Precise algorithm for inverse-time overload protection;
反时限过载保护精确算法
Three curve-fitting methods of inverse-time characteristic are introduced and compared by simulation and experiments respectively.
介绍3种反时限特性曲线的拟合方法,通过仿真和实验进行了比较。
The generator low-voltage blocking inverse-time current protection can be adopted for generator or generator-transformer set or 6～10kV busbar system on generator s side as a backup protection against short-circuit faults under the operating conditions that the short-circuit current is smaller than the rated current of generator.
发电机、发变组或发电机机端6～10kV母线系统可以采用发电机低压闭锁反时限电流保护,作为短路电流小于发电机额定电流工况下短路故障的后备保护,也可以作为主变压器高压侧母线或线路短路故障的远后备。
The feasibility,effectiveness and limitation of four improvement measures are studied:raise protection settings or prolong protection delay;apply inverse time limit;use additional criterion to distinguish valve fault from AC system fault;and adjust 100 Hz protection configuration principle.
为减小交流系统故障期间直流100Hz保护动作的概率,利用PSCAD/EMTDC仿真分析软件,就阀故障和交流系统故障时直流线路50Hz/100Hz电流特性进行了分析,研究了提高保护定值或延长保护动作延时、采用反时限特性、利用附加判据区分交流故障和阀故障、调整直流100Hz保护配置原则4种措施的可行性、使用后的效果及局限性。
The distance protection with inverse time characteristic is the best choice to solve the conflict between fast trip near the protecting relay and reliable trip at the end of protection zone.
反时限距离保护是解决近范围快速动作与保护范围末端可靠动作之间矛盾的最好策略。
The current protection is divided into two types that are definite time lag and inverse time lag.
电流保护分为定时限和反时限两大类,定时限电流保护应用广泛,反时限电流保护也十分简单,以存在配合的线路反时限零序电流保护和发电机负序反时限过流保护为例,介绍了选择曲线、确定待定参数的方法和技巧。
The scheme has the character of inverse time lag.
对解微分方程算法做了改进,通过数字仿真计算验证了改进后算法的优良估计性能,并且把它与递推最小二乘法、全周傅立叶算法作了比较,并根据各算法的估计性能特点,提出了一种具有反时限特性的距离保护算法的实现方案。
According to the characteristics of different algorithms,an implementation scheme of distance protection with inverse time charac-teristic is brought forward.
并根据各算法的估计性能特点,提出了一种具有反时限特性的距离保护算法的实现方案。