JP4445423B2

JP4445423B2 - Motor control method and control apparatus

Info

Publication number: JP4445423B2
Application number: JP2005094035A
Authority: JP
Inventors: 誠渋谷; 秀樹渡辺; 一広原; 真一郎若生
Original assignee: Honda Motor Co Ltd; Sanden Corp
Current assignee: Honda Motor Co Ltd; Sanden Holdings Corp
Priority date: 2005-03-29
Filing date: 2005-03-29
Publication date: 2010-04-07
Anticipated expiration: 2025-03-29
Also published as: JP2006280070A

Description

本発明は、モータの制御方法および制御装置に関し、とくに、バッテリー等から電源の供給を受け、インバータ回路を介してモータを駆動制御するに際し、電源遮断用リレーや予備充電回路開閉用リレーの溶着を容易に検出できるようにし、所望のモータの制御を確実に行うことができるようにした方法および装置に関する。本発明は、とくに、車両用空調装置に使用される冷媒圧縮用圧縮機の駆動用モータ、中でもモータを内蔵した電動圧縮機のモータの制御に好適なものである。 The present invention relates to a motor control method and control device, and in particular, when a power supply is supplied from a battery or the like and the motor is driven and controlled via an inverter circuit, welding of a power cutoff relay and a precharge circuit switching relay is performed. The present invention relates to a method and an apparatus which can be easily detected and can reliably control a desired motor. The present invention is particularly suitable for controlling a motor for driving a compressor for compressing a refrigerant used in a vehicle air conditioner, particularly an electric compressor having a built-in motor.

バッテリー等からの電圧を電源平滑用コンデンサーを介してモータ駆動用として供給するモータの制御回路に、電源からの回路を開閉する電源遮断用リレーを設ける構造はよく知られている（たとえば、特許文献１、特許文献２）。また、モータの制御回路に予備充電回路を設け、その回路に予備充電回路開閉用リレーを設ける構造も知られている。 A structure in which a power supply cutoff relay that opens and closes a circuit from a power supply is well-known in a motor control circuit that supplies a voltage from a battery or the like for driving a motor through a power supply smoothing capacitor is well known (for example, Patent Documents). 1, Patent Document 2). There is also known a structure in which a precharge circuit is provided in a motor control circuit and a precharge circuit switching relay is provided in the circuit.

上記のような、電源遮断用リレーと電源平滑用コンデンサーを備えた従来のモータの制御装置においては、該電源遮断用リレーが溶着した場合、それを検出できるようにはなっていなかった。また、予備充電回路を有し、その回路に予備充電回路開閉用リレーが設けられている場合にも、該予備充電回路開閉用リレーの溶着を検出できるようにはなっていなかった。これらリレーが溶着すると、モータの制御回路全体の正常な制御動作はできなくなる。また、インバータ回路を介してモータを駆動制御する装置の場合、モータが回転しているときに溶着検出動作を行わせると、インバータ回路に組み込まれている半導体スイッチング素子を破壊するおそれがある。
特開平８−８５３３５号公報特開平９−１０９６６７号公報 In the conventional motor control apparatus including the power cutoff relay and the power smoothing capacitor as described above, when the power cutoff relay is welded, it cannot be detected. Further, even when a precharge circuit is provided and a precharge circuit switching relay is provided in the circuit, the welding of the precharge circuit open / close relay cannot be detected. When these relays are welded, normal control operation of the entire motor control circuit cannot be performed. Further, in the case of a device that drives and controls a motor via an inverter circuit, if the welding detection operation is performed while the motor is rotating, the semiconductor switching element incorporated in the inverter circuit may be destroyed.
JP-A-8-85335 JP-A-9-109667

そこで本発明の課題は、インバータ回路を介してモータを駆動制御する装置において、とくに電源遮断用リレーの溶着を、好ましくは予備充電回路開閉用リレーの溶着まで、容易にかつ確実に検出できるようにしたモータの制御方法および制御装置を提供することにある。 SUMMARY OF THE INVENTION An object of the present invention is to make it possible to easily and reliably detect welding of a power shut-off relay, preferably welding of a relay for opening / closing a precharge circuit, in an apparatus for driving and controlling a motor via an inverter circuit. It is an object of the present invention to provide a motor control method and a control apparatus.

上記課題を解決するために、本発明に係るモータの制御方法は、電源遮断用リレーと、前記電源遮断用リレー開閉回路と、予備充電回路及び予備充電回路開閉用リレーと、前記予備充電回路開閉用リレー開閉回路と、電源平滑用コンデンサーと、モータ制御用インバータ回路を備えたモータの制御装置に関して、前記電源遮断用リレー及び予備充電回路開閉用リレーをオフするよう両リレー開閉回路が動作している場合、前記電源平滑用コンデンサーに電圧がある閾値Ｖ１以上残っているとき、前記電源平滑用コンデンサーに残っている電荷を前記モータ制御用インバータ回路を通じて前記モータに通電することで放電し、放電前後の前記電圧の差がある閾値Ｖ２以下のとき、電源遮断用リレーが溶着していると判断し、放電前後の前記電圧の差が前記閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したときは、放電動作終了から一定時間経過前後の前記電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断することを特徴とする方法からなる。 In order to solve the above-described problems, a motor control method according to the present invention includes a power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, and the preliminary charging circuit switching. With regard to a motor control device including a relay switching circuit for power supply, a capacitor for smoothing power, and an inverter circuit for motor control, both relay switching circuits are operated so as to turn off the power cutoff relay and the precharging circuit switching relay. When the voltage remaining in the power supply smoothing capacitor exceeds a certain threshold value V1, the electric charge remaining in the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit. wherein when the voltage difference is the threshold value V2 of the following, it is determined that the power cut-off relay is welded, the discharge before and after the voltage of the When the difference is larger than the threshold value V2 and it is determined that the power cutoff relay is not welded, when the voltage difference before and after a certain time has elapsed from the end of the discharge operation is greater than or equal to the threshold value V3, It is determined that the relay is welded .

このモータの制御方法においては、前記放電前後の電圧の差がある閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したとき、放電動作終了から一定時間経過したとき、該一定時間経過前後の電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断することができる。 In this motor control method, when it is determined that the voltage difference between before and after the discharge is greater than a certain threshold value V2 and the power shut-off relay is not welded, and when a certain time has elapsed from the end of the discharge operation, the certain time When the voltage difference before and after the lapse is equal to or greater than a certain threshold value V3, it can be determined that the precharge circuit switching relay is welded.

すなわち、本発明においては、電源遮断用リレーと電源平滑用コンデンサーを内蔵したモータの制御装置で、前記リレーの溶着を検出するため、前記リレーをオンする前に、前記コンデンサーにチャージされている電荷をある通電パターンにてモータ巻線に通電することで放電し、放電前後の電圧を比較することで、前記リレーの溶着を判断するのである。電源遮断用リレーが溶着していると、電源から電圧が供給され続けるので、放電してもコンデンサー部の電圧が下がらず、放電前後の電圧の差が閾値Ｖ２以下にならないので、リレーが溶着していると判断できる。また、電源遮断用リレーが溶着していないと判断したときには、放電動作終了から一定時間経過前後の電圧を比較することで、予備充電回路開閉用リレーが正常に働いているか否か、つまり、予備充電回路開閉用リレーの溶着を判断するのである。予備充電回路開閉用リレーが溶着していると、上記一定時間の間に予備充電回路から電圧が供給され続けるので、コンデンサー部の電圧が上がってしまい、一定時間経過前後の電圧の差が閾値Ｖ３以上になるので、予備充電回路開閉用リレーが溶着していると判断できる。 That is, in the present invention, in a motor control device incorporating a power cutoff relay and a power smoothing capacitor, the charge charged in the capacitor before the relay is turned on in order to detect welding of the relay. Is discharged by energizing the motor winding in a certain energization pattern, and the welding of the relay is determined by comparing the voltages before and after the discharge. If the power shut-off relay is welded, the voltage will continue to be supplied from the power supply. Therefore, even if it is discharged, the capacitor voltage will not drop, and the voltage difference before and after the discharge will not fall below the threshold V2. Can be judged. If it is determined that the power shut-off relay is not welded, it is determined whether or not the pre-charging circuit switching relay is operating normally by comparing the voltages before and after the elapse of a certain time from the end of the discharging operation, that is, The welding of the charging circuit opening / closing relay is determined. If the preliminary charging circuit switching relay is welded, the voltage continues to be supplied from the preliminary charging circuit during the predetermined time, so that the voltage of the capacitor portion rises, and the voltage difference before and after the predetermined time elapses is the threshold value V3. As described above, it can be determined that the preliminary charging circuit switching relay is welded.

また、本発明に係るモータの制御方法は、電源遮断用リレーと、前記電源遮断用リレー開閉回路と、予備充電回路及び予備充電回路開閉用リレーと、前記予備充電回路開閉用リレー開閉回路と、電源平滑用コンデンサーと、モータ制御用インバータ回路と、モータ回転検出手段を備えたモータの制御装置に関して、前記電源遮断用リレー及び予備充電回路開閉用リレーをオフするよう両リレー開閉回路が動作しているとき、前記電源平滑用コンデンサーに電圧がある閾値Ｖ１以上残っているとき、前記電源平滑用コンデンサーに残っている電荷を前記モータ制御用インバータ回路を通じて前記モータに通電することで放電し、放電前後の前記電圧の差がある閾値Ｖ２以下のとき、電源遮断用リレーが溶着していると判断し、放電前後の前記電圧の差が前記閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したときは、放電動作終了から一定時間経過前後の前記電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断する制御方法であって、前記電源平滑用コンデンサーに残っている電荷を放電する前に、モータが回転しているかを確認し、モータが回転しているときは、モータの回転が停止するまで放電動作を行わないようにすることを特徴とする方法からなる。すなわち、前述の如く、モータが回転しているときに溶着検出動作を行わせると、インバータ回路に組み込まれている半導体スイッチング素子を破壊するおそれがあるので、モータの回転が停止してから溶着検出動作を行い、スイッチング素子の破壊のおそれを完全に除去した状態で溶着検出動作を行わせるようにしたものである。 The motor control method according to the present invention includes a power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, and the preliminary charging circuit switching relay switching circuit, With respect to a motor control device including a power supply smoothing capacitor, a motor control inverter circuit, and a motor rotation detection means, both relay open / close circuits operate to turn off the power shutoff relay and the precharge circuit open / close relay. When the voltage of the power supply smoothing capacitor exceeds a certain threshold value V1, the electric charge remaining in the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit. wherein when the voltage difference is the threshold value V2 of the following of, determines that the power cut-off relay is welded, the electric before and after discharge Is larger than the threshold value V2, and when it is determined that the power shut-off relay is not welded, the precharge circuit is opened and closed when the voltage difference is greater than or equal to the threshold value V3 before and after a predetermined time has elapsed since the end of the discharge operation. Control method for judging that the relay is welded, and before discharging the electric charge remaining in the power supply smoothing capacitor, check whether the motor is rotating, and when the motor is rotating The discharge operation is not performed until the rotation of the motor is stopped. That is, as described above, if the welding detection operation is performed while the motor is rotating, the semiconductor switching element incorporated in the inverter circuit may be destroyed. Therefore, the welding detection is performed after the rotation of the motor is stopped. The operation is performed, and the welding detection operation is performed in a state where the possibility of destruction of the switching element is completely removed.

このモータの制御方法においても、前記放電前後の電圧の差がある閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したとき、放電動作終了から一定時間経過したとき、該一定時間経過前後の電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断することができる。 Also in this motor control method, when it is determined that the voltage difference between before and after the discharge is larger than a certain threshold value V2 and the power-off relay is not welded, when the predetermined time has elapsed from the end of the discharge operation, the predetermined time When the voltage difference before and after the lapse is equal to or greater than a certain threshold value V3, it can be determined that the precharge circuit switching relay is welded.

また、本発明に係るモータの制御方法は、電源遮断用リレーと、前記電源遮断用リレー開閉回路と、予備充電回路及び予備充電回路開閉用リレーと、前記予備充電回路開閉用リレー開閉回路と、電源平滑用コンデンサーと、モータ制御用インバータ回路を備えたモータの制御装置に関して、制御用電源が投入された直後であって、前記電源遮断用リレー及び予備充電回路開閉用リレーをオフするよう両リレー開閉回路が動作しているとき、前記電源平滑用コンデンサーに電圧がある閾値Ｖ１以上残っているとき、前記電源平滑用コンデンサーに残っている電荷を前記モータ制御用インバータ回路を通じて前記モータに通電することで放電し、放電前後の前記電圧の差がある閾値Ｖ２以下のとき、電源遮断用リレーが溶着していると判断し、放電前後の前記電圧の差が前記閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したときは、放電動作終了から一定時間経過前後の前記電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断することを特徴とする方法からなる。すなわち、制御用電源が投入された直後で未だモータの回転制御が行われていない段階で、先ず、電源遮断用リレーの溶着検出動作を行わせるようにしたものである。 The motor control method according to the present invention includes a power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, and the preliminary charging circuit switching relay switching circuit, Regarding a motor control device including a power supply smoothing capacitor and a motor control inverter circuit, both relays immediately after the control power supply is turned on and to turn off the power supply cutoff relay and the precharge circuit switching relay When the switching circuit is operating, when the voltage remains in the power supply smoothing capacitor over a certain threshold value V1, the electric charge remaining in the power supply smoothing capacitor is supplied to the motor through the motor control inverter circuit. in discharging, when the difference of the voltage is the threshold V2 follows before and after the discharge, it is determined that the power cut-off relay is welded, release When the voltage difference between before and after is greater than the threshold value V2, and it is determined that the power cutoff relay is not welded, when the voltage difference between before and after a certain time has elapsed from the end of the discharge operation is greater than or equal to a threshold value V3, It is determined that the precharge circuit switching relay is welded . That is, immediately after the control power supply is turned on, at the stage where the motor rotation control is not yet performed, the welding detection operation of the power cutoff relay is first performed.

さらに、本発明に係るモータの制御方法は、電源遮断用リレーと、前記電源遮断用リレー開閉回路と、予備充電回路及び予備充電回路開閉用リレーと、前記予備充電回路開閉用リレー開閉回路と、電源平滑用コンデンサーと、モータ制御用インバータ回路と、モータ回転検出手段を備えたモータの制御装置に関して、制御用電源が投入された直後であって、前記電源遮断用リレー及び予備充電回路開閉用リレーをオフするよう両リレー開閉回路が動作しているとき、前記電源平滑用コンデンサーに電圧がある閾値Ｖ１以上残っているとき、前記電源平滑用コンデンサーに残っている電荷を前記モータ制御用インバータ回路を通じて前記モータに通電することで放電し、放電前後の前記電圧の差がある閾値Ｖ２以下のとき、電源遮断用リレーが溶着していると判断し、放電前後の前記電圧の差が前記閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したときは、放電動作終了から一定時間経過前後の前記電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断する制御方法であって、前記電源平滑用コンデンサーに残っている電荷を放電する前に、モータが回転しているかを確認し、モータが回転しているときは、モータの回転が停止するまで放電動作を行わないようにすることを特徴とする方法からなる。すなわち、制御用電源が投入された直後において、念のためモータが回転しているかを確認し、モータが回転しているときは、モータの回転が停止してから溶着検出動作を行い、スイッチング素子の破壊のおそれを完全に除去した状態で溶着検出動作を行わせるようにしたものである。 Further, the motor control method according to the present invention includes a power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, and the preliminary charging circuit switching relay switching circuit, A power supply smoothing capacitor, a motor control inverter circuit, and a motor control device including a motor rotation detection means, the power supply cutoff relay and the precharge circuit open / close relay immediately after the control power supply is turned on When both relay switching circuits are operating so as to turn off the power, when the voltage remaining in the power supply smoothing capacitor exceeds a certain threshold value V1, the electric charge remaining in the power supply smoothing capacitor is passed through the motor control inverter circuit. discharged by energizing the motor, when the difference of the voltage is the threshold V2 follows before and after the discharge, the power cut-off relay Was judged to be dressed, the difference of the voltage before and after the discharge is larger than the threshold value V2, when the power cut-off relay is determined not to be welded, of the voltage before and after a predetermined time has elapsed from the discharge operation ends When the difference is greater than or equal to a threshold value V3, the control method determines that the precharge circuit switching relay is welded, and before the electric charge remaining in the power smoothing capacitor is discharged, the motor rotates. And when the motor is rotating, the discharging operation is not performed until the motor stops rotating. That is, immediately after the control power is turned on, it is checked whether the motor is rotating just in case. When the motor is rotating, the welding detection operation is performed after the rotation of the motor is stopped. In this state, the welding detection operation is performed in a state in which the fear of destruction is completely removed.

上記のようなモータの制御方法は、基本的に、電源平滑用コンデンサーとモータ制御用インバータ回路を備えたあらゆるモータの制御装置に適用可能であるが、とくに、前記モータが電動圧縮機駆動用のモータである場合に好適である。 The motor control method as described above is basically applicable to any motor control device having a power supply smoothing capacitor and a motor control inverter circuit. In particular, the motor is used for driving an electric compressor. This is suitable for a motor.

本発明に係るモータの制御装置は、電源遮断用リレーと、前記電源遮断用リレー開閉回路と、予備充電回路及び予備充電回路開閉用リレーと、前記予備充電回路開閉用リレー開閉回路と、電源平滑用コンデンサーと、モータ制御用インバータ回路を備えたモータの制御装置において、前記電源遮断用リレー及び予備充電回路開閉用リレーをオフするよう両リレー開閉回路が動作している場合、前記電源平滑用コンデンサーに電圧がある閾値Ｖ１以上残っているとき、前記電源平滑用コンデンサーに残っている電荷を前記モータ制御用インバータ回路を通じて前記モータに通電することで放電し、放電前後の前記電圧の差がある閾値Ｖ２以下のとき、電源遮断用リレーが溶着していると判断し、放電前後の前記電圧の差が前記閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したときは、放電動作終了から一定時間経過前後の前記電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断する制御・判断手段を有することを特徴とするものからなる。 The motor control device according to the present invention includes a power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, the preliminary charging circuit switching relay switching circuit, and a power smoothing circuit. In the motor control device including the condenser for motor and the inverter circuit for motor control, when both relay switching circuits are operating so as to turn off the power shut-off relay and precharge circuit switching relay, the power smoothing capacitor when the voltage remains certain threshold V1 or more, the charge remaining on the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit, a threshold of a difference of the voltage before and after discharge V2 when the following is determined that the power cut-off relay is welded, a large difference between the voltage before and after discharge than the threshold value V2 In addition, when it is determined that the power shutoff relay is not welded, the precharge circuit switching relay is welded when the voltage difference before and after the lapse of a predetermined time from the end of the discharge operation is equal to or greater than a threshold value V3. consisting of those characterized by having a control and determination means for determining for.

このモータの制御装置においては、前記制御・判断手段が、さらに、前記放電前後の電圧の差がある閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したとき、放電動作終了から一定時間経過したとき、該一定時間経過前後の電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断することができる。 In this motor control device, when the control / determination means further determines that the voltage difference before and after the discharge is greater than a certain threshold value V2 and the power cutoff relay is not welded, the discharge operation ends. When a certain time has elapsed, when the voltage difference before and after the certain time elapses is equal to or greater than a threshold value V3, it can be determined that the precharge circuit switching relay is welded.

また、本発明に係るモータの制御装置は、電源遮断用リレーと、前記電源遮断用リレー開閉回路と、予備充電回路及び予備充電回路開閉用リレーと、前記予備充電回路開閉用リレー開閉回路と、電源平滑用コンデンサーと、モータ制御用インバータ回路と、モータ回転検出手段を備えたモータの制御装置において、前記電源遮断用リレー及び予備充電回路開閉用リレーをオフするよう両リレー開閉回路が動作しているとき、前記電源平滑用コンデンサーに電圧がある閾値Ｖ１以上残っているとき、前記電源平滑用コンデンサーに残っている電荷を前記モータ制御用インバータ回路を通じて前記モータに通電することで放電し、放電前後の前記電圧の差がある閾値Ｖ２以下のとき、電源遮断用リレーが溶着していると判断し、放電前後の前記電圧の差が前記閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したときは、放電動作終了から一定時間経過前後の前記電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断する制御・判断手段を有し、該手段はさらに、前記電源平滑用コンデンサーに残っている電荷を放電する前に、モータが回転しているかを確認し、モータが回転しているときは、モータの回転が停止するまで放電動作を行わないようにするモータ回転検出手段を有することを特徴とするものからなる。 The motor control device according to the present invention includes a power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, and the preliminary charging circuit switching relay switching circuit, In a motor control device provided with a power smoothing capacitor, a motor control inverter circuit, and a motor rotation detecting means, both relay open / close circuits operate to turn off the power shut-off relay and the precharge circuit open / close relay. When the voltage of the power supply smoothing capacitor exceeds a certain threshold value V1, the electric charge remaining in the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit. wherein when the voltage difference is the threshold value V2 of the following of, determines that the power cut-off relay is welded, the electric before and after discharge Is larger than the threshold value V2, and when it is determined that the power shut-off relay is not welded, the precharge circuit is opened and closed when the voltage difference is greater than or equal to the threshold value V3 before and after a predetermined time has elapsed since the end of the discharge operation. Control / determination means for judging that the relay for welding is welded, which means further confirms whether the motor is rotating before discharging the electric charge remaining in the power supply smoothing capacitor, When the motor is rotating, it has a motor rotation detecting means for preventing the discharging operation until the rotation of the motor is stopped.

このモータの制御装置においても、前記制御・判断手段が、さらに、前記放電前後の電圧の差がある閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したとき、放電動作終了から一定時間経過したとき、該一定時間経過前後の電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断する構成とすることができる。 Also in this motor control device, when the control / determination means further determines that the voltage difference before and after the discharge is greater than a certain threshold value V2 and the power cutoff relay is not welded, the discharge operation ends. When a certain time elapses, when the voltage difference before and after the certain time elapses is a threshold value V3 or more, it can be determined that the precharge circuit switching relay is welded.

また、本発明に係るモータの制御装置は、電源遮断用リレーと、前記電源遮断用リレー開閉回路と、予備充電回路及び予備充電回路開閉用リレーと、前記予備充電回路開閉用リレー開閉回路と、電源平滑用コンデンサーと、モータ制御用インバータ回路を備えたモータの制御装置において、制御用電源が投入された直後であって、前記電源遮断用リレー及び予備充電回路開閉用リレーをオフするよう両リレー開閉回路が動作しているとき、前記電源平滑用コンデンサーに電圧がある閾値Ｖ１以上残っているとき、前記電源平滑用コンデンサーに残っている電荷を前記モータ制御用インバータ回路を通じて前記モータに通電することで放電し、放電前後の前記電圧の差がある閾値Ｖ２以下のとき、電源遮断用リレーが溶着していると判断し、放電前後の前記電圧の差が前記閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したときは、放電動作終了から一定時間経過前後の前記電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断する制御・判断手段を有することを特徴とするものからなる。 The motor control device according to the present invention includes a power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, and the preliminary charging circuit switching relay switching circuit, In a motor control device including a power supply smoothing capacitor and a motor control inverter circuit, both relays immediately after the control power supply is turned on to turn off the power shutoff relay and the precharge circuit open / close relay When the switching circuit is operating, when the voltage remains in the power supply smoothing capacitor over a certain threshold value V1, the electric charge remaining in the power supply smoothing capacitor is supplied to the motor through the motor control inverter circuit. in discharging, when the difference of the voltage is the threshold V2 follows before and after the discharge, it is determined that the power cut-off relay is welded, release When the voltage difference between before and after is greater than the threshold value V2, and it is determined that the power cutoff relay is not welded, when the voltage difference between before and after a certain time has elapsed from the end of the discharge operation is greater than or equal to a threshold value V3, It comprises control / determination means for determining that the precharge circuit switching relay is welded .

このモータの制御装置においても、前記制御・判断手段が、さらに、放電前後の前記電圧の差がある閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したとき、放電動作終了から一定時間経過したとき、該一定時間経過前後の電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断することができる。 Also in the control apparatus of the motor, the control and determination means further discharge the voltage is greater than the threshold value V2 which is the difference between before and after, when the power cut-off relay is determined that not welded, the discharging operation ends When a certain time has elapsed, when the voltage difference before and after the certain time elapses is equal to or greater than a threshold value V3, it can be determined that the precharge circuit switching relay is welded.

さらに、本発明に係るモータの制御装置は、電源遮断用リレーと、前記電源遮断用リレー開閉回路と、予備充電回路及び予備充電回路開閉用リレーと、前記予備充電回路開閉用リレー開閉回路と、電源平滑用コンデンサーと、モータ制御用インバータ回路と、モータ回転検出手段を備えたモータの制御装置において、制御用電源が投入された直後であって、前記電源遮断用リレー及び予備充電回路開閉用リレーをオフするよう両リレー開閉回路が動作しているとき、前記電源平滑用コンデンサーに電圧がある閾値Ｖ１以上残っているとき、前記電源平滑用コンデンサーに残っている電荷を前記モータ制御用インバータ回路を通じて前記モータに通電することで放電し、放電前後の前記電圧の差がある閾値Ｖ２以下のとき、電源遮断用リレーが溶着していると判断し、放電前後の前記電圧の差が前記閾値Ｖ２よりも大きく、電源遮断用リレーが溶着していないと判断したときは、放電動作終了から一定時間経過前後の前記電圧の差がある閾値Ｖ３以上のとき、予備充電回路開閉用リレーが溶着していると判断する制御・判断手段を有し、該手段はさらに、前記電源平滑用コンデンサーに残っている電荷を放電する前に、モータが回転しているかを確認し、モータが回転しているときは、モータの回転が停止するまで放電動作を行わないようにするモータ回転検出手段を有することを特徴とするものからなる。 Furthermore, the motor control device according to the present invention includes a power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, and the preliminary charging circuit switching relay switching circuit, In a motor control device including a power supply smoothing capacitor, a motor control inverter circuit, and a motor rotation detection means, immediately after the control power supply is turned on, the power cutoff relay and the precharge circuit open / close relay When both relay switching circuits are operating so as to turn off the power, when the voltage remaining in the power supply smoothing capacitor exceeds a certain threshold value V1, the electric charge remaining in the power supply smoothing capacitor is passed through the motor control inverter circuit. discharged by energizing the motor, when the difference of the voltage is the threshold V2 follows before and after the discharge, the power cut-off relay Was judged to be dressed, the difference of the voltage before and after the discharge is larger than the threshold value V2, when the power cut-off relay is determined not to be welded, of the voltage before and after a predetermined time has elapsed from the discharge operation ends Control / determination means for determining that the precharge circuit switching relay is welded when the difference is greater than or equal to a threshold value V3 , and further, before discharging the electric charge remaining in the power supply smoothing capacitor. And a motor rotation detecting means for checking whether the motor is rotating and, when the motor is rotating, preventing the discharging operation until the motor stops rotating. .

上記のようなモータの制御装置も、基本的に、電源平滑用コンデンサーとモータ制御用インバータ回路を備えたあらゆるモータの制御装置に適用可能であるが、とくに、前記モータが電動圧縮機駆動用のモータである場合に好適である。 The motor control device as described above is basically applicable to any motor control device including a power supply smoothing capacitor and a motor control inverter circuit. In particular, the motor is used for driving an electric compressor. This is suitable for a motor.

本発明に係るモータの制御方法および制御装置によれば、電源平滑用コンデンサーとモータ制御用インバータ回路を備えたモータの制御装置において、電源遮断用リレーをオンする前に、電源平滑用コンデンサーにチャージされている電荷をある通電パターンにてモータ巻線に通電することで放電し、放電前後の電圧を比較することで、電源遮断用リレーの溶着を容易にかつ確実に判断することができる。また、電源遮断用リレーが溶着していないと判断したときには、放電動作終了から一定時間経過前後の電圧を比較することで、予備充電回路開閉用リレーの溶着を容易にかつ確実に判断することができる。インバータ回路に不具合を生じさせることなくこれらリレーの溶着を判断することにより、モータの制御装置の正常な動作の確保、信頼性の向上が可能となる。 According to the motor control method and control device of the present invention, in the motor control device including the power supply smoothing capacitor and the motor control inverter circuit, the power supply smoothing capacitor is charged before turning on the power cutoff relay. It is possible to easily and surely determine the welding of the power shut-off relay by discharging the charged electric charge to the motor winding in a certain energization pattern and comparing the voltages before and after the discharge. In addition, when it is determined that the power shut-off relay is not welded, it is possible to easily and reliably determine the welding of the precharge circuit switching relay by comparing the voltages before and after the elapse of a certain time from the end of the discharging operation. it can. By determining whether or not these relays are welded without causing problems in the inverter circuit, it is possible to ensure the normal operation of the motor control device and improve the reliability.

以下に、本発明の望ましい実施の形態を、図面を参照しながら説明する。
図１は、本発明の一実施態様に係るモータの制御装置の回路図を示している。図１において、１はバッテリー等の直流電源を示しており、電源１から、電源遮断用リレー２を介して（つまり、電源遮断用リレー２オンの状態にて）、電源平滑用コンデンサー３を介してモータ制御用インバータ回路４に電圧が印加される。電源遮断用リレー２は、電源遮断用リレー開閉回路５を介して開閉制御される。電源遮断用リレー開閉回路５の制御手段は、本実施態様では、インバータ制御回路６内に組み込まれている。インバータ回路４の各スイッチング素子Ｕ、Ｖ、Ｗ、Ｘ、Ｙ、Ｚは、インバータ制御回路６の制御部７からの信号に基づいて作動される。インバータ制御回路６からは、Ｕ、Ｖ、Ｗ相の三相形態にてモータ８に電圧が印加され、モータ８の回転が制御される。モータ８としては、たとえば、車両用空調装置に使用される電動圧縮機に内蔵されたモータを使用できる。モータ８の回転は、上記Ｕ、Ｖ、Ｗ相に接続され、インバータ制御回路６内に組み込まれたモータ回転検出部９によって検出できるようになっている。また、電源平滑用コンデンサー３における電圧（つまり、放電前後の電圧および放電後の一定時間経過前後の電圧）は、インバータ制御回路６内に組み込まれた電圧検出部１０によって検出できるようになっている。このインバータ制御回路６には、制御用電源１１から制御回路に必要な電力が供給されるようになっている。 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a circuit diagram of a motor control apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a direct current power source such as a battery, which is connected from a power source 1 through a power shut-off relay 2 (that is, when the power shut-off relay 2 is on) and through a power smoothing capacitor 3. Thus, a voltage is applied to the motor control inverter circuit 4. The power cutoff relay 2 is controlled to open and close via a power cutoff relay switching circuit 5. In this embodiment, the control means of the power cutoff relay switching circuit 5 is incorporated in the inverter control circuit 6. Each switching element U, V, W, X, Y, Z of the inverter circuit 4 is operated based on a signal from the control unit 7 of the inverter control circuit 6. From the inverter control circuit 6, a voltage is applied to the motor 8 in a three-phase form of U, V, and W phases, and the rotation of the motor 8 is controlled. As the motor 8, for example, a motor built in an electric compressor used in a vehicle air conditioner can be used. The rotation of the motor 8 is connected to the U, V, and W phases, and can be detected by a motor rotation detector 9 incorporated in the inverter control circuit 6. Further, the voltage in the power supply smoothing capacitor 3 (that is, the voltage before and after the discharge and the voltage before and after the lapse of a certain time after the discharge) can be detected by the voltage detection unit 10 incorporated in the inverter control circuit 6. . The inverter control circuit 6 is supplied with power necessary for the control circuit from the control power supply 11.

また、電源１の回路に対し、予備充電回路１２が設けられており、予備充電回路１２には、予備充電回路開閉用リレー１３および予備充電回路開閉用リレー開閉回路１４と、電流制限抵抗１５が設けられている。予備充電回路開閉用リレー開閉回路１４の制御手段も、本実施態様では、インバータ制御回路６内に組み込まれている。 Further, a preliminary charging circuit 12 is provided for the circuit of the power source 1, and the preliminary charging circuit 12 includes a preliminary charging circuit switching relay 13, a preliminary charging circuit switching relay switching circuit 14, and a current limiting resistor 15. Is provided. In this embodiment, the control means for the relay charging / closing circuit 14 for opening / closing the precharging circuit is also incorporated in the inverter control circuit 6.

上記のような回路構成を備えたモータの制御装置について、図２に示すようなフローに沿ってリレーの溶着検出が行われる。ただし、図２には図示していないが、該フローは上記制御用電源１１が投入された直後に実行されるようになっている。 With respect to the motor control device having the circuit configuration as described above, relay welding is detected along a flow shown in FIG. However, although not shown in FIG. 2, the flow is executed immediately after the control power supply 11 is turned on.

図２に示す溶着検出フローにおいては、先ず、モータ回転検出部９によってモータ回転中か否かが検出され、モータの回転が停止してから溶着検出が行われる（ステップＳ１）。次に、電圧検出部１０によって検出された電源平滑用コンデンサー３の残電圧が、予め設定されたある閾値Ｖ１以上残っているか否かが判断され（ステップＳ２）、残っていない場合はフローを終了し、Ｖ１以上残っている場合には、コンデンサー３部における放電前の電圧Ｖｂを格納する（ステップＳ３）。 In the welding detection flow shown in FIG. 2, first, whether or not the motor is rotating is detected by the motor rotation detection unit 9, and welding detection is performed after the rotation of the motor is stopped (step S1). Next, it is determined whether or not the remaining voltage of the power supply smoothing capacitor 3 detected by the voltage detection unit 10 remains over a predetermined threshold value V1 (step S2). If V1 or more remains, the pre-discharge voltage Vb in the capacitor 3 is stored (step S3).

次いで、放電動作を行わせ、電源平滑用コンデンサー３に残っている電荷が、モータ制御用インバータ回路４を通じてモータ８の巻線に通電されることで放電される（ステップＳ４）。コンデンサー３部における放電後の電圧Ｖａが格納され（ステップＳ５）、放電前後の電圧の差Ｖｂ−Ｖａが予め設定されたある閾値Ｖ２以下か否かが判断される（ステップＳ６）。閾値Ｖ２以下である場合には、電源遮断用リレー２が溶着していると判定され、電源遮断用リレー溶着確定処理が行われる（ステップＳ７）。この溶着確定処理としては、たとえば、警告発信や、モータ制御動作停止が挙げられる。 Next, a discharging operation is performed, and the electric charge remaining in the power supply smoothing capacitor 3 is discharged by energizing the windings of the motor 8 through the motor control inverter circuit 4 (step S4). The voltage Va after discharging in the capacitor 3 is stored (step S5), and it is determined whether or not the voltage difference Vb−Va before and after discharging is equal to or less than a predetermined threshold value V2 (step S6). When it is equal to or lower than the threshold value V2, it is determined that the power cutoff relay 2 is welded, and a power cutoff relay welding confirmation process is performed (step S7). Examples of the welding confirmation process include a warning transmission and a motor control operation stop.

ステップＳ６で、電源遮断用リレー２が溶着していないと判断された場合、まず、一定時間経過前のコンデンサー３部における電圧Ｖｔａが検出されて格納され（ステップＳ８）、一定時間経過したか否かが判断され（ステップＳ９）、一定時間経過後のコンデンサー３部における電圧Ｖｔｂが検出されて格納される（ステップＳ１０）。そして、これら一定時間経過前後の電圧の差Ｖｔｂ−Ｖｔａが予め設定されたある閾値Ｖ３以上か否かが判断され（ステップＳ１１）、閾値Ｖ３以上と判定されたときには、予備充電回路開閉用リレー１３が溶着していると判断され、予備充電回路開閉用リレー溶着確定処理が行われる（ステップＳ１２）。予備充電回路開閉用リレー溶着確定処理後、およびステップＳ１１で予備充電回路開閉用リレー１３が溶着していないと判断された場合には、このフローを終了する。 If it is determined in step S6 that the power shut-off relay 2 is not welded, first, the voltage Vta in the capacitor 3 portion before a certain time has elapsed is detected and stored (step S8), and whether or not a certain time has elapsed. Is determined (step S9), and the voltage Vtb in the capacitor 3 after a predetermined time has elapsed is detected and stored (step S10). Then, it is determined whether or not the voltage difference Vtb−Vta before and after the lapse of the predetermined time is greater than or equal to a predetermined threshold value V3 (step S11). Is determined to be welded, and preliminary welding circuit opening / closing relay welding confirmation processing is performed (step S12). After the preliminary charging circuit opening / closing relay welding confirmation process and when it is determined in step S11 that the preliminary charging circuit opening / closing relay 13 is not welded, this flow is ended.

本発明に係るモータの制御方法および制御装置は、基本的に、電源平滑用コンデンサーとモータ制御用インバータ回路を備えたあらゆるモータの制御装置に適用可能である。とくに、対象となるモータが電動圧縮機駆動用のモータである場合、中でも車両用空調装置に使用される電動圧縮機駆動用のモータである場合に好適である。 The motor control method and control device according to the present invention are basically applicable to any motor control device including a power supply smoothing capacitor and a motor control inverter circuit. In particular, it is suitable when the target motor is a motor for driving an electric compressor, especially when it is a motor for driving an electric compressor used in a vehicle air conditioner.

本発明の一実施態様に係るモータの制御装置の回路図である。It is a circuit diagram of the control apparatus of the motor which concerns on one embodiment of this invention. 図１の装置の制御の一例を示すフロー図である。It is a flowchart which shows an example of control of the apparatus of FIG.

Explanation of symbols

１電源
２電源遮断用リレー
３電源平滑用コンデンサー
４モータ制御用インバータ回路
５電源遮断用リレー開閉回路
６インバータ制御回路
７制御部
８モータ
９モータ回転検出部
１０電圧検出部
１１制御用電源
１２予備充電回路
１３予備充電回路開閉用リレー
１４予備充電回路開閉用リレー開閉回路
１５電流制限抵抗 DESCRIPTION OF SYMBOLS 1 Power supply 2 Power supply cutoff relay 3 Power supply smoothing capacitor 4 Motor control inverter circuit 5 Power supply cutoff relay open / close circuit 6 Inverter control circuit 7 Control section 8 Motor 9 Motor rotation detection section 10 Voltage detection section 11 Control power supply 12 Precharge Circuit 13 Pre-charging circuit switching relay 14 Pre-charging circuit switching relay switching circuit 15 Current limiting resistor

Claims

A power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, the preliminary charging circuit switching relay switching circuit, a power smoothing capacitor, and a motor control inverter circuit. With respect to the motor control device provided, when both relay switching circuits are operating so as to turn off the power cutoff relay and the precharging circuit switching relay, the voltage in the power smoothing capacitor remains above a certain threshold value V1. when the the remaining charge in the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit, when the difference of the voltage before and after the discharge is the threshold value V2 or less, the power cutoff relay was judged to be welded, the difference of the voltage before and after the discharge is larger than the threshold value V2, and the power cut-off relay is welded When it is determined that it is not, when the discharge end of the operation of the front and rear fixed time elapses the voltage higher than the threshold value V3 there is a difference in, pre-charging circuit opening and closing relay is characterized in that judged to be welded, the motor Control method.

A power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, the preliminary charging circuit switching relay switching circuit, a power source smoothing capacitor, and a motor control inverter circuit; In the motor control device provided with the motor rotation detecting means, when both relay open / close circuits are operating so as to turn off the power cutoff relay and the precharge circuit open / close relay, there is a voltage in the power smoothing capacitor. when remaining threshold V1 or higher, said remaining charge on power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit, when the difference of the voltage before and after the discharge is the threshold value V2 or less , it is determined that the power cut-off relay is welded, greater than the difference of the voltage before and after discharging the threshold V2, the power supply When the cross-sectional relay is determined not to be welded, when the discharge end of the operation of the front and rear fixed time elapses the voltage higher than the threshold value V3 there is a difference in, pre-charging circuit opening and closing relay is determined to be welded control Before discharging the electric charge remaining in the power supply smoothing capacitor, check whether the motor is rotating, and if the motor is rotating, perform a discharging operation until the motor stops rotating. A method for controlling a motor, characterized in that it is not performed.

A power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, the preliminary charging circuit switching relay switching circuit, a power smoothing capacitor, and a motor control inverter circuit. When the control power supply is turned on and the both relay open / close circuits are operating to turn off the power shut-off relay and the precharge circuit open / close relay, the power smoothing is performed. when the use condenser remains above the threshold V1 with the voltage, the charge remaining on the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit, the difference of the voltage before and after discharge when a threshold V2 or less, it is determined that the power cut-off relay is welded, the difference of the discharge around the voltage than the threshold value V2 When it is determined that the relay for power cutoff is not welded, the precharge circuit opening / closing relay is welded when the voltage difference is greater than or equal to the threshold value V3 before and after the lapse of a certain time from the end of the discharge operation. A method for controlling a motor, comprising: determining.

A power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, the preliminary charging circuit switching relay switching circuit, a power source smoothing capacitor, and a motor control inverter circuit; With regard to the motor control device provided with the motor rotation detecting means, immediately after the control power is turned on, both relay open / close circuits operate so as to turn off the power cutoff relay and the precharge circuit open / close relay. When the voltage of the power supply smoothing capacitor exceeds a certain threshold value V1, the electric charge remaining in the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit. wherein when the voltage difference is the threshold value V2 of the following, it is determined that the power cut-off relay is welded, the discharge before and after the voltage of the When the difference is larger than the threshold value V2 and it is determined that the power cutoff relay is not welded, when the voltage difference before and after a certain time has elapsed from the end of the discharge operation is greater than or equal to the threshold value V3, It is a control method for determining that the relay is welded. Before discharging the electric charge remaining in the power supply smoothing capacitor, check whether the motor is rotating, and when the motor is rotating, A method for controlling a motor, wherein the discharging operation is not performed until the rotation of the motor is stopped.

It said motor is a motor for driving an electric compressor, the motor control method according to any one of claims 1-4.

A power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, the preliminary charging circuit switching relay switching circuit, a power smoothing capacitor, and a motor control inverter circuit. In the motor control apparatus provided, when both relay switching circuits are operating so as to turn off the power shut-off relay and the precharging circuit switching relay, the voltage in the power smoothing capacitor remains above a certain threshold value V1. when the the remaining charge in the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit, when the difference of the voltage before and after the discharge is the threshold value V2 or less, the power cutoff relay was judged to be welded, further, difference between the voltage before and after the discharge is larger than the threshold value V2, the power cut-off relay When it is determined not to be wearing, when the discharge operation is completed a predetermined time has elapsed the voltage threshold V3 or there is a difference in the front and rear, the control and determination means for pre-charging circuit opening and closing relay is determined to be welded A motor control device comprising: a motor control device;

A power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, the preliminary charging circuit switching relay switching circuit, a power source smoothing capacitor, and a motor control inverter circuit; In the motor control device provided with the motor rotation detecting means, when both relay open / close circuits are operating so as to turn off the power shut-off relay and the precharge circuit open / close relay, the power smoothing capacitor has a voltage. when remaining threshold V1 or higher, said remaining charge on power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit, when the difference of the voltage before and after the discharge is the threshold value V2 or less , it is determined that the power cut-off relay is welded, further larger than the difference of the voltage before and after discharging the threshold V2 , When the power cut-off relay is determined that not welded, when the discharge end of the operation of the front and rear fixed time elapses the voltage higher than the threshold value V3 which is the difference, determines that the pre-charging circuit opening and closing relay is welded Control / judgment means for checking whether the motor is rotating before discharging the electric charge remaining in the power supply smoothing capacitor, and when the motor is rotating, A motor control device comprising motor rotation detecting means for preventing discharge operation until rotation of the motor stops.

A power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, the preliminary charging circuit switching relay switching circuit, a power smoothing capacitor, and a motor control inverter circuit. In the motor control apparatus provided, the power supply smoothing is performed immediately after the control power is turned on and when both the relay open / close circuits operate to turn off the power shut-off relay and the precharge circuit open / close relay. when the use condenser remains above the threshold V1 with the voltage, the charge remaining on the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit, the difference of the voltage before and after discharge when a threshold V2 or less, it is determined that the power cut-off relay is welded, further, difference between the voltage before and after the discharge is the threshold If it is greater than 2 and it is determined that the power shut-off relay is not welded, the precharge circuit switching relay is welded when the voltage difference before and after a certain time has elapsed from the end of the discharge operation is equal to or greater than a threshold value V3. A motor control apparatus comprising a control / determination unit that determines that the motor is present.

A power cutoff relay, the power cutoff relay switching circuit, a preliminary charging circuit and a preliminary charging circuit switching relay, the preliminary charging circuit switching relay switching circuit, a power source smoothing capacitor, and a motor control inverter circuit; In the motor control device equipped with the motor rotation detecting means, immediately after the control power is turned on, both relay open / close circuits operate to turn off the power shut-off relay and the precharge circuit open / close relay. When the voltage of the power supply smoothing capacitor exceeds a certain threshold value V1, the electric charge remaining in the power supply smoothing capacitor is discharged by energizing the motor through the motor control inverter circuit. the when the voltage difference is the threshold value V2 of the following, it is determined that the power cut-off relay is welded, further, the discharge of the front and rear When the voltage difference is larger than the threshold value V2 and it is determined that the power cutoff relay is not welded, the precharge circuit is used when the voltage difference before and after elapse of a certain time from the end of the discharge operation is a threshold value V3 or more Control / determination means for determining that the open / close relay is welded, which means further confirms whether the motor is rotating before discharging the electric charge remaining in the power supply smoothing capacitor, A motor control device comprising motor rotation detection means for preventing a discharging operation from being performed until the motor stops rotating when the motor is rotating.

It said motor is a motor for driving an electric compressor, the motor control device according to any one of claims 6-9.