Patent ID: 6507167
Filing Date: 2003-01-14
Classification: H02M,Y02B

Abstract:
In a motor driving inverter system rectifying/smoothing an alternating current power, and driving a motor by performing pulse width modulation, a power factor compensation device for the motor driving inverter system, comprising:an inverter connected to the motor; a microprocessor for detecting zero crossing points of the alternating current power to determine time periods therebetween, and for sequentially outputting a driving snal corresponding to one of a plurality of sine wave form voltage values each representing an interval between two consecutive zero crossing points, wherein said one is selected according to the detected result of a time period between the detected zero crossing points and a voltage of the alternating current power, in a state where the plurality of sine wave form voltage values corresponding to the voltage of the alternating current power and frequencies are internally stored; and a switching transistor connected in parallel to the inverter, and switched according to the driving signal, a duty of the driving signal being varied correspondingly to said selected one of the plurality of sine wave form voltage values.