采样值差动保护动作特性的研究

针对不同的制动方式,研究了采样值差动保护中S、R取值应满足的基本条件,对于和差制动和最大值制动方式,S的选取应满足NS25.0>,对于模值和制动,S应满足NS27.0>;分析了和差制动方式下采样值差动保护动作的模糊区问题, 并给出了相应的表达式;在复相量平面上,采用动作特性相量分析方法,研究了采样值差动保护的动作区、制动区和模糊区,分析表明该方法在实际应用中,特别是差动特性测试中将是非常有益的。

STUDY ON THE OPERATING CHARACTERISTIC OF SAMPLED VALUE DIFFERENTIAL PROTECTION

This paper studies the selections of S, R in the sampled value differential protection according to different restraint modes. For the sum and differential restraint mode as well as the maximum value restraint mode, the selections of S should satisfy S>0.25N. For the restraint mode with sum of modules, S should satisfy S>0.27N. The fuzzy operating zone for sum and differential res traint mode is also discussed and its expressions are presented. The operation characteristic analyzing method is proposed to analysis the characteristic of sampled value differential protection, which is based on the phasor plane and uses the phasor relationship of currents between two terminals to represent operating zone, restraint zone and fuzzy zone. Study shows this method is good for the practical use and performance test of sampled differential protection.