【《光伏逆变器故障建模分析及故障特征量提取分析案例》3800字】

光伏逆变器故障建模分析及故障特征量提取分析案例目录TOC\o"1-3"\h\u1323光伏逆变器故障建模分析及故障特征量提取分析案例 [45]。1.1.1极值比值法原理首先，在一个周期内分别提取逆变器交流侧A、B、C三相输出电流的极大值点和极小值点，记为、、、、、。然后，通过式（1.1）~（1.3），得到极大值比值、、。(1.1)(1.2)(1.3)通过式（1.4）~（1.6），可以得到特征量、、。(1.4)(1.5)(1.6)通过式（1.7）~（1.9），得到极小值比值、、。(1.7)(1.8)(1.9)通过式（1.10）~（1.12），可以得到特征量、、。(1.10)(1.11)(1.12)同理，通过式（1.13）~（1.15）可以得到极大值比值、、。(1.13)(1.14)(1.15)通过式（1.16）~（1.18），可以得到特征量、、。(1.16)(1.17)(1.18)通过式（1.19）~（1.21），得到极小值比值、、。(1.19)(1.20)(1.21)通过式（1.22）~（1.24），可以得到特征量、、。(1.22)(1.23)(1.24)通过以上公式，可以得到在一个采样周期内一组共12个故障特征量。如表1.3为一组原始采集数据通过极值比值法计算后的故障特征量。表1.3基于极值比值法的故障特征量Tab1.3Faultcharacteristicquantitiesbasedonextremevalueratiomethod故障IGBT故障编号正常10.3340.3320.3340.3360.3340.3300.3360.3330.3310.3310.3330.336VT120.0430.0410.9160.2930.3880.3190.9560.0420.0020.2190.3520.429VT230.4760.2950.2290.0250.5020.4730.3540.2830.3640.0220.4740.504VT340.9530.0450.0020.2640.2990.4370.0480.0450.9070.4340.3360.230VT450.2870.3790.3340.0440.0440.9110.2390.3570.4050.9510.0470.002VT560.0240.4870.4890.4670.3060.2280.0240.4890.4870.3260.2870.386VT670.2520.2880.4610.9480.0490.0030.4630.3310.2070.0450.0460.910VT1480.0280.0280.9440.0370.0350.9280.9700.0290.0010.9630.0360.001VT3690.9560.0420.0020.9580.0410.0020.0410.0410.9180.0360.0370.927VT25100.0250.4790.4960.0180.4880.4950.0270.4950.4780.0180.4940.487VT13110.9690.0220.0100.0090.4230.5680.8550.0440.1010.0170.5640.419VT15120.0010.0180.9820.9640.0350.0010.7620.2340.0040.0160.0240.960VT35130.2570.7020.0410.0370.0260.9370.0010.0560.9430.9810.0190.001VT46140.0060.4020.5920.9790.0160.0040.0130.5880.3990.7780.0480.174VT42150.9690.0310.0010.0010.0230.9760.0150.0220.9630.6920.3010.007VT62160.0370.0250.9370.2830.6790.0380.9810.0180.0010.0010.0530.946VT16170.0300.0310.9390.9180.0780.0040.9650.0330.0010.0290.0480.923VT12180.0980.0590.8430.0200.5160.4640.9570.0410.0030.0160.4660.518VT34190.9280.0690.0030.0310.0340.9360.0300.0450.9250.9600.0390.001VT32200.9660.0330.0010.0200.4010.5790.0440.0370.9190.0410.5660.393VT54210.0210.5120.4670.1010.0660.8340.0180.4690.5130.9480.0490.004VT56220.0200.3760.6050.9640.0350.0010.0490.5860.3650.0380.0360.927由表1.3可知，极值比值法通过对采集到的故障情况下A、B、C三相输出电流波形的600个原始数据进行简化处理，最终得到12个故障特征量，并将这12个故障特征量当作故障诊断识别的信号输入，这样极大地降低了信号输入维数，减轻了后续故障诊断识别的运算量和复杂度，为故障诊断识别准确、快速、灵敏打下良好基础。1.1.2极值比值法特征量提取为模拟光伏逆变器实际运行环境干扰，并获取足够数量的训练数据和测试数据，对于原始采集数据进行了不同程度的加噪处理，然后再通过极值比值法进行特征量提取。如表1.4为对原始采集数据进行5dB加噪后极值比值法特征量提取结果。表1.4基于极值比值法的故障特征量（5dB加噪）Tab1.4Faultcharacteristicquantitiesbasedonextremevalueratiomethod(5dBplusnoise)故障IGBT故障编号正常10.3340.3320.3340.3360.3340.3300.3370.3330.3300.3310.3330.336VT120.0470.0460.9070.2950.3870.3180.9510.0460.0020.2210.3520.428VT230.4760.2950.2290.0260.5000.4740.3530.2820.3640.0240.4750.502VT340.9530.0450.0020.2620.2990.4390.0480.0450.9070.4340.3370.230VT450.2890.3780.3330.0470.0480.9050.2390.3560.4050.9470.0510.003VT560.0230.4870.4890.4670.3060.2270.0230.4890.4870.3260.2870.387VT670.2510.2880.4610.9510.0470.0020.4620.3310.2070.0420.0440.915VT1480.0340.0340.9320.0390.0380.9230.9630.0360.0010.9600.0380.002VT3690.9540.0440.0020.9540.0440.0020.0430.0420.9150.0380.0400.921VT25100.0260.4780.4960.0230.4830.4940.0280.4950.4770.0240.4940.483VT13110.9630.0250.0120.0100.4220.5680.8530.0470.0990.0170.5640.419VT15120.0010.0200.9790.9610.0380.0010.7270.2670.0060.0180.0260.957VT35130.3220.6420.0360.0410.0280.9310.0010.0530.9460.9790.0210.001VT46140.0080.4010.5910.9750.0190.0060.0180.5850.3970.8140.0470.139VT42150.9660.0330.0010.0010.0240.9740.0170.0230.9600.6890.3030.008VT62160.0420.0290.9290.2930.6680.0390.9790.0210.0010.0010.0550.944VT16170.0340.0350.9320.9190.0770.0040.9610.0370.0010.0290.0470.925VT12180.1040.0620.8340.0220.5160.4620.9540.0430.0030.0180.4640.518VT34190.9190.0770.0040.0330.0370.9310.0330.0500.9170.9560.0420.002VT32200.9650.0340.00