Research on VSC-HVDC Double Closed Loop Controller Based on Variable Universe Fuzzy PID Control

With the development of flexible DC transmission technology, its application scope is more widespread. However, the small loop steady state model with double closed loop control, in the case of large system disturbance, is below the average control because of the constant parameter. In this paper, fuzzy PID control with the variable domain is introduced, and the initial value of the controller is obtained by using empirical formula. Considering that the initial domain does not necessarily meet the control requirements of all input signals, it introduces the scaling factor to adjust the domain of variables, improving the dynamic performance and control accuracy of the system. Finally, combined with double closed loop control, the simulation proves that the fuzzy PID control with the variable universe has better control effect and a wider range of VSC-HVDC application.