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永磁直驱风电系统变流器的开路故障严重影响系统的运行特征.为了提高系统可靠性,要求能够及时检测到故障的发生,并能准确定位故障功率管.为此,提出了基于线电压误差的永磁直驱风电系统变流器开路故障诊断方法.该方法利用正常状态和故障情况下线电压的偏差进行故障诊断和定位,并且采用电压幅值和时间宽度的双重标准提高故障诊断的可靠性.首先,将线电压误差值与设定的阈值相比较;然后通过设置诊断变量的最小持续时间,来消除测量误差和外界环境的影响等引起的误判;最后,利用故障定位标志位判定故障功率管.仿真和实验结果验证了故障诊断方法的有效性和可靠性.“,”The open-circuit faults in converters of direct-driven permanent magnet wind power generation system (D-PMWPGS) seriously affect the operation of the system.To improve the reliability of the system,it is necessary to detect the faults timely and to locate the fault switches.Hence,a diagnostic method is proposed for the open-circuit faults in converters of D-PMWPGS based on line voltage errors.In this method,the fault diagnosis and localization is achieved by the line voltage deviations between normal and faulty conditions,where the double standards of voltage amplitude and the time width are applied to further improve the reliability of the fault diagnosis.The line voltage errors are firstly compared to the preset threshold.Then a minimum detection time is established to avoid misdiagnosis due to the effect of measurement noise and external environment.Finally,the fault switches are judged by the fault location flags.Both the simulation and experimental results verify the effectiveness and reliability of the proposed diagnosis method.