Linear Active Disturbance Rejection Controller for VSC-HVDC to Improve System Transient Stability

This paper proposed an effective voltage source converter-high voltage direct current transmission (VSC-HVDC) transient stability control strategy based on linear active disturbance rejection control (LADRC). According to the controllability of VSC-HVDC on synchronous generators, some synchronous generators are chosen to be transformed into a VSC-HVDC equivalent controlled system (ECS). Furthermore, the number of the generators can be reduced according to the controllability. Based on the model of ECS, a stability controller is designed based on LADRC. The controller simultaneously modules synchronous generators' speed deviation and unbalanced power, and thus can make full use of its ability to maintain the stability of the power system. The design procedure of the controller does not require the exact model of the power system or VSC-HVDC, and meanwhile the controller has a good robustness to different operation modes of the system. Simulations carried in modified IEEE 39 system verify effectiveness and robustness of the controller.