9.3kW 3-phase BLDC inverter/controller

[zenerbjt]

Dear Engineers,
The Flame 180A is a 3-phase inverter and inverter controller for a BLDC. It runs off a 6S or 14S lithium battery. (22-52v)
https://store-en.tmotor.com/goods.php?id=733

This video shows it..

There is no documentation with it. (as the video says)
Does the “180A” refer to the average supply current to the inverter from the battery…or does it refer to the peak phase current?

Also, with a 14S, that’s 52Vin, which means at 180A, that’s 9.3kW……just looking at the Flame 180A, it just doesn’t look like a 9.3kW inverter. It looks way too small. Would you agree? (Even with high speed blown air going over it)...see it at1:32 in the video if you wish

In the video at 1:32 you can see the tiny input capacitor bank…that’s all it is…7 capacitors of the size you see there…they are each 330uF,63V, 105degc....this surely is nowhere near enough for a 9.3kW 3-phase inverter to a BLDC. (I will try and find out the part numbers and do the calcs.)



Current measurement:
We’d like to use a 250A unidirectional Allegro-Micro Hall sensor to sense the current from the battery when the Flame 180A is operating.…..
ACS772 Hall current sensor
ACS772ECB-250U-PFF-T
https://www.allegromicro.com/en/Pro...ed-Amp-Integrated-Conductor-Sensor-ICs/ACS772
Do you believe 250A will be big enough to catch the peak of the battery supply current?

 

[rjenkinsgb]

180A is likely the peak current it can stand, on a short duty cycle.

If you look at the specs for the U13 II motor used in the video, that has a maximum current rating of 118A for three minutes.
The 50% throttle current is only around 20A.

The motor controller likely needs to be close to the prop airflow to give some level of forced cooling.

But, do remember that power switching capability and power dissipation are two totally different things; eg. If the power FETs in the controller have an on resistance of three milliohms (not unreasonable from a quick search), the heat dissipation in a FET at 100A is around 30W not thousands of watts..

 

[zenerbjt]

Brill thanks.
Also, why are there no interactive sims of 3phase BLDC inverter currents on the web?

 

[rjenkinsgb]

why are there no interactive sims of 3phase BLDC inverter currents on the web

No idea..