基于网络采样的变压器差动保护异步闭锁技术研究

Research on asynchronous blocking technology of transformer differential protection based on network sampling

以网络采样的智能变电站为背景,提高变压器差动保护的网络适应性为目的,提出了基于网络采样的变压器差动保护异步闭锁机制。阐述了网络采样及其同步方式,并分析产生异步的各种原因;分析了不同厂家变压器稳态量差动在异步情况下的动作特性;根据负荷变化及不同差动启动值得出保护动作时的角差,并据此分析出导致差动误动的采样异步帧数,提出了解决方法。采用该闭锁机制的变压器差动保护已经在智能变电站工程中投入运行,在避免因异步导致的保护误动方面取得良好效果。

This paper presents asynchronous blocking mechanism of transformer differential protection based on network sampling. The purpose is to improve the network adaptability of the transformer differential protection based on the background of smart substation of network sampling. It introduces the network sampling and its synchronism mode, as well as the reasons of asynchronous state. It studies the operation characteristic of steady-state differential transformers in the asynchronous situation from different manufacturers. Then the deviation angle of operation of transformer differential protection can be achieved according to the load change and different start values. Then the sampling asynchronous frames causing the mal-operation of differential protection are analyzed and solutions are presented. The transformer differential protection which uses the asynchronous blocking mechanism has been put into practice in the smart substation projects and it achieved good results in avoiding the protection mal-operation caused by asynchronous performance.