Multi-VSG-based frequency regulation for uninterruptible power AC micro-grid with distributed electric vehicles

Abstract

In view of the energy storage performance of electric vehicles (EVs) can be regarded as backup power sources to provide electric energy for residents in case of power failure in the community. With the aim to improve the dynamic frequency regulation ability of EVs accessed uninterruptible power AC micro-grid, the virtual synchronous generator (VSG) technology is utilized to EV inverter, and a consensus-based cooperative adaptive virtual inertia (CAVI) strategy is designed between VSGs. Meanwhile, according to the time-varying topology switching method, each VSG can select the optimal communication direction based on the real-time system state. Then, a derivative-free cooperative VSG control structure is designed to avoid the noise of frequency derivation in the CAVI strategy. The important feature of CAVI is that the virtual inertia can be regulated by the VSG frequency deviation, and local VSG can sense the state of neighboring VSGs to realize the consensus of the frequency response of multi-VSG with different parameters. The proposed CAVI is completely distributed, it can be implemented on each local VSG with directed communication among neighboring VSG, and avoid the requirement on the central controller. The effectiveness of the proposed control strategy is demonstrated by the Case study.