Cooperative Adaptive Control of Multi-Parameter Based on Dual-Parallel Virtual Synchronous Generators System

Abstract

Presently, conventional fixed parameters are applied in dual-parallel virtual synchronous generators (VSGs), resulting in poor frequency response characteristics. Therefore, a multi-parameter cooperative adaptive control strategy is proposed in this paper as a solution. The principle of the method is that when a frequency transient fluctuation occurs in the VSG, the frequency deviation and rate of frequency change are combined with the virtual inertia, damping coefficient, and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i> /ω droop coefficient to form an adaptive control system. A small-signal model of dual-parallel VSGs was built to analyse the impacts of the parameters on the stability of the system in each phase. The boundary conditions of the parameters such as virtual inertia, damping coefficient, P/ω droop coefficient and virtual inertia adjustment coefficient are further pinpointed to improve parameters' values. In the simulation results, the strategy put forward in this paper can increase the frequency and amplitude by 54.66% and the recovery time by 49.65% when the system is disturbed. The simulation and the StarSim experimental platform are verified that the strategy proposed in this paper can effectively optimize the frequency fluctuation response characteristics of the grid-connected VSG system in different cases, enhancing the dynamic performance and safety and stability of the system.