Power Factor Compensation of a Controlled Rectifier with Non-Sinusoidal Generator Voltage using Passive Components

In a recent paper we introduced a framework for analysis and design of (possibly nonlinear) power factor (PF) compensators for electrical systems operating in non-sinusoidal (but periodic) regimes with nonlinear loads. In particular, under the standard assumption that the generator is a voltage source with no impedance, we characterized all nonlinear loads whose PF is improved with a given nonlinear compensator. In this brief note we use this framework to study the problem of passive PF compensation of a classical half-bridge controlled rectifier (terminated by a resistor) with non-sinusoidal generator voltage. We give necessary and sufficient conditions for improvement of PF with linear inductors or capacitors, which determine ranges for the compensator parameters that depend on the rectifier fire angle and the amplitude of the voltage source. Given the "phase advance" operation of the rectifier it is expected that capacitive compensation improves PF, it is however less obvious that this can also be achieved (under some suitable conditions) with inductors.