考虑直流极间切换运行特点的交直流混合配电网可靠性评估方法

Reliability Evaluation Method of AC/DC Hybrid Distribution Network Considering the Operation Characteristics of DC Inter-polar Switching

随着直流配电技术的不断发展,交直流混合配电网成为配电网发展新方向。可靠性是电网建设需要考虑的第一要素,因此准确评估交直流混合配电网可靠性具有重要的意义。首先,针对双极接线的交直流混合配电网,分析了直流线路单极运行对可靠性的影响机理;接着,考虑换流站控制模式调整、电源供电能力和直流线路单极运行对可靠性的影响,提出了基于最小割集法的交直流混合配电网负荷点区域划分和修正方法;然后,建立了完整的交直流混合配电网可靠性评估模型;最后,通过算例与传统可靠性评估方法进行对比,并对交直流混合配电网关键元件可靠性进行灵敏度分析,结果表明所提方法能够准确评估交直流混合配电网可靠性。

With the continuous development of DC distribution technology,AC/DC hybrid distribution network has become a new direction of distribution network development.Reliability is one significant element to be considered in power grid construction.Therefore,it is of great significance to accurately evaluate the reliability of AC/DC hybrid distribution network.Firstly,the effect mechanism of DC line monopolar operation on reliability is analyzed for bipolar connection hybrid AC/DC distribution network.A load area division and correction method based on the minimal cut set method for AC/DC hybrid distribution network is proposed,considering the influence of converter station control mode adjustment,power supply capacity and DC line monopolar operation on reliability.On this basis,a complete reliability evaluation model of AC/DC hybrid distribution network is established.Finally,the method is compared with the traditional reliability evaluation method through an example,and the sensitivity analysis of the reliability of key components in hybrid AC/DC distribution network is carried out.The results show that the proposed method can accurately evaluate the reliability of AC/DC hybrid distribution network.