摘要中国已成为世界第一大能源消费国，以煤为主的能源结构不但带来了严重的生态环境问题，而且使我国成为世界第一大温室气体排放国。的十八大提出了将“推动能源生产和消费”，反映出国家转变能源发展方式的重要性和急迫性，而且风力发电是我国目前商业化程度较高的可再生能源之一[1]，因此以风电为代表的可再生能源迎来历史性发展。84308

由于我国过风力资源分布与电力需求的不匹配的情况，迫使沿海地区风力发电技术的发展成为必定趋势，使得近年来海上风力发电的快速发展。由于海上风力发电与内陆风力发电的环境因素不同，使得其成本相对很高，如何减少海上风力发电的成本，成为近年来突破海上风力发电技术发展瓶颈的关键。本文主要根据同济大学向大为教授的一次座谈会，提出了针对变流器故障的监测方法，快速检测出故障类型，方便检修，从而达到减少不必要的恶性故障的发生，从维修费用上减少成本。

论文首先提出了选题目的与意义，并针对目前国内外海上风力发电技术进行了介绍，并提出本论文主要研究内容，其次，以双馈异步发电机为基础模型，对变流器的组成及工作原理进行了介绍，再次，总结出变流器的各种故障情况并分类，并提出小波分析的概念，引出小波包分析方法，针对小波包分析方法对变流器各种元件故障情况下的输出波形进行特征向量提取，最后，利用PLC控制技术的抗扰能力强，运行可靠的特点，根据提取出来的故障特征向量，利用PLC仿真软件，编写出故障监测程序，并进行仿真。通过仿真，验证了该方法能准确快速地识别出变流器故障类型，并对简单故障进行智能处理，能有效预防大型故障的发生。

毕业论文关键词：海上风力发电；变流器；故障监测；小波包分析；PLC仿真

ABSTRACT China has become the world's largest energy consuming country, the coal based energy structure has not only brought serious environmental problems, but also make our country become the world's largest greenhouse gas emitters。The eighteen party put forward the "promotion of energy production and consumption revolution", reflecting the importance and urgency of the country to change the mode of energy development, and wind power generation is one of the renewable energy sources with higher degree of commercialization in China。So the wind power as the representative of renewable energy facing the historic development。

And because of the mismatch between wind resource distribution and electric power demand, the development of wind power technology in coastal area has become an inevitable trend, which makes the rapid development of wind power in the near and the sea。Because of the differences between environmental factors of offshore wind power generation and the inland wind power, making the cost is relatively high。 How to reduce the cost of offshore wind power in recent years has become a breakthrough in the key of offshore wind power technology development bottleneck。This paper mainly according to a discussion by professor of Tongji University Xiang Dawei, proposed for the converter fault monitoring method in order to quickly detect fault type, convenient maintenance, so as to reduce the occurrence of unnecessary vicious fault and the cost of maintenance。

First of all, this paper puts forward the purpose and significance of the topic, and introduces the current domestic and international offshore wind power technology, and puts forward the main research content of this paper。Secondly, based on the model of double fed induction generator, the composition and working principle of the converter are introduced。Thirdly, it summarizes the classification do converter faults, and put forward the concept of wavelet analysis,and leads to the wavelet packet analysis method, according to the wavelet package analysis method extracting the converter component faults of the output waveform feature vector。Finally, the PLC control technology is used to carry out the fault feature vector, which is based on the feature of strong anti-interference ability and reliable operation。 According to the extracted fault feature vector, the PLC simulation software is used to write the fault monitoring program。By simulation, it is proved that this method can identify the fault