Finite set model predictive control method for suppressing common-mode voltage of five-phase inverter

Abstract

The invention discloses a finite set model prediction control method for suppressing a common-mode voltage of a five-phase inverter. The method specifically comprises the steps that ten large vectorsoutput by a five-phase inverter are used for synthesizing a virtual voltage vector, four adjacent large vectors are selected to synthesize ten virtual effective voltage vectors in an alpha-beta subspace, and two large vectors opposite in direction are selected to synthesize a virtual zero vector; the virtual voltage vector is used as a vector control set, and a current change trend is predicted through a simplified prediction model; an optimal virtual voltage vector is selected by using a simplified evaluation function; and finally a symmetrical switch sequence is designed to output an optimalvector. According to the invention, the common-mode voltage and the low-order harmonic wave current are effectively suppressed, so that the steady-state performance of the output current of the inverter is improved; and due to the characteristic that the virtual voltage vector suppresses the common-mode voltage and the low-order harmonic waves, a prediction model and an evaluation function are simplified, the algorithm calculation complexity is low, and digital implementation is easy.

Description

technical field [0001] The invention belongs to the field of design and manufacture of a five-phase motor AC control system in the field of power electronics and electric transmission, and in particular relates to a finite set model predictive control method for suppressing the common-mode voltage of a five-phase inverter. Background technique [0002] Due to the limitation of the three-phase power supply system of the power system, the research work on AC electric drives mainly focuses on the theoretical research and practical application of the three-phase motor drive system. With the development of society and the progress of industry, more and more applications put forward higher requirements for the output power of the transmission system, and the multi-phase motor frequency conversion transmission system can provide greater power in the occasion of limited voltage. Moreover, the torque ripple is small, the operating efficiency is high, the fault tolerance performance i...

AI Technical Summary

Problems solved by technology

However, the traditional model predictive control will also bring higher common-mode voltage. For this reason, some scholars have proposed some improved model predictive control algorithms, which can suppress the common-mode voltage by adding constraints to suppress the common-mode voltage. However, it still has the disadvantages of complex algorithm, heavy calculation burden, and high content of low-order harmonics.

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