考虑低电压穿越锁相稳定与暂态过电压的VSC参数安全域OA

Short-circuit faults of power grid cause voltage source converters(VSCs)to be in the low voltage ride-through(LVRT)state.During this process,the stability of the phase-locked loop(PLL)and the transient overvoltage after recovery are two critical problems of security and stability.The PLL parameters and the current reference values during the LVRT process are key influencing parameters.This paper proposes a method for calculating the parameter security region that comprehensively considers PLL stability during the LVRT process and transient overvoltage after recovery.Firstly,to address the issue of deviation between the initial point and the equilibrium point affecting the effectiveness of traditional small-disturbance stability criteria,a phase-locked stability analytical analysis method and a parameter security region considering initial point deviation are proposed.Secondly,transient overvoltage constraints are specified,and the parameter security region under transient overvoltage constraints is calculated based on the analytical expression of the terminal voltage throughout the entire process.Finally,the intersection is found to obtain the parameter security region that comprehensively considers PLL stability and transient overvoltage.The effectiveness of the derived parameter security region is validated by MATLAB/Simulink simulation results.