微机保护二次回路中应注意的几个问题

随着城乡电网改造的不断深入,电网日趋完善,继电保护装置大部分已更新为微机保护.由于微机保护具有比较完善的保护功能,一般不会发生保护误动现象,使保护装置可靠性大幅度提高.从近年来的继电保护动作分析来看,继电保护不正确原因多出现在二次回路上,二次回路中应注意保护装置的重合闸问题,接入保护装置模拟量、开关量的正确性,保护装置的直流电源可靠性,二次回路抗干扰和电压切换等问题.确保二次回路的正确可靠,保证电网的安全稳定运行.

Some issues of microcomputer protection secondary circuit for attention

With the progress of township and rural power grid alteration, the grid is becoming perfect gradually and most relay protection equipment have been replaced by microcomputer protection apparatus. Misoperation is generally prevented from fairly perfect protective function of microcomputer protection, so the liability of protective device is greatly upgraded. The information about relay protective action in recent years have demonstrated that secondary circuit is the origin of most incorrect relay protection. Issues in need of attention for secondary circuit shall include reclosing of protective device, correctness of analogue and digital quantities to be input of protective device, reliability of DC power supply for protective device, anti-interference and voltage changeover of secondary circuit etc. The secondary circuit shall be correct and reliable to ensure the safe and stable operation of power grid.