Optimal Design of Excitation Systems of Synchronous Condensers for HVDC Systems in Power Grid Environment Based on Variable Universe Fuzzy Adaptive PID Controller

In a gesture to optimize the reactive power properties of synchronous condensers and improve capabilities of condensers to support the voltages of AC systems, the outer loop control of the reactive power of condensers and the outer loop control of the voltages of AC systems are introduced into the conventional design of the main excitation systems of condensers in high voltage direct current (HVDC) systems in this study. Moreover, variable universe fuzzy adaptive PID controller is proposed to serve excitation systems of condensers to improve the response ability of condensers in power grid faults and the recovery speed of condensers after power grid faults, and to reduce overvoltage of power grids generated by condensers in the process of fault recovery. To verify its experimental validation, the model of ±100 kV HVDC system containing a condenser is set up in MATLAB/Simulink. The verified results reveal that the optimal design strategy of excitation systems of synchronous condensers in the proposal can ensure rapid regulation of the voltages of AC systems arising from condensers, and reduce overcompensation of the voltages and reactive power of AC systems arising from condensers when faults recover.