110kV及220kV系统变压器中性点经小电抗接地方式的研究及其应用

110kV及220kV变压器中性点经小电抗接地方式既可降低过电压又可限制单相短路电流,又可解决由变压器中性点绝缘所带来的不安全因素,文章指出接地电抗成套装置的妥善设计、性能良好电抗器的研制、接地电抗装置的智能化自动控制是实现该方式的三个关键技术,并给出了实现的具体方法。介绍了作者研制的110kV变压器中性点接地电抗装置在某变电站成功运行的情况,经过两次单相故障的考验证明了该接地方式的优越性。

Research on Neutral Grounding via Small Reactor for 110kV and 220kV Power Transformers and Its Application

The superiority of the neutral grounding via small reactor for 110kV and 220kV power transformers,such as reducing overvoltage,restricting single-phase short circuit current and overcoming the insecurity caused by insulated neutral point of the transformers,is dissertated.The authors point out that to implement this grounding mode it is necessary to properly design the packaged grounding reactor,develop the reactor with good performance and adopt intelligent control for grounding reactor,and the concrete approach to realize above-mentioned technology is given.The successful experience of applying such a grounding set developed by the authors for 110kV transformer in a certain substation is presented.The superiority of this grounding mode is verified by two times of single-phase faults.