Dynamic Stability Analysis of Sub-synchronous Oscillation Mode of Phase Locked Loop

This paper introduced dynamic stability analysis of sub-synchronous oscillation mode of PLL with the generalized torque analysis method. Firstly, the configuration and the model of the power system connected with PMSG, including PLL, GSC and AC network is given. Then, the generalized torque analysis method in the research of power system subsynchronous oscillation is illustrated. In this method, the idea of damping torque analysis method in power system electromechanical oscillation is extended, and the generalized torque analysis method is proposed. This method is no longer limited to the analysis of the oscillation in the frequency band of 0.1-2.5Hz, and can also analyze the phenomenon of sub/super-synchronous oscillation. Finally, the dynamic stability analysis of sub-synchronous oscillation mode of PLL with the generalized torque analysis method is given, which demonstrated the correctness of the method.