含多分布式电源配电网自适应保护研究

Adaptive protection improvement of multi-distributed power supply access and distribution network based on positive sequence current

根据逆变型分布式电源(inverter interfaced distributed generator, IIDG)的特性,基于抑制负序的控制策略、接入容量以及故障类型,提出一种更适应多个分布式电源接入配电网的自适应电流保护,并通过PSCAD搭建含有IIDG的10 kV配电网验证方法的可行性。结果表明:在抑制负序的控制策略下,基于正序电流计算新的外汲分支系数,对上游保护整定值进行实时调整,相比传统三段式电流保护,可以有效提高上游保护灵敏度,灵敏度均能达到1.3,满足保护要求。

According to the characteristics of the inverter interfaced distributed generator(IIDG),based on the negative sequence suppression control strategy,access capacity and fault type,an automatic control system that is more suitable for multiple distributed generation access to the distribution network was proposed.Adapt to current protection,and build a 10 kV distribution network with IIDG through PSCAD to verify the feasibility of the method.The results show that under the control strategy of suppressing the negative sequence,the new branch coefficient of the external draw is calculated based on the positive sequence current,and the upstream protection setting value is adjusted in real time.Compared with the traditional three-stage current protection,the sensitivity of the upstream protection can be effectively improved.It can reach 1.3,meeting the protection requirements.