Power Supply Reliability Evaluation For Distribution Networks With Distributed Generations And Electric Vehicles

With the large consumption of traditional energy consumption and the pollution to the environment, people are working to find a way to reduce energy consumption and protect the environment. Therefore, the development of intelligent distribution network has become the focus of attention of the power industry in recent years. The development of distribution network intelligent is inseparable from the DG (distributed generation, DG) and electric vehicles (electric vehicle EV), because the distributed power has the characteristics of environmental protection, economic and renewable energy; the use of electric vehicles has the advantages of reducing oil consumption and environmental pollution. But affected by the seasons and the weather situation, the distributed power supply (such as wind power, solar power and other) output is uncertainty, randomness of wind speed caused by the randomness of the output power of wind turbine and the uncertainty of the solar radiation caused by the output power of the uncertainty, will bring containing distributed power distribution network reliability impact. Because of the beginning of the charging time, driving behavior and the impact of the uncertainty of the charging mode, the electric vehicle charging is random. If a large number of electric vehicle charging disorderly in the power grid, may improve the peak maximum power load caused by overload phenomenon. For the distribution network with renewable energy power generation and electric vehicles at the same time, if not coordinated relationship between the randomness of the electric vehicle charging and discharging of the randomness and distributed power generation will not only increased the cost of power generation and resource waste caused by, but also greatly reduce the reliability of distribution network.Based on the above distributed power generation and electric vehicle charging uncertainty to the grid operation reliability has brought a challenge. The main content of this paper is:1) Reliability evaluation of distribution network with distributed generation.The probability model is established according to the randomness of the distributed power output, and the fault rate of the distributed power supply is considered, and the state space of the system operation is established. On the basis of this, the reliability evaluation index of distribution network is constructed, and the reliability evaluation method of distribution network is formed. Evaluating the reliability index of distribution network with distributed generation in different output power. Evaluating influence of different locations and different number of distributed power distribution network on the reliability of distribution network.2) Reliability evaluation of distribution network with electric vehicle. Established probability model for electric vehicles of various charging and discharging modes, different modes of electric vehicle charging power or discharge power of the state space is formed, and calculate the probability of different states, and proposed containing electric vehicle distribution network reliability evaluation method. The reliability indices of distribution network are calculated under different operation condition of electric vehicle in different mode, and the effect of electric vehicle on the reliability of distribution network is analyzed quantitatively.3) Optimization of distribution network reliability with distributed power and electric vehicles. Give full consideration to the distributed power output of uncertainty and electric vehicle charging randomness, considering distributed generators and loads due to malfunction and the outage, construction of the operation of the state space of the system, based on established distribution network in distributed power supply output power and dynamic vehicle charging and discharging operation reliability optimization model, with optimal distribution network reliability cost value as the goal, which is to minimize the expected cost of society, including the expected operating cost and expected outage loss.4) Application of second-order cone programming algorithm. For the optimization of objective function, using second-order cone programming, the nonlinear form of the objective function and constraint function by rotating cone conversion to a linear form, and new variables with special structure of cone set representation, which simplifies the optimization model. And compared with the calculation results of the particle swarm optimization algorithm, the feasibility and superiority of the proposed algorithm is proved.Through the verification and analysis of Bus IEEE-RBTS test system, this paper proves the feasibility of the power supply reliability assessment method of distribution networks with distributed power and electric vehicles. The feasibility of the optimization model of distribution network operation reliability of distribution network with distributed generations and electric vehicles is verified, and the superiority of the algorithm is proved. It shows that the research results of this paper have important guiding significance and reference value for the planning and construction of distribution network and operation scheduling.