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石家庄铁道大学毕业设计I摘要随着电力系统额定电压的提高,对系统供电可靠性的要求也愈高,由于设备绝缘不可靠而引起事故所带来的损失远远超过电气设备本身价值,而且现阶段各种绝缘试验还是验证高压电气设备绝缘能否在现场安全可靠运行的重要手段。因此对于交流高压电气设备,工频耐压试验在高电压技术中具有非常重要和不可替代的地位和作用。以往的工频耐压试验控制线路一般均为继电器、接触器所组成的手动继电控制系统,实现操作顺序和升降压速度变化、升降压过程等均由人工控制,容易出错,且精度得不到保证,若试验过程中出现故障还需技术人员进行分析查找,很是费时,对试验人员来说,工作量很大,而且手动操作的过程,对试验的准确性,也有影响。以工控机为核心的工频耐压控制系统具有编程复杂、价格昂贵、抗干扰能力差的弱点。针对上述情况,本文提出了以可编程控制器(PLC)为核心,同时又能与手动控制系统并行使用的新型工频耐压控制系统。本文通过对常用的几种高电压测量方法进行分析比较,选择电容分压器法测量试验电压,同时采用全波傅立叶算法分析谐波分量并设计滤波电路消除试验电压中的谐波。设计了工频耐压控制系统的主回路包括接触式调压器、试验变压器、NSP保护装置等。同时设计控制回路包括:工作方式设定、动作顺序控制、耐压时间设定、调压器位置检测与报警、试验电路过电流保护等。设计电压、电流、试验电压测量电路。研究了暂态恢复过电压保护系统。最后,使用西门子S7-300编程软件进行包括数字信号、模拟信号的处理以及整个控制系统的软件编程与调试。同时制作WINCC界面,配合硬件控制系统实现了监控试验过程的功能。本文通过软、硬件的设计满足了相关试验标准规程要求,提高了试验的准确性、科学性,通过调式达到了预期的效果。关键词:工频耐压试验,可编程控制器,控制系统设计,WINCC石家庄铁道大学毕业设计IIAbstractTherequirementforthereliabilityofelectricPowersupplyinelectricPowersystemisever-increasinglyhighwiththeimprovementofratedvoltage.ThelossincurredbyUnreliableequipmentinsulationfarexceedsthevalueofelectricalequipment,buttheInsulationtestisanimportantmethodtodemonstratewhetherhigh-voltageelectricequipmentcanrunreliablyandsafelyonsite.Therefore,forhigh-voltagetestelectricequipmentwithautomatingcurrent,Powerfrequencyvoltageendurancetestplaysanimportantroleinhigh-voltagetechnique.ThetraditionalcontrolcircuitofPowerfrequencyvoltage-withstandtestisamanualrelaysystemcomposedofrelayandcont.actor,whichPerformsoperatingsequenceandratechangeofascendingordescendingvoltage.Voltagechangebymanualcontrolisnotveryaccurate,inthemeantime,technicianmustspendtimeandvigoranalyzingandfindingthereasonoffault.Atthesametime,therearesomeweaknessesofProgrammingcomplex,expensive,pooranti-interferenceabilityforindustrialcomputercontrolsystem.Accordingtothesecircumstances,thisdissertationputsforwardanovelPowerfrequencyvoltage-withstandcontrolsystemthatthenuclearPartisaPLC,whichcanbeusedwithmanualcontrolsysteminParallel.Inthisdissertation,capacitancedividerisselectedtomeasurestestvoltageincomparisonwithseveralkindsofcannonhigh-voltagemeasurement.InthemeanwhileanalyzingnominatecomponentbasedontheImprovedFourierTransformationsandDesigningfiltercircuittoeliminateharmonicwavesoftestvoltage.ThedesigningofthemaincircuitofPowerfrequencyvoltage-withstandcontrolsystemwhichconsistscontactvoltageregulator,testtransformer,NPSProtectionequipmentandsoon.Thecontrolcircuitconsistsworkingmodesetting,movementsequencecontrol,andvoltage-withstandtimesetting,voltageregulatorPositiondetectionandalarming,over-currentProtectionoftestcircuitetc.Inaddition,detectioncircuitofvoltage,current,andtestvoltagearedesignedand石家庄铁道大学毕业设计IIIOver-voltageProtectionsystemfortransientrecoveryisdeveloped.Finally,S7-300ProgramsoftwareisappliedtoProgramminganddebuggingdigitalsignalandanalogsignal.Furthermore,WINCCinterfaceismadetomatehardwarecontrolsystemtomonitortest.Thedesignofsoftwareandhardwareinthisdissertationmeetstheneedofrelatedteststandardspecifications,improvePrecisionandscientificoftest,andattainthetargetresultbydebugging.KeyWords:PowerFrequencyVoltage-WithstandTest,ProgrammableController,ControlSystemDesign,WINCC石家庄铁道大学毕业设计IV目录摘要...............................................................IAbstract...........................................................I第一章绪论....................................................-1-1.1关于工频耐压试验.........................................-1-1.2工频耐压试验控制系统研究的目的及意义.....................-1-1.3国内研究的现状...........................................-4-1.4课题研究的主要工作内容...................................-5-第二章试验原理及模拟试验电压谐波分析..........................-6-2.1工频耐压试验原理.........................................-6-2.2试验电压测量方法选择.....................................-7-2.2.1球隙法测量...........................................-7-2.2.2静电压表法测量.......................................-9-2.2.3峰值电压表法测量....................................-10-2.2.4分压器法测量........................................-11-2.3模拟试验电压谐波分析....................................-15-2.3.1试验电压谐波的产生..................................-15-2.3.2谐波分析算法........................................-16-2.3.3仿真模型及结果分析..................................-17-2.4工频耐压试验过程中应注意事项............................-21-2.5本章小结................................................-23-第三章工频耐压试验控制系统硬件设计...........................-24-3.1控制系统主回路设计......................................-24-3.1.1电气图设计原则......................................-24-石家庄铁道大学毕业设计V3.1.2工频耐压试验对控制系统的要求........................-25-3.1.3控制系统主回路......................................-25-3.2控制系统控制回路设计....................................-27-3.3控制系统测量电路设计....................................-31-3.3.1电压测量电路设计....................................-31-3.3.2试验电压测量电路设计................................-34-3.3.3电流测量电路设计....................................-34-3.3.4电源电路设计........................................-36-3.3.5电源滤波电路设计....................................-37-3.4PLC控制系统整体设计方案.................................-39-3.5.1暂态恢复过电压的产生及危害..........................-40-3.5.2暂态恢复过电压消除方法..............................-40-3.6变频调速系统的设计...............