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成都理工大学工程技术学院毕业论文基于FPGA直流电机的PWM控制作者姓名：2B专业名称：测控技术与仪器指导教师：2B导师II摘要如果采用CPU控制产生PWM信号，一般的PWM信号是通过模拟比较器产生的，比较器的一端按给定的参考电压，另一端接周期性线性增加的锯齿波电压。当锯齿波电压小于参考电压时输出低电平，当锯齿波电压大于参考电压时输出高电平。改变参考电压就可以改变PWM波形中高电平的宽度。若用单片机产生PWM信号波形，需要通过D/A转换器产生锯齿波电压和设置参考电压，通过外接模拟比较器输出PWM波形，因此外围电路比较复杂。FPGA中的数字PWM控制与一般的模拟PWM控制不同，用FPGA产生PWM波形，只需FPGA内部资源就可以实现。用数字比较器代替模拟比较器，数字比较器的一端接设定值计数器输出，另一端接线性递增计数器输出。当线性计数器的计数值小于设定值时输出低电平，当计数值大于设定值时输出高电平。与模拟控制相比，省去了外接的D/A转换器和模拟比较器，FPGA外部连线很少，电路更加简单，便于控制。脉宽调制式细粉驱动电路的关键是脉宽调制，转速的波动随着PWM脉宽细分数的增大而减小。直流电机控制电路主要由三部分组成：FPGA中PWM脉宽调制信号产生电路。FPGA中的工作/停止控制和正/反转方向控制电路。由功率放大电路和H桥组成的正反转功率驱动电路。关键词：直流电机脉宽调制FPGA数字比较器IIIFPGA-basedDCmotorcontrolPWMAbstractIftheCPUcontrolofaPWMsignal,thegeneralPWMsignalthroughtheanalogcomparator,comparedwiththeendofagivenbythereferencevoltage,andtheotherterminationcyclicallinearincreaseinthesawtoothvoltage.Whenthesawtoothvoltagereferencevoltageoutputislessthanlow,whenthesawtoothreferencevoltagegreaterthanhigh-voltageoutput.ChangethereferencevoltagecanchangethePWMwaveforminthehigh-width.IftheMCUhavePWMsignalwaveform,throughD/AconvertershaveasawtoothvoltageandsetreferencevoltagethroughanexternalanalogcomparatoroutputPWMwaveform,theexternalcircuitisrathercomplicated.ThefiguresintheFPGAPWMcontrolandthesimulationofthegeneralPWMcontroldifferent,withaFPGAPWMwaveform,justFPGAinternalresourcescanbeachieved.Comparedwithfiguresforcomparisoninsteadofanalog,digitalcomparisonwiththeterminationofasetofcounteroutput,andtheothercounterterminationlinearincrementaloutput.Whenthelinearcounterlessthanthevalueofexportsoflowvalueset,whenthesetofvaluesthanhigh-valueoutput.Comparedwithanalogcontrol,eliminatingtheexternalD/Aconverterandanalogcomparator,FPGAfewexternalconnections,circuitmoresimple,easycontrol.PWMpowderdrivecircuit,thekeyisPWM,withfluctuationsinspeedPWMpulsebreakdownincreasedthenumberofdecreases..DCmotorcontrolcircuitsmainlyconsistsofthreeparts:(1)FPGAinthePWMPWMsignalcircuits.(2)FPGAinthework/controlandstop/reversedirectioncontrolcircuit.(3)thepoweramplifierandH-bridgecomposedofpositiveandpower-drivencircuitKeyword:DCmotor,pulsewidthmodulation,FPGA,comparisonwitIV目录摘要...................................................................................................................................IIAbstract..................................................................................................................................III目录..................................................................................................................................IV前言.....................................................................................................................................-5-1FPGA芯片简介与使用..................................................................................................-6-1.1FPGA部分介绍..................................................................................................-6-1.2直流电机...........................................................................................................-11-1.2.1直流电动机的介绍......................................................................................-11-1.3关于QuartusII软件的使用........................................................................-13-1.3.1QuartusII简介.........................................................................................-13-2PWM基础理论分析以及电路分析............................................................................-16-2.1PWM波调制原理...............................................................................................-17-2.2数字脉冲宽度调制器的实现..........................................................................-19-3基于FPGA直流电动机的PWM控制实现.................................................................-21-3.1基于FPGA的PWM控制....................................................................................-22-3.2FPGA电动机控制电路的设计.........................................................................-23-3.2.1设计的硬件电路外部部分....................................................................-25-3.2.2QuartusII内部设计模块.................................................................-26-3.3调试与仿真......................................................................................................-35-3.4设计结果...........................................................................................................-36-总结.....................................................................................................................................-37-致谢...................................................................................................................................-38-参考文献.......................................................................................................................-40-附录............................................................................................................................-41-FPGA直流电机控制模块结构图.............................................................................-41--5-前言在数字电子系统领域，存在三种基本的器件类型：存储器、微处理器和逻辑器件。存储器用来存储随机信息，如数据表或数据库的内容。微处理器执行软件指令来完成范