一种基于同弦多圆弧相位比较式失步保护方法

An Out of Step Protection Method with Phase Comparison Based on Multi Circular Arc With Same String

失步保护是大型发电机组必须配置的重要保护,根据失步时发电机电势与系统电势的功角δ变化规律及失步要求,提出了同弦多圆弧边界的失步保护方案,圆弧边界可与机组功角的静稳边界δJ和动稳边界δM对应。圆弧边界识别采用相位比较算法实现,每增加一条圆弧δX边界,只须给定sinδX、cosδX值,运行时增加两个乘法计算,然后实现逻辑判别即可。判据逻辑清晰,实现方法简单。

Out-of-step protection is an important and necessary protection of large generators. According to power angle δ variation rule between the electric potential of generator and the one of power system when out of step,and re- quirements of out of step, this paper presents an out-of-step protection scheme based on multi arc boundaries with same string. Arc boundaries may correspond to static stability boundary δ1 and dynamic stability boundary δM of gener- ator power angle. Arc boundary recognition is realized by using phase comparison algorithm, when adding an arc boundary δx , only given a sinδx value and a cosδx value, adding two multiplications when running, then implementing logic discrimination. Criterion logic is clear, and implementation method is simple.