Patent ID: 6307759
Filing Date: 2001-10-23
Classification: H02M,H02P

Abstract:
A control device for an electric power translating device which comprises a converter or converting an AC voltage into a DC voltage through rectification, a smoothing capacitor connected at the DC side of the converter, an inverter for inverting the DC voltage across the smoothing capacitor into an AC and for supplying the AC to an AC motor and means for controlling the voltage, frequency or phase in the AC output from the inverter, further comprising means for detecting an instantaneous output current of the inverter, means for subjecting the detected instantaneous output current to a coordinate conversion into a rotary coordinate system and for computing two current components of orthogonal axes in vector, means for detecting a ripple component associated with the rectification by the converter from one of the said two current components of exciting and torque current components, and means for regulating one of frequency and phase in the AC output of the inverter based on the detected ripple component so as to reduce the detected ripple component.