A high-performance model predictive control algorithm for diode-clamped three-level converters

Abstract

The invention discloses a high-performance model predictive control algorithm for a diode-clamped three-level converter, which belongs to the field of power electronics and electric transmission. The algorithm selects a basic voltage vector with a small common-mode voltage amplitude as a control set, so that The amplitude of the modulus voltage is reduced by half, and the number of iterations is reduced from 27 to 19; a pair of redundant vector control is formed by constructing a virtual voltage vector with the same amplitude and direction as the basic voltage vector, but with a different midpoint current or both are 0 Midpoint potential balance. Compared with the traditional model predictive control algorithm, this algorithm simultaneously realizes common-mode voltage suppression and midpoint potential balance control, saves the design of weight items, reduces the harmonic content of output current, and solves the problem of midpoint potential pull-off. The current distortion problem in the transient process of the control balance has the advantages of simple algorithm and strong applicability.

Description

technical field [0001] The invention relates to the field of modulation and control of diode-clamped three-level converters in the field of power electronics and electric transmission, and specifically relates to a design without weight items that can realize common-mode voltage suppression and midpoint potential balance control, and has low harmonics A high-performance model predictive control algorithm for diode-clamped three-level converters. Background technique [0002] Diode-clamped three-level converters are gradually being widely used in medium and high voltage applications due to their advantages such as low harmonic content in output voltage and high withstand voltage level. The output side of the diode-clamped three-level converter generates a large common-mode voltage, which will induce a high-amplitude shaft voltage on the motor shaft, forming a shaft current, thereby destroying the electrical insulation and shortening the service life of the motor. In addition...

AI Technical Summary

Problems solved by technology

The output side of the diode-clamped three-level converter produces a large common-mode voltage, which will induce a high-amplitude shaft voltage on the shaft of the motor, forming a shaft current, thereby destroying the electrical insulation and shortening the service life of the motor.

For diode-clamped three-level converters, common-mode voltage suppression is not considered in the traditional model predictive control algorithm, and the control set contains all basic voltage vectors, and the number of loop iterations is large; in addition, through the constraints of the objective function Point potential balance control, but additional weight items need to be designed, and the weight items will affect the harmonics of the output current, especially in the transient process of controlling the balance after the midpoint potential is pulled, the current distortion is serious, and the value of the weight coefficient is different. Difficult to calculate

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