Patent ID: 8049455
Filing Date: 2011-11-01
Classification: B60L,H02H,Y02T,Y10S

Abstract:
1. An electric power converter comprising: a converter having switching elements, for converting AC power from an AC power supply into DC power; a capacitor connected in parallel to a DC side of said converter; an inverter having switching elements and being connected in parallel with said capacitor, for driving and controlling a permanent-magnet synchronous motor; a supply-side switch interposed between the AC power supply and an AC side of said converter; a motor-side switch interposed between said inverter and the permanent-magnet synchronous motor; a capacitor-voltage sensor for measuring voltage across said capacitor; and a system controller for controlling said supply-side switch, said converter, said inverter, and said motor-side switch by receiving an input signal from said capacitor-voltage sensor, wherein said system controller, when a voltage measured by said capacitor-voltage sensor becomes equal to or lower than a first predetermined value, turns off all switching elements of said converter and all switching elements of said inverter; when the voltage measured by said capacitor-voltage sensor becomes equal to or lower than a second predetermined value that is smaller than the first predetermined value, turns off said supply-side switch; and when the voltage measured by said capacitor-voltage sensor becomes higher than the second predetermined value, does not turn off said supply-side switch.