Risk assessment of power system with high penetration of wind power considering negative peak shaving and extreme weather conditions

The variation of wind power affects the operation of coal-wind intensive system. With the negative peak character, the variation of wind power daily output is in contrast to that of the load in power system. Even worse case is the common-mode tripping of wind turbines closing to cut-off wind speed while a wind farm experience extreme wind speeds caused by a severe weather situation. Based on actual operation data of Gansu Grid, China, in 2013, the probability characters of negative peak shaving and ramp rate are obtained. Then some risk indices are defined for risk assessment and the UC model is applied to probe the increment of reserve demand. A simulation based on Gansu Grid is given at last. The results show that the reserve demand increases with the wind power integration and the operation risk has a typical distribution of exponential function contains two types of risk events: HILF (High Impact and Low Frequency) and LIHF (Low Impact and High Frequency).