Boost Rectifier Power Factor Correction Circuits with Improved Harmonic and Load Voltage Regulation Responses

The time domain step response for rapid load changes can be improved in boost type power factor correction circuits by using a capacitor voltage model. In single phase PFC circuits, the dc bus voltage must have a significant voltage ripple at twice the mains frequency due to energy balance requirements. In traditional implementations, the presence of this ripple voltage causes a trade-off between line current wave shape and speed of the dc output regulatory response. The capacitor voltage model provides a ripple free estimate of the storage capacitor voltage. This allows the bandwidth of the dc bus voltage regulation loop to increase without causing a degradation of line current wave shape. Simulations show that the dc regulatory response is complete within one mains cycle and significant reductions in voltage over and under-shoots are achieved.