一种高可靠性小电流接地故障选线装置的设计与验证

Design and Verification of a High Reliability Small Current Grounding Fault Line Selection Device

目前小电流接地故障选线装置产品功能及性能不一,选线算法原理多样,装置设计容错能力不强,装置选线准确率不高。为此,设计了一种高可靠性小电流接地故障选线装置,硬件设计上采用暂态高频互感器提高采样速率,确保真实反映故障暂态信号,选线策略上运用自适应捕捉特征频带的暂态零序电流幅值与零序电流低频有功分量幅值比较的综合选线原理。PSCAD仿真测试结果表明,该装置选线准确率高,实用性强。

At present,the function and performance of small current grounding line selection devices are different,the principles of line selection algorithms are various,the designed fault tolerance capabilities of devices are not strong and the line selection accuracy of devices is not high.Therefore,a small current grounding fault line selection device with high reliability is designed.The transient high frequency transformer is used in hardware design to improve the sampling rate so that the real reflection of fault transient signal can be ensured.In the line selection strategy the integrative line selection principle is used which includes two comparing criteria:the transient high frequency zero-sequence current amplitude with adaptive capturing of the feature band and the low frequency active component amplitude of zero-sequence current.The PSCAD simulation results show that the device has high line selection accuracy rate and strong practicability.