A Dead Time Compensation Method and Device Based on Bridge Arm Current Prediction

Abstract

The invention provides a dead zone time compensation method and device based on bridge arm current prediction, which are used for controlling an inverter. The dead time compensation method described above includes: determining the switching cycle period at which each pulse inversion moment of the upper switching tube and the lower switching tube switches in the next switching cycle; for each time period, based on the initial moment of the next switching cycle of the bridge arm The output current before filtering and the voltage drop of the filter inductor in this period determine the output current before filtering in this period; and based on the polarity of the output current before filtering in this period and the switching state of the upper and lower switching tubes at the moment of pulse inversion, it is judged whether it is necessary to perform dead Zone time compensation to advance the pulse inversion moment by one dead-time unit. The present invention also provides a device for realizing the above compensation method. According to the dead time compensation method and device provided by the present invention, the dead time can be compensated based on the accurately judged polarity of the bridge arm current, and the performance of the inverter can be effectively improved.

Description

technical field [0001] The invention relates to a converter module in the electrical field, in particular to a dead-time compensation method and device for an inverter based on bridge arm current prediction. Background technique [0002] The inverter is a converter that converts DC power into AC power with constant frequency and constant voltage or frequency modulation and voltage regulation. It often converts the DC voltage on the DC grid into a 220V / 50Hz sine wave. Usually, high-power motors, frequency converters, etc., end up with H-bridges or 3-phase bridges composed of high-power tubes, IGBTs and other components. The upper half bridge and the lower half bridge of each bridge can never be turned on at the same time, but when the high-speed PWM drive signal reaches the control pole of the power element, it often has a delay effect due to various reasons, causing One of the half-bridge components did not turn off when it should, causing the power components to burn out. ...

AI Technical Summary

Problems solved by technology

[0006] As described above, in order to solve the problem in the prior art that the polarity of the bridge arm current at the zero-crossing point cannot be accurately judged, the present invention provides a dead-time compensation method based on bridge arm current prediction, which is used to control the inverter , the above-mentioned inverter includes several bridge arms, and each bridge arm includes at least an upper switch tube and a lower switch tube, wherein, for each bridge arm, the above-mentioned dead time compensation method includes:

Images