Single-phase high-frequency link matrix inverter and modulation method

Abstract

The invention relates to a single-phase high-frequency link matrix inverter and a modulation method. A positive electrode of a direct current power supply DC of the inverter is connected with drain electrodes of a first MOSFET tube and a third MOSFET tube and a negative electrode of a first diode respectively; the negative electrode of the direct-current power supply DC is connected with the source electrodes of the second MOSFET, the fourth MOSFET and the positive electrode of the second diode; the first end of a primary coil of a transformer circuit is connected with the source electrode of the first MOSFET and the drain electrode of the second MOSFET; the second end of the primary coil of the transformer circuit is respectively connected with the anode of the first diode and the cathode of the second diode; the third end of the primary coil of the transformer circuit is respectively connected with the source electrode of the third MOSFET and the drain electrode of the fourth MOSFET; and the secondary coil of the transformer circuit, the post-stage matrix converter, the output filter and the load form a closed circuit in sequence. According to the invention, the pre-stage ZVZCS form soft switching is realized, and the capacitance oscillation on a post-stage switching tube is reduced.

Description

technical field [0001] The invention relates to the field of power electronic power converter topology and its modulation, in particular to a single-phase high-frequency chain matrix inverter and a modulation method. Background technique [0002] The traditional DC-AC high-frequency link topology adopts unipolar phase-shift modulation. The main soft switching form of this topology is ZVS; the ZVS switch-on of the switching tube is mainly realized in the 0 state, that is, the process of inductor freewheeling, but in this way It will increase the loss; some scholars have proposed the soft switching form of ZVZCS. Usually, the capacitor is added to the single-phase full-bridge circuit, and the lagging bridge arm is connected in series with diodes. However, passive devices such as capacitors have service life problems; Therefore, how to reduce the use of passive components, realize ZVZCS at the same time, and improve the efficiency of single-phase DC-AC topology has become an ur...

AI Technical Summary

Problems solved by technology

In order to solve the ringing problem caused by the capacitance on the switching tube of the subsequent stage, some scholars have proposed to use a clamping circuit composed of two flyback circuits on both sides of the post-stage transformer. However, using this method, the control is complicated and the clamping circuit The switch tube is a hard switch; some scholars have proposed a lossless clamping circuit composed of a full bridge circuit in the latter stage, but the control of such a circuit is complicated; some scholars have proposed a front stage circuit composed of three half bridges and two switch tubes , using secondary side modulation (SSM), considering the capacitance C of the MOSFET tube ds and the voltage across the MOSFET tube U ds The nonlinear relationship solves the problem of voltage ringing, but the calculation of such a circuit is too complicated and the effect is not good

Images