T-type three-level inverter fault diagnosis method based on phase voltage residual

Abstract

The invention discloses a T-type three-level inverter fault diagnosis method based on phase voltage residual. In the method, firstly, three-phase voltage of a to-be-diagnosed T-type three-level inverter is obtained, and the three-phase voltage is subjected to filtering and amplification or reduction treatment; residual voltage between reference voltage of each phase and treated voltage of each phase is calculated; whether a circuit of each phase has fault is judged according to a sampling voltage value in the residual voltage of each phase; under the premise that the fault happens, an averagevalue of the residual voltage in one time cycle of starting of sampling moment of the sampling voltage value varying abnormally and a positive and negative peak difference value are calculated; then,specifically, which device has an open circuit fault is judged according to the average value and the positive and negative peak difference value. The method provided by the invention has the advantages that only voltage of three phases needs to be acquired, original information of fault diagnosis is relatively less, moreover, fault diagnosis cost is low, fault diagnosis accuracy is high, the specific device can be located automatically through the fault diagnosis result, and consequently, work reliability of the T-type three-level inverter can be improved effectively.

Description

technical field [0001] The invention relates to an inverter fault detection technology, in particular to a T-type three-level inverter fault diagnosis method based on phase voltage residual. Background technique [0002] Multilevel inverters have been increasingly used in a wide range of power applications. Compared with traditional two-level inverters, multi-level inverters can obtain more levels, have fewer harmonics, and can reduce the voltage stress requirements of devices. In recent years, some scholars have proposed a topology called T-type neutral-point-clamped inverter (T-type neutral-point-clamped inverter, hereinafter referred to as T-type three-level inverter or TNPC). , which are mainly used in high-efficiency applications such as solar energy and electric vehicle inverters. During the operation of the circuit, due to overload, temperature rise, irregular operation and other reasons, various faults will occur in the circuit, among which the fault of semiconduct...

AI Technical Summary

Problems solved by technology

This method has high reliability, but this method not only needs to detect the DC midpoint current and three-phase current, but also needs to obtain the switch state in the circuit, and there are many original information requirements for fault diagnosis.

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