XL-Classic Solarracing - Auxiliary power consumption

Introduction

This very short blog is supposed to give a very simple insight into the power consumption of the XL-Classic Solarracing Edition on it's 12V rail.

Test setup

The controller is powered through an external 12V supply, while the current consumption is measured by means of a Crenova MS8233D multimeter in Milliampere mode.
The switching frequency (Option name "Zero-Vector-Frequency" in VESC Tool®) is varied throughout the test and the corresponding current consumption recorded.

The inverter phases are left open while outputting space-vector modulated sine waves at 50% duty cycle.

In the bringup phase, the power stage input voltage as well as the duty cycle are varied to verify they have no effect on the drawn 12V current.

Result

Idle consumption of the XL-Classic Solarracing Edition on the externally supplied 12V rail is 40mA. When connecting VESC® Tool and enabling "Realtime Data", the idle consumption is 41mA.

When driving the open phases at 50% duty cycle, the consumption is:

Remark: The Zero Vector Frequency is double the PWM frequency of the MOSFETs.

Conclusion

The 12V current consumption shows a strong linear dependency on the switching frequency of the converter, varying between 41mA (0.5W) idle and 265mA (3.2W) switching at 40kHz Zero Vector Frequency.