ABNORMALITY DETERMINATION DEVICE AND ABNORMALITY DETERMINATION METHOD FOR PUMP DRIVE DEVICE AND ABNORMALITY DETERMINATION DEVICE AT START OF MOTOR

To appropriately make an abnormality determination of a pump driven by a motor even when there is a period in which actual rotational frequency of the motor cannot be detected due to control of an operation of the motor.SOLUTION: In an abnormality determination of a pump drive device, actual rotational frequency of a motor driving a pump is calculated without a sensor, target rotational frequency of the motor is instructed to control the operation of the motor, and an abnormality is determined when a cumulative period of a case where a difference between the target rotational frequency and the actual rotational frequency is a predetermined value or greater exceeds a predetermined threshold value. When the difference between the target rotational frequency and the actual rotational frequency is within a predetermined range, reduction processing for reducing the cumulative period to a value smaller than the threshold value is performed, and in a period in which the actual rotational frequency cannot be detected due to control of the operation of the motor, the reduction processing is suppressed.SELECTED DRAWING: Figure 3 【課題】モータの運転の制御のためにモータの実回転数を検出できない期間があっても、モータにより駆動されるポンプの異常判定を的確に行なう。【解決手段】ポンプ駆動装置の異常判定は、ポンプを駆動するモータの実回転数をセンサレスで求め、モータの目標回転数を指示して、モータの運転を制御し、目標回転数と前記実回転数との乖離が所定以上である場合の累積期間が予め定めた閾値を超えた場合に異常と判定する。ここで、目標回転数と実回転数との前記乖離が予め定めた範囲内となった場合には、累積期間を閾値より小さな値に低減する低減処理を行ない、かつモータの運転の制御のために実回転数を検出できない期間には、この低減処理を抑制する。【選択図】図３