【摘要】 针对逆变型分布式电源(IIDG) T接方式接入配电网后传统三段式电流保护难以适用的问题,提出了一种含T接逆变型分布式电源配电网的纵联保护方案。该方案讨论了在低电压穿越期间IIDG采用恒功率控制策略对故障输出的影响;通过定义复合差动阻抗并分析其在被保护馈线区内外故障的幅值差异,提出一种基于复合差动阻抗的含逆变电源T接配网的纵联保护原理;为消除该保护原理在三相金属性短路故障时的死区,引入T型电流差动保护作为辅助判据。在PSCAD/EMTDC仿真平台搭建了含IIDG的10 k V配电网仿真模型,仿真结果验证了该方案的合理性与有效性。更多还原

【Abstract】 Aiming at the problem that traditional three-stage current protection is difficult to be applied after inverter interfaced distributed generation( IIDG) T-shaped access to distribution network,a pilot protection scheme for IIDG T-connected distribution network is proposed in this paper. The effect of constant power control strategy on fault output during low voltage crossing is discussed. Secondly,the pilot protection principle of the inverter interfaced distributed generation T-connected network based on the composite differential impedance is proposed by defining the composite differential impedance and analyzing the amplitude difference of the fault in and outside the protected feeder area. Meanwhile,in order to eliminate the dead zone in the three-phase gold short circuit fault,the differential current protection of T-type transmission lines is introduced as the auxiliary criterion. Finally,a 10 k V distribution network simulation model with IIDG is built on the PSCAD/EMTDC simulation platform. The simulation results prove that the proposed scheme is reasonable and effective.更多还原