introduction
L'equipementelectroniquedepuissanceestunappareilcomposédediverscircuitsélectroniquesdepuissance.Utilisépourlaconversionetlecontrôledel'énergieélectriquedehautepuissance.Égalementappelédispositifconvertisseur.
Amongthem, theDCpowersupplycanbecomposedofarectifieroraDCconverter, whichisusedforthepowersupplyofDCmotorspeedregulation, charge (rechargeablepowersupply), electroplatingandscientificinstruments.TheACpowersupplycanbecomposedofafrequencyconverter (seeACconversioncircuit) .Itisdividedintovariablefrequencyvariablevoltagepowersupply (usedforACcageasynchronousmotorspeedregulation), constantfrequencyconstantvoltagepowersupply (usedtoformACuninterruptedpowersupply), ACstabilizedpowersupply, intermediatefrequencyinductionheatingpowersupply (poweroutputfrequencyupto8kHz, Usedforinductionheatingandquenching), de haute frequencyheatingpowersupply (poweroutputfrequencyishigherthan8kHz, usedforquenchingandwelding) andsoon.Utilizingthefastswitchingperformanceofpowerelectronicdevices, astaticnon -l'interrupteur haute puissance à contact peut être réalisé pour remplacer l'interrupteur haute puissance électromagnétique traditionnel par contact.
Protection de l'appareil
Powerelectronicdevicesareaffectedbytheperformanceofthedevicesused, andtheirabilitytowithstandovervoltageandovercurrentisrelativelypoor.Forexample, moteurs, transformateurs, etc.usuallycanworkforseveralsecondsorminutesatseveraltimestheratedcurrent, whilepowerelectronicdevicescanbedamagedin0.1secondorlessunderthesameconditions.Therefore, inadditiontothereasonableselectionofthevoltageandcurrentcapacityofthedevicewhendesigningthepowerelectronicdevice, itisalsonecessarytotakesomespecialprotectivemeasurestopreventthedevicesinthedevicefrombeingdamagedduetoovercurrentandovervoltage.Somepowerelectronicdeviceshavespecialrequirementsforenvironmentalconditions (suchastemperature, coolingwaterpressure, vitesse du vent, etc.), Andtheseconditionsneedtobemonitoredtoensurereliableoperationofthedevice.
Protection contre les surintensités
Overcurrentwillquicklyheatupthedevice.Iftheovercurrentisnotcutofforlimitedintime, thedevicewillsoonbedamaged.Thegreatertheovercurrent, theshorterthetimethedevicecanwithstandtheovercurrent.Commonlyusedovercurrentprotectionmeasuresare: ①Usingfastfuse.Thefusingtimeisusuallywithin20milliseconds.However, thefastfuseisexpensiveandtroublesometoreplace, andisoftenusedasthelastmeasureofavarietyofovercurrentprotectionmeasures.②SetupanACcircuitbreaker.Theactiontimeislonger, rangingfrom0.1to0.2seconds.ItismainlyusedtocutofftheconnectionbetweentheACcircuitandtheACpowersupplytopreventfurtherexpansionofovercurrent.③InstallafastDCswitch.Itsactiontimeisabout10-20milliseconds, whichcanprotectthethyristorandothercomponentswithoutthefastfusebeingblown.InstalledontheDCendofACcircuits, usedforlargeandmedium-capacitypowerelectronicdevices.④Addafastshort- Le temps d'action est d'environ 2 à 3 millisecondes. Lorsqu'une surintensité se produit, elle provoque un court-circuit direct du transformateur de puissance via un dispositif de court-circuit rapide la surintensité d'entrer dans le dispositif électronique de puissance.
Protection de survoltage
Overvoltagewilldamagetheinsulationofthedeviceandmakeitunabletowork.Commonlyusedover-voltageprotectionmeasuresare: ①Usingresistance-capacitanceabsorptioncircuit.Itisformedbyaseriesconnectionofacapacitorandaresistor.Thecapacitorisusedtoabsorbtheovervoltageinthepeakstate, andtheresistanceinserieswiththecapacitorisusedtoconsumetheenergyoftheovervoltage, therebysuppressingtheoscillationofthecircuit.②Selectnon-linearresistancedevices.Utilizethevolt-amperecharacteristicofthiskindofdeviceclosetoZenertubeandthecharacteristicthatitscharacteristiccanberestoredautomaticallyafterbreakdown, realizetheovervoltageprotectionofthepowerelectronicdevice.Commonlyuseddevicesareseleniumstackovervoltagesuppressorandvaristor.③Usingelectroniccircuitsforover-voltagedetectionandprotection.
Technologie anti-interférence
Powerelectronicdevicesarehigh-powerelectricenergyconversionequipment, andseriouselectromagneticinterferenceisinevitableattheinstallationandusesite.Inadditiontodirectlycausingthepowerelectronicdevicestomalfunctiondirectly, thestronginterferencesignalenteringthedevicemainlyinterfereswiththecontrolcircuitofthedeviceandcausesthedevicetomalfunction.Commonanti-jammingtechnicalmeasuresinclude: ①Suppressthestrengthoftheinterferencesignal.Forexample, ACrelays, ACcontactorcontactsandparallelcapacitorscanreducetheelectricsparkinterferencewhenthecontactsareonandoff.②Reasonablewiringtoreducethedistributedcapacitance, distributedinductanceandmutualinductancebetweenthewirestopreventinterferencesignalsfromentering.③Implementelectromagneticshielding.④Choosethegroundingpointcorrectlyandgrounditwell.⑤Strengthentheanti-interferenceabilityofthecircuititself.Selectelectroniccomponentswithgoodanti-interferenceperformancewhendesigning.⑥WhenthecontrolcircuitsharesaDCstabilizedpowersupply, eachpartofthecircuitshouldbe Essayez de réduire l'impédance d'entrée et de sortie de chaque circuit d'unité lorsque la puissance du signal le permet.
Application
Thepowersystemisthemaincarrierofenergyutilization, transmissionanddistribution, anditplaysanimportantroleinthesocialeconomy.Thecrisisoffossilenergyandclimaticenvironmenthascausedthepowersystemtobetransformedfromlarge-scaledevelopmenttosustainabledevelopmentandintelligentization.Large-scaleaccessofdistributedpowersourcesandenergystoragedevices, coordinationoflocalpowergrids, microgridsandbackbonepowergrids, efficientandflexiblepowertransmissionmethods, intelligenttwo-wayinteractionofpowerdistributionandpowerconsumption, andimprovementofpowersupplyqualityandreliability.Itisacharacteristicofpowersystemtransformation.
Inthepowersystem, grille-connectedpowergenerationofrenewableenergy, powerconversionofenergystoragedevices, flexibleinterconnectionofACandDCpowergrids, deux wayflowofdistributedpower, dynamiccompensationofreactivepowerandharmonicsAllneedtorelyonpowerelectronicdevicestoachieve.Withthedevelopmentofhigh-voltageandhigh-powerpowerelectronicdevices, theimprovementofthemodularization, unitizationandintelligenceofconverters, theimprovementoftheperformanceofcontrolstrategiesandmodulationstrategies, powerelectronicdeviceswillplayagreaterroleinthepowersystem.