De-Loaded Technique Enhanced by Fuzzy Logic Controller to Improve the Resilience of Microgrids Based on Wind Energy and Energy Storage Systems

Abstract

Wind turbine generators (WTGs) are highly sensitive to the disturbances of the grid and tend to disconnect quickly during a voltage dip (when the voltage value is less than 80% of the nominal voltage) or when the frequency is greatly changed. As an increasing number of permanent magnet synchronous generators (PMSGs) are incorporated into the modern power grid, system operators expect PMSG-WT to play an active role in low-voltage ride-through (LVRT) and primary frequency regulation (PFR). Consequently, PMSG-WTs must be capable of supplying additional active power in response to changes in system voltage and frequency. In this context, a new de-loaded technique enhanced by a fuzzy-logic controller is suggested to develop the PMSG-pitch angle control (PMSG-PAC). The studied MG consists of a wind farm (WF), variable load, and a battery energy storage system (BESS). The WF contains five PMSG-WTs which are considered to be the principal resource. The proposed DT-FLC ensures maximum aerodynamic reserve power for the plant, enhances its capability to regulate the PAC, adjusts the WTG drop in response to the wind speed, and increases the resilience of the PMSG-WT in the presence of low voltage. Moreover, the PFR is significantly improved in terms of controlling the PAC (−0.0007 Hz) which meets the frequency maximum droop recommended by the IEEE Std 1547-2018 and the Moroccan grid code, −3 Hz and −2.5 Hz, respectively.

Keywords

• microgrid resilience
• low-voltage ride-through
• primary frequency regulation
• permanent magnet synchronous generator
• de-loaded technique
• fuzzy-logic controller