Mixed phase-shifting control method used for dually-active full-bridge direct current converter

Abstract

The invention discloses a mixed phase-shifting control method used for a dually-active full-bridge direct current converter, and belongs to the technical field of power electronics. The mixed phase-shifting control method comprises the following steps: drive pulses of eight switching tubes in the converter are all set to be square waves; the drive pulse of the first switching tube and the drive pulse of the third switching tube in a first full bridge are set to be complementary with the drive pulse of the second switching tube and the drive pulse of the fourth switching tube in the first full bridge respectively, and the drive pulse of the first switching tube and the drive pulse of the third switching tube in a second full bridge are set to be complementary with the drive pulse of the second switching tube and the drive pulse of the fourth switching tube in the second full bridge respectively; a phase-shifting angle D1 is formed between the drive pulse of the first switching tube and the drive pulse of the fourth switching tube in the first full bridge, another phase-shifting angle D1 is formed between the drive pulse of the second switching tube and the drive pulse of the third switching tube in the first full bridge, and similarly a phase-shifting angle D2 is formed between the drive pulses of the switching tubes in the second full bridge; a phase-shifting angle D3 is formed between the drive pulse of the first switching tube in the first full bridge and the drive pulse of the corresponding switching tube in the second full bridge, and another phase-shifting angle D3 is formed between the drive pulse of the second switching tube in the first full bridge and the drive pulse of the corresponding switching tube in the second full bridge; the magnitude and flow direction of output voltage and the magnitude and flow direction of transmission power of the converter are controlled by adjusting the three phase-shifting angles. By means of the mixed phase-shifting control method, the voltage and current stress of the converter can be reduced, loop currents are reduced, and efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of power electronics and relates to a dual-active full-bridge DC converter, in particular to a hybrid phase-shift control method for a dual-active full-bridge DC converter. Background technique [0002] The existing dual-active full-bridge DC converter is a DC converter that can operate in two quadrants. Its structure is as follows: figure 1 As shown, it mainly includes: two full-bridge converters (H 1 、H 2 ), an auxiliary inductor (L), an isolation transformer (T) and two DC filter capacitors (C 1 、C 2 ). Since it is functionally equivalent to two unidirectional DC converters, it can greatly reduce the volume, weight and cost of the system. It is widely used in DC motor drives, uninterruptible power supplies and electric vehicles where bidirectional energy flow is required. [0003] In order to realize the control of the output voltage of the dual-active full-bridge DC converter and the magnitude and f...

AI Technical Summary

Problems solved by technology

However, in this method, the energy is mainly transferred through the transformer leakage inductance (or a small amount of series inductance). When the input and output voltage amplitudes do not match, the power circulation and current stress of the converter will greatly increase, which in turn increases the power devices, Losses in magnetic components, reducing converter efficiency

[0004] In order to improve the shortcomings of the above-mentioned traditional control methods, some literatures have proposed a PWM plus phase shift control, but the circuit structure of this method is no longer a dual-active full-bridge DC converter.

In addition, some literatures have proposed hybrid phase-shift control methods such as dual-phase-shift control and extended phase-shift control to improve converter characteristics. The dual-phase-shift control is mainly by adding a The same internal phase shift angle, the extended phase shift control is mainly through adding an internal phase shift angle inside a full bridge of the dual active full bridge DC converter, but these control methods only have two phase shift angles, which is very important for the converter Limited performance improvement and insufficient tuning flexibility

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