Quantitative analysis of shunt active filter compensation characteristics under different rectifier load situations

Active filters have been drawing a lot of attention and have been put into practice to compensate the harmonies generated by nonlinear loads, mainly rectifiers, in electric power systems. By now, the shunt active filter is the most popular type of active filter. It has been noticed that the shunt active filter may have very different compensation characteristics for different types of rectifier loads but no detailed quantitative analysis and results have been reported so far. The purpose of this paper is to investigate and have a good understanding of the compensation characteristics of the shunt active filter under different type and parameters of rectifier converter load. Two approaches are employed. Firstly, circuit analysis based on simplified models for the active filter and the rectifier with different load is carried out, which generates qualitative results that are very helpful to the understanding of different compensation effects. Then computer simulations on a shunt active filter compensating a rectifier load is the major approach to this investigation. The simulation results verify the theoretical analysis and provide a thorough insight of the compensation characteristics of the shunt active filter under different type and parameter of rectifier loads, and therefore hopefully reveal answers to some of the previous questions regarding the compensation characteristics.