜ロータの空転時の電流検出方法２＞
　次に、本開示における“ロータの空転時の電流検出方法２”について説明する。 <Current detection method 2 when the rotor is idling>
Next, the "current detection method 2 when the rotor is idling" in the present disclosure will be described.
　図１２は、一例としていずれもデューティ比が５０％の各相のＰＷＭ信号に従ってインバータの全アームのうち一部のアームをオンさせることで電流検出器２４に流れるＵ相電流の電流波形の一例を示す拡大図である。図１２において、上段の波形は、ロータの停止時を示し、下段の波形は、ロータの空転時を示す。図１２は、ＰＷＭ信号が約１６周期分の波形を例示する。両波形は、ほぼ変化なく上下にずれており、この上下のずれは、ロータの空転によってモータ４の各相のコイルに発生する誘起電圧に起因する。 FIG. 12 shows an example of the current waveform of the U-phase current flowing through the current detector 24 by turning on a part of all the arms of the inverter according to the PWM signal of each phase having a duty ratio of 50%. It is an enlarged view which shows. In FIG. 12, the upper waveform shows the rotor when the rotor is stopped, and the lower waveform shows the rotor when the rotor is idling. FIG. 12 illustrates a waveform in which the PWM signal has about 16 cycles. Both waveforms are shifted up and down with almost no change, and this vertical shift is caused by the induced voltage generated in the coils of each phase of the motor 4 due to the idling of the rotor.
　図１３は、インバータがロータを回転させる前に電流検出器２４に流れる電流の電流値を検出するときのＰＷＭ信号の波形の第２例を示す図である。インバータ２３は、全アームのうち通電パターン毎に異なる一部のアームをオンすることで、ロータを有するモータ４を通電させる。ＰＷＭ信号生成部３２は、一部のアームをロータの空転中に第１通電パターンでオンさせる第１区間と一部のアームをロータの空転中に第２通電パターンでオンさせる第２区間と全ての上アーム又は全ての下アームをロータの空転中に第３通電パターンでオンさせる第３区間とを含む第１周期区間とを有する各相のＰＷＭ信号を、いずれも同一値のデューティ比で生成する。これにより、図１３に示すような各アームのスイッチング状態が得られる。 FIG. 13 is a diagram showing a second example of the waveform of the PWM signal when detecting the current value of the current flowing through the current detector 24 before the inverter rotates the rotor. The inverter 23 energizes the motor 4 having a rotor by turning on some of all the arms that are different for each energization pattern. The PWM signal generation unit 32 includes a first section in which some arms are turned on in the first energization pattern while the rotor is idling, and a second section in which some arms are turned on in the second energization pattern while the rotor is idling. The PWM signals of each phase having the first period section including the third section in which the upper arm or all the lower arms are turned on in the third energization pattern while the rotor is idling are generated with the same duty ratio. do. As a result, the switching state of each arm as shown in FIG. 13 can be obtained.
　図１３に示す例において、一部のアームが第１通電パターンでオン状態になっている第１電流検出区間Ｐ１（検出１回目のタイミングを含む期間）は、第１区間の一例であり、一部のアームが第２通電パターンでオン状態になっている第２電流検出区間Ｐ２（検出２回目のタイミングを含む期間）は、第２区間の一例である。全ての上アームがオン状態且つ全ての下アームがオフ状態になっている非通電区間Ｐ３は、第３区間の一例である。この例では、第３区間は、第１区間と第２区間との間に存在する。 In the example shown in FIG. 13, the first current detection section P1 (the period including the timing of the first detection) in which some of the arms are turned on in the first energization pattern is an example of the first section. The second current detection section P2 (the period including the timing of the second detection) in which the arm of the unit is turned on in the second energization pattern is an example of the second section. The non-energized section P3 in which all the upper arms are in the on state and all the lower arms are in the off state is an example of the third section. In this example, the third section exists between the first section and the second section.
　第１電流検出区間Ｐ１（第１区間の一例）では、上アームＵｐ及び下アームＶｎ，Ｗｎが第１通電パターンでオン状態になっているので、モータ４のＵ相端子から流入する負のＵ相電流“－Ｉｕ”が電流検出器２４に流れる（図１４参照）。第２電流検出区間Ｐ２（第２区間の一例）では、下アームＵｎ及び上アームＶｐ，Ｗｐが第２通電パターンでオン状態になっているので、モータ４のＵ相端子から流出する正のＵ相電流“＋Ｉｕ”が電流検出器２４に流れる（図１５参照）。電流検出部２７は、第１区間に電流検出器２４に流れる第１相の第１電流値と第２区間に電流検出器２４に流れる第１相の第２電流値とを検出する。この例では、第１電流値は、負のＵ相電流“－Ｉｕ（＝Ｉｖ＋Ｉｗ）”の電流値であり、第２電流値は、正のＵ相電流“＋Ｉｕ”の電流値である。 In the first current detection section P1 (an example of the first section), the upper arm Up and the lower arms Vn and Wn are turned on in the first energization pattern, so that the negative U flowing in from the U-phase terminal of the motor 4 A phase current "-Iu" flows through the current detector 24 (see FIG. 14). In the second current detection section P2 (an example of the second section), the lower arm Un and the upper arms Vp and Wp are turned on in the second energization pattern, so that the positive U flowing out from the U-phase terminal of the motor 4 A phase current "+ Iu" flows through the current detector 24 (see FIG. 15). The current detection unit 27 detects the first current value of the first phase flowing through the current detector 24 in the first section and the second current value of the first phase flowing through the current detector 24 in the second section. In this example, the first current value is the current value of the negative U-phase current “−Iu (= Iv + Iw)”, and the second current value is the current value of the positive U-phase current “+ Iu”.
　電流検出方法２では、電流検出部２７は、ＰＷＭ信号の1周期内において検出される第１相の相電流が対となることを利用し、第１相の第１電流値と第１相の第２電流値との和の半分と零との差分を誘起電圧による影響分として検出する。そして、電流検出部２７は、検出した誘起電圧による影響分を、１回目又は２回目の検出タイミングで検出された第１電流値又は第２電流値から差し引くことで、第１相のオフセット電流値を演算する。電流検出部２７は、第１相以外の第２相又は第３相についても、同様の手法で、ロータの空転中でもオフセット電流値を演算することができる。 In the current detection method 2, the current detection unit 27 utilizes the fact that the phase currents of the first phase detected in one cycle of the PWM signal are paired, and the first current value of the first phase and the first phase are The difference between half of the sum of the second current value and zero is detected as the effect of the induced voltage. Then, the current detection unit 27 subtracts the influence of the detected induced voltage from the first current value or the second current value detected at the first or second detection timing, so that the offset current value of the first phase is obtained. Is calculated. The current detection unit 27 can calculate the offset current value even during idling of the rotor by the same method for the second phase or the third phase other than the first phase.
　図１６は、ロータの空転時のＰＷＭ信号の１０周期(例えば、４００μｓ)におけるＵ相オフセット電流値を演算する処理の一例を示す波形図である。図１７は、図１６に示す点線枠で囲まれた部分の拡大図であり、ロータ空転時のＰＷＭ信号の１周期(例えば、４０μｓ)におけるＵ相オフセット電流値を演算する処理の一例を示す波形図である。Ｕ相は、第１相の一例である。 FIG. 16 is a waveform diagram showing an example of processing for calculating the U-phase offset current value in 10 cycles (for example, 400 μs) of the PWM signal when the rotor is idling. FIG. 17 is an enlarged view of the portion surrounded by the dotted line frame shown in FIG. 16, and is a waveform showing an example of processing for calculating the U-phase offset current value in one cycle (for example, 40 μs) of the PWM signal when the rotor idles. It is a figure. The U phase is an example of the first phase.
　電流検出部２７は、第１区間の検出１回目に電流検出器２４に流れるＵ相の第１電流値（－Ｉｕ＋ｅ）と第２区間の検出２回目に電流検出器２４に流れるＵ相の第２電流値(Ｉｕ＋ｅ)との和の半分を算出することで、誘起電圧による影響成分ｅを導出できる。図１６，１７に示す例では、電流検出部２７は、検出２回目のＵ相の第２電流値(Ｉｕ＋ｅ)から影響成分ｅを差し引くことで、Ｕ相オフセット電流値Ｉｕを算出できる。 The current detection unit 27 has a first current value (−Iu + e) of the U phase flowing through the current detector 24 at the first detection of the first section and a U-phase first current value (−Iu + e) flowing through the current detector 24 at the second detection of the second section. By calculating half of the sum of the two current values (Iu + e), the influence component e due to the induced voltage can be derived. In the examples shown in FIGS. 16 and 17, the current detection unit 27 can calculate the U-phase offset current value Iu by subtracting the influential component e from the second current value (Iu + e) of the U-phase for the second detection.
　このように、電流検出方法２によれば、ＰＷＭ信号の１周期の時間で、Ｕ相オフセット電流値を算出できる。つまり、ロータの空転中でもＵ相オフセット電流値を短時間で算出できるので、ロータの空転が阻害されにくい。その結果、例えば、モータ４の減速や異音などの意図しない挙動の発生を抑制できる。 As described above, according to the current detection method 2, the U-phase offset current value can be calculated in the time of one cycle of the PWM signal. That is, since the U-phase offset current value can be calculated in a short time even during the idling of the rotor, the idling of the rotor is less likely to be hindered. As a result, for example, it is possible to suppress the occurrence of unintended behavior such as deceleration of the motor 4 and abnormal noise.
　図１８は、Ｕ相オフセット電流値を演算する処理の一例を示す波形図である。図１９は、Ｗ相オフセット電流値を演算する処理の一例を示す波形図である。図１９に示されるように、Ｗ相オフセット電流値（又は、Ｖ相オフセット電流値）も、Ｕ相オフセット電流値と同様に算出できる。 FIG. 18 is a waveform diagram showing an example of processing for calculating the U-phase offset current value. FIG. 19 is a waveform diagram showing an example of processing for calculating the W-phase offset current value. As shown in FIG. 19, the W-phase offset current value (or V-phase offset current value) can be calculated in the same manner as the U-phase offset current value.
　図１８は、ＰＷＭ信号生成部３２が第１周期区間を有する各相のＰＷＭ信号をいずれも５０％のデューティ比で生成する場合を例示する。ＰＷＭ信号生成部３２は、一部のアームをロータの空転中に第１通電パターンでオンさせる第１区間Ｑ１と一部のアームをロータの空転中に第２通電パターンでオンさせる第２区間Ｑ２と全ての上アーム又は全ての下アームをロータの空転中に第３通電パターンでオンさせる第３区間Ｑ３とを含む第１周期区間を有する各相のＰＷＭ信号を生成する。図１８に示す例では、第１周期区間は、検出１回目のタイミングを含む第１区間Ｑ１と検出２回目のタイミングを含む第２区間Ｑ２と全ての上アームをオンさせる第３区間Ｑ３とを含む。電流検出部２７は、第１区間Ｑ１に電流検出器２４に流れる第１相の第１電流値と第２区間Ｑ２に電流検出器２４に流れる第１相の第２電流値との和の半分を、第１電流値又は第２電流値から差し引く。この例では、電流検出部２７は、第２電流値から差し引くことで、第１相のオフセット電流値を演算する。図１８は、第１相がＵ相の場合を例示する。 FIG. 18 illustrates a case where the PWM signal generation unit 32 generates the PWM signals of each phase having the first period section at a duty ratio of 50%. The PWM signal generation unit 32 has a first section Q1 in which some arms are turned on in the first energization pattern while the rotor is idling, and a second section Q2 in which some arms are turned on in the second energization pattern while the rotor is idling. And all the upper arms or all the lower arms are turned on in the third energization pattern during idling of the rotor, and the PWM signal of each phase having the first period section including the third section Q3 is generated. In the example shown in FIG. 18, the first period section includes a first section Q1 including the timing of the first detection, a second section Q2 including the timing of the second detection, and a third section Q3 in which all the upper arms are turned on. include. The current detector 27 is half the sum of the first current value of the first phase flowing through the current detector 24 in the first section Q1 and the second current value of the first phase flowing through the current detector 24 in the second section Q2. Is subtracted from the first current value or the second current value. In this example, the current detection unit 27 calculates the offset current value of the first phase by subtracting it from the second current value. FIG. 18 illustrates the case where the first phase is the U phase.
　図１９は、ＰＷＭ信号生成部３２が第２周期区間を有する各相のＰＷＭ信号をいずれも５０％のデューティ比で生成する場合を例示する。ＰＷＭ信号生成部３２は、一部のアームをロータの空転中に第４通電パターンでオンさせる第４区間Ｑ４と一部のアームをロータの空転中に第５通電パターンでオンさせる第５区間Ｑ５と全ての上アーム又は全ての下アームをロータの空転中に第６通電パターンでオンさせる第６区間Ｑ６とを含む第２周期区間を有する各相のＰＷＭ信号を生成する。図１９に示す例では、第２周期区間は、検出１回目のタイミングを含む第４区間Ｑ４と検出２回目のタイミングを含む第５区間Ｑ５と全ての上アームをオンさせる第６区間Ｑ６とを含む。電流検出部２７は、第４区間Ｑ４に電流検出器２４に流れる第２相の第３電流値と第５区間Ｑ５に電流検出器２４に流れる第２相の第４電流値との和の半分を、第３電流値又は第４電流値から差し引く。この例では、電流検出部２７は、第４電流値から差し引くことで、第２相のオフセット電流値を演算する。図１９は、第２相がＷ相の場合を例示する。なお、第２周期区間は、第１周期区間に隣接する区間でもよいし、第１周期区間との間に一又は複数の周期区間を挟んだ区間でもよいし、第１周期区間と同じ区間でもよい。 FIG. 19 illustrates a case where the PWM signal generation unit 32 generates PWM signals of each phase having a second period section at a duty ratio of 50%. The PWM signal generation unit 32 has a fourth section Q4 in which some arms are turned on in the fourth energization pattern while the rotor is idling, and a fifth section Q5 in which some arms are turned on in the fifth energization pattern while the rotor is idling. And generate a PWM signal for each phase having a second period section including a sixth section Q6 that turns on all upper arms or all lower arms in a sixth energization pattern during idling of the rotor. In the example shown in FIG. 19, the second period section includes a fourth section Q4 including the timing of the first detection, a fifth section Q5 including the timing of the second detection, and a sixth section Q6 in which all the upper arms are turned on. include. The current detector 27 is half the sum of the third current value of the second phase flowing through the current detector 24 in the fourth section Q4 and the fourth current value of the second phase flowing through the current detector 24 in the fifth section Q5. Is subtracted from the third current value or the fourth current value. In this example, the current detection unit 27 calculates the offset current value of the second phase by subtracting it from the fourth current value. FIG. 19 illustrates a case where the second phase is the W phase. The second cycle section may be a section adjacent to the first cycle section, a section having one or more cycle sections sandwiched between the first cycle section, or the same section as the first cycle section. good.
　例えば、電流検出部２７は、インバータ２３がロータを回転させている時に電流検出器２４に流れる第１相の相電流の電流値を、第１相のオフセット電流値に応じて補正してもよい。同様に、電流検出部２７は、インバータ２３がロータを回転させている時に電流検出器２４に流れる第２相の相電流の電流値を、第２相のオフセット電流値に応じて補正してもよい。例えば、第１相はＵ相、第２相はＷ相であるが、他の組み合わせでもよい。 For example, the current detection unit 27 may correct the current value of the phase current of the first phase flowing through the current detector 24 when the inverter 23 is rotating the rotor according to the offset current value of the first phase. .. Similarly, the current detection unit 27 may correct the current value of the phase current of the second phase flowing through the current detector 24 when the inverter 23 is rotating the rotor according to the offset current value of the second phase. good. For example, the first phase is the U phase and the second phase is the W phase, but other combinations may be used.
　電流検出部２７は、例えば、第１相のオフセット電流値と第２相のオフセット電流値から、３相の相電流の総和が零であることを利用して、第３相のオフセット電流値を検出（演算）してもよい。第３相は、例えばＶ相である。電流検出部２７は、インバータ２３がロータを回転させている時に電流検出器２４に流れる第３相の相電流を、検出（演算）された第３相のオフセット電流値に応じて補正してもよい。 For example, the current detection unit 27 obtains the offset current value of the third phase from the offset current value of the first phase and the offset current value of the second phase by utilizing the fact that the sum of the phase currents of the three phases is zero. It may be detected (calculated). The third phase is, for example, the V phase. Even if the current detection unit 27 corrects the phase current of the third phase flowing through the current detector 24 when the inverter 23 is rotating the rotor according to the detected (calculated) offset current value of the third phase. good.
　例えば、電流検出部２７は、第１相のオフセット電流値を演算し、第２相のオフセット電流値を演算し、それらの演算結果から残りの第３相のオフセット電流値を演算し、演算した３相のオフセット電流値をメモリに記憶する。３相のオフセット電流値がメモリに記憶された後、モータ４がインバータ２３により起動し、インバータ２３がロータを回転させる。 For example, the current detection unit 27 calculates the offset current value of the first phase, calculates the offset current value of the second phase, calculates the offset current value of the remaining third phase from those calculation results, and calculates the calculation. The three-phase offset current value is stored in the memory. After the three-phase offset current values are stored in the memory, the motor 4 is started by the inverter 23, and the inverter 23 rotates the rotor.
　電流検出部２７は、インバータ２３がロータを回転させている時に、少なくとも２回の電流検出を行うことで、３相の相電流の各々の電流値を検出する。電流検出部２７は、ＰＷＭ信号の１周期ごとに検出される３相の相電流の各々の電流値から、メモリに事前に記憶した３相のオフセット電流値を、ＰＷＭ信号の１周期ごとに差し引くことで、３相の相電流Ｉｕ，Ｉｖ，Ｉｗのそれぞれの電流検出値を演算する。これにより、電流検出部２７は、インバータ２３がロータを回転させている時に電流検出器２４に流れる各相の相電流を、各相のオフセット電流値に応じて補正することになるので、３相の相電流Ｉｕ，Ｉｖ，Ｉｗの各々の電流検出値から検出誤差が除去される。ＰＷＭ信号生成部３２は、検出誤差が除去された補正後の３相の相電流Ｉｕ，Ｉｖ，Ｉｗの各々の電流検出値を用いて、インバータ２３がロータを回転させている時の３相のＰＷＭ信号を生成することで、モータ４の回転をインバータ２３により高精度に制御できる。 The current detection unit 27 detects the current value of each of the three-phase phase currents by detecting the current at least twice while the inverter 23 is rotating the rotor. The current detection unit 27 subtracts the three-phase offset current value stored in advance in the memory from each of the three-phase phase currents detected in each cycle of the PWM signal for each cycle of the PWM signal. Therefore, the current detection values of the three-phase phase currents Iu, Iv, and Iw are calculated. As a result, the current detection unit 27 corrects the phase current of each phase flowing through the current detector 24 when the inverter 23 is rotating the rotor, according to the offset current value of each phase. Therefore, the three-phase current detection unit 27 corrects the phase current of each phase. The detection error is removed from each of the current detection values of the phase currents Iu, Iv, and Iw. The PWM signal generation unit 32 uses the current detection values of the corrected three-phase currents Iu, Iv, and Iw from which the detection error has been removed, and uses the current detection values of the three-phase when the inverter 23 is rotating the rotor. By generating the PWM signal, the rotation of the motor 4 can be controlled with high accuracy by the inverter 23.
　なお、電流検出部２７、通電パターン生成部３５、電流検出タイミング調整部３４、初期位置推定部３８の各機能は、不図示の記憶装置に読み出し可能に記憶されるプログラムによってＣＰＵ（Central Processing Unit）が動作することにより実現される。例えば、これらの各機能は、ＣＰＵを含むマイクロコンピュータにおけるハードウェアとソフトウェアとの協働により実現される。 The functions of the current detection unit 27, the energization pattern generation unit 35, the current detection timing adjustment unit 34, and the initial position estimation unit 38 are CPU (Central Processing Unit) by a program readable and stored in a storage device (not shown). Is realized by the operation of. For example, each of these functions is realized by the collaboration of hardware and software in a microcomputer including a CPU.
　以上、モータ制御装置、モータシステム及びモータ制御方法を実施形態により説明したが、本発明は上記の実施形態に限定されるものではない。他の実施形態の一部又は全部との組み合わせや置換などの種々の変形及び改良が、本発明の範囲内で可能である。 Although the motor control device, the motor system, and the motor control method have been described above by the embodiment, the present invention is not limited to the above embodiment. Various modifications and improvements, such as combinations and substitutions with some or all of the other embodiments, are possible within the scope of the present invention.
　例えば、インバータの直流側に流れる電流の電流値に対応する検出信号を出力する電流検出器は、正側母線に流れる電流の電流値に対応する検出信号を出力するものでもよい。また、電流検出器は、ＣＴ（Current Transformer）等のセンサでもよい。 For example, the current detector that outputs the detection signal corresponding to the current value of the current flowing on the DC side of the inverter may output the detection signal corresponding to the current value of the current flowing on the positive bus. Further, the current detector may be a sensor such as CT (Current Transformer).
　本国際出願は、２０２０年３月３１日に出願した日本国特許出願第２０２０－０６４１４７号に基づく優先権を主張するものであり、日本国特許出願第２０２０－０６４１４７号の全内容を本国際出願に援用する。 This international application claims priority based on Japanese Patent Application No. 2020-064147 filed on March 31, 2020, and the entire contents of Japanese Patent Application No. 2020-064147 are included in this international application. Invite to.
　１－１　モータシステム
　４　モータ
　２１　直流電源
　２２ａ　正側母線
　２２ｂ　負側母線
　２３　インバータ
　２４　電流検出器
　２７　電流検出部
　３０　ベクトル制御部
　３２　ＰＷＭ信号生成部
　３３　駆動回路
　３４　電流検出タイミング調整部
　３５　通電パターン生成部
　３６　クロック発生部
　３７　キャリア発生部
　３８　初期位置推定部
　１００－１　モータ制御装置
　Ｕｐ，Ｖｐ，Ｗｐ，Ｕｎ，Ｖｎ，Ｗｎ　アーム 1-1 Motor system 4 Motor 21 DC power supply 22a Positive side bus 22b Negative side bus 23 Inverter 24 Current detector 27 Current detection unit 30 Vector control unit 32 PWM signal generation unit 33 Drive circuit 34 Current detection timing adjustment unit 35 Energization pattern generation Part 36 Clock generation part 37 Carrier generation part 38 Initial position estimation part 100-1 Motor control device Up, Vp, Wp, Un, Vn, Wn arm

Claims (8)

  1. 　全アームのうち通電パターン毎に異なる一部のアームをオンすることで、ロータを有するモータを通電させるインバータと、
    　前記インバータの直流側に接続される電流検出器と、
    　前記全アームを前記ロータの空転中にオフさせる第１期間と前記一部のアームを前記空転中に第１通電パターンでオンさせる第２期間と前記一部のアームを前記空転中に第２通電パターンでオンさせる第３期間とを１周期に含む各相のＰＷＭ信号を生成するＰＷＭ信号生成部と、
    　前記第２期間に前記電流検出器に流れる第１基準電流と前記第３期間に前記電流検出器に流れる第２基準電流とを検出する電流検出部と、を備える、モータ制御装置。     An inverter that energizes a motor with a rotor by turning on some of the arms that are different for each energization pattern,
    A current detector connected to the DC side of the inverter and
    The first period in which all the arms are turned off during the idling of the rotor, the second period in which some of the arms are turned on in the first energization pattern during the idling, and the second energization of the part of the arms during the idling. A PWM signal generator that generates a PWM signal for each phase that includes a third period that is turned on in a pattern in one cycle.
    A motor control device including a current detection unit that detects a first reference current flowing through the current detector in the second period and a second reference current flowing through the current detector in the third period.
  2. 　前記第２期間と前記第３期間との合計期間は、前記第１期間よりも短い、請求項１に記載のモータ制御装置。 The motor control device according to claim 1, wherein the total period of the second period and the third period is shorter than that of the first period.
  3. 　前記電流検出部は、
    　前記インバータが前記ロータを回転させている時に前記電流検出器に流れる第１相の相電流を、前記第１相の前記第１基準電流に応じて補正し、
    　前記インバータが前記ロータを回転させている時に前記電流検出器に流れる第２相の相電流を、前記第２相の前記第２基準電流に応じて補正する、請求項１に記載のモータ制御装置。     The current detector
    The phase current of the first phase flowing through the current detector when the inverter is rotating the rotor is corrected according to the first reference current of the first phase.
    The motor control device according to claim 1, wherein the phase current of the second phase flowing through the current detector when the inverter is rotating the rotor is corrected according to the second reference current of the second phase. ..
  4. 　前記ＰＷＭ信号生成部は、
    　補正後の前記第１相の相電流を用いて、前記インバータが前記ロータを回転させている時の前記第１相のＰＷＭ信号を生成し、
    　補正後の前記第２相の相電流を用いて、前記インバータが前記ロータを回転させている時の前記第２相のＰＷＭ信号を生成する、請求項３に記載のモータ制御装置。     The PWM signal generation unit
    Using the corrected phase current of the first phase, the PWM signal of the first phase when the inverter is rotating the rotor is generated.
    The motor control device according to claim 3, wherein the corrected phase current of the second phase is used to generate a PWM signal of the second phase when the inverter is rotating the rotor.
  5. 　前記電流検出部は、
    　前記第１相の前記第１基準電流と前記第２相の前記第２基準電流から、第３相の第３基準電流を演算し、
    　前記インバータが前記ロータを回転させている時に前記電流検出器に流れる前記第３相の相電流を、前記第３相の前記第３基準電流に応じて補正する、請求項３に記載のモータ制御装置。     The current detector
    From the first reference current of the first phase and the second reference current of the second phase, the third reference current of the third phase is calculated.
    The motor control according to claim 3, wherein the phase current of the third phase flowing through the current detector when the inverter is rotating the rotor is corrected according to the third reference current of the third phase. Device.
  6. 　前記ＰＷＭ信号生成部は、
    　補正後の前記第３相の相電流を用いて、前記インバータが前記ロータを回転させている時の前記第３相のＰＷＭ信号を生成する、請求項５に記載のモータ制御装置。     The PWM signal generation unit
    The motor control device according to claim 5, wherein the corrected phase current of the third phase is used to generate a PWM signal of the third phase when the inverter is rotating the rotor.
  7. 　請求項１項に記載のモータ制御装置と、前記モータと、を備える、モータシステム。 A motor system including the motor control device according to claim 1 and the motor.
  8. 　インバータの全アームのうち通電パターン毎に異なる一部のアームをオンすることで、ロータを有するモータを通電させるモータ制御装置が行うモータ制御方法であって、
    　前記全アームを前記ロータの空転中にオフさせる第１期間と前記一部のアームを前記空転中に第１通電パターンでオンさせる第２期間と前記一部のアームを前記空転中に第２通電パターンでオンさせる第３期間とを１周期に含む各相のＰＷＭ信号を生成し、
    　前記インバータの直流側に接続される電流検出器に前記第２期間に流れる第１基準電流と前記電流検出器に前記第３期間に流れる第２基準電流とを検出する、モータ制御方法。     This is a motor control method performed by a motor control device that energizes a motor having a rotor by turning on some of all the arms of the inverter, which are different for each energization pattern.
    The first period in which all the arms are turned off during the idling of the rotor, the second period in which some of the arms are turned on in the first energization pattern during the idling, and the second energization of the part of the arms during the idling. Generate a PWM signal for each phase that includes the third period to be turned on in the pattern in one cycle.
    A motor control method for detecting a first reference current flowing in the second period and a second reference current flowing in the current detector in the third period in a current detector connected to the DC side of the inverter.
PCT/JP2021/011058 2020-03-31 2021-03-18 Motor control device, motor system, and motor control method WO2021200209A1 (en)

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JP2007166695A (en) * 2005-12-09 2007-06-28 Hitachi Appliances Inc Control device of motor
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JP2012147599A (en) * 2011-01-13 2012-08-02 Mitsubishi Electric Corp Air conditioner
JP2013220007A (en) * 2012-03-14 2013-10-24 E-Bike Corp Control method of sensorless motor, control device of sensorless motor and electric device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007166695A (en) * 2005-12-09 2007-06-28 Hitachi Appliances Inc Control device of motor
JP2009077503A (en) * 2007-09-20 2009-04-09 Hitachi Appliances Inc Motor controller and controller for air conditioner
JP2012147599A (en) * 2011-01-13 2012-08-02 Mitsubishi Electric Corp Air conditioner
JP2013220007A (en) * 2012-03-14 2013-10-24 E-Bike Corp Control method of sensorless motor, control device of sensorless motor and electric device

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