Three-level DC converter of zero-voltage and zero-current switch

Abstract

The invention discloses a three-level DC converter of a zero-voltage and zero-current switch. The three-level DC converter comprises a transformer T, a primary circuit and a secondary circuit, whereinthe primary circuit is connected with a primary side of the transformer, the secondary circuit is connected with a secondary side of the transformer, the primary circuit comprises an inversion circuit, a balancing branch, a capacitor C<in1> and a capacitor C<in2>, the capacitor C<in1> and the capacitor C<in2> are connected in series and then are connected in parallel with two ends of a full-bridge inversion circuit, a first end of the balancing branch is connected between the capacitor C<in1> and the capacitor C<in2>, a second end of the balancing branch is connected with the full-bridge inversion circuit, the secondary circuit comprises a rectification circuit and an LC filtering circuit, the rectification circuit is connected with the transformer T, and the LC filtering circuit is connected with an output end of the rectification circuit. By the three-level DC converter, the problem of the prior part is solved, the problem of current unbalance of an existing three-level circuit is solved, current stress of a primary device is equalized and reduced, and zero-voltage and zero-current on / off of a switch tube is achieved.

Description

technical field [0001] The invention belongs to the technical field of high-voltage direct-current converters, and in particular relates to a three-level direct-current converter with zero-voltage and zero-current switching. Background technique [0002] Because high-performance and high-input power DC converters have great potential in market applications, three-level DC converters have become the object of extensive research. Compared with the traditional two-level DC converter, the switching tube of the three-level DC converter only bears half of the voltage stress of the switching tube in the two-level DC converter. Therefore, compared with the two-level DC converter, Three-level DC converters are more commonly used in DC converters with high voltage input. [0003] However, the traditional three-level DC converter also has the problem of current imbalance in the primary side of the transformer. Especially when the duty cycle is asymmetrical or the duty cycle is small, ...

AI Technical Summary

Problems solved by technology

[0004] The invention provides a zero-voltage zero-current three-level DC converter, which solves the problems existing in the prior art, overcomes the current unbalance problem existing in the existing three-level circuit, and balances and reduces the primary side device Current stress, realizing the zero-voltage and zero-current turn-on and turn-off of the switch tube

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