Internal Resistance Optimization Utilizing “Just in Time” Control 2015-01-1234
Inspection of cell internal resistance (Rint) derived by the hybrid pulse power characterization (HPPC) tests indicates that Rint is a function of relative capacity (state of charge, or SOC), thus some SOC ranges are more efficient than others. Therefore energy losses can be minimized by placing charge sustaining operation in a more efficient SOC range. This creates three operational stages; the initial charge depleting stage to an efficient SOC, a charge sustaining stage until a recharge station is within reach, and a final charge depleting stage until arrival.
When coupled with a known drive distance, this three segment Internal Resistance Based (IRB) control strategy increases the extended range electric vehicle (EREV) net battery efficiency from 96.8 to 97.3 % with an associated 14 % decrease in energy losses across the urban domestic drive schedule. Indirect benefits include an increased active SOC range, decreased urban emissions, and decreased waste heat generation, meeting the goals of Advanced Vehicle Technology Competitions.
Citation: Ellsworth, P., Scott, W., Fowler, M., Fraser, R. et al., "Internal Resistance Optimization Utilizing “Just in Time” Control," SAE Technical Paper 2015-01-1234, 2015, https://doi.org/10.4271/2015-01-1234. Download Citation
Author(s):
Patrick Ellsworth, William Scott, Michael Fowler, Roydon Fraser, Ben Gaffney, Daniel VanLanen
Affiliated:
University Of Waterloo
Pages: 7
Event:
SAE 2015 World Congress & Exhibition
ISSN:
0148-7191
e-ISSN:
2688-3627
Related Topics:
Electric vehicles
Drag
Batteries
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