| This paper is sponsored by the project (Study on Optimal Switching Model and Algorithm for Electrical Distribution Networks Using Immune-Algorithm, No.50307015) of the national natural science fund of China. This paper presents the technique for comprehensive evaluation the reliability of composite generation, transmission and distribution system (CGTD) which contains wind turbine generation (WTG).With the increasing demand of energy and the exploitation of new energy, wind energy is regard as a renewable clean energy and WTG is one of the most prospective new generation ways. However, wind has the characters of randomness and intermittence. The large-scale wind farm leads to some adverse effects to the safety and stability of generation and transmission power system(PS) while interconnecting to the power grid. To study the impact of WTG on the PS reliability, this paper presnets the model of wind farm reliability using the sequential Monte Carlo method , and the technique for evaluating the reliability of CGTD using the algorithm of reliability evaluation for distribution networks based on the effecting are controlled by switches. The main work has been done as follows:①The paper introduces the idea and the classes of the Monte Carlo method, and discusses the principle and characteristic of sequential Monte Carlo method in detail. The validity and practicability of the algorithm is verified by the reliability comparision of Monte Carlo method and FD method.②Based on the definition of the switch-pair and the aera controlled by the switches, the paper proposes the down-stream algorithm of reliability evaluation for distribution networks(DN). According to the down-stream searching method for DN, this algorithm can quickly determine the aera controlled by the switch-pairs and the father-son relationship matrix of switch pairs, and save the relationships using the sparse matrix. The algorithm analyzes the switch-pairs as the enumerating unit, and searches the area controlled by switch pairs and father-son relationship matrix to form the FMEA table. Because the nodes controllde by a switch pair have the same failure class, it can reduce the computing complexity of reliability evaluation.③According to the randomness and intermittence characters of wind, the paper builds a model which is suitable for simulating the characteristics of wind and introduces the method to sample the random wind speed. According to analysis, the model and its way forms normal random function are suitable for the actual situation of a district. So the model can simulate the random wind speed rapidly and accurately when the simulation in the simulating compartment.④The paper proposes a wind farm reliability model based on Monte Carlo method using the reliability models of the general generation, the line and the transformer, and the load model. Combining the wind farm reliability model with the generation and transmission system, the reliability of generation and transmission system with WTG is evaluated and the reliability indices are obtained. Accroding to the indices, Multi-state Sevice Provider(MSP) equivalent model of the node connecting with distribution system is established, and the algorithm for distribution system based on switches considering the influence of WTG is adopted to realize the reliability comprehensive evaluation for the CGTD.⑤The reliability of RBTS and actual system is evaluated Using the switches-based algorithm for distribution system, and the algorithm is proved correct and practiacal. Combined with the algrithm, Seuential Monte Carlo simluation of RBTS system with WTG is accomplished, and the MSP parameters of CGTD system are formed. reliability comprehensive evaluation of CGTD system containing WTG is implemented accordingly, also, the effects of penetration power and wind speed to the system reliability are analysed.
|
PDF Full Text Request