Capasitor size at the esc

[Christian Lucas]

Hi,
another question about electric drives.
Every ESC has a capacitor bank in front of the ESC. Are there limits on the capacitance of the capacitors?
For example, can I use high-power capacitors there that were not pre-charged before the competition. The energy comes only from the battery cells, the capacitors are only charged with it.
Would that be allowed by the rules?

Happy Amps Christian

 

[LohringMiller]

The NAMBA rules aren't clear, but:
"Racers wishing to run alternative chemistries to those listed will be required to
provide data to the contest official to verify the chemistry’s volts per cell and
any special safety requirements. Allowing alternative chemistries will be at
the discretion of the Contest Directory based on the data provided."

I bet many CDs wouldn't allow it.

Lohring Miller

 

[Christian Lucas]

HI Lohring,

every esc has the capasitors to lower high volt peak . So there is no question every budy has capasitors but the size . Some have one , some have 4 or 6 . But the size can play a big rule when it comes to peak current . The capasitor bigger ultracapasitor can handle much higher power than lithium batteries. I have some they can load up to 1000 amps and 1000 cycles and moore .
This gives much higher aceleration out of a corner or for a dragster style start . belong to your what you want.
And yes i think like you, the CDs will not allow them.

Happy Amps Christian

 

[RaceMechaniX]

Christian,

Under the current rules there are no regulations on the size and quantity of capacitors, but it is understood these are for ripple voltage buffering and not energy storage. I assume you are thinking of using Ultra-caps and then you would have to prove the caps and ESC are at 0 volts before connecting your main battery. Hopefully you have a softstart circuit otherwise you will vaporize the plugs upon connection. The Ultra-caps should not give any benefit of runtime, but should allow for higher transient currents then the batteries would normally output.

Be safe! Ultra-caps and lipos both contain a lot of energy and may not always play nice together.

-Tyler

 

[Christian Lucas]

Hi Tyler,
yes i know about capasitors. I have a carging electronic where i can set the current , so the peak amps draw is limitet from the batterie . You know we have some know how about high power short time power use when we designed the coil gun . Itxs just an idea to use high energie dens liion batterie with lower peak amps and capasitor that deliver the higher amps for acceleration.
In our busses we used the flywheel storage for peak power acceleration , Porsche won 1000 km Nürburgring and Audi won LeMans with such flywheel system.

Happy Amps Christian