Unit start-up dispatching strategy during night peak load period in power systems with wind power penetration

The uncertainty caused by loads and wind power made the system face high pressure to accommodate the night peak period. This paper proposed a small generation unit start-up dispatching strategy during night peak load period. An observing point was set before night peak load period came. At the observing point, the power system had to judge whether to start a small generation unit or not. Once the netload prediction error before the observing point was large, the day-ahead predicted netload curve should be modified immediately. After that, the day-ahead dispatching plan was updated according to the modified netload curve. If the load shedding in new dispatching plan was in the safety range, the day-ahead unit commitment stayed unchanged. On the contrary, if the optimized results had load shedding value which was out of the safety range, the small generation unit should be started immediately. Finally, a dispatching model with small generation units during night peak load period was built. In order to improve the calculation efficiency, the model fully used the original plan information to simplify the optimization variables and security constraints. Results show that the proposed unit start up dispatching strategy is feasible.