Dual-active-bridge series resonant converter and control method thereof

Abstract

The invention discloses a control method of a double-active-bridge series resonant converter. The control method comprises the following steps that: the output voltage of each half bridge of a primary side is controlled by DA1 and DA4, the switching-on time of Q1 and Q4 is the same, the switching-off time of Q2 and Q3 is the same, an upper switching tube and a lower switching tube of any bridge arm of the primary side are complementarily conducted, and an upper switching tube and a lower switching tube of any half bridge of a secondary side are complementarily conducted according to a specified duty ratio; when the double-active-bridge series resonant converter works less than or equal to half load, the working mode is that: D alpha < DA1 < D alpha+1 - DyB < DA4; when the double-active-bridge series resonant converter works at a half load, a working mode 2 is that DA1 is greater than D alpha+1 - DyB and less than DA4; and Q1, Q2, Q3 and Q4 are switching tubes of the primary side respectively, Q5, Q6, Q7 and Q8 are switching tubes of the secondary side respectively, DA1 is the duty ratio of Q1, DA4 is the duty ratio of Q4, DyB is the duty ratio of output voltage vcd between midpoints of secondary side bridge arms, and D alpha is the phase angle of Q1 leading the secondary side Q5. The circuit works under a half-load or light-load working condition, zero-voltage switching of each switching tube in the circuit can be ensured, meanwhile, the current stress of the device is reduced, and the transmission efficiency is improved.

Description

technical field [0001] The invention relates to the electrical field, in particular to a double active bridge series resonant converter and a control method thereof. The invention also relates to a dual active bridge series resonant converter implementing said control method. Background technique [0002] The bridge circuit is a rectifying circuit (rectifying circuit), which consists of four diodes connected into a "bridge" structure, and its function is to convert the alternating current output by the alternating current transformer circuit into a unidirectional pulsating direct current. The full bridge circuit is an oscillation composed of four triodes or switch tubes, and the half bridge circuit is an oscillation composed of two triodes or switch tubes. The full bridge circuit is not easy to produce effusion current, but the half bridge circuit is easy to bleed current between oscillation transitions, which will deteriorate the waveform and cause interference. [0003] ...

AI Technical Summary

Problems solved by technology

There are three control degrees of freedom in the triple phase-shift control method, and the duty cycle of the output voltage of the primary side bridge arm is D y A, a secondary bridge arm output voltage duty cycle D y B and the phase angle difference between the midpoint of the original and secondary bridge arms When the circuit works at half-load or light-load, the triple phase-shift control strategy is difficult to achieve zero-voltage turn-on of all switches, and power electronic converters often require the circuit to work within a wide range of load changes. None of the patents and documents have proposed a better solution to the above problems

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