General Analysis and Design Guideline for a Battery Buffer System With DC/DC Converter and EDLC for Electric Vehicles and its Influence on Efficiency

Abstract

In this paper, the general design of a battery buffer system (BBS) consisting of a dc/dc converter and electric double layer capacitors for an electric vehicle is presented. This is intended to save the regenerative braking energy and to support the battery during acceleration. The design of a multiphase converter in interleaved operation with nonideal coupled inductors is stated to minimize volume and power losses while maintaining given current ripple limitations. A reduced sensor current-sharing control method is developed and its correct choice of the sensor position is explained. The peak efficiency of the designed and built converter can be measured to nearly 99%. The corresponding BBS is implemented in a lead-acid battery powered electric lift truck propulsion system. The system operation with and without the BBS is compared to examine the behavior and the overall efficiency. It can be shown that the traction battery stress can be strictly reduced as well as the temperature rise in the battery. Furthermore, the efficiency can be increased in the range of 5-6%. The battery's lifetime improvement is estimated by means of the difference in the temperature rise to approximately 20%.Index Terms-Battery efficiency, dc-dc converter, electric double layer capacitor (EDLC), electric vehicle, interleaved, power electronics.

An Output Ripple-Free Fast Charger for Electric Vehicles Based on Grid-Tied Modular Three-Phase Interleaved Converters

“…13). Thus, a design of the mutually coupled inductors is a multi-objective optimization problem, which aims to minimize the volume and total losses in inductors [29]. In this subsection, we evaluate the influence of the mutual coupling on the proposed ripple-free fast charger.…”

Isolated DC/DC converter with three‐level high‐frequency link and bidirectional power flow ability for electric vehicles

“…As a result, some electric vehicles utilise the low-voltage batteries as the power supply, especially when the rating power is small. In that case, step-up DC/DC converters are usually employed to raise the voltage of the battery to drive the motor [7][8][9][10]. Considering the requirements such as high power density, low voltage turn ratio and bidirectional power flow on electric vehicles, lots of topologies are investigated in the past few years.…”

Average power balance method for power failure compensation control of high‐speed turbo molecular pump with AMB system

“…The regenerative braking of the high‐speed electric machine has drawn researchers’ attention due to the same feedback process [16, 17]. In [18, 19], only an offline flyback dc/dc converter, which supplies the electric power for the whole system using the rotor energy, was connected between the dc‐link and AMB system.…”