POWER SUPPLY AND METHOD FOR GENERATING SWITCHING SIGNAL FOR TURNING ON/OFF SWITCHING ELEMENT OF CONVERTER UNIT CONSTITUTING THE POWER SUPPLY

摘要

A control circuit (1) calculates the amplitude of a current command every half cycle of the input voltage from an AC power supply (20) by PI control on the basis of the difference between a reference voltage command and the voltage of a capacitor measured by a DC voltage sensing circuit (30) when the sign of the input voltage from the AC power supply (20) measured by an input voltage sensing section (31) changes, divides the amplitude of the current command by the peak value of the previous input voltage, multiplies the quotient by the input voltage to calculate a normalized current command, compares the normalized current command with the input current measured by an input current sensing circuit (32), and thereby generates a switching signal for turning on/off a switching element (38).