Motor control apparatus having function for protecting LCL filter

摘要

A motor control apparatus includes: a PWM rectifier which converts an AC power to a DC power; an LCL filter provided between the AC power supply and the PWM rectifier; a cooling fan for cooling the LCL filter; a temperature detection unit for the LCL filter; an alarm detection unit for detecting an alarm state when a temperature detection value is a predetermined value or more; a time measurement unit for measuring elapsed time from a start of a normal operation of the PWM rectifier; and a protection unit which determines, in accordance with the elapsed time, an alarm generation cause whether the alarm state is generated due to a reverse connection of a power line of the LCL filter or due to a stop of the cooling fan when the alarm state is notified, and performs a protection operation in accordance with the alarm generation cause.

主权项

1. A motor control apparatus comprising:
a PWM rectifier which converts AC power supplied from a three-phase AC power supply to DC power; an LCL filter provided between the three-phase AC power supply and the PWM rectifier; a cooling fan configured to cool the LCL filter; a temperature detection unit configured to detect a temperature of the LCL filter; an alarm detection unit configured to detect an alarm state when a temperature detection value of the temperature detection unit is a predetermined value or more; a time measurement unit configured to measure elapsed time from a start of a normal operation of the PWM rectifier; and a protection unit configured to determine, in accordance with the elapsed time measured by the time measurement unit, an alarm generation cause whether the alarm state is generated due to a reverse connection of a power line of the LCL filter or the alarm state is generated due to a stop of the cooling fan when the alarm state is notified from the alarm detection unit, and performs a protection operation in accordance with the alarm generation cause, wherein the protection unit determines that the power line of the LCL filter has been reversely connected when the alarm state is notified from the alarm detection unit and the elapsed time measured by the time measurement unit is less than the predetermined time, and wherein the protection unit determines that the cooling fan has stopped when the alarm state is notified from the alarm detection unit and the elapsed time measured by the time measurement unit is equal to or more than the predetermined time.