Current predictive control method of pwm rectifier with dead zone compensation

Abstract

The invention discloses a PWM rectifier current prediction control method including dead zone compensation. The control method includes the following steps: using the discrete mathematical model of the rectifier circuit as the prediction model at k+1 time; selecting a Effective switching state and two zero-switching states, and the action time of the two zero-switching states is the same; given the dead time added when the upper and lower switching tubes of the same bridge arm switch, calculate the different switching states according to the direction of the input current The optimal action time and the corresponding predicted current value; Substituting the relevant parameters into the objective function, and selecting the effective switching state that minimizes the objective function as the effective switching state of the next cycle. The invention realizes the predictive control of the fixed-frequency current, adds dead zone compensation, effectively reduces the harmonic content of the input current, and improves the reliability of the system operation.

Description

technical field [0001] The invention relates to the technical field of PWM rectifier control, in particular to a PWM rectifier current prediction control method including dead zone compensation. Background technique [0002] With the increasingly serious energy crisis and environmental problems, the research of new energy technology has received more and more attention. In small and medium power applications, PWM rectifiers are widely used. Model predictive control has the advantages of simple control structure and fast dynamic response, but there are also problems such as unstable switching frequency, large amount of calculation, high harmonic content of grid-side current, and simultaneous conduction of two switching tubes of the same bridge arm. [0003] At present, the predictive control of single-phase PWM rectifiers has fixed-frequency predictive power control, but this method has a large amount of calculation and complex control, and there is only one zero-switching s...

AI Technical Summary

Problems solved by technology

Model predictive control has the advantages of simple control structure and fast dynamic response, but there are also problems such as unstable switching frequency, large amount of calculation, high harmonic content of grid-side current, and simultaneous conduction of two switching tubes of the same bridge arm.

[0003] At present, the predictive control of single-phase PWM rectifiers has fixed-frequency predictive power control, but this method has a large amount of calculation and complex control, and there is only one zero-switching state in one sampling period, and the harmonic suppression is not ideal due to low switching frequency. In the process of model derivation, the influence of dead zone is not considered, which makes the model inaccurate

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