基于数值微分的阻尼灵敏度方法比较

Comparison of numerical differentiation based damping sensitivity method

为了克服系统模型不准时特征值灵敏度解析法结果失效的问题,提出基于数值微分的特征值灵敏度计算方法.系统地研究差商法、插值法和改进正则化法这3种数值微分方法的原理,从特征值样本点的摄动步长影响和测量误差影响两方面综合分析3种方法的计算性能,比较分析得出改进型正则化方法能够较好地考虑特征值计算时的测量误差,具有相对较好的计算稳定性.在现有商业小扰动计算软件的基础上,实现了大规模电网的阻尼灵敏度自动化计算.通过实际大电网算例,验证了基于数值微分的阻尼灵敏度法的有效性.

A numerical differentiation based damping sensitivity analysis(NDDS)method was presented in order to overcome the noneffectiveness of the analytic damping sensitivity method(ADS)based on the close-form sensitivity expression when the system model is inaccurate.The principle of three numerical differentiation methods,the difference quotient method,the interpolation method and the modified regularization method,were analyzed.The performance of all these methods were analyzed on two influence factors:the perturbation step setting and the measurement error.The modified regularization method can consider the measurement error of the eigenvalue and outperforms other two methods with better computation stability.The NDDS calculation procedure based on a commercial small signal analysis package for large-scale power grid was developed.The effectiveness of NDDS was validated by a simulation study on a real power system.