Two-stage three-phase four-leg matrix converter with direct-current constant-voltage output function

Abstract

The invention discloses a two-stage three-phase four-leg matrix converter with a direct-current constant-voltage output function. A direct-current conversion part can evolve based on a double-transistor forward circuit, a double-transistor reverse excitation circuit or a full-bridge conversion circuit, and adopts multiplexing of the midline leg of the matrix converter. The control method is achieved by synchronous cooperation of the direct current-to-direct current conversion circuit and the matrix converter. An alternating-current output part of the three-phase four-wire system can provide stable three-phase power for the unbalanced or nonlinear load; and simultaneously, the direct-current output part can provide an isolated direct-current voltage source for the direct-current load. The new two-stage three-phase four-leg matrix converter has a compact topological structure and high circuit utilization rate; the control method maintains high sinusoid of the input current and the rectifier-stage zero-current switch condition, therefore, no influence between the alternating-current output and the direct-current output exists, and then, the higher application value is achieved.

Description

technical field [0001] The invention relates to a matrix converter, in particular to a novel topology of a dual-stage three-phase four-arm matrix converter with a DC voltage stabilizing output function for the application occasion of an independent power supply system. Background technique [0002] The matrix converter (MC) does not contain energy storage capacitors. It has the advantages of compact structure, small volume and weight, good stability, and long service life. It can persist in working in harsh natural environments. The two-stage matrix converter is a new type of topology developed based on the concept of the matrix converter. It inherits the advantages of the traditional MC without energy storage capacitors, and at the same time overcomes the difficulty of commutation due to the absence of a freewheeling circuit on the output side and the need for clamps. There are many shortcomings such as bit circuits, and it has higher application value. [0003] On the bas...

AI Technical Summary

Problems solved by technology

Patent [3] uses the DC link of TSMC as the input voltage of the DC regulator circuit, but its three-phase three-wire output structure has insufficient ability to operate with unbalanced loads, and the independent control mode of the H-bridge and MC affects the rectification stage circuit to achieve zero-current switching (ZCS), that is, it cannot guarantee that the DC bus current is zero when the rectifier stage switch is switched.

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