Study on Frequency Emergency Coordination and Optimal Control with Multitype Measures

System moment of inertia and frequency regulation ability is decreasing with the increasing scale of UHVDC and new energy integration in China. Therefore, the frequency stability of the system is becoming increasingly prominent. The cost of traditional security control measures such as generator tripping and load-shedding is high, the low-cost DC emergency power support, the new energy frequency modulation, load control and other continuous regulation control measures get more attention in daily operation. Aiming at different types of control measures, this paper puts forward a frequency security margin measurement index, which takes multi-type control measures into account. On the premise of ensuring frequency security and stability of power grid, the cost of frequency control after power grid failure can be reduced and the requirement of lean frequency stability control of modern power grid can be met by coordinating the continuous and discrete control measures. Based on the actual planning of UHVDC transmission network, the feasibility of the proposed method is verified.