Research On Modeling Of Distributed Generation And Effect On Distribution System Reliability

With the access of distributed generation, the distribution network topology structure and failure modes and effects analysis process change fundamentally. Compared with the traditional distributed power supply, the power output of distributed generation is more random. And island operation mode containing distributed generation may appear. Therefore, the corresponding reliability assessment models and methods will also change.Firstly the basic timing output model of wind power, photovoltaic power generation are established considering the effect of resource factors such as sunlight and wind. A parameter called operation state coefficient (OSC) is introduced to characterize the impact of equipment operation on the output of wind power and PV generation system. Through combining the volatility of light resource with the equipment operation, the multi-state and timing output power modeling of wind power and PV generation system is proposed. Considering energy storage charge and discharge power limitation and external factors, timing series model of energy storage device is established.Secondly, on the basis of reliability modeling, reliability assessment method of power system with wind power, PV generation and energy storage is given. Considering the influence of different capacity ratio between wind power and PV generation system, energy storage capacity and storage coordination operation modes on the reliability of power system, the capacity of power generation system with wind power, PV generation and energy storage tracking the load is studied.Aimed at reliability evaluation of distribution network with distributed power, the author analyzes the grid-connected way, access mode, operation mode and equivalent reliability models of distributed generation. And the island operation mode is also discussed. Giving the corresponding solving process, an island operation model of dynamic load cuts to matching real-time load power, is established. Series of reliability indexes are used to evaluate the impact of grid-connected distributed generation for the distribution network.The paper improves a reliability evaluation method combined the feeder partition method with sequential Monte Carlo method, which is applied to the reliability analysis of distribution network with distributed generation. By an example of an IEEE-RBTS Bus6 test system, the results show that the capacity, type and access location of distributed power have a different impact on the reliability of the distribution network.