On-line detection device and detection method for open-circuit fault of power tubes of inverter

Abstract

The invention discloses an on-line detection device for open-circuit fault of power tubes of an inverter and a detection method thereof, relates to the field of on-line detection, and solves the problem of low detection speed existing in the conventional detection method and detection device. The detection device consists of three on-line detection circuits for the open-circuit fault of the power tubes; the circuit is used for detecting the open-circuit fault state of two power tubes in a bridge-arm circuit, and consists of a photocoupler circuit for detection, a logic circuit and a rising-edge delay circuit, wherein the rising-edge delay circuit receives a switch signal for time delay to acquire a time-delay switch signal, and sends the time-delay switch signal to the logic circuit; meanwhile, the photocoupler circuit for detection receives the switch signal controlled lower output signal, and transforms the output signal into a logic signal and sends the logic signal to the logic circuit; and logical operation is carried out to obtain the fault state, when the logical operation result is zero, the power unit correspondingly controlled by the switch signal is in a open-circuit fault state, otherwise, the power unit is normal. The invention is applicable to the open-circuit fault diagnosis of the single pipe or bridge arm of the inverter in various controlled motor drive systems and power-supply systems with current-open or close loop.

Description

[0001] technical field [0002] The invention relates to the field of on-line detection, in particular to an on-line detection device and method for an open circuit fault power tube in an inverter. Background technique [0003] Motor drives and power systems powered by voltage source inverters have been widely used in aerospace, military, and industrial fields, such as figure 1 As shown, the power device of the inverter in the whole system is the weak link most prone to failure, and the reliability of the power device of the inverter directly affects the normal operation of the whole system. In order to improve the reliability of the system, fault-tolerant control strategies are often applied to power conversion units. The premise of implementing fault-tolerant control is to detect, locate and isolate faults in power devices effectively in real time. [0004] The wide application and fragility of voltage source inverter make its fault detection more important. In many pate...

AI Technical Summary

Problems solved by technology

[0005] The present invention solves the problems of slow detection speed in the existing detection methods and devices, and is not applicable to systems using current closed-loop control strategies or requires additional voltage sensors, which increases hardware cost and complexity, and prevents The system shutdown caused by power tube failure improves the reliability of the inverter system to provide detection guarantees, and proposes an online detection device and detection method for inverter power tube open circuit faults

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