A method for estimating the parameters of ZnO-varistor-equivalent circuit model based on FDS

Abstract

The invention relates to method for estimating the parameters of ZnO-varistor-equivalent circuit model based on FDS, belonging to the technical field of lightning arrester model. The method comprisesthe following steps. S1: The measuring instrument of frequency domain dielectric spectroscopy (FDS) and the ZnO varistors are prepared as a part of the experiment platform. S2: The parameters are properly set on the measuring instrument of frequency domain dielectric spectrum. S3: The FDS of the ZnO varistors are measured multiple times until the final results are obtained. S4: The complex impedance of the equivalent model is calculated using ZnO-varistor-equivalent polarized circuit model. S5: The parameter function of the equivalent model is optimized based on the measured FDS data of ZnO varistors and the results calculated by the model. S6: The iterative calculation on the optimized parameter function is performed using genetic algorithm to finalize the parameter estimation for the equivalent model. The method of the invention satisfactorily describes the dielectric response of ZnO varistors, and remediates the insufficient explanations by R C parallel model and the IEEE model on the microscopic behavior of ZnO varistors in terms of polarization and electric conductance among others.

Description

technical field [0001] The invention belongs to the technical field of lightning arrester models, and relates to a method for estimating parameters of an FDS-based equivalent circuit model of a ZnO valve plate. Background technique [0002] Metal Oxide Arrester (MOA) is an important equipment for overvoltage protection in the power grid. It protects other equipment from overvoltage. It will gradually deteriorate and will directly endanger the operation and power supply reliability of other protected equipment in the power grid. Therefore, it is of great significance to accurately evaluate the operation status of metal oxide arresters to ensure the safe and stable operation of the power grid. The ZnO valve plate located inside the bushing is the core component of the arrester, and the insulation state of the ZnO valve plate will directly determine the insulation state of the entire arrester. [0003] Establishing a unified equivalent circuit model of the ZnO valve is an impo...

AI Technical Summary

Problems solved by technology

In addition, most of the models currently established are mostly used for system simulation. The parameters in the models are mostly set artificially based on the relevant experience and the size of the arrester. The parameter identification of the remaining few models mostly uses the step voltage response curve in the time domain. To reflect the polarization state of the medium and use the curve obtained by the oscilloscope to "draw the reading" to obtain the parameter value of the model. Because the method is carried out in the time domain, it is susceptible to the interference of time domain noise and the accuracy of the measurement signal. The method is greatly affected by human factors, thus affecting the accuracy of equivalent model parameter identification

In contrast, Frequency Domain Spectroscopy (FDS) carries rich information and has strong anti-interference ability, but the current research on the equivalent model of ZnO based on FDS is extremely scarce

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