Advanced nonlinear control of WEC system in AC microgrid connected to the main grid with electric vehicle integration

Abstract

This research investigates an AC microgrid interconnected with the utility grid, comprising a 5.2 kW wind power system using a Permanent Magnet Synchronous Generator (PMSG), a 6.1 kW photovoltaic system (PVS), and integrated electric vehicles (EVs) with 600 V, 10Ah batteries operating in V2G and G2V modes. Bidirectional back-to-back converters, controlled via a voltage-oriented control (VOC) strategy, facilitate the interconnections. The PMSG system is controlled using vector control methodology, while the PVS employs a double-stage configuration with a perturb and observe algorithm for maximum power point tracking (MPPT). Advanced controllers based on Active Disturbance Rejection Control (ADRC) regulate generator speed and the DC link voltage of the grid-connected converters. The backstepping technique is utilized for internal loop control of PMSG currents and coupling filter currents for the grid-connected converters. A comparative study between the ADRC-Backstepping controller and the PI controller was conducted, demonstrating the superior efficacy of the ADRC-Backstepping approach. Simulation results show accurate regulation of DC link voltage at reference levels, operation with unit power factor, with a current THD below 4 %, demonstrating the effectiveness and robustness of the proposed control strategies under varying conditions.

Keywords

• Active disturbance rejection control
• Backstepping control
• Smart grid
• Photovoltaic system
• Electric vehicles
• Permanent magnet synchronous generator