Project 03
A transient MATLAB Simulink and Simscape thermal-management model used a representative race-cycle load to identify the minimum radiator configuration capable of maintaining acceptable motor and motor-controller temperatures.
Project overview
The radiator was sized using a transient thermal-management model rather than a single steady-state operating condition. The model reproduced the electric powertrain response over a representative lap, coupled the resulting motor and controller heat loads to the liquid-cooling circuit, and enabled the radiator to be reduced iteratively to the minimum effective configuration.
01 / Duty cycle
Motor demand was driven by lap-time simulation data rather than a single design point. The resulting time history formed the input for powertrain response and heat-generation calculations.
02 / Model development
Built a transient Simulink/Simscape model of the cooling circuit, driven by the time-varying motor power profile from lap-time simulation data to represent a realistic race-cycle load. Derived motor and inverter heat loads from the motor's efficiency-versus-power graphs — all efficiency losses treated as heat absorbed by the coolant — with a custom PI current controller reproducing the EMRAX 228 MV transient response. Modelled the radiator with the Simscape Simple Heat Exchanger and estimated coolant-side heat transfer using a Nusselt-number correlation.
Monitored motor inlet and other critical coolant and component temperatures across each transient simulation. Iteratively reduced the radiator size until the minimum configuration maintaining acceptable motor and controller temperatures was identified, rejecting approximately 1.4 kW.
03 / System architecture
04 / Results
Repeated transient runs were used to reduce the effective radiator size while monitoring motor inlet and other critical temperatures. The final configuration maintained acceptable thermal behaviour and rejected approximately 1.4 kW from the combined motor and motor-controller loop.
| Design item | Implemented method | Outcome |
|---|---|---|
| Duty cycle | Lap-time power profile | Transient race-load evaluation |
| Heat sources | Motor and controller losses | Combined cooling-loop load |
| Radiator model | Simple Heat Exchanger with Nusselt correlation | Iteratively minimized effective size |
| Verified heat rejection | Transient thermal simulation | Approximately 1.4 kW |
05 / Prototype
