Method for compensating dead area of universal frequency transformer

Abstract

The invention discloses a method for compensating a dead area of a universal frequency transformer. The method comprises the following steps of: (1) acquiring three-phase current signals IU, IV and IW of a motor, and transmitting the signals to a digital signal processor to perform digital filtration by adopting a hardware filter; and (2) performing linear processing on the compensation magnitude according to the magnitude and positive and negative of the detected current, namely when the current of one phase is positive, correspondingly increasing a dead area time to the switch-on time of an upper bridge arm Qx of an inverting bridge corresponding to the current, and correspondingly reducing a dead area time from the switch-on time of a lower bridge arm Qy of the inverting bridge corresponding to the current; and when the current of the phase is negative, correspondingly reducing a dead area time from the switch-on time of the upper bridge arm Qx of the inverting bridge corresponding to the current, and correspondingly increasing a dead area time to the switch-on time of the lower bridge arm Qy of the inverting bridge corresponding to the current. The method is simple to compensate the dead area, has high compensation accuracy, and well overcome the defect of the conventional related compensation.

Description

technical field [0001] The invention relates to a dead zone compensation method of a frequency converter, in particular to a general frequency converter dead zone compensation method capable of improving the accuracy of current zero-crossing detection and reducing large current crossover distortion caused by inaccurate dead zone compensation. Background technique [0002] Existing typical general inverter system structure, such as figure 1 As shown, the system adopts the VVVF control method based on the appropriate modulation of the voltage space. The basic principle is: the three-phase AC is rectified by the rectifier bridge and filtered by the bus capacitor to provide DC power for the inverter bridge composed of IGBTQ1-Q6. DSP or MCU The controller detects the two-phase current. Comprehensively set the frequency for pulse width modulation, generate three-phase six-tube PWM drive signals, control the upper and lower bridge arms of each phase to adjust the output voltage of...

AI Technical Summary

Problems solved by technology

[0012] The technical problem to be solved by the present invention is to provide a general frequency converter dead zone compensation method with relatively simple steps in view of the technical problem of complicated steps existing in the existing dead zone compensation method

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