低压直流断路器热脱扣器温度场分析

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引用格式：，等.低压直流断路器热脱扣器温度场分析[J].现代电子技术，2025，48（20）：120-126

关键词：低压直流断路器；热脱扣器；热双金属片；温度场；多物理场耦合；有限元分析；热时间常数中图分类号：TN602-34；TM561 文献标识码：A 文章编号：1004-373X（2025）20-0120-07

Analysis of temperature field of low-voltage DC circuit breaker thermal trip

SU Xiuping1，²，WANG Dongyuel，²，JIA Yanqing1，2，WANG Linlin1，² （1.School of Electrical Engineering，Hebei University of Technology，Tianjin 30o13o，China; 2.StateKeybooofliiitdlgaltbeesitofcoa

Abstract：Low-voltageDCcircuit breakerthermal tripcompletes theoverload protectionactionmainlybymeans of the thermalbimetalshetsbendingduetoheat.Inordertoanalyzethetemperaturedistributionofthethermalbimetalsheetsduring service，anelectric-thermal-fluidcouplingmodelofthelow-voltageDCcircuitbreakerisestablishdinfiniteelementsoftware COMSOLfortheactual workingcondition，soastoobtainthetemperaturerisecurveofthethrmaltrip.Thecorectnessof the simulationresultsisverifiedbyexperiments.Thesimulationandexperimentalresultsindicatethattheindirectlyheatedtheal bimetalsheetsandtheheatingelementsexhibitthedistributionfeatures：hightemperaturesinthecentralregionandlow temperaturesatthebothextremities.Theheattransfermodeofthethermalbimetalsheetandtheheatingelementisresearched byanalyzingtheheatconduction，heatconvection，andheatradiationwithinthecircuitbreaker.Itshowsthattheindirectly heatedthermalbimetalsheetisprimarilyheatedbymeansofthethermalconvection，andthethermalradiationcannotbe disregardedathighertemperatures.ThenonlineartemperatureofthethermalbimetalshetwasfitedbymeansoftheLevenbergMarquardtleastsquaresmethod，anditsthermaltimeconstantwascorrected.Thecorrectedthermal timeconstantcanreflect actualworkingconditionofthecircuit breaker，andcanprovideareferenceforthedegradationresearchandoptimizationdesign of the thermal trip.

Keywords：low-voltageDCcircuit breaker;thermal trip；thermalbimetalshet;temperature field;multi-physical field coupling;finiteelement analysis;thermal timeconstant

0 引言

近年来，随着直流输配电技术的快速发展，直流断路器作为最常用的保护电器之一，能够闭合、承载和关断正常电流，也可以在规定时间内承载和开断过载或者短路电流，起到保护和控制的双重作用，因而受到广泛关注[1-3]。（剩余5979字）