SHUNT HYBRID ACTIVE POWER FILTER TO ALLEVIATE THE HARMONICS OF VSC-HVDC IN OFF-SHORE WIND FARMS

This paper studies the possible reduction of total harmonic distortion via shunt hybrid active power filter implemented in wind farms with transmission network using Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) link. In general, the conversion process in the VSC-HVDC stations produces significant current harmonic problems and interfaces with other system associated. Conventionally, the passive filters were implemented to reduce such current harmonics, but they were suffering from creating resonance with other parameters of the power system. So, this paper aims to design a novel shunt hybrid active power filter on a basis of sinusoidal current control to reduce the current harmonics of the HVDC converter in wind farm generation unit. It is revealed that, hybrid active filters in these conditions provide the best achievable harmonic damping with lower rating than pure active filters and without any adverse interference with power system than passive filters. With implementation of shunt hybrid active power filter, the harmonic currents produced by the HVDC converter at the generation side are greatly attenuated. So, the source only needs to supply the fundamental component of the load. Simulation results with PSCAD/EMTDC verify the effectiveness of the proposed method.