Design of switched-capacitor dc-dc converter for battery management system in electric vehicle

• Main Author: Hendika, Fatkhi Nurhuda
• Other Authors: Goh, Wang Ling
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Integrated circuits
• Online Access: http://hdl.handle.net/10356/61466
• Institution: Nanyang Technological University

Novel Battery Management System (BMS) for electric vehicle is proposed to enhance system accuracy and reliability with regards to safety issue. Unlike conventional BMS which is done in module level, Embedded System Integrated Circuit (ESIC) is implemented in this design to exclusively control each Lithium-ion battery cell of electric vehicle. This report presents transistor level design and simulation of power supply management module of ESIC. Switched capacitor (SC) based DC-DC converter is implemented for cost and area optimization. A Global Foundries (GF) 0.18µm CMOS technology is used in this design. A combined three conversion topologies at 100 kHz is proposed to cater wide input range of the converter, 2.5V-4.5V. Excellent accuracy and output regulation capability is obtained with output ripple and error of ≤6mV and ≤1.3% respectively from fixed output voltage of 1V. Proportional Integral (PI) compensator is built for close-loop feedback compensation and successfully enhances load and line regulation. Finally, the peak efficiency of 70.76% is obtained with proper selection of dead time between two non-overlapping clocks.