Five-level ANPC full-bridge isolation DC-DC converter and control method thereof

Abstract

The invention discloses a five-level ANPC full-bridge isolation DC-DC converter and a control method thereof, and belongs to the field of DC-DC converters, and the converter comprises a main circuit which comprises a transformer and active bridges at two sides of the transformer, and at least one active bridge is provided with a 5L-ANPC full-bridge circuit; the 5L-ANPC full-bridge circuit is obtained by serially connecting a switching tube S9 between a positive electrode of a direct-current side bus and a switching tube S1 connected with the positive electrode and serially connecting a switching tube S10 between a negative electrode of the direct-current side bus and a switching tube S4 connected with the negative electrode on the basis of a five-level active neutral-point clamped full-bridge circuit, and comprises three zero states of O1, O2 and O3; and the control driving unit controls the O3 state in the 5L-ANPC full-bridge circuit to be an intermediate state of switching between the O1 state and the O2 state, and realizes switching between the zero state and the non-zero state through the O1 state and the O2 state. According to the invention, the dead zone effect existing in the dead zone time of two adjacent half cycles when the converter works can be eliminated, and the full soft switching of the high-voltage switch tube can be realized.

Description

technical field [0001] The invention belongs to the field of DC-DC converters, and more specifically relates to a five-level ANPC full-bridge isolated DC-DC converter and a control method thereof. Background technique [0002] The double active bridge (Double Active Bridge, DAB) isolated DC-DC converter is one of the preferred circuits for constructing a DC transformer. The bridge arm structure of a traditional DAB isolated DC-DC converter is usually an H-bridge circuit, and the voltage stress on each switch tube is the DC bus voltage. Limited by the withstand voltage rating of the switching tube, it is difficult to realize the application of the bidirectional DC-DC converter with this structure under high voltage conditions. In addition, the high withstand voltage switching tube has the problems of large switching loss and low switching frequency, which limits the improvement of converter performance and efficiency. [0003] In high-voltage and high-power applications, th...

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Problems solved by technology

[0004] Aiming at the defects and improvement needs of the prior art, the present invention provides a five-level ANPC full-bridge isolated DC-DC converter and its control method, the purpose of which is to solve the DAB conversion of the existing 5L-ANPC full-bridge topology construction There is a technical problem of the dead zone effect in the dead zone between two adjacent half cycles when the converter is in operation

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