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.