保护装置开关操作回路的设计优化

针对目前的保护产品在工程现场经常发生开关机构因某种原因而失灵拒动，造成分合闸回路长期保持而烧毁分合闸线圈的问题，分析了典型操作回路，选择小型大容量电磁中间继电器作为操作执行的重动中间，将微机装置出口接点设置为有限延时，通过切断低功耗的分合闸重动回路间接解除操作回路的保持，有效解决了命令保持与开关机构失灵的矛盾，实践表明改造后的方案既有效保证了正常情况下可靠分合闸，又在异常时保证操作回路设备的完好，并能及时上报开关失灵远方信号。

Design optimization of switch operating circuits in protective equipment

When the switching mechanism fails action,the current keeps in the trip or close cir cuits of protective equipment for a long period,which may damage the trip of close winding.Based on the analysis of typical operating circuits,a solution is proposed to treat between command holding and mechanism failure.A miniature interposing relay is used and the output contact of protective equipment is set for a limited time delay for releasing the command holding of trip/close circuits.The practice shows that the improved circuits ensure the reliable trip or close of breaker under normal conditions and prevents the damage of operating circuits under abnormal conditions.In addi-tion,it can send upward the remote signal of breaker failure in time.