Reliability Evaluation And Credible Capacity Model Of Joint System Consist Of Multi-Wind Farms And Pumped Storage Power Station

With the depletion of fossil energy and deterioration of environment problem, the utilization of wind power attracts attention all over the world. Wind power has the characteristics of randomness and intermittence, and large-scale integration of wind power results in great challenges to power systems. In order to maintain the secure and stable operation of power systems, the amount of the integrated wind power should be restricted. The integration of pumped-storage power station has the features of storage systems, which can be used to improve the penetration of wind power. The effectiveload-carry-capability(ELCC) and reliability contribution of wind energy are different from traditional generators because of its uncertainty. Based on the criterion of same reliability performance, credit capacity can intuitively reflect the contributions of wind power from the reliability point of view, which has the importance for both theoretical guide and practical application in the planning of power systems containing large-scale wind energies. Considering the impacts of electrical collector system of wind farms on the reliability, this thesis proposed the methods for evaluating the reliability of multi-wind farms and integtation system of multi-wind farms and pumped storage power station, wihch can be used to evaluate the credit capacity of wind farm.Electrical collector system affects the reliability of wind farm. To obtain the connection path sets and isolation sets of wind turbine generators(WTG), the depth-first traversal method is used in this thesis. A sequential Monte Carlo method is proposed to evaluate the reliability of wind farms, which can consider the failures of wind turbine generators and electrical collector system, disconnection and switching operation of switch devices, and different collector system topologies. Novel indices for describing the impact of collector system on wind farms are presented in this thesis. Four typical electrical collector structures of wind farm are analyzed using the proposed method. Case studies show that WTG outage probability, effective operation WTG number and annual generating capacity of wind farms with different collector structure varies from each other. It is necessary to take the influence of the collector system into consideration.Based on the fact that wind speeds of adjacent wind farms have strong correlation, using dichotomy to get the optimal shifting time. The shifting ARMA method is used to generate two wind speed time series which can keep the characteristic of autocorrelation and cross-correlation. Based on the proposed reliability model of wind farm, a sequential Monte Carlo method is proposed to evaluating the reliability of multi-wind farms. Based on the results of reliability evaluation and the definition of effective load carry capability and equivalent conventional capacity, the credit capacity of multi-wind farms is calculate using secant method. A modified RTS system containing multi-wind farms is used to calculate the effect of correlation coefficient, penetration of wind power, peak load to the reliability indices and credit capacity of multi-wind farms. According to the results of the case studies, the correlation between two wind farms will reduce the reliability of multi-wind farms. With the increased penetration of wind power and decreased peak load, the capacity credit will decrease.Considering the operation strategy, pumping efficiency, limits of reservoir capacity and installed capacity of pumped-storage power station, a reliability evaluation model for the integration system of multi-wind farms and pumped storage power station is proposed based on the reliability evaluation model for multi-wind farms. The indices for system reliability and abandoned wind power are evaluated using a sequential Monte Carlo method. The credit capacity of multi-wind farms is calculated using a secant method. A modified IEEE-RTS system containing multi-wind farms and pumped storage power station is used to study the impacts of wind power restriction and operation strategies on the system reliability and capacity credit. The results of the case studies show that integration of pumped-storage power station can be used to improve the system reliability preformance, credit capacity and utilization of wind power.