Class
Article
College
College of Engineering
Department
Electrical and Computer Engineering Department
Faculty Mentor
Regan Zane
Presentation Type
Oral Presentation
Abstract
Energy storage systems that incorporate hybrid Lithium-ion (Li-ion) battery packs leveraging the energy density and power density characteristics of different Li-ion chemistries have shown promise in reducing weight and volume while improving overall lifetime. A capacitively-coupled architecture, composite hybrid energy storage system (CHESS), has been proposed and demonstrated as a viable design for hybrid energy storage systems that combine energy-dense and power-dense battery packs. However, this architecture requires effective energy balancing among the battery packs to ensure optimal utilization.This work proposes an energy transfer unit (ETU) that consists of modular low-power dc-dc converters configured in a series-input, parallel-output arrangement. This ETU design serves three main purposes: 1) achieving energy balancing among the battery packs, 2) increasing the auxiliary power provision capability of the hybrid battery system, and 3) balancing the state of charge (SOC) among cell modules in a cost-effective and efficient manner. The functionalities of the ETU are realized through a multi-loop control strategy for the dc-dc converters in the ETU, which is detailed in this work. The CHESS design with the proposed energy management system achieves a 40% weight reduction compared to a conventional system using single-chemistry cells. Experimental results verifying the natural distribution of the system current between the energy-dense and the power-dense packs are provided for a 100 kW, 20 kWh prototype with 50 Ah NMC and 2.9 Ah LTO battery cells, and a 44 F supercapacitor.
Location
Logan, UT
Start Date
4-12-2023 10:30 AM
End Date
4-12-2023 11:30 AM
Included in
Active Energy Management of Hybrid Lithium-Ion Batteries for Electric Vehicle Applications
Logan, UT
Energy storage systems that incorporate hybrid Lithium-ion (Li-ion) battery packs leveraging the energy density and power density characteristics of different Li-ion chemistries have shown promise in reducing weight and volume while improving overall lifetime. A capacitively-coupled architecture, composite hybrid energy storage system (CHESS), has been proposed and demonstrated as a viable design for hybrid energy storage systems that combine energy-dense and power-dense battery packs. However, this architecture requires effective energy balancing among the battery packs to ensure optimal utilization.This work proposes an energy transfer unit (ETU) that consists of modular low-power dc-dc converters configured in a series-input, parallel-output arrangement. This ETU design serves three main purposes: 1) achieving energy balancing among the battery packs, 2) increasing the auxiliary power provision capability of the hybrid battery system, and 3) balancing the state of charge (SOC) among cell modules in a cost-effective and efficient manner. The functionalities of the ETU are realized through a multi-loop control strategy for the dc-dc converters in the ETU, which is detailed in this work. The CHESS design with the proposed energy management system achieves a 40% weight reduction compared to a conventional system using single-chemistry cells. Experimental results verifying the natural distribution of the system current between the energy-dense and the power-dense packs are provided for a 100 kW, 20 kWh prototype with 50 Ah NMC and 2.9 Ah LTO battery cells, and a 44 F supercapacitor.