Improving the dynamic response of power factor correctors using simple digital filters: Moving average filter comparative evaluation

Traditionally, single-phase power factor correctors suffer from a slow response time, characterized by a low voltage loop bandwidth (<; 1Hz) that is necessary to ensure a suitable THD in the input current. This paper examines practical discrete filters to substantially improve the voltage feedback loop bandwidth. As a result of the analysis, the form of a Moving Averaging Filter proves to be an effective solution. The analysis shows that it is an excellent practical filter for PFC control that requires low computational overhead and basic discrete signal theory literacy for its implementation. Often ignored, useful theory/methods with simple implementation are the most important criterion for practicing engineers. Simulation and experimental results confirm the advantages of the technique and validates the theoretical analysis presented in the paper.