The insulated gate bipolar transistor (IGBT) is the core component of a photovoltaic (PV) inverter, and its stability and reliability are crucial to the normal operation of the inverter. Therefore, it is important to ensure the safety and stable operation of the power system through the fault diagnosis of a PV grid-connected inverter. Aimed at the single-tube open-circuit fault which is common for the IGBT in a three-phase PV grid-connected two-level inverter, a diagnosis method for the open-circuit fault of IGBT in the three-phase PV grid-connected inverter based on Markov transition field-convolutional neural network (MTF-CNN) is presented. A simulation model of the three-phase PV grid-connected inverter is built on MATLAB/Simulink to simulate the open-circuit fault of several kinds of IGBTs. The output of fault current signal from the inverter is collected as one-dimensional time-domain signal, which is further converted into two-dimensional images by MTF as a 2D-CNN data set for training. Finally, the fault detection and diagnosis are completed. Experimental results show that the proposed method has strong anti-interference capability. In addition, it has a faster diagnosis speed and higher accuracy than other conventional methods.
| 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 |