摘要
该文首先针对混联等效电路模型基于智能优化算法的参数辨识结果不唯一和精度欠佳等问题,构建去极化电流二次微分时域谱线,分析其子谱线特性及其与对应极化支路参数的内在联系;其次利用解谱法分解各个子谱线,并根据子谱线参数进一步辨识混联等效电路参数;最后通过实例验证该方法的可靠性。研究结果表明:基于混联等效电路模型的时域谱线解谱法能够有效且准确地判定各个子谱线参数,以及混联型极化支路和串联型极化支路的极化支路数、极化支路参数等信息;基于解谱法的混联等效电路参数辨识过程简单,辨识结果准确且唯一,避免了传统参数优化过程中的随机性和多解性问题。采用该文微分解谱法所对应的拟合度最低为0.96,平均为0.97,比传统法平均提升0.10。
The extended Debye equivalent circuit model fails to accurately represent the aging characteristics of complex oil-paper insulation medium in transformers.Additionally,the identification method for the hybrid equivalent circuit,which relies on intelligent optimization algorithms,often produces non-unique and inaccurate results.Based on the functional relationship between the depolarization current and the hybrid equivalent circuit parameters,quadratic differential spectrum of depolarization current is constructed,and the characteristics of the sub spectra,as well as their internal relations to the corresponding polarization branch parameters,are analyzed.A method for identifying the parameters of the hybrid equivalent circuit is suggested.The specific idea and identification steps are as follows:(1)Beginning from the end of the quadratic differential time-domain spectrum of the depolarization current,the parameters of the series-type sub-spectrum at large time constants(t≥200 s)are resolved using the point-selection method.This step determines the polarization resistance and polarization capacitance of the corresponding branches with large time constants.(2)The parameters of the hybrid-type sub-spectrum at medium-time constants(2 s<t<200 s)are resolved using the point-selection method.This step determines the polarization resistance and polarization capacitance of the corresponding branches with medium time constants.(3)The parameters of the series-type sub-spectrum at small time constants(t≤2 s)are resolved using the point-selection method.The sub spectra are decomposed using the spectral decomposition method,and hybrid equivalent circuit parameters are further identified based on the parameters of the sub spectra.Finally,The traditional identification method and the spectral identification method are respectively applied to study the transformer T1 to verify the reliability of the method.The experiment results demonstrate that the traditional identification method has the following disadvantages:(1)Artificially assuming different numbers of polarization branches in advance will also affect the identification results of hybrid equivalent circuit parameters.(2)In the light of the complex relationship between the characteristics of the recovery voltage and the parameters of the hybrid equivalent circuit in the objective function of Equ.(10),different equivalent circuit parameters will also be obtained when the identification program is run each time under the condition of ensuring the identification accuracy.the quadratic differential time domain spectra of the depolarization current can effectively and accurately decompose the information related to the number of polarization branches,sub spectra parameters,and polarization branch parameters that are embedded within the depolarization current.The parameter identification process for the hybrid equivalent circuit,based on the spectrum decomposition method,is straightforward.The results of this identification are both accurate and unique,effectively reflecting the aging information of the depolarization current.It avoids the problems of randomness and multiple solutions in traditional parameter optimization processes.Furthermore,a comparative analysis is performed on multiple transformers in various aging states,utilizing the proposed method and the traditional method.The results indicate that the average fitting degree achieved by the proposed method is 0.97,which is on average 0.10 higher than that of the traditional method.This further substantiates that the quadratic differential spectral decomposition method can reliably and accurately identify the hybrid equivalent circuit parameters.
作者
林智勇
李荣华
邓东平
吴勇海
林仁杰
Lin Zhiyong;Li Ronghua;Deng Dongping;Wu Yonghai;Lin Renjie(School of Electrical Engineering and Automation,Xiamen University of Technology,Xiamen,361024,China;Xiamen Key Laboratory of Frontier Electric Power Equipment and Intelligent Control,Xiamen,361024,China;State Grid Fujian Electric Power Co.Ltd,Zhangping Power Supply Company,Zhangping,364400,China;State Grid Fujian Electric Power Co.Ltd,Longyan Power Supply Company,Longyan,364000,China;State Grid Fujian Electric Power Co.Ltd,Jinjiang Power Supply Company,Jinjiang,362200,China)
出处
《电工技术学报》
北大核心
2025年第19期6283-6292,共10页
Transactions of China Electrotechnical Society
基金
国家自然科学基金青年基金(51407151)
福建省自然科学基金(2020J01281)资助项目。
关键词
混联型子谱线
混联等效电路
峰值点
拟合度
Hybrid-type sub-spectrum
hybrid equivalent circuit
peak point
fitting degree
