An improved hybrid filter for compensation of current and voltage harmonics for varying rectifier loads

This paper presents a topology of an Improved Hybrid Filter System (IHF) with self supporting DC bus, to eliminate harmonics in supply current and voltage at the point of common coupling (PCC), created due to nonlinear load, typically rectifier load. The compensation principle and filtering characteristics of the system are discussed in detail. A PI controller over average DC bus voltage of hybrid combination of active filters is used for the control of IHF. Operation of IHF is investigated under dynamic change of loading conditions. The effectiveness of the scheme to protect overloading of passive filters is demonstrated under distorted supply conditions along with harmonic compensation.