Research On Reserve Optimization Dispatch Method For Multi-Area Interconnected Power System With Wind Power Integration

Recently in the growth process of wind power integrated into the power grid, the intrinsic characteristics of wind power, such as uncertainty, randomness and volatility, bring a huge challenge to power system security and reliability. As interconnected power system has gradually become the main platform of optimal allocation of resources, inter-regional accommodation has emerged as an attractive and challenging research area due to the fact that wind energy resource is usually far away from load center and hard to use locally. Through coordinated optimal operation of multi-area interconnected power systems, the wind power accommodation in a larger spatial scale and also the system efficiency from both the economic and security point of view are promoted.Meantime, with the expansion of the scale of interconnected power grid, some problems have emerged, such as large memory use, low computing speed, data transmission bottleneck and so on. So it’s of significance to propose a novel decomposition coordinated approach for interconnected power system.This thesis firstly designs a determination method of reserve requirement for the power system. Based on the probabilistic characteristics of wind power and load forecast errors, a new random variable is introduced. Considering uncertain factors such as forced outage rate of units, prediction error of loads and wind power, two indexes named as loss of load probability and wind spillage probability are proposed and the quantitative relationship between them and operating reserve requirement is established, to analyze the required reserve in the system precisely.Further, a cross-regional dispatch method for multi-area power system with wind power integration is proposed in this thesis. The co-optimization of generating and reserve and network security constraints are all considered, and the configuration and coordination of reserve resources between different areas is decided based on the tie-lines’ dual responsibilities of both power transmission and reserve assistant from neighboring areas. The aim of this method is to achieve optimized allocation of electricity and reserve resources on a larger scale, to improve security level of power system and promote wind power accommodation by reserve assistant from adjacent areas, and to improve economic performance by reducing the marginal cost of generating and scheduling. The reasonableness and effectiveness of the constructed model is validated by case study.Finally, an operation pattern for decomposed and coordinated multi-area power system is designed. This decomposition-coordination algorithm is based on the method of optimality condition decomposition. In this algorithm, the global optimization problem is decomposed into sub-problems of each area. Tie-line power flows are recognized as coupling variables. The inter-area coordination is achieved by exchanging between adjacent areas. The centralized scheduling optimization model is revised by decomposition-coordination algorithm and a decomposed and coordinated dispatching optimization model for multi-area power system is built. The regional independence and the global optimization is achieved at the same time from the point of scheduling. The case study shows that the proposed model is able to achieve the global optimization level of multi-area power system by through the interaction coordination between areas, and meantime the complexity of the problem solving is reduced.