基于故障信息同步的有源配电网电流纵联差动保护方法

Active Distribution Network Current Longitudinal Differential Protection Method Based on Fault Information Synchronization

在有源配电网中,分布式电源和负载点众多且分布广泛,故障的发生会受到各个节点的影响。不同的保护设备通常通过监测和分析电流、电压等参数判断是否发生故障,并通过采取相应的保护动作隔离故障区域。然而,由于有源配电网的复杂性和分散性,不同保护设备之间获取到的故障信息可能存在时钟偏差,导致保护设备对故障的判断存在误差,进而引发保护动作的延迟或错误。因此,文章设计并提出了一种基于故障信息同步的有源配电网电流纵联差动保护方法。该方法先对有源配电网故障电流特性进行分析,判断是否需要进行差动保护。在判断需要进行差动保护的基础上,为了确保保护设备之间获得同步的故障信息,使用时钟校正法同步各个设备的时钟,实现故障信息同步。同时,计算同步误差允许裕度,确定保护设备对于时钟偏差的容忍度范围;最后,基于故障信息同步方法,构建电流差动保护复合判据,实现有源配电网电流纵联差动保护。实验结果表明,所提方法的有源配电网电流纵联差动保护准确性较佳,整体应用效果好。

In active distribution networks,distributed power sources and load points are numerous and widely distributed,and the occurrence of faults will be affected by various nodes.Different protection devices usually determine whether a fault has occurred by monitoring and analyzing parameters such as current and voltage,and isolate the fault area by taking corresponding protection actions.However,due to the complexity and dispersion of active distribution networks,there may be clock bias in the fault information obtained between different protection devices,which can lead to errors in the judgment of faults by the protection devices,thereby causing delays or errors in protection actions.Therefore,a current longitudinal differential protection method for active distribution networks based on fault information synchronization is designed and proposed.This method first analyzes the fault current characteristics of the active distribution network to determine whether differential protection is necessary.On the basis of determining the need for differential protection,in order to ensure synchronous fault information between protection devices,the clock correction method is used to synchronize the clocks of each device,achieving fault information synchronization.At the same time,the allowable margin of synchronization error is calculated and the tolerance range of the protection equipment for clock deviation is determined.Finally,based on the fault information synchronization method,a composite criterion for current differential protection is constructed to achieve active distribution network current longitudinal differential protection.The experimental results show that the proposed method for active distribution network current longitudinal differential protection has better accuracy and overall application effect.