SVPWM control method of fast multilevel inverter

Abstract

The invention discloses a space sector pulse width modulation (SVPWM) control method of a fast multilevel inverter, and belongs to inverter control methods. The control method includes the following steps that a, transformation of coordinates is carried out, and vector coordinates are converted into integers; b, preliminary calculation is carried out on coordinates of even number complement vectors closest to vertexes of reference voltage vectors; c, the coordinates obtained in the step 2 through calculation are corrected; d, the reference voltage vectors are decomposed; e, polarity judgment and action time calculation are conducted; f, on-off state calculation is carried out and drive pulses of the inverter are generated. The control method has the advantages that sector judgment and table look-up are needless, trigonometric functions and root sign operations do not exist, and only simple addition, subtraction and multiplication are needed; on-off states of various phases can be obtained directly through simple calculations, the number of programming codes is small, and the operating speed of a system is improved; the control method can be applied to inverters of random levels, and the calculated quantity is slightly increased along with increasing of the number of levels.

Description

technical field [0001] The invention relates to a modulation technology in the field of multi-level power electronic inverters, in particular to a SVPWM control method for a fast multi-level inverter. Background technique [0002] The idea of ​​a multi-level inverter was first proposed in 1980 by Nagaoka University of Science and Technology Nanba Ezhang et al. Its basic idea is to synthesize a step wave from several power levels to approximate a sinusoidal output waveform. The multi-level inverter starts from the circuit topology. While obtaining high-quality output waveforms, it overcomes many shortcomings of the two-level inverter. It does not need an output transformer and a dynamic voltage equalizing circuit. The switching frequency is low and there are switching devices. A series of advantages such as small stress and high system efficiency. [0003] Since the concept of multilevel inverter was put forward, three types of basic topologies and a series of improved topol...

AI Technical Summary

Problems solved by technology

Traditional SVPWM is not too complicated when applied to lower than three-level inverters, but it will become very complicated when applied to multi-level and above inverters, and it is difficult to apply to multi-level inverters. To some extent, it limits the development of multilevel inverters

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