毕业论文（设计）基于DSP 全数字控制应急电源设计10848.doc

基于DSP全数字控制应急电源设计 作者：夏超英天津大学 夏超英 许晓萍 余慧峰中国科学院电工研究所 李 峰 摘要：基于高性能数字信号处理器(DSP)设计了全数字控制的智能型应急电源。首先给出了该应急电源的主电路拓扑，详述了其工作原理。其次介绍了基于TMS320LF2407 DSP芯片的控制电路硬件设计，分析了充电和逆变管理的软件设计，给出了主程序流程图。最后给出该应急电源的实验波形。 关键词：不间断电源；充电；逆变器数字信号处理器 1 引言随着社会信息化、现代化的发展，对供电可靠性的要求越来越高，大型建筑，如机场、车站、会展中心、体育馆、政府机构办公楼及高层建筑等，一旦供电系统突然发生故障而中断供电，将会破坏社会的正常生活秩序，甚至造成重大的政治影响和经济损失。然而，电力故障突发性强，往往不以人的意志为转移，因为无论供电部门管理多严格，电网设施多先进，断电也在所难免。因此就需要做到电源的不间断，即供电线路停电时由备用电源供电。 急电源又称EPS(Emergency Power System)，具有下述优点：电网有电时，处于静态，无噪音；供电时，噪音小于60dB。不需排烟和防震处理，具有节能、无公害、无火灾隐患的特点。自动切换，可实现无人值守。电网供电与EPS电源供电相互切换时间均为0.10.25s。带载能力强。EPS适应于电感性、电容性、及综合性负载的设备，如电梯、水泵、风机、办公自动化设备、应急照明等。使用可靠。主机寿命长达20年以上。适应恶劣环境。可放置于地下室或配电室，也可紧靠应急负荷使用场所就地设置，以减少供电线路。 本文介绍一种基于DSP对应急电源的充电和逆变等过程进行控制的设计方案。此外，利用DSP和51单片机的串口进行通信，设计了界面友好的人机接口，用户可通过人机接口启动、停止电源，使电源进入强迫逆变状态，了解电源的工作状态、故障类型和输出电压、输出电流等参数。 2 应急电源工作原理图1示出应急电源的主回路电气原理图。电路板上电以后，根据6号检测通道判断电网电压是否正常。 图中电池电压UH的检测点 VI1VI6IGBT 充电电流ic的检测点 KM1KM5继电器 逆变电流ib的检测点 逆变电压ub的检测点 电容电压uc的检测点 电网电压Us的检测点如果Us正常，系统先检测是否在逆变状态，若不在逆变状态，则要求外部主电路KM1吸合，KM5断开；若在逆变状态，则要先停止逆变，KM3，KM4断开，再要求外部主电路KM1吸合，KM5断开。同时 KM2吸合，负载开始由市电供电；认输入给变压器，变压器抽出两个抽头取出150V电压输入给单相整流桥ZL，ZL的输出端接有电容，使ZL的输出电压为输入电压的1.4倍，大约是210V左右，ZL输出的直流电通过电阻给电容C预充电，当Uc>200V后，要求KM4闭合，由市电直接给C充电，C充满后由 DSP控制VI1(VI2常断)，经过电抗器和熔断器给电池充电。 如果Us不正常，即存在欠压或过压，则KM1， KM2，KM4断开，KM3，KM5闭合，由于在充电过程中 uc高于UH，所以需在蓄电池放电之前先对C放电，当uc接近UH时，KM4闭合，此时VI3VI6由DSP控制，负载由电源供电。检测点为ub检测点，ub的有效值U6100V时为正常电压；若不符合，需在软件中通过PID算法进行调整。检测点为ib检测点， ib>30A时为过流故障状态。由此可见，该应急电源可通过DSP实时检测 Us，实现自动切换，在市电异常时及时对负载供电。 3 DSP硬软件设计该电源的中心控制处理电路是以DSP为核心的控制系统，它由TMS320LF2407型DSP、采样电路、驱动电路、故障监测和处理电路、串口通信电路等组成。EPS电源的各种功能是在此基础上，通过软件编程实现的。软件主要完成检测各种模拟和数字输入量；对输入的信息进行运算和处理；充电管理和逆变控制；安时计算和串口通信等功能。 3.1 TMS320LF2407简介1 TMS320LF2407是美国TI公司推出的一种低价格、高性能的16位定点运算DSP，TMS320LF2407的性价比极高，目前已成为高档单片机的理想替代品，因其内部集成的PWM模块，使其在电机控制、仪器仪表、电力电子、工业控制等领域得到了广泛应用。TMS320LF2407的主要性能有:晶振为30MHz时的指令周期为33ns。可扩展的外部存储器总共为192K。其中64K为程序存储器，64K为数据存储器，64K为I/O寻址空间。丰富的片内资源。含10位A/D转换模块、控制器局域网络(CAN)2.0B模块、串行通信接口、16位的串行外设接口模块等。有两个事件管理器模块EVA和EVB，每个含两个 16位通用定时器和8个16位的PWM通道。强大的指令集。有单周期乘/加旨令，块移动、多条件转移和调用等指令。遵循IEEEll49.1标准的片内 JTAG仿真逻辑。 3.2 硬件设计2 硬件电路采用以DSP芯片TMS320LF 2407 为核心的设计。它包括： (1)电压电流采样 应急电源对电压的采样是通过差分电路实现的。图2示出电压采样的差分电路。对电流的采样是通过霍尔电流传感器经过滤波、电平调整后实现的。本设计中，交流量需计算其有效值，是通过对瞬时采样值的整流、滤波实现的。图2中 R1R8=2M R9=R10=100k R11=10k C1C3=0.01F (2)IGBT驱动 DSP对充电控制采用EVA模块的定时器1的PWM比较输出，对逆变控制采用 EVA模块的比较单元1和比较单元2的比较输出。 IGBT驱动通过专用驱动芯片EXB840实现。 EXB840是混合IC，内部具有光耦信号隔离电路和过流保护电路，能驱动高达150A/600V的IGBT和高达75A/1.2kV的IGBT，最高开关频率达40kHz。 (3)一般I/O信号的处理 DSP通过通用I/O口采集和输出各种信号。消防、开机、强迫逆变、停止、备用等输入信号，通过光电隔离电路送至I/O口。继电器、接触器的控制信号由I/O口经辅助继电器输出。 (4)故障监测 该应急电源对电池过压欠压、逆变器过压、逆变器过流、IGBT故障等严重故障，专门设计了硬件锁死电路，系统上电时，其被清零，故障到来时，将其置位，同时封锁PWM输出，引发故障中断，在故障中断程序中检测故障类型。对一般故障则采用查询方式。 (5)串口通信 DSP将采样电路采集的ic，UH， ih，ub等参数以及监测到的故障类型、系统的工作状态通过异步串行口输出至人机接口单元。 3.3 软件设计该系统在主程序中检测Us，并置系统状态：充电状态为状态1，此时使能定时器1的比较输出，禁止其它PWM比较输出；逆变状态为状态2，此时禁止定时器1的比较输出，使能比较单元的 PWM1PWM4的比较输出。另外，还有一个状态0，作为状态1和状态2转换的中间状态，此时关闭所有的PWM输出通道。当Us正常时，若电源处在状态2，则需经状态0再进入状态1；同样，当Us异常时，若电源处在状态1，则需经状态0再进入状态2。当uH低于其最低放电电压时，电源即退出运行，进入待机状态。图3示出主程序流程图。系统利用定时器每100s申请一次PWM中断，即调制频率为10kHz，在中断服务程序中，根据状态标志位判断是状态1，还是状态2，分别调用充电管理子程序和逆变管理子程序。在中断服务程序中还设置了安/时计算计数器和数据传输计数器，当计数到一定值后，分别设置安/时计算标志位和数据传输标志位(安/时计算计数到10000，即1s计算一次安/时，数据传输计数到200，即20ms传输一次数据)，在主程序中根据标志位判断是否调用安/时计算子程序和数据传输子程序。对蓄电池的充电采用恒流和恒压充电，即在充电的第一阶段实施均充，即由DSP控制以恒定的 5A电流给电池组充电。当电池充到每节12.5V时，充电过程转为第二阶段的涓充状态，涓充电流的大小为0.5A；当电池组充电至每节13V后，系统进入浮充状态，浮充阶段采用恒压充电，即维持UH每节13V不变。逆变管理采用SPWM3技术，调制 频率为10kHz，输出电压u0采用电压有效值反馈，其中给定电压逐步增加，u0采样后用软件完成整流滤波，由DSP通过PID算法调节。 4 实验结果图4示出市电正常供电情况下瞬间掉电时，逆变输出端经过滤波后测得的正弦波。由图可知，应急电源启动后，输出频率为50Hz的正弦波，其幅值逐渐增大，在第4个周期后逐渐趋于稳定，这与逆变管理程序中给定电压的逐步增加相符。 5 结束语基于DSP芯片TMS320LF2407对应急电源的充电和逆变等过程进行控制，并通过实时检测电网电压实现停电后的自动切换，达到了一定的智能化程度。 参考文献： 1 刘和平, TMS320LP240x DSP 结构、原理及应用M北京：航空航天大学出版社，2002 2 张雄伟，陈亮，徐光辉DSP芯片的原理与开发应用(第3版)M.北京：电子工业出版社，2003 3 黄俊，王兆安电力电子变流技术M.北京：机械工业出版社，1999 Editor's note: Judson Jones is a meteorologist, journalist and photographer. He has freelanced with CNN for four years, covering severe weather from tornadoes to typhoons. Follow him on Twitter: jnjonesjr (CNN) - I will always wonder what it was like to huddle around a shortwave radio and through the crackling static from space hear the faint beeps of the world's first satellite - Sputnik. I also missed watching Neil Armstrong step foot on the moon and the first space shuttle take off for the stars. Those events were way before my time.As a kid, I was fascinated with what goes on in the sky, and when NASA pulled the plug on the shuttle program I was heartbroken. Yet the privatized space race has renewed my childhood dreams to reach for the stars.As a meteorologist, I've still seen many important weather and space events, but right now, if you were sitting next to me, you'd hear my foot tapping rapidly under my desk. I'm anxious for the next one: a space capsule hanging from a crane in the New Mexico desert.It's like the set for a George Lucas movie floating to the edge of space.You and I will have the chance to watch a man take a leap into an unimaginable free fall from the edge of space - live.The (lack of) air up there 待添加的隐藏文字内容2Watch man jump from 96,000 feet Tuesday, I sat at work glued to the live stream of the Red Bull Stratos Mission. I watched the balloons positioned at different altitudes in the sky to test the winds, knowing that if they would just line up in a vertical straight line "we" would be go for launch.I feel this mission was created for me because I am also a journalist and a photographer, but above all I live for taking a leap of faith - the feeling of pushing the envelope into uncharted territory.The guy who is going to do this, Felix Baumgartner, must have that same feeling, at a level I will never reach. However, it did not stop me from feeling his pain when a gust of swirling wind kicked up and twisted the partially filled balloon that would take him to the upper end of our atmosphere. As soon as the 40-acre balloon, with skin no thicker than a dry cleaning bag, scraped the ground I knew it was over.How claustrophobia almost grounded supersonic skydiverWith each twist, you could see the wrinkles of disappointment on the face of the current record holder and "capcom" (capsule communications), Col. Joe Kittinger. He hung his head low in mission control as he told Baumgartner the disappointing news: Mission aborted.The supersonic descent could happen as early as Sunday.The weather plays an important role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause), he can expect a lot of turbulence.The balloon will slowly drift to the edge of space at 120,000 feet (22.7 miles/36.53 kilometers). Here, "Fearless Felix" will unclip. He will roll back the door.Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.Below, the Earth becomes the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still, he'll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end.Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound - 690 mph (1,110 kph) - in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him completely.If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it's not needed. Instead, he plans to deploy his 270-square-foot (25-square-meter) main chute at an altitude of around 5,000 feet (1,524 meters).In order to deploy this chute successfully, he will have to slow to 172 mph (277 kph). He will have a reserve parachute that will open automatically if he loses consciousness at mach speeds.Even if everything goes as planned, it won't. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).It might not be the moon, but Kittinger free fell from 102,800 feet in 1960 - at the dawn of an infamous space race that captured the hearts of many. Baumgartner will attempt to break that record, a feat that boggles the mind. This is one of those monumental moments I will always remember, because there is no way I'd miss this.