基于数据的风力发电系统变流器的故障诊断研究

发布时间：2018-04-04 03:10

本文选题：风力发电　切入点：PWM变流器　出处：《江南大学》2014年硕士论文

【摘要】：风电产业的迅猛发展，对风力发电系统中的各组成部件装置的可靠性和稳定性提出了更高的要求。双脉冲宽度调制(Pulse Width Modulation, PWM)变流器作为风电系统与电网的接口，既要控制电压的稳定，又要配合实现最大风能利用率，同时也是最容易发生故障的部件之一。变流器一旦发生故障，如不及时处理，轻则会降低供电质量，重则威胁到整个风电系统的正常工作和电网安全。因此，如何在双PWM变流器发生故障时，准确、快速地判断故障类型，并及时进行故障的定位与诊断是有效提高风电系统的安全性和可靠性，降低风电成本的重要手段。论文首先介绍了风电系统中双PWM变流器的工作特点，对绝缘栅双极型晶体管(Insulated Gate Bipolar Transistor, IGBT)开路故障进行了分类，分析了整流工作状态下PWM变流器的输出电压特性，讨论了IGBT功率管发生开路故障时对变流器输出电压的影响，借助仿真实验，验证了故障分类的合理性。其次，利用小波包变换更好的分析能力，对变流器的输出电压进行处理，得到了不同类型故障的故障特征信息，实现了对整流工作状态下PWM变流器的初步故障识别，仿真结果表明该方法的有效性。再次，针对PWM变流器的逆变工作状态，探讨了故障对逆变器工作特性的影响，采用小波包变换获取不同故障类型时的故障特征信息，再利用支持向量机的分类能力对故障信息进行分类，实现了对PWM变流器IGBT功率管开路故障诊断，仿真结果证明了该方法的准确性。最后，针对双PWM变流器的结构特点，为了使双PWM变流器发生IGBT功率管开路故障后能尽早地恢复正常运行状态，提出了一种变流器开路故障容错拓扑结构，，通过仿真分析验证了该容错策略的合理性。
[Abstract]:With the rapid development of wind power industry, the reliability and stability of the components of wind power system are required.As the interface between wind power system and power grid, the dual pulse width modulation pulse Width modulation (PWM) converter not only controls the stability of voltage, but also realizes the maximum wind energy utilization ratio, and is also one of the most vulnerable components.Once the converter fails, if it is not dealt with in time, it will reduce the quality of power supply, and threaten the normal operation of the whole wind power system and the safety of the power grid.Therefore, how to judge the fault type accurately and quickly, and to locate and diagnose the fault in time is an important means to improve the safety and reliability of wind power system and reduce the cost of wind power.This paper first introduces the working characteristics of double PWM converter in wind power system, classifies the open circuit faults of insulated gate bipolar transistor insulated Gate Bipolar transistor (IGBT), and analyzes the output voltage characteristics of PWM converter under rectifying operation.The effect of open circuit fault of IGBT power transistor on output voltage of converter is discussed. The rationality of fault classification is verified by simulation experiment.Secondly, the output voltage of the converter is processed by using wavelet packet transform, and the fault characteristic information of different types of faults is obtained, and the initial fault identification of PWM converter under rectifying working condition is realized.Simulation results show the effectiveness of the method.Thirdly, aiming at the inverter working state of PWM converter, the influence of fault on inverter performance is discussed. Wavelet packet transform is used to obtain the fault characteristic information of different fault types.Then the classification ability of support vector machine is used to classify the fault information, and the open circuit fault diagnosis of IGBT power transistor in PWM converter is realized. The simulation results prove the accuracy of the method.Finally, according to the structural characteristics of the double PWM converter, in order to restore the normal operation state of the double PWM converter as soon as possible after the open circuit fault of the IGBT power transistor occurs, a fault tolerant topology for open circuit fault of the converter is proposed.The rationality of the fault-tolerant strategy is verified by simulation analysis.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

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