Power Quality Improvement with Reduced Switching Frequency in Grid Connected Wind Energy System

The rapid developments in the technology, industrial revolution and growing population stimulated the demand for energy. Fossil fuels have dominated energy sector for many years. But the situation is rapidly changing due to climate changes trigged by greenhouse gas emissions of fossil fuels and fast depletions in the reserves of fossil fuels. This has forced the policy makers to encourage use of renewable energy instead of fossil fuels. The use of grid integrated wind turbines has been increasing at a greater pace, leading to power quality problems in the grid. In this a paper, a STATCOM control scheme is proposed to mitigate the power quality problems posed due to grid integration of wind turbines. Power Balance Theory (PBT) is employed to generate reference currents for grid synchronization. Another advantage of the proposed scheme is to obtain the desired Unity Power Factor (UPF) and Total Harmonic Distortion (THD) in the system at the desired levels with a reduced switching frequency of the IGBT switches of the STATCOM. The proposed system along with control scheme is simulated in MATLAB/SIMULINK. To highlight the reduced switching frequency capability of proposed Space Vector Current Controller (SVCC), a comparative analysis is also performed with simple two step On-Off Current Controller (OOCC) and the results have been presented for both the controllers for the purpose of comparison.