A Switched Reluctance Generator Based WEGS and a Bidirectional DC-DC Converter Interfaced BES Microgrid with Uninterrupted Power

Abstract

A microgrid consisting of a wind energy generation system (WEGS) using a switched reluctance generator (SRG) and a bidirectional buck-boost converter (BDC) interfaced battery energy storage (BES) is presented in this work. The high efficiency, simple construction, neither magnets nor windings on the rotor, less heat dissipation on the rotor, suitable for wide speed range, fault-tolerant capability, and low maintenance are the attractive features of switched reluctance machine as compared to other electrical machines. The DC power sources are integrated at the point of common coupling (PCC) via a voltage source converter (VSC) where the utility grid and AC loads are connected. The microgrid operates in two modes: grid-connected mode (GCM) and standalone mode (SAM), according to the availability of the utility grid. The microgrid operates in GCM in the presence of the utility grid where WEGS, BES and utility grid function to meet the load requirements. Different power quality indices at the utility grid in GCM are improved by controlling the VSC according to reference grid currents generated by a mixed second and third-order generalized integrator (MSTOGI). Thereby, the microgrid follows the IEEE-519 recommended limits of interconnection. In the utility grid failure, the microgrid transfers from GCM to SAM and provides uninterrupted power to the connected loads. In SAM, the load requirements are fulfilled from WEGS and BES following the IEEE-1547 standard.