A Novel Hybrid Dual Active Bridge Converter For Wide Input Voltage Range Condition

In the fields of new energy and electric vehicles,bidirectional DC-DC converters are widely used.This paper proposes a new topology based on wide voltage range and low voltage stress.The left side of the topology is a three-level circuit that can be applied to a wide voltage range.The converter has wide input voltage range,low voltage stress and high efficiency..This article is only for the possibility of verifying the new topology.The right side uses a simple half-bridge structure.The circuits on both sides are connected by a DC blocking capacitor,a transmission inductor,and an isolation transformer.For the sake of convenience,considering the structure of the circuit,it is referred to by a double-ended active hybrid bridge converter.In this paper,the basic principle and driving method of double-ended active hybrid bridge converter,as well as the working mode,transmission power characteristics and soft switching characteristics of phase shift control and single PWM plus phase shift control are analyzed.In order to improve converter efficiency,an optimization strategy based on minimum current RMS is proposed under single PWM plus phase shift control.This paper first gives the topology of the double-ended active hybrid bridge converter,and introduces the working principle of the converter;the three-level circuit on the left side of the converter can be used for wide input voltage applications,and the three-level circuit has two kinds of work.Mode,the soft switching performance is not good at the switching point of the two modes.In this paper,the driving mode is designed to make the final equivalent circuit of the converter and the single-ended active full-bridge converter under single PWM plus phase shift control.The equivalent circuit is the same.By analyzing the charge and discharge states of different switch combinations,after considering the conditions of midpoint potential balance and conduction loss balance,the two-cycle combined drive mode is finally adopted.Then the paper analyzes the working mode under phase shift control,and studies the operating characteristics of the converter from the two aspects of converter transmission power and soft switching range.It is found that the converter is only in V1=nV2 under phase shift control.In this case,the full load range soft switch can be realized.In order to solve this problem,the introduction of single PWM plus phase shift control theoretically proves that under the single PWM plus phase shift control,by reasonable control of D1,D?,the converter can achieve full load range softness at any voltage ratio m.The final soft-switching range is a region.Under the condition that the voltage ratio is determined,the D1 of the soft-switching of the full load range is satisfied,and the degree of freedom of D? is large.The single PWM plus phase-shifting control is given by the limitation condition of the minimum inductor current RMS.At the end of this paper,a 1.5kW prototype is built to verify the theoretical analysis of the working characteristics of the double-ended active hybrid bridge converter under phase shift control,single PWM plus phase shift control and optimized control strategy.