采用原子分解法的同步电机参数辨识
2017-07-10倪良华肖李俊吕干云李军
倪良华 肖李俊 吕干云 李军
摘 要:为了准确辨识出同步电机参数,提出了一种基于原子分解的新算法。首先构建相关原子库并将原子离散化参数连续化,运用进化匹配追踪算法,快速从同步电机突然短路电流中提取基波电流、直流电流、倍频电流;然后从分解的各原子信号特征参数中推算出同步电机参数。通过截取稳态短路电流的采样信号,辨识出同步电机的同步电抗和短路初相角值。以理想突然短路电流和含噪声的短路电流为例,仿真进行了对信号的原子分解,获得了相似度较好的重构信号。较之经验模态分解(EMD)和Prony算法,所提出的方法对含噪声信号短路电流的分解效果更佳。实测算例表明,应用原子分解方法可准确地提取同步电机参数,且有较好的抗噪性能。
关键词:原子分解;连续相关原子库;同步电机;参数辨识;进化匹配追踪算法
DOI:10.15938/j.emc.(编辑填写)
中图分类号:TM 341 文献标志码:A 文章编号:1007 -449X(2017)00-0000-00(编辑填写)
Application of atom decomposition algorithm in
synchronous machine parameters identification
NI Liang-hua, XIAO Li-jun, LV Gan-yun, LI Jun
(School of Electric Power Engineering, Nanjing Institute of Technology, Nanjing 211167, China)
Abstract: Aiming at accurately identifying parameters of synchronous machine, a new algorithm of atomic decomposition is presented in this paper. Firstly, constructing the coherent atom dictionary and serializing the discrete parameters of atoms, evolutionary matching pursuit algorithm is adopted to extract fundamental current, the DC current and harmonic current from the sudden short circuit current quickly, and then synchronous machine parameter is derived from each atom signal characteristic properties. By cutting out the sampling signals to obtain steady short circuit current, synchronous reactance and short-circuit initial phase value of synchronous machine is identified. Both the ideal sudden short circuit current and short circuit current with noise as examples, when the simulation is carried out on the atomic decomposition of the signal, the reconstruction signal with good similarity is obtained. Compared with the empirical mode decomposition(EMD) and Prony, the proposed method has better decomposition effect on short circuit current with noise. The simulative results show that, the atomic decomposition method is less influenced by noise and has higher parameter identification precision.
Keywords: atom decomposition, continuous coherent atom dictionary, synchronous machine; parameters identification, evolutionary matching pursuit algorithm
0 引 言
準确的同步电机参数辨识对研究分析电力系统运行和设计控制系统有着重要意义。其中,反映同步电机暂态过程的瞬态参数与电力设备选择、电力系统稳定性计算以及故障计算等密切相关[2-11]。GB/T1029-2005[1]推荐使用的同步电机参数测量方法是三相突然短路法,通过短路电流上下包络线提取周期分量和非周期分量。这种数据处理方法获取瞬态参数的结果误差较大。短路电流可用指数函数来表示,而Prony算法适合指数函数的参数辨识,提取的参数效果较好,但Prony算法存在对噪声敏感以及阶数确定问题[2]。……
