Oscillation Suppression Method in Multi-VSC System Based on Parameter Optimization

Voltage source converters (VSCs) connecting to the power grid and interacting with it may cause system oscillations. One significant reason for the oscillations is the mismatch of control parameters in VSCs. Therefore, parameter optimization is an important method to suppress system oscillations. However, the existing parameter optimization methods have failed to provide quantified values for parameter optimization. To solve this issue, a stability evaluation function based on double Gerschgorin discs is proposed in this article to quantitatively evaluate the stability of the multi-VSC system. Then, based on the stability evaluation function, a parameter sensitivity method is proposed to identify the key parameters that cause system oscillations. Finally, the corresponding parameter optimization method is used to obtain the quantified parameter optimization values through iterative calculations, which provides targeted guidance and suggestions for suppressing system oscillation. The parameter optimization method is validated based on the simulation results of a three-VSC system with differentiated control parameters.