保护继电器间直接数字逻辑通信技术的应用

APPLICATION OF DIRECT RELAY-TO-RELAY DIGITAL LOGIC COMMUNICATION

安全性、可依赖性和快速性是高压输电线路纵联保护最重要的性能参数 ,允许式、闭锁式及直接式远方跳闸保护对 3种性能参数的要求各不相同 ,对同一种保护而言 ,安全性和可依赖性是一对不可调合的矛盾。文中介绍了东北电网 5 0 0 k V辽—长—吉—哈工程中 ,我国第一次采用镜像比特技术构成的 5 0 0 k V线路允许式纵联保护 ,在线路两端继电器间通过 RS— 2 32串行接口复用数字通信系统终端设备的子速率接口 ,将继电器内部元件的逻辑状态以数字编码形式 ,按异步串行通信方式互相重复传送和接收。与采用传统方法构成的纵联保护相比 ,采用镜像比特技术构成的纵联保护不但提高了整套保护的安全性、可依赖性和快速性 ,能够灵活适用于各种纵联保护方式 。

Security,reliability and high speed are the m ost im portant characteristics of HV transmission line pilot protection. The requirements of three characteristics are different for the perm issive tripping schem e,blocking schem e and direct transfer tripping scheme.As one kind of protection equipment is concerned,its security and reliability are two sides of a contradiction that can hardly be solved. The paper introduces the first permissive tripping pilot protection of 5 0 0 k V line with m irror bits technique,in5 0 0 k V L iao- Chang- Ji- Ha project of Northeast Power Network,China.Both relays at two terminals of a line mutually transmit their internal logic status in digital code.In an asynchronous com munication manner,the transmission is com pleted by a set of comm unication system that consists of the RS- 2 32 serial ports and m ultiplex sub- speed ports that are parts of the digital comm unication system terminals.Com pared with conventional schem e,it has many advantages,such as higher security,higher reliability,faster operation,better adaptability and m ore economical investm ent. Mirror bits technique can flexibly be applied to any kind of pilot protection schem e. One- year excellent running experience proves itself satisfactory in operation.