Average Modeling and Hybrid Control of a Three-Phase Series Hybrid Power Filter

This paper presents a detailed study of a Series Hybrid Power Filter (SHPF). The system consists of a small-rated series active power filter and a series tuned passive filter. This combination is suitable for compensating voltage type harmonics-producing load. The hybrid control approach adopted is based on detecting both source current and load voltage harmonics. This technique enhances the compensation characteristics of the proposed system. A low-frequency mathematical model of the series hybrid filter is established. The elaboration of the control law is based on a small-signal averaged model of the converter, computed in the (d,q) synchronous frame. Then, suitable multiple-loops PI controllers are designed on the basis of the system's transfer functions and the use of the linear feedback control. Simulation results are shown in an attempt to verify the mathematical model of the filter and the effectiveness of the hybrid control approach for voltage harmonics compensation.