Bipolar DC Micro-Grid Based Wind Energy Systems

Abstract

This paper describes a bipolar DC micro-grid with a predictive controlled three-level boost converter interfaced wind energy conversion system (WECS). The micro-grid consists of a permanent magnet synchronous generator (PMSG)-based wind energy conversion system, battery energy storage system (BESS) on each pole with DC-loads. The BESS is interfaced to each pole of the bipolar DC micro-grid with a bidirectional buck–boost converter which regulates the individual pole voltages to its reference. The power imbalance in each pole due to unbalanced loading/power generation will lead to the deviation in the pole voltages. In order to balance these bipolar DC-link voltages, a three-level boost converter (TLBC) is used to interface the PMSG and a predictive control is developed to achieve the objectives of maximum power extraction and balancing of bipolar DC-link voltages. Simulation studies are carried using MATLAB/Simulink to examine the performance of the controller for variation in loads and power generation and results are found to be satisfactory.