Research On The Reliability Of Distribution Networks Containing Photovoltaic Plant

Photovoltaic plant has these characteristics of renewable, environmentally friendly and so on, it gradually access to distribution network will become a development direction in the future. A large number of photovoltaic power station connected to the distribution network will bring challenge to the operation and control of the system. From the perspective of reliability, this paper will study the influence of distribution network after photovoltaic plant access to.On the basis of section algorithm, this paper puts forward an improved section algorithm for reliability research. The method according to the fault isolation characteristics of switch which the branch configured, divided the distribution network into several improved section, then used the mathematical models to calculate the reliability index of load points, and finally get the reliability index of the system. Because this method put the improved block as a unit instead of the single element of distribution network, it can simplify network structure; and the number of improved section less than block, therefore it needed shorter time to enumerate fault, that algorithm has a higher efficiency. By the calculation of IEEE RBTS-BUS2 test system, it has validated the correctness and computing rapidity of the algorithm.According to the history statistics of light intensity and the mathematical model of light-electric conversion, we can obtain the output power and the formative probability of photovoltaic plant by the calculation, thus it concluded the output and probability distribution model of the photovoltaic plant. With the islanding partition method, this text puts forward the island calculation model. Using the island formation algorithm in the form of a root tree, it can determine the scope of the island and the formation probability, thus establish a multi-state reliability model of photovoltaic plant. An example illustrated the process of establishing the model, and verified the effectiveness of the proposed model at the same time.According to the characteristics of the multiple state reliability models, the reliability index calculation model is corrected. On the premise of the improved section algorithm, the proposed algorithm is suitable for photovoltaic plant in distribution network reliability research. After calculation of RBTS-BUS6 test system, it verified the feasibility and the practicability of the model and method presented in this paper. At the same time, this text analyzed the influence of reliability according to photovoltaic plant centralized/distributed, different position and different capacity access to distribution network.