基于转子瞬时功率谱的双馈风力发电机定子绕组故障诊断

摘要

提出一种基于转子瞬时功率谱分析的双馈风力发电机定子绕组故障的在线监测与诊断新方法。理论分析表明，与常见的电流或电压谱诊断方法相比，转子瞬时功率谱法既具有无需外加传感器与硬件设备的优点，又由于其特征频率不受转差的影响，当转差存在一定的跟踪或计算误差时，特征频率不会改变，具有很强的抗干扰能力。在 PSCAD 软件中建立了双馈风力发电机并网模型，对正常及故障状态进行仿真分析，得出转子瞬时功率谱法在双馈风力发电机定子绕组故障诊断中更具敏感性的结论。在动模实验室建立了定子绕组故障诊断的实验平台，进一步证明了转子瞬时功率谱法在双馈风力发电机定子绕组故障诊断中的可行性。%A new on-line approach based on rotor instantaneous power spectrum is proposed to detect doubly-fed induction generator stator winding fault.Theoretical analysis shows that,compared with the common current or voltage spectrum analysis methods,the instantaneous power spectrum has the advantage that external sensors and hardware devices are not needed.Moreover,the spectrum has good interference immunity.Once some slip tracking or calculation errors occur,the characteristic frequency will not change because the characteristic frequency is not affected by slip.A doubly-fed induction generator model is established using PSCAD software.Through normal and stator faults conditions simulations and analysis,it is concluded that the rotor instantaneous power spectrum is more sensitive than the current or voltage spectrum on dealing with the stator winding faults conditions.Finally,the experimental platform of stator faults diagnosis is built in laboratory which further proves that it is feasible to use the rotor instantaneous power spectrum to diagnose the stator winding faults. This work is supported by National Natural Science Foundation of China (No. 5 1 1 77039) and Ph.D. Programs Foundation of Ministry of Education of China(No.200909441 1001 1).