Supervised shutdown algorithm for an offshore wind power plant to meet the required ramp rate of a grid code in a storm-driven situation

This paper proposes a supervised shutdown algorithm for an off-shore wind power plant (WPP) to meet a required rampdown rate of a grid code in a storm-driven situation. The algorithm determines the number of wind generators (WGs) to shutdown simultaneously by considering the required ramp-down rate of a WG without using a brake. Based on the wind direction and speed measured at a wind mast (WM), wind arrival times from a WM to each WG are calculated. Then, a sequence of WGs is generated in the order of wind arrival time and subsequently a group sequence is generated. The shutdown end time of each group is determined as the minimum wind arrival time in the group whilst the shutdown start time is determined by subtracting the duration of the shutdown from the end time. If the shutdown start/end times of adjacent groups are overlapped, the start/end times of the preceding group are re-scheduled by considering the overlapped time. The performance of the algorithm is verified under various storm conditions. The results indicate that the algorithm can shut down the WPP without exceeding the required ramp rate in a grid code.