Research On Maximum Capacity Of Distributed Generators In Smart Distribution Network Considering Operation Constraints

Under the decline of conventional source of energy and increasing pollution, exploring renewable energy represented as wind energy and solar energy has become an inevitable choice for achieving long-term sustainable development of human society. With the stochastic fluctuant and intermittent characteristics, high DG penetration brings a great impact to the security of distributed system. Research on the maximum allowable capacity of distributed generators has great significance to the planning and operation of distributed system as well as the development of distributed generation. Considering the operation characteristics of DGs and loads, this paper makes thorough and systematic studies on the maximum allowable capacity of DGs.In this paper, steady-state modeling and simulation method of smart distribution network with distributed generation is realized including the modeling of different types of DGs and control elements, the operation power flow calculation considering fluctuation characteristics is also studied. Then the impact of distributed generation on voltage distribution is mainly analysed and the maximum capacity model is established with constraints of node voltage and line capacity, and the operation characteristics of distributed generators and loads are also considered. A modified pattern search algorithm and a stochastic method based on Monte Carlo algorithm are presented to solve this problem. Finally, a coordination control strategy is presented aiming at solving the over-limit voltage problem and increasing maximum capacity. Example analysis shows that, distributed generation brings significant impact on the operation of distributed network, the maximum capacity model presented in this paper is accurate and effective and the modified pattern search algorithm and the stochastic method based on Monte Carlo algorithm can be adopted to solve this problem effectively. The storage device's smoothing power control strategy can improve voltage level and relieve the over-limit voltage problem.