Frequency conversion equipment

Abstract

The invention provides frequency conversion equipment. The frequency conversion equipment is used for performing fault diagnosis on frequency conversion driving on the basis of switching characteristics of an IGBT switch and different gate driving charges of capacitance distribution in a gate charging and discharging process of the IGBT switch. Specifically, in a turn-on transient stage, a turn-on steady-state stage, a turn-off transient stage or a turn-off steady-state stage of the IGBT switch, the variation of the gate driving charges of the parasitic capacitance of an IGBT power module is acquired; the fault condition of the IGBT power module is judged through the variation of the gate driving charges, so that the problem of signal fluctuation caused by direct sampling of gate current can be avoided, misoperation caused by signal fluctuation can be avoided, the fault detection speed is increased, and therefore, the speed of protection for a device can be increased; the detection mode is not sensitive to the temperature characteristic of the device, and the influence of the temperature on a detection circuit can be reduced.

Description

Technical field [0001] The present invention relates to a variable frequency drive technology, and particularly relates to a quick and accurate fault detection is frequency devices IGBT power module. Background technique [0002] Design of conventional commercial air conditioning because of its high frequency drive voltage and current to the design of large, insulated gate bipolar transistors (Insulated Gate Bipolar Transistor, IGBT) is generally used in an integrated PIM (Power IntegratedModule) module as the inverter frequency power device. [0003] Safe and reliable device protection determine the safety and reliability of the device applications. Device operation overcurrent, short circuit, open circuit and a series of drive failure, need rapid and efficient detection method for real-time detection and identification. In the present design variable frequency drive, a protection circuit is mainly based on the use of conventional drive IC and its peripheral circuits to complete...

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Problems solved by technology

[0004] The above method is also called the IGBT desaturation protection method. Its disadvantages are: the method itself cannot monitor the abnormality of the switch state, and it needs to avoid the switch state to detect the Vce voltage and increase C1, which increases the Tblink time to reduce the impact of the instantaneous Vce voltage on the switch. , so its protection time is relatively slow, generally 5~8us, and the stress of IGBT devices is relatively large

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