线路电流差动保护自适应CT变比的方法

A method of CT ratio self-adaptation of line differential protection

提出了一种仅整定本侧CT变比的方法,保护传送及接收的不是电流二次采样值,而是由二次采样值根据本侧CT变比处理后得到的一次电流值,技术关键是传输一次电流值不能溢出。解决了两侧同一套保护定值不一致的问题,方便了运行及管理。该方法已应用于基于32位DSP的WXH-803数字式光纤电流差动保护。

In this paper, a new method of only adjusting the CT ratio at the current side is given. Values transmitted and received by the protection are not the secondary sampled current value, but the primary current value which comes from treated secondary sampled value according to the CT ratio at the current side. The key point of this technology is that the transmission of primary current value cannot overflow. It solves the problem of settings in conformity of the same complex protections on two sides, and makes the operation and management convenient. This method has been applied in WXH-803 digital optical fiber current differential protection based on 32-bit DSP.