I'm wondering if there's any limit to how fast and or frequently one can adjust the pilot signal during a charging session?
This is to allow for maximum use of available power on the circuit while taking into account other dynamic loads on same site or circuit.
Any insights on this would be appreciated.
The OpenEVSE box uses the pilot signal to control the charging current which is currently used by the safety temperature monitor, the PV load following feature and maybe the ohmconnect depending on how it's configured. My openEVSE box is running hot and I see the current change by 1/2 in a matter of a few seconds. The increase in current is limited by the EV onboard charger which in my case takes about a minute to ramp from 16A to32A once the safe temperature had been reached. Based on the observed 30 to 60 second ramp time for the onboard charger response I would limit the power adjustments to one per minute but your EV may have different response reaction times and consulting the EV manufacturer maybe helpful.
Thanks Keith. Very much appreciated.
Would be very interesting to hear more experiences form working with other EVs.
The SAE J1772 standard requires the vehicle to react to a change in pilot within 5 seconds. Depending on the actual reaction time it may not make sense to do it any faster than once every 5 seconds.