A new zero voltage switching (ZVS) full-bridge DC-DC converter for battery charging is proposed in this paper. The proposed isolated DC-DC converter is used for the DC-DC conversion stage of electric vehicle charger. The primary switches in DC-DC converter turn-on at zero voltage over the battery charging range with the help of passive auxiliary circuit. The diode clamping circuit on the primary side minimizes the severity of voltage spikes across the secondary rectifier diodes which are commonly present in conventional full-bridge DC-DC converters. The main switches are controlled with asymmetrical pulse width modulation (APWM) technique resulting in higher efficiency. APWM reduces the current stress of the main switches and the circulating losses compared to the conventional phase-shift modulation (PSM) method by controlling the auxiliary inductor current over the entire operating range of the proposed converter. The steady-state analysis of auxiliary circuit and its design considerations are discussed in detail. A 100-kHz, 1.2-kW full-bridge DC-DC converter prototype is developed. The experimental results are presented to validate the analysis and efficiency of the proposed converter.

The number of Stationary Battery Systems (SBS) connected to various power distribution networks across the world has increased drastically. The increase in the integration of renewable energy sources is one of the major contributors to the increase in the number of SBS. SBS are also used in other applications such as peak load management, load-shifting, voltage regulation and power quality improvement. Accurately modeling the charging/discharging characteristics of such SBS at various instances (charging/discharging profile) is vital for many applications. Capacity loss due to the aging of the batteries is an important factor to be considered for estimating the charging/discharging profile of SBS more accurately. Empirical modeling is a common approach used in the literature for estimating capacity loss, which is further used for estimating the charging/discharging profiles of SBS. However, in the case of SBS used for renewable integration and other grid related applications, machine-learning (ML) based models provide extreme flexibility and require minimal resources for implementation. The models can even leverage existing smart meter data to estimate the charging/discharging profile of SBS. In this paper, an analysis on the performance of different ML approaches that can be applied for lithium iron phosphate battery systems and vanadium redox flow battery systems used as SBS is presented for the scenarios where the aging of individual cells is non-uniform.

This study proposes an efficient soft‐switched full‐bridge DC/DC converter (FBDC) topology operated with modified pulse width modulation (MPWM) for electric vehicle (EV) battery chargers, as the role of DC/DC converter is more prominent in on‐board charging. The proposed auxiliary circuit offers zero voltage switching (ZVS) turn‐on to all the active switches of the converter during full battery charging range. In consequence, the losses associated with the proposed FBDC are minimal and offer maximum efficiency as compared to available benchmark topologies operated with different gating schemes. The size of magnetic elements used in the proposed topology also reduced as to conventional FBDC operating with trailing edge pulse width modulation and phase shifted modulation gating techniques. A detailed designing and analysis of the MPWM operated ZVS FBDC is presented. Besides, the rationale behind the selection of switching frequency in order to ensure wide‐range ZVS is detailed. Further the proposed topology is compared with the other competent topologies for proving its significant merits. Simulation of the proposed configuration is performed at 3.3 kW. Following which, the experimental results obtained from a laboratory prototype of 500 W, 80 kHz validating the operability and feasibility of the proposed converter are presented.