新型线路保护选相方案

通过对故障前数据的有效处理和选相过程的优化，延长了补偿电压突变量选相元件的工作时间，使之可在整个故障过程中发挥作用，并可在系统无振荡时的各种工况下正确指示故障相;通过所设计的保持元件和方向元件，克服了电流突变量选相结果无法有效保持且无方向性的缺点，提高了选相正确率;提出了综合电流选相原理，解决了一些稳态量选相元件在特殊工况下无法正常工作的难题;在对各种选相原理进行优化配置的基础上，设计并实现了一种性能突出的新型选相方案。

A New Scheme for Fault Phase Selection and Transmission Line Protection

By effective data processing prior to the fault and optimization of the phase selection process,improvement has been made on the ability of the fault phase selector based on the fault component of compensation voltage to enable it to work better in the whole process of fault development,with the fault phase correctly indicated under different operation conditions when the power system is free from swing.Thus the inability of effectively maintaining the results of the fault phase selector based on the fault component of current and the lack of directionality are overcome using the maintaining and directional elements designed,increasing the rate of correct phase selection.The principle of synthetic fault phase selector based on the integration current is proposed and the incapability of normal operation of the fault phase selector based on stable electric components under abnormal operating conditions is resolved.A workable scheme for fault phase selection is described.