基于畸变电流的直驱式永磁风电变流器故障诊断研究

Study on fault diagnosis of direct drive permanent magnet wind power converter based on distorted current

针对直驱式永磁风电变流器开关管开路故障诊断的问题,提出了一种基于机侧电流畸变规律的故障诊断方法。该方法研究了在不同开路故障类型下的机侧三相电流的畸变规律,总结畸变规律并设计诊断变量,实时监测低通滤波后的机侧三相电流并计算诊断变量,然后根据诊断变量得出诊断信号,最后根据诊断信号完成实时故障诊断,并在单管故障诊断方法的基础上提出了支持双管故障诊断的方法。实验结果表明,该方法对单管故障和双管故障均能进行准确且快速的诊断,诊断成本较低,鲁棒性较好,不容易出现误诊和漏诊。

Aiming at the problem of open circuit fault diagnosis of direct drive permanent magnet wind power converter,a fault diagnosis method based on generator side current distortion law is proposed.This method studies the distortion law of three-phase current under different open circuit fault types,summarizes the distortion law and designs diagnostic variables,monitors the three-phase current of generator side after low-pass filtering in real time and calculates diagnostic variables,then obtains diagnostic signals according to the diagnostic variables,and finally completes real-time fault diagnosis according to the diagnostic signals,On the basis of single tube fault diagnosis method,a method supporting double tube fault diagnosis is proposed.The experimental results show that this method can diagnose single tube fault and double tube fault accurately and quickly,with low cost,good robustness and less misdiagnosis and missed diagnosis.