Power factor preregulators with improved dynamic response

An improved control strategy of standard power factor preregulators (PFPs) is proposed which allows fast output voltage response while maintaining a high power factor. This is obtained by compensating for the intrinsic low-frequency output voltage ripple, thus allowing a higher bandwidth of the output voltage control loop. This method does not require additional sensing, but only a multiplier and simple analog circuitry, and works well with a universal input voltage range. Experimental tests on a boost power converter with average current control confirm the validity of the approach.