A Comprehensive Electric Vehicle Model for Vehicle-to-Grid Strategy Development

TL;DR

This paper develops a detailed electric vehicle model incorporating thermal and electrical dynamics, validated with laboratory and field data, to support vehicle-to-grid strategy development and assess battery aging.

Contribution

It introduces a comprehensive EV model with thermal and electrical components, validated with real data, and provides a full parameter set for V2G strategy research.

Findings

Battery end-of-life after 431-589 days at 100% SOC and 40°C

Cell cycling at 80% DOD reaches 80% capacity after 3634 cycles

Model achieves RMSE between 18.49 mV and 67.17 mV per cell

Abstract

An electric vehicle model is developed to characterize the behavior of the Smart e.d. (2013) while driving, charging and providing vehicle-to-grid services. The battery model is an electro-thermal model with a dual polarization equivalent circuit electrical model coupled with a lumped thermal model with active liquid cooling. The aging trend of the EV's 50 Ah large format pouch cell with NMC chemistry is evaluated via accelerated aging tests in the laboratory. The EV model is completed with the measurement of the on-board charger efficiency and the charging control behavior via IEC 61851-1. Performance of the model is validated using laboratory pack tests, charging and driving field data. The RMSE of the cell voltage was between 18.49 mV and 67.17 mV per cell for the validation profiles. Cells stored at 100 % SOC and 40 $^{\circ}C$ reached end-of-life (80 % of initial capacity) after 431 days to 589 days. The end-of-life for a cell cycled with 80 % DOD around an SOC of 50 % is reached after 3634 equivalent full cycles which equates to a driving distance of over 420000 km. The full parameter set of the model is provided to serve as a resource for vehicle-to-grid strategy development.