低励磁阻抗变压器接地装置接入配电网方式探讨

Discussion on the Way of Connecting Low Excitation Impedance Transformer Grounding Device into Power Distribution Network

本文对低励磁阻抗变压器接地装置(LEIT)的原理和优点进行了阐述,通过分析LEIT现场应用实例,发现将LEIT直接接入接地站用变中性点会严重影响接地站用变运行的可靠性。之后,本文对LEIT经专用断路器接入10 k V配电网方式进行了探讨,该新的接入方式可以保证在不影响接地站用变的正常运行的情况下,实现LEIT保护人身安全、接地选线等功能,具有现场应用可行性。

The paper introduces the principle and its good points of the low excitation impedance transformer grounding device（ LEIT）. A practical case of the LEIT adopting in distribution network is investigated,and it was found that the access mode would reduce the operational reliability of grounding transformer when the LEIT is accessing the 10 k V distribution network through neutral point of grounding transformer. In addition,an optimal method is proposed that the LEIT is accessed to the distribution network by using a special breaker. Moreover,that accessing method would not influence the operational reliability of grounding transformer,and it could protect lives and select earth route,and so on. Hence,it is feasible to apply that connection mode in field.