Improved dual voltage control method and device thereof for matrix converters

Abstract

The invention provides an improved dual voltage control method and a device thereof for matrix converters. The method comprises the following steps: re-dividing voltage sectors; carrying out custom calculation on variables required by duty ratio and ranking the variables; calculating the duty ratio of the matrix converter system according to the general calculation formula of the duty ratio; obtaining the duty ratio of each two-way power switch based on the corresponding relation between the duty ratio of the matrix converter system and that of each two-way power switch in a switch matrix; calculating the turn-on time of each two-way power switch in real time after the duty ratio of each two-way power switch is multiplied by the switch cycle, and realizing on-off control of the matrix converter. The device comprises an input voltage sampling unit, a DSP control circuit, a CPLD switch gate circuit, a detecting unit of output current direction and a drive circuit. The invention simplifies the system switch combination and the system has little amount of calculation, thus improving the efficiency and real-time and being suitable for application in controlling the matrix converters in the field of AC variable frequency speed regulating.

Description

Technical field [0001] The invention belongs to matrix converter control technology, and specifically relates to an improved dual voltage control method and device for matrix converters. Background technique [0002] Matrix converter is an AC-AC direct converter with excellent input and output characteristics. It has the advantages that traditional AC-DC-AC inverters can’t match: it eliminates the intermediate DC link; the output voltage has less low-order harmonic content; the output frequency Not affected by input frequency; energy can flow in both directions, suitable for four-quadrant operation of AC motors. [0003] The three-phase-three-phase matrix converter is named after 9 bidirectional power switches SaA, SaB, SaC, SbA, SbB, SbC, ScA, ScB, ScC arranged in a matrix, and the three-phase input voltage is U a , U b And U c , The three-phase output voltage is U A , U B And U C , Its circuit topology such as figure 1 Shown. Among them, SaA is a bidirectional power switch tha...

AI Technical Summary

Problems solved by technology

[0019] The purpose of the present invention is to overcome the above-mentioned deficiencies existing in the prior art, to provide an improved dual-voltage control method and its device for matrix converters, and to solve the problems that the general dual-voltage control system has a large amount of calculation and is difficult to implement. The purpose of this invention is to reduce the calculation amount of the system by re-dividing the input and output voltage sectors and giving a unified duty ratio calculation formula, so as to facilitate the realization of software programming and improve the efficiency and real-time performance of the program.

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