Optimized Isolated Operation of a WECS- Powered Microgrid with a Battery-Assisted qZSI

This paper presents a battery-assisted quasi-Z source inverter (qZSI) powered by a wind energy conversion system (WECS) with a self-excited induction generator (SEIG). The proposed control algorithm ensures stable supply of the AC load and battery charging in isolated operation. The batteries store excess power so that no wind energy is wasted and also compensate for the WECS power shortage. In addition, fuzzy logic-based optimization algorithms are implemented to capture the maximum available power from both the wind turbine and SEIG at all operating conditions. Their operation, as well as the operation of the battery current controller (BCC), which takes into account the batteries' state of charge (SOC), is coordinated by the master control algorithm to achieve optimal system operation. The performance of the proposed system has been tested through simulations in the MATLAB Simulink over wide ranges of wind speeds and SOC levels.