Patent ID: 6320772
Filing Date: 2001-11-20
Classification: H02M,Y02B,Y02P

Abstract:
A converter circuit comprising:a reactor connected to an AC power supply;a PWM converter circuit connected to the reactor, said PWM converter circuit having a high speed diode, a rectifier diode and a switching element connected in parallel to the rectifier diode;an input current detection means for detecting an input current of said PWM converter circuit;a DC voltage detection means for detecting an output voltage of said PWM converter circuit;a voltage level detection means connected to said AC power supply, said detection means detecting whether or not an input voltage is at a constant level; anda control means for measuring a variation period of a detection result of the voltage level detection means to judge a power supply frequency and for controlling said PWM converter circuit based on a judgment result for the power supply frequency, a detection result from said voltage level detection means, an input current detected by said input current detection means, and an output voltage detected by said DC voltage detection means.