毕业论文（设计）在线监测系统在风力发电机上的应用31967.doc

在线监测系统在风力发电机上的应用 时 轶 崔新维 李春兰/ 新疆农业大学 梁 斌/ 新疆金风科技股份有限公司摘要：介绍了在线监测系统在风力发电机上的运用背景及意义。通过在线监测系统在风力发电机上的工作原理和运用方式，以风力发电机的主轴为实例进行分析，达到在线监测系统能够实时监控风力发电机的目的，从而确保风力发电机能够正常安全的运行。分析结果表明：在线监测系统在风力发电机上有很大的运用前景。关键词：在线监测；风力发电机；振动频率中图分类号：TM614 文献标识码：B文章编号：1006-8155（2007）04-0074-03The Application of On-line Monitor System on Anemo-electric GeneratorAbstract: This paper presents the operation background and significance of on-line monitor system on anemo-electric generator. Through the working principles and operation means of on-line monitor system on anemo-electric generator, and taking the main shaft of anemo-electric generator as an example to analyze, so that we could continually monitor anemo-electric generator by on-line monitor system, then the anemo-electric generator can be running normally and safely. The results show that on-line monitor system will have a great prospect on anemo-electric generator in the future. Key words: on-line monitor； anemo-electric generator；vibration frequency 0 引言在线监测系统是近20年来在大型机组上发展起来的一门新兴交叉性技术，这是由于近代机械工业向机电一体化方向发展，机械设备高度的自动化、智能化、大型化和复杂化，在许多的情况下都需要确保工作过程的安全运行和高的可靠性，因此对其工作状态的监视日益重要1。 随着大型风力发电机容量的迅猛增加，现在风力发电机正从百千瓦级向兆瓦级发展，机械结构也日趋复杂，不同部件之间的相互联系、耦合也更加紧密，一个部件出现故障，将可能引起整个发电过程中断。另外，近年来随着风力发电机的快速发展，其技术的成熟度跟不上风力发电机的发展速度,在媒体上出现了大量关于风力发电机齿轮箱、主轴、叶片的损坏，甚至有风力发电机倒塌的报道。保险公司非常抱怨其高损坏率，因此在保险合同中加入了维修条款：保证其风力发电机能够正常运转40000h或者至少运行5年，除非装上在线监测设备，接受保险公司的定期监测。在这种环境下，在线监测在风力发电机行业得到了飞速的发展。国外在线监测技术发展得比较成熟，有专门用于风力发电机的监测设备2，例如德国的普鲁夫公司（pruftechnik）；在监测服务方面，国外有专门的风力发电机监测服务公司，例如德国的flender公司等3。而国内由于风力发电机行业本身起步较晚，因此在线监测系统在国内风力发电机上的运用还处于起步状态。1 在线监测系统的工作原理风力发电机监测系统最重要的工作是通过对设备运行过程中所表现出的各种外部征兆及信息，提取反映状态的正确信息并进行分析和识别其内涵故障。因此在开始设计和建立系统前，必须对监测对象的结构与工作过程有充分的了解。由于风力发电机设备结构及工作过程复杂，对其进行深入分析和深层故障诊断，不仅要依靠一定的理论和方法，而且更重要的是必须了解、熟悉具体设备的结构与运行机理，并取得维护人员的经验和技巧。 如图1风力发电机在线监测流程图所示，风力发电机监控任务主要由3部分组成：信号拾取、信号处理和监控决策。信号拾取主要由主轴传感器、齿轮箱传感器和定子传感器来采集风力发电机的基本运行状况。信号处理是将各传感器所采集到的信号经过信号处理转换成数字信号，通过网络传输到监控室。由于风力发电场一般建设在 图1 风力发电机在线监测流程图岛屿、农田等边远地区，通讯设施相对比较差，因此网络传输可以使用CDMA，GSM等无线传输方式，从而省去了铺设光缆等昂贵设备。 监控决策就是计算机将传送的信号数据与风力发电机数据库中的数据进行比较，监控人员根据比较的结果最终给出风力发电机的运行状况分析表。计算机的数据比较过程主要是辨别3类过程状态（正常、预警、异常），如使用表示传感器信号，表示风力发电机预警值，表示风力发电机异常值。当风力发电机运行正常；监控设备发出警报,监控人员必须密切关注运行状况；风力发电机自动停机,等待工作人员的检修。2 风力发电机工作特性及在线监测的必要性现在大多数风机上运用的通用监测程序叫风场监测，这种方法主要监测输出电量同时也包含部分故障信息的存储。通常控制系统的状态信息、输出电量以及风速情况将被存储，并且将其传送给制造商和运营商。但是只有通过详细的记录才有可能观察到故障。在大多数的情况下，当控制系统发出警报的时候故障已经发生了，然而整个系统能做的只是自动的使风力发电机停机以防止故障的进一步恶化。风场监测通常与周期点相连，这些周期测试点基本能反映整机的特性，例如监测旋转叶片和基座的裂纹、齿轮箱的振动或者机械部分的磨损等情况。但是这些检测不能揭示其产生的时间和原因，所能确认的是风机运行的状况明显的受限制。就算与以前的数据进行对照比较，检查的结果也不可能提供故障原因。近来一些保险公司为了避免那些预防性更换风力发电机零部件的要求，在线监测系统被广泛的推广，在实际风力发电机监测的运用中有以下两个步骤。（1）连续的在线监控设备（在线诊断仪）使用合适的传感器与风力发电机的控制系统相连，当风力发电机的零部件特征开始变形时能够发出警报声音，其中包含齿轮箱、主轴及电机定子等的振动。自动评估其频率范围并与所设定的频率谱图相比较，当监控系统给出超出系统设定异常值时，风力发电机会自动地停机并且通过网络把警报值传送到维修中心。这样可以在早期状态，探测到潜在的危险并能使生产商提出一个有针对性的维护和修复方案。通过零距离不间断地观测其零部件，可以设计一个专门的维护计划方案，从而避免灾难性的结果。（2）周期性机械诊断（手持式诊断仪）是为了对在线诊断仪发出有预警值或异常值的零部件上进行进一步的监测。在周期性的检查过程中，可将移动测量设备安装在齿轮箱、发电机及轴等机械零部件上，记录其频谱图并与以前的确定的频谱图相比较和储存。通过与标准的频谱特性曲线比较，最终判断出其产生故障的原因。3 实例分析笔者主要以风力发电机的主轴为例介绍在线监测系统在风力发电机上的运用情况，图2图5描述的是一些关于风力发电机的状况图。 图2描述的是风力发电机的发电机定子转速，从图中可以看到风力发电机正常运行（1500r/min）以及停机的运行状态，从而达到实时监控风力发电机运行状况的目的。 图3是图2所对应风力发电机运行时主轴的振动时域图，图中上条粉红线是所对应的主轴振动零峰值，下条蓝色线是所对应的主轴振动平均值。从图中得出：图2 风力发电机的发电机定子转速 (1)风力发电机在起停时所对应 的振动值较大;(2)当主轴恒速运行时可得出其对应的固定振动值为a=2.2mm/s;(3)当主轴转速变换时，主轴振动值随其正比例变化。 图3 风力发电机主轴振动图图4 描述的是风力发电机主轴某 时刻振动的频谱图，从图中可以得出其主轴的振动频率是以25 Hz为基频的频率谱，当在线监测频谱图监测到有其他较大的频率值时，维护人员可以从频谱图中较早地确认其发生故障，从而避免进一步发生故障恶化。图4 风力发电机主轴某时刻振动频谱图图5 是主轴振动频率在不同时间 所对应的瀑布图，从而可以建立数据库进行参数比较,进一步对其风力发电机主轴状况进行分析。图5 风力发电机主轴振动频率在不同时间的瀑布图4 结论 制造商可以运用在线监测系统将故障信息通过E-mail自动传递到世界的任何地方，诊断专家可通过Internet接触到在线监测系统，从而对整个运行系统的状态作出判断4。同时在线监测系统给客户也提供了很多的好处与方便，例如：（1）通过在现监测系统能够最大程度地使整机安全运行 ；（2）提前检测到故障减少过多的损坏；（3）可以对风力发电机有效地保护；（4）通过在线检测的结果可以对风力发电机有针对性地修复。由于在线监测系统对制造商和投资商都有很大的益处，并且随着风力发电机行业的大型化、海上化和产业化，在线监测系统在风力发电机上的运用必然会有前所未有的发展和很好的市场。参 考 文 献1 陈大禧，朱铁光. 大型旋转机械诊断现场实用技术M. 北京：机械工业出版社，2002，6.2 H. Söker, H. Seifert; DEWI Preventive Load Monitoring and Condition Monitoring - How to Reach the Scheduled Service Life without Financial Damage DEWI Magazin Nr. 23, August 2003.3 The condition monitoring magazine of PRÜFTECHNIK AG and Flender Service GmbH No. 05 - September 2003.4 待添加的隐藏文字内容3 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 Watch 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.