The Power loss of the Wave-sculptor 22 motor controllers is given by the following equations where:
Ploss = Req*Io2 + (α*Io+β)*Vbus + Cfeq*V2bus
| Description | Value | |
|---|---|---|
| Vbus | Bus (Battery) Voltage of the controller | 129.6V Nominal (100V - 151.2V) |
| Io | Ouput current of the controller | Pmax/Vbus (Roughly, This will actually be off by ~1.2x) |
| Req | Equivalent resistance of the entire controller | 0.0108 Ohms |
| β | Constant component of the switching loss (per unit of bus voltage) | 0.018153 |
| α | Linear component of the switching loss (per unit of bus voltage) | 0.003345 |
| Cfeq | Equivalent capacitance*frequency of the controller | 0.00015625 |
Using an approximated value of Pmax for the entire car as 9kW, including mechanical and non-controller electrical losses, the per motor controller peak power is 4.5kW. Meaning the approximated output current will vary between 29.8A - 45A (Nominal 34.7A)
From this we can plot the efficiency of the motor controllers versus the voltage and the current using Desmos.
https://www.desmos.com/calculator/kwklxrs8g3
For more detailed information see the linked data sheet:
https://drive.google.com/file/d/1XMdPXyh2Yv-zCBCM8KNiVlM04B9diN-6/view?usp=sharing