1. State Grid Jiangsu Electric Power Company, Nanjing 211000, China; 2. NARI Group Corporation(State Grid Electric Power Research Institute), Nanjing 211106, China; 3. NARI Technology Co. Ltd., Nanjing 211106, China; 4. State Key Laboratory of Smart Grid Protection and Control, Nanjing 211106, China

It will be a serious impact on the receiving power system of safe operation when power of the ultra-high voltage direct current(UHVDC)system gets lost. A “source-grid-load” coordinated control strategy is proposed for steady control problems such as frequency restoring, transmission section overloading, tie-line power overusing, spinning reserve lacking, etc, with the power of the UHVDC system lost. By using interruptible loads, through integrated dispatch-marketing and provincial-regional control, the generation, load and grid coordinated optimization control is achieved, which provides an important reference for the dispatcher to cope with the receiving power system with the power of the UHVDC system lost.