Novel universal four-phase-shift modulation method for improving dynamic performance of dual-active bridge

Abstract

The invention provides a novel universal four-phase-shift modulation method for improving the dynamic performance of a dual-active bridge. All carrier signals are kept synchronous, and the universal four-phase-shift modulation method adjusts a corresponding phase shift angle by changing parameters of a comparison register in each carrier. The control method provided by the invention is based on a traditional phase shift control method, only input and output voltages need to be measured, and an auxiliary circuit does not need to be added. Compared with other control methods, the method provided by the invention has the advantages that dynamic response is completed instantly, a transition process and inductive current detection are not needed, and the whole control process is irrelevant to an inductance value. The method provided by the invention reduces the cost and calculation complexity, achieves the quick dynamic response of the circuit, eliminates the DC bias of the inductive current in a response process, and can be suitable for all application scenes of hard switching, soft switching, unidirectional power transmission, bidirectional power transmission and the like. Meanwhile, the method is also suitable for all control methods such as single-phase-shift modulation and three-phase-shift modulation.

Description

technical field [0001] The invention relates to a novel universal four-phase-shift modulation strategy for improving the dynamic performance of a dual active bridge, relates to a dual active bridge DC converter, and belongs to the technical field of power electronics. Background technique [0002] With the continuous development of power electronics technology and the diversification of application scenarios, more and more application scenarios require bidirectional transmission of electric energy. Bidirectional isolated DC / DC converters have been used more and more widely. Dual active bridge circuits are widely used because of their simple control, easy implementation of soft switching, and high efficiency. figure 1 It is a traditional dual active bridge circuit topology. The original and secondary sides are respectively composed of four MOSFETs. Each full bridge can be divided into two bridge arms, and there are four bridge arms L 1 -L 4 , each bridge arm consists of up...

AI Technical Summary

Problems solved by technology

However, with the sudden change of the phase shift angle, the traditional method will cause the transient bias current of the inductor due to the sudden change of the duty cycle

This results in slow dynamic response, increased current stress, increased losses

At the same time, the bias current may also cause the saturation of the inductor, which will lead to serious consequences such as loss of converter function or circuit damage.

[0004] The Chinese invention patent with the application number CN201410678003.0 and the name "A Transient Phase-Shift Control Method for Dual-Active Full-Bridge DC Converter" proposes a method for eliminating bias current for single phase-shift control. However, the transient DC bias suppression capability cannot be achieved in the multi-phase shift modulation strategy

[0005] The Chinese invention patent with the application number CN202010365209.3 and the name "Universal Phase Shift Control Method for Transient DC Bias of Dual Active Bridge DC Converters" proposes a method for eliminating bias current for multi-phase shift control , but the control process is more complicated, and the transient transition process affects the response speed

[0006] To sum up, in the process of dynamic change of dual active bridge load based on the traditional single-phase-shift modulation strategy, it is very easy to generate a DC bias of the inductor current, which will seriously affect the dynamic response and reliability of the converter.

Existing solutions have certain limitations

Images