电容器宽频等效模型与损耗分析

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中图分类号：TM855 文献标志码：A 文章编号：1000-582X（2026）03-013-12

Wideband modeling and loss analysis of power capacitors under harmonic voltages

ZHANG Zheng'，DU Lin'，CHEN Weigen'，HUI Shixian²

（1. State Key Laboratory of Power Transmission Equipment Technology， Chongqing University， Chongqing

400044，P.R. China; 2.Wenshan Power Supply Bureau of Yunnan Power Grid Co.，Ltd.， Wenshan，Yunnan 663000，P.R.China）

Abstract：Power capacitors are widely used for reactive power compensation，harmonic filtering，carrier transmission，and high-frequency protection in power systems.In practical operating conditions，the voltage applied to power capacitors contains significant harmonic components，resulting in complex loss characteristics. To accurately characterize the active power losss of capacitors under harmonic voltages，a wideband distributed equivalent model based on the extended Debye model is proposed，taking into account the actual physical structure of thecapacitor.Analytical expressions for the voltage and currnt distributions on the capacitor plates arederived，and their spatial characteristics aresystematicallyanalyzed.By considering both electrode （plate） lossesand dielectric losses，thedistribution ofactive power loss within thecapacitor is investigated，and the corresponding rules are summarized.The results indicate that harmonic voltages increase the amplitude of the current flowing on the capacitor plates，leading to a nonlinear current distribution.Moreover，as the voltage frequency increases，the active powerlossofthecapacitorrises significantly，and inthe high-frequencyrange，the plate losses become the dominant contributors to the total active power loss.Based on these findings，a loss reduction strategyisproposed，inwhich thenumberofvoltage input points isincreased topromotea more uniform electrode current distribution， thereby eectively reducing the active power loss of the capacitor.

Keywords： power capacitor; harmonic voltage; wideband equivalent model; active power loss

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