Joint corrective optimization based on VSC-HVDC and distributed energy storage for power system security enhancement

Abstract

The growing integration of flexible control devices like VSC-HVDC links and distributed energy storage (DES) devices into power systems introduces new challenges in addition to increasing the flexibility for power system operation. To explore the potential advantages of flexible controllable devices in power system operation, this paper proposes a joint corrective measure (JCM). Based on the VSC-HVDC and DES devices, post-contingency power flow violations in the hybrid AC/DC power system can be cured. The power sensitivity of adjusting line overloads with VSC-HVDC and DES is derived and calculated. Considering that not all corrective control variables are required to participate in subsequent optimization decision-making calculations, a dynamic search algorithm for the action threshold is designed to screen qualified control variables. Furthermore, to achieve an optimal tradeoff between the actions of the VSC-HVDC and DES, a corrective decision optimization modelling is performed with which the individual solutions to the line overloads after the contingencies are obtained. Finally, numerical tests on two modified hybrid AC/DC power systems are conducted to validate that the proposed JCM decision method can efficiently coordinate VSC-HVDC and DES, eliminate overload, and reduce decision-making time.