DG接入容量对配电网电流保护的影响

The Influence of DG Access Capacity for Distribution Network Current Protection

DG(Distributed Generation)接入配电网改变了原有配电网的供电结构,使得潮流大小和功率方向发生变化,这对配电网原有的电流保护提出了挑战。在原有电流保护配置不变的情况下,分析了DG接入配电网后,配电网的不同位置发生短路故障时,DG对每个故障点短路电流的影响,并通过典型的10KV配电网模型,推导出了短路电流与DG容量的数学表达式,并通过保护的整定值,求得DG接入的最大准容量值,最后对传统继电保护装置提出了改进方法。

DG(Distributed Generation)access to distribution network has changed the original power supplyof the distribution network structure,make the trend direction change size and power,which poseschallenges to the distribution of the original current protection.In the original unchanged under the conditionof current protection,and analyzes the DG access to distribution network,different locations of the distributionnetwork fault occurs,DG influence on each failure point short circuit current,and through the typical 10kv distributionnetwork model,deduced the short circuit current and the mathematical expression of DG capacity,and through the protection setting value,obtained by DG access the largest capacity value,finally puts forwardthe improved method of traditional relay protection device.