Narrow-pulse-free modulation method suitable for three-phase high-frequency link matrix converter

Abstract

The invention relates to a narrow-pulse-free modulation method suitable for a three-phase high-frequency link matrix converter. The method is characterized in that a matrix converter is equivalent totwo three-phase inverter circuits according to the positive and negative polarities of input voltage, the duty ratio of each bridge arm of the two three-phase inverter circuits is deduced by utilizingthe change rule of the voltage at the two ends of a power switch and is matched, and a duty ratio of the matrix converter in the whole period is generated; two mutually associated modulation waves are constructed according to a duty ratio function; the two modulation waves are respectively modulated with a carrier wave, a modulation result is subjected to logic calculation and a trigger to generate a power switch driving signal with a duty ratio of 0.5 all the time, and the power switch driving signal does not contain narrow pulses; the driving signal is used for controlling the switching ofeach power switch in the high-frequency link matrix converter, and finally three-phase symmetrical output voltage and current waveforms are obtained. The method provided by the invention effectively solves the problem that the narrow pulse of the driving signal cannot be eliminated in the prior art. The method has the advantages of scientificity, reasonability, high applicability, good effect andthe like.

Description

technical field [0001] The invention relates to the field of power electronics, and is a non-narrow pulse modulation method suitable for a three-phase high-frequency chain matrix converter. Background technique [0002] An inverter is a converter that directly converts direct current into alternating current to supply an alternating current load. With the increase of load types and capacity, the requirements for inverters are getting higher and higher, and miniaturization and high frequency have become the development trend of inverters. Therefore, the existing technology uses high-frequency transformers to replace traditional power-frequency transformers, which have the advantages of small size, light weight, and high efficiency, overcome the shortcomings of power-frequency transformers, and significantly improve the operating characteristics of the inverter. Although the use of high-frequency transformers to replace traditional power-frequency transformers is the overall ...

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Problems solved by technology

[0004] The purpose of the present invention is to propose a non-narrow pulse modulation method that is scientific and reasonable, has strong applicability and good effect, and is suitable for three-phase high-frequency chain matrix converters, aiming at solving the problem that the existing control method cannot eliminate the narrow pulse of the driving signal question

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