Question about esc's

Hey, I wanted to ask what the purpose of capacitors are in a vsec. Looking online it seems to be safer for your battery’s because they smooth the ripple current. My question is where this ripple current it coming from? Are we talking about the back emf? Which I assumed would not be there since mosfet’s only allow current in one direction? Another thing I keep reading is that they are especially important when braking, when you break isn’t the polarity simply being switched and spiked? To cause an outburst of torque, again would’nt the mosfet’s stop the back emf current of this ?

I’m just trying to understand how esc’s work better. So far all I know is that they create a ac current on each terminal for the motor.

@devin or @Hummie can either of you answer this question ?

not sure about the ripple current you mention but i assume it’s the current being drawn from the battery as the mosfets switch on off the current draw will jump up and down, the capacitor will help supply these current peaks.

from what i’ve seen escs have diodes across the mosfets in the opposite direction so that current from the battery cannot flow through it but current from the motor can, which is how the regen braking works.

I think current flowing out of the motor due to back emf causes an opposing force in the motor coils creating the negative torque. so the mosfets are switched to force the current to flow from the motor coils(not sure about this the voltage in the coils has to be higher than the battery voltage).

for basic understanding of esc’s look at how a H-bridge circuit acts to switch the voltage applied to the motor , the vesc is just a 3 phase version of this

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