Multi-level rectifying T-shaped converter topological structure

Abstract

The invention discloses a topology structure used for a multi-level T-shaped converter, which can achieve rectifier conversion and is characterized in that the longitudinal axis of the T-shaped converter consists of 2k capacitors such as CT1, CT2, and to CTk-1, CTk, CB1, CB2, and to CBk-1 and CBk; the transverse axis of the T-shaped converter consists of k bidirectional controllable switch such as S1, S2, and to Sk-1 and Sk; a branch is arranged between nodes Di of Si and Si+1 (i is equal to 1, 2, and to k-1) and nodes DTi of CTi and CTi+1 (i is equal to 1, 2, and to k-1); a unidirectional rectifier branch flowing from the transverse axis to the longitudinal axis consists of STk1, STk2, and to STk2k; another branch is arranged between the nodes Di, CBi>and CBi+1 (i is equal to 1, 2, and to k-1); the branch is a unidirectional rectifier branch which flows from the longitudinal axis to the transverse axis and consists of SBk1, SBk2, and to SBk2k, with the direction reverse to the previous branch; one end of the bidirectional controllable switch S1 is connected with the middle point of the longitudinal axis capacitor. Number of levels can be increased by extending switch tubes, capacitors and rectifier branches; single-phase circuit combination can be applied to multi-phase systems. The topology structure can easily improve the number of levels of the converter and overcome the shortages that the capacitor of the prior art has non-uniform voltage and large quantity of devices.

Description

technical field [0001] The invention relates to a topological structure of a rectification circuit, in particular to a topological structure of a multilevel converter capable of realizing rectification. Background technique [0002] Two-level converter circuits are widely used in various fields such as railways and industries. However, in high-voltage applications, the two-level converter must be connected to the high-voltage power grid through a transformer due to the limitation of the withstand voltage of the device. The power frequency transformer greatly increases the cost and volume of the power electronic conversion device. [0003] At present, in the topology of the existing multilevel converter, as the number of levels increases, the number of semiconductor devices required increases sharply; as the number of levels increases, it is not easy to balance the voltages of each capacitor. The common problems in the multi-level structure make the multi-level have certain ...

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Problems solved by technology

[0002] Two-level converter circuits are widely used in various fields such as railways and industries. However, in high-voltage applications, the two-level converter must be connected to the high-voltage power grid through a transformer due to the limitation of the withstand voltage of the device. The power frequency transformer greatly increases the cost and volume of the power electronic conversion device

[0003] At present, in the topology of the existing multilevel converter, as the number of levels increases, the number of semiconductor devices required increases sharply; as the number of levels increases, it is not easy to balance the voltages of each capacitor. The common problems in the multi-level structure make the multi-level have certain limitations in practical use

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