低励限制动态特性优化实用技术机理分析

Mechanism Analysis of Practical Technology for Dynamic Characteristics Optimization of Under-excitation Limiter

在国内外主流励磁调节器低励限制(UEL)涉网性能测试及建模仿真的基础上,基于阻尼转矩方法推导了竞比型和叠加型UEL控制方式下的阻尼转矩公式。通过详细分析UEL中有功测量环节后的惯性滤波环节对于改善竞比型和叠加型UEL动态稳定性的作用机理,指出了竞比型方式下UEL动作后的系统阻尼转矩基本为正值;而叠加型方式下UEL动作后的系统阻尼转矩与UEL参数有关,增大比例增益可以增强阻尼,增大积分增益则降低阻尼。最后,以数字物理混合仿真测试及特征值分析验证了增加惯性滤波环节可以大幅增强UEL默认参数对接入系统适应性的结论。

Based on performance tests and models on the under-excitation limiter（UEL）of main excitation regulator at home and abroad,damping torque formulas under constant reactive control have been deduced,including superimposed and comparative types of UEL.This paper analyses the mechanism of improving UEL dynamic stability by increasing an inertial filter link after active power measuring link.Besides,it is pointed out that damping torque is always a positive number under comparative type of UEL while under superimposed type of UEL,damping torque is related to parameters of UEL.Increasing proportional gain may enhance system damping and increasing integral gain may decrease system damping.Finally,by mixing physical tests with mathematical tests and eigenvalue analysis,it has been verified that adding an inertial filter link can greatly improve the suitability of UEL access to power system with default parameters.