3/2接线互感器优化布置的继电保护改进新方法

Novel Improved Method of Relay Protection Based on Optimized Arrangement of Transformers under 3/2 Connection

针对超高压系统3/2断路器接线方式的结构特点及存在问题,提出基于串断路器保护的继电保护改进新方案。该方案利用断路器两侧电流信息构成小差保护,单串内所有断路器小差保护组成串断路器保护。利用单串的串断路器保护与所对应线路保护相配合,站内所有串断路器保护与母线保护相配合,实现了对串内故障的准确定位,可有效缩小原有保护配置下部分区域切除故障时的停电范围,增强了继电保护的选择性,且该方案改造实施简便,具有较强的工程实用性。

Aimed at the structural characteristics of the 3/2 circuit breaker connection mode in an ultra-high voltage sys⁃tem and the existing problem,a novel improved scheme of relay protection based on string circuit breaker protection is proposed,which uses the current information on both sides of the circuit breaker to construct a small differencial protec⁃tion.Then,all the small differencial protections within one single string form a string circuit breaker protection.Under this scheme,one single string circuit breaker protection is coordinated with the corresponding line protection,while all the string circuit breaker protections within a substation are coordinated with the bus protection,thereby realizing the accurate location of fault within the string.As a result,the power outage range can be effectively reduced when the fault is removed from some area under the original protection configuration,which enhances the selectivity of relay protec⁃tion.In addition,the proposed scheme is simple to implement,and it has strong engineering practicability.