Tool/software:
Hello,
we have compared the 1-PWM Mode to the 3-PWM Mode with FOC. The 3-PWM Mode with FOC was used with the Evalkit DRV8353H-EVM (Hardware Configuration, NOT SPI).
The are driving a BLDC Pump with this setup. With the 3-PWM Mode with FOC the pump required about 5.5A Peak Current on each phase at 48V to run at full capacity. When we use the 1-PWM Mode with directly fed back HALL-Sensor output to the DRV Inputs, we get peak currents of roughly 10A at 48V.
This mode shows significant inefficiency with our setup. The load remains the same for both scenarios.
Is there an explanation for this? We are aware that the sine wave running on a FOC-commutated design will always be more efficient, however it does not explain a 2-time increase between the two setups.
We also noticed that the SOx Output is highly disturbed by noise. This noise corresponds to the PWM frequency. The measurement input on SPx/SNx does not show this noise. It is a product of the IC. How can this effectively be counteracted?
Best regards,
