An Improved DC Bias Elimination Strategy with Extended Phase Shift Control for Dual-Active-Bridge DC-DC

Renewable Energy Systems and Power Electronics: Advances, Applications, and Integration

“…Although there are studies in the literature that try to explain EPS with shorter equations , the waveforms and mathematical expressions shown in Figure 2 depending on the relationship between the internal phase shift ratio and the external phase shift ratio of the EPS control are as follows (Zhang, et al 2019) (Qin and Kimball 2012) There is a point to be noted in these equations and conditions. In studies focusing only on EPS in the literature (Zhang, et al 2019) (Kumar, Bhat, and Agarwal 2017), Equation 4 is formed by considering the internal phase shift ratio D 1 as the internal phase shift ratio of the H bridge in the direction the power is coming from. However, in EPS control, the ZVS region can be adjusted and the current stress can be reduced by controlling the internal phase shift ratio of the H bridge in the direction of power transmission .…”

“…φ is the phase difference between V 1 and V 2 , ω is the radial switching frequency and L is the total leakage inductance. It should be noted that the total leakage inductance is the sum of the transformer leakage inductance and the inductance connected in series with the transformer (Zhang, et al 2019).…”

“…The voltage conversion ratio d defines the voltage ratios on both sides of the leakage inductance as given in Equation (2). Although the conditions of the voltage conversion ratio and phase shift ratio for soft switching are specified in the literature, it is accepted in many publications that the DAB circuit operates under soft switching conditions regardless of the value of the phase shift ratio if the voltage conversion ratio is equal to one (S. Zengin 2019) (A. Kızıcı 2019) (Texas Instruments 2019) (Zhang, et al 2019).…”

Phase shift control of dual active bridge DC‐DC converter based on feedforward compensation and transient optimization strategy

“…The SPS control strategy of the DAB converter is the simplest, but it not only lacks flexibility in power regulation but also brings additional stress to the switching devices in the converter [8][9][10] ; the DAB converter based on SPS control produces the return power of the DAB converter that is relatively large, which will inevitably lead to a decrease in efficiency, and at light load or even zero power transmission, the inherent soft switching properties of the DAB converter may fail, which will cause transmission power loss 7 ; Guan et al 11 expounds the mechanism and suppression method of backflow power, but this method cannot reduce the current stress; Chen et al 12 consider the magnetizing inductance and can realize full-load zero voltage switching (ZVS) under SPS control. By introducing an inner phase shift to suppress the backflow power, it can even eliminate the backflow power and can realize full-load ZVS from the control strategy, which forms various control strategies: EPS control, 13 DPS control, [14][15][16] and TPS control. 17 Compared with EPS, DPS which can not only reduce the requirements for switching devices and reduce losses but also improve the efficiency of the converter.…”

“…18 There are few researches on the control strategy of DAB converter in the transient state when the power changes, especially the research on the reverse power conversion. Zhange et al 13 expound that under the EPS control strategy, based on the minimum current stress model, the transient DC bias generated by the power change in the same direction is optimized, but it does not discuss the situation when the power changes in the opposite direction. Yin et al 19 describe a method that is only suitable for eliminating the DC bias generated by DAB converter power reversal during SPS control.…”