High-performance model predictive control algorithm for diode clamping type three-level converter

Abstract

The invention discloses a high-performance model predictive control algorithm for a diode clamping type three-level converter, which belongs to the field of power electronics and power transmission, and comprises the steps of selecting a basic voltage vector with smaller common-mode voltage amplitude as a control set, reducing the common-mode voltage amplitude by half, and reducing the number of iterations from 27 to 19; and forming a pair of redundant vectors to control neutral-point potential balance by constructing a virtual voltage vector which has the same amplitude and direction as the basic voltage vector and has different neutral-point currents or a neutral-point current of zero with the basic voltage vector. Compared with a traditional model predictive control algorithm, the algorithm achieves common-mode voltage suppression and neutral-point potential balance control at the same time, design of weight items is omitted, the harmonic content of output current is reduced, the problem of current distortion in the transient process that balance is controlled after neutral-point potential pulling deviation is solved, and the algorithm has the advantages of being simple and high in 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

Images