Transient power angle stability analysis and improvement strategy for parallel system of virtual synchronous generator and static var generator

Virtual synchronous generators (VSGs) can actively support the frequency and voltage of the grid and are widely used in new energy power plants. Static var generators (SVGs) can improve the reactive power-voltage drop characteristics of the VSG and increase its ability to cope with complex operating conditions. However, the interaction between the VSG and the SVG can affect the output characteristics of the VSG and thus its transient power angle stability. Therefore, this paper proposes a method for analyzing the transient power angle stability of a VSG-SVG parallel system and its improvement strategy. Firstly, based on the equivalent circuit of the parallel system, the interaction-coupled power model and the transient power angle characteristic model are derived. On this basis, the influence law of various parameters on the transient stability of VSG is analyzed based on the phase plane method. Secondly, a strategy is proposed to improve the transient power angle stability of the VSG-SVG parallel system based on the adaptive regulation of active power, and the feasibility of the strategy is verified by comparing the phase plane diagrams before and after the improved control. Finally, the effectiveness of the proposed model and strategy is verified by Matlab/Simulink simulation. In this paper, a transient power angle stability analysis method for VSG-SVG parallel system and its enhancement strategy are proposed. Under the extreme fault conditions of the grid, the VSG-SVG parallel system can still operate stably, and its transient power angle stability is significantly improved.image