Decentralized Under-frequency Load Shedding Scheme Based on Response Information

In areas where there are no control centers or communication devices are unsound, real-time inertia is hard to obtain, and validity of system adaptive under-frequency load shedding (UFLS) scheme will be affected. Therefore, an optimal adaptive load shedding scheme (ALSS) is proposed only based on local load information. Meanwhile, the requirements of the UFLS scheme for communication conditions and dependence on control center are reduced. Firstly, a method for real-time identification of virtual equivalent inertia of load is proposed according to the load response information after disturbance. Then, a real-time calculation method of local power shortage is derived. Finally, an ALSS without control center is proposed according to estimated local power shortage based on frequency response model. Finally, accuracy of the proposed real-time identification method of virtual equivalent inertia and validity of ALSS are verified with simulation carried out in island system under IEEE 39-bus system. © 2019, Power System Technology Press. All right reserved.