CONTROL OF SOLID–STATE TRANSFORMERS FOR WIND POWER INTERFACING

Abstract

Use of renewable energy sources (RES) due to population growth and decentralization is increasing all over the world. Urbanization and consideration for the environment also contribute to the increased use of RES. With advancements in turbine and battery storage technology, the use of wind power has increased significantly. Of the total amount of installed renewable energy capacity of India, 68% of the total production is from wind energy. The intermittent nature of wind energy and related power quality issues like voltage flashing and harmonics, however, provide a substantial barrier. By integrating wind energy into the grid utilising solid state transformers (SST), this issue can be resolved. The regulated and unregulated DC link voltages on either side of the SST are coupled by the DC-DC converter component of the SST. To obtain regulated output voltage, the current fed PWM PS (Phase Shifted) controlled full bridge converter is controlled. A Single Active Bridge (SAB) based SST is utilised for wind energy integration to prevent the circuit’s complexity and to give ease of control. The performance of the system is studied for varying wind speeds using PI, PID and Fuzzy-PID controllers and their performances are compared. The system performance after introduction of a disturbance is also studied. The system is simulated using SIMULINK in MATLAB software.