基于CT二次回路安全措施的分析研究

Research on the Safety Measures Based on a CT Secondary Circuit

摘要: 在基建投产、保护改造、周期校验、处理缺陷以及开关耐压等项目中，均会对二次采样回路进行验收或做安全措施，其方法是否正确，行为是否得当，直接影响到保护的动作行为。针对开关检修试验项目，探讨500 kV罐式开关的CT布置及二次回路接线方式。结合具体实例，深入研究保持保护装置运行状态下CT的封堵措施，着重研讨停电检修模式下各类二次回路安全措施的做法，分析各方法存在风险点和应对措施。通过线路、主变保护的动作行为，指出最优的安全措施做法。

Abstract: In the going into operation of infrastructure, transformation of protection, cycle check, treatment defects and switch pressure resistance, secondary sampling circuits need to be accepted or done safety measures. The behavior of the protection is directly affected by correction of the method and the behavior. Aiming at switch maintenance test items, the CT layout and the secondary circuit connection mode of 500 kV tank switch are discussed. Combined with concrete examples, this paper deeply studies the blocking measures of CT under the running state of the protection device, focuses on the practice of all kinds of secondary circuit safety measures under the power outage maintenance mode and analyzes the risk points and countermeasures of each method. Through the action of line and main transformer protection, we point out the best safety measures.