Efficient diagnosis of IGBT open-circuit faults in grid-tied inverters is helpful for quickly detecting the fault and ensuring the stable operation of the grid-tied inverter system and the safety of equipment. The existing IGBT open-circuit fault diagnosis methods have problems such as difficult feature extraction and poor diagnosis accuracy. On this basis, a method is proposed for IGBT open-circuit fault diagnosis of grid-tied inverter based on modified random forest. First, the wavelet packet energy of each frequency band of three-phase current signal is extracted by maximum overlapping discrete wavelet (MODWT) decomposition as the characteristic values for IGBT open-circuit fault diagnosis; Then, the modified random forest method is used to identify different types of faults; Finally, the various IGBT open-circuit faults of grid-tied inverters are diagnosed. The experimental results show that the proposed method has higher diagnosis accuracy and is suitable for IGBT open-circuit fault diagnosis of grid-tied inverters compared with the traditional diagnosis methods such as back propagation (BP) neural network and support vector machine (SVM).
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |