Dichotomy-based multi-level simplified space voltage pulse width modulation (SVPWM) adjustment strategy

Abstract

The invention discloses a dichotomy-based multi-level simplified space voltage pulse width modulation (SVPWM) adjustment strategy. The adjustment strategy comprises the steps of firstly, performing Alpha Beta 2gh coordination conversion on a reference voltage vector under a rectangular coordinate system; performing vertical integer operation on reference vector coordinate under a gh coordinate system, judging the nearest triangular position where the reference vector is located on the basis of dichotomy, and calculating acting time of neatest three basic vectors under the gh coordinate system on the basis of a volt-second balancing principle; and finally, arranging an acting sequence of the basic vectors. According to the adjustment strategy, simple arithmetic is only needed in calculation of the basic vector acting time, a large amount of trigonometric function calculation is omitted, and the operation time of a processor is reduced; the dichotomy is used for judging the reference vector position, the position where the reference vector is located can be rapidly searched, so that a switch vector sequence can be directly generated according to control requirement, and complicated logic judgment is omitted; and with the increase of level number, no influence is generated on simplification of complexity of a space vector modulation algorithm, and the adjustment strategy has relatively good adaptability.

Description

technical field [0001] The invention relates to the technical field of modulation of multi-level power electronic inverters, in particular to a multi-level simplified SVPWM modulation strategy based on a dichotomy method. Background technique [0002] The basic idea of ​​multi-level technology is to synthesize a staircase wave by several level steps to approximate the sinusoidal output waveform. Compared with the traditional two-level inverter, the multi-level inverter has the advantages of low withstand voltage of power devices, The output waveform has the advantages of good harmonic characteristics, low switching frequency and high efficiency, and is suitable for high-voltage and large-capacity power conversion occasions. [0003] At present, the multi-level inverter topologies mainly include: diode-clamped type, flying capacitor type, cascaded H-bridge type, modular multi-level inverter and hybrid type based on the above topologies. According to different topological str...

AI Technical Summary

Problems solved by technology

Among them, the 60° coordinate system SVPWM modulation strategy eliminates the sector judgment process and complex trigonometric function calculation of the traditional modulation strategy, which simplifies the calculation. However, for the final determination of the inverter switch state, the modulation strategy needs to be listed All switch states of the three nearest basic vectors, for more tedious conditional judgment

Images