Optimal Passive Filter Designs for Offshore Wind Farm

Abstract

Today, wind energy plays a significant role in the energy market due to its potential to reduce the dependence of electric power generation on fossil fuels and enhance environmental sustainability. Particularly, offshore wind farms offer more efficient energy generation by providing access to higher and more consistent wind speeds compared to onshore wind farms. However, the integration of offshore wind farms into electrical grids presents various power quality problems, such as harmonic distortion and under or over-voltage levels. In this study, harmonic analysis and passive filter designs are addressed for an offshore wind farm utilizing a type 3 doubly-fed induction generator (DFIG) turbine. Firstly, an offshore wind turbine with DFIG is modelled in the MATLAB Simulink environment. Secondly, the harmonic pollution of the system is analyzed. Then, two passive filter types, Ctype and LCL filters, are optimally designed. The studied optimization design approach aims to minimize the total voltage harmonic distortion and voltage levels in p.u. as defined in IEEE 519 standards. In addition to that, one of the most widely used metaheuristic optimization algorithm in the literature, the Particle Swarm Optimization (PSO) algorithm, is employed to find optimal filter solutions.