含分布式电源区域节点的配电网模型和可靠性计算

Model and Reliability Calculation of Distribution Network with Zone-nodes Including Distributed Generation

大量分布式电源(DG)接入配电网以后,电源模型的多样化及运行方式的复杂化将会对配电网可靠性带来深刻影响。分析了多种DG模型及运行方式,在配电网中引入含DG区域节点的网络划分方法,根据影响区域节点故障的不同类型建立可靠性的计算模型,同时明确了孤岛运行原则,在此基础上形成了适合求解的蒙特卡洛模拟算法,并采用算例验证了模型及算法的有效性和实用性。算例结果表明,DG对配电网可靠性既有改善作用,也有不利影响,传统可靠性指标不能很好地评估DG影响的优劣,应规范DG对配电网可靠性影响的评估体系。

With a large scale of distributed generations （DGs） being installed and operated in distribution network, variety of power sources and complexity of their operation will greatly effects the reliability of distribution network. Different DGs＇ models and various operation situations have been studied, in which a network model called zone-nodes including DGs is introduced. The calculation model of reliability is build based on different failure types affected by zone-nodes, and the principle of island operations is definite. Then, on the above basis, a Monte Carlo simulation method is applied to solve this model. An Example demonstrates the validity and practicability of the model and simulation method. The result of test example indicates that DGs can improve the reliability of distribution network, but also have some adverse impacts on it. The traditional reliability indices can not perfectly evaluate advantages or disadvantages of DGs＇impact, it is recommended to standardize the evaluation system of the impacts of DGs on distributed system.