Fault diagnosis method of photovoltaic diode clamping type three-level inverter

Abstract

The invention discloses a fault diagnosis method of a photovoltaic diode clamping type three-level inverter. The fault diagnosis method of the photovoltaic inverter combining with a wavelet multi-scale decomposition method and a support vector machine classification algorithm is provided by aiming at a three-level inverter fault diagnosis problem of a photovoltaic micro-grid, taking a system inversion state as an example, and analyzing fault types of various power tubes. The fault diagnosis method adopts the bridge arm voltage signal of the diode clamping type three-level inverter as a research object, and various frequency band energies are extracted as fault characteristic samples by using the wavelet analysis multi-scale decomposition method, and in addition, a multiple valued support vector machine fault classification model is established, and finally, the open circuit fault diagnosis of the three-level inverter power device is completed. The fault diagnosis method is advantageous in that the various fault states of the diode clamping type three-level inverter are obviously discriminated, and the extraction is convenient, and in addition, problems of a conventional data sample diagnosis extraction method such as large data size and tedious process are overcome.

Description

technical field [0001] The invention relates to the field of fault diagnosis of power electronic devices, in particular to a fault diagnosis method for a photovoltaic diode clamped three-level inverter. Background technique [0002] With the rapid development of the photovoltaic industry, the application of photovoltaic microgrids is becoming more and more extensive. The direct current output by the photovoltaic array must be converted into alternating current to meet our daily needs. Therefore, in the photovoltaic microgrid, the photovoltaic inverter has become an indispensable part. Among inverters with different structures, multi-level inverters have received widespread attention due to their advantages such as series voltage equalization of power devices, small switching losses, low output voltage harmonic content, and high work efficiency. Because a large number of switching devices are used, the reliability of the circuit is relatively low. The failure of any device ...

AI Technical Summary

Problems solved by technology

Among inverters with different structures, multi-level inverters have received widespread attention due to their advantages such as series voltage equalization of power devices, small switching losses, low output voltage harmonic content, and high work efficiency. Because of the use of a large number of switching devices, the reliability of its circuit is relatively low

The failure of any device may lead to abnormal operation of the circuit, and sometimes even affect the safety of other circuits, causing serious accidents or immeasurable economic losses

[0003] Due to the variety of types and reasons for the failure of power electronic equipment, and the real-time requirements of the system, it is often difficult to deal with the failure by traditional manual detection and maintenance. Therefore, a more intelligent method is needed to diagnose the failure of the equipment.

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