论微机负序距离继电器

On microprocessor-based negative sequence distance relay

介绍了多相补偿距离继电器的应用基础是故障前系统的三相对称 ,而其动作方程是三相不对称的 ,因此要调整该继电器对不同相别的两相短路有相同的灵敏度 ,会加大机械制造和调试的难度。而微机负序距离继电器动作判据的依据是序分量 ,它是三相对称的 ,使该继电器能对不同相别的不对称故障有完全相同的特性。两种继电器都不反应负荷与振荡。当故障与振荡同时发生时 ,多相补偿距离继电器会不正确动作 ,故它仍需加设振荡闭锁 ;而微机负序距离继电器由软件实现 ,只需增加简单的辅助判据 ,就可以完全不受振荡的影响而正确动作。

An important basis of the polyphase compensated distance relay is the symmetry of the three phases,but its operation equation is unsymmetrical.For mechanical type polyphase distance relay,to set identical sensitivities for different phase to phase faults is difficult.The action criteria of microprocessor based negative sequence distance relay is the sequence components,which is symmetrical for the three phases and hence has the same characteristic for different phase to phase faults.Both distance relays are insensitive to load and power swing.When the unsymmetrical fault happens during the power swing,the polyphase compensated distance relay will operate incorrectly and the power swing locking is required.The microprocessor based negative sequence distance relay is based on SW and functions properly without the influence of the power swing.