A novel control strategy for multi-modular shunt active power filter system

In order to solve the problem of large capacity of harmonic compensation, this paper proposes a novel structure for multi-modular Shunt Active Power Filter (SAPF) system, which consists of N unified double DSP-controlled SAPFs and a monitoring unit. An average current control strategy is put forward to improve the system reliability and achieve the redundancy operation. Inside each module, a compound control strategy in abc frame combing PI control with repetitive control is adopted to ensure both the steady-state and dynamic performance. Finally, the proposed control scheme is applied to a prototype, which composes of three modular 50 kVA SAPF, and the results have validated its feasibility and validity.