Control of a multimodule parallelable three-phase active power filters

This paper describes different approaches to implement a multi module parallelable three-phase active power filters (APF). These approaches are based on power splitting using several identical active filter modules, or on frequency splitting where each module is dedicated to take car of a specific current harmonic. In this paper, the constraints related to their control blocks allowing to generate the current reference and to drive gating signals for the IGBTs or GTOs are analysed. A pq algorithm associated with resonant current control loops (RCC) are successfully used to control the active power filters. The RCC uses a high dynamic feedback loop with analogy components. For all approaches, the same voltage IP controller is used to regulate the DC bus voltages. Simulation results are presented for a 6 KVA load to demonstrate the effectiveness and the performances of the compensation for the proposed approaches.