3 Phase config in ESP32_Wifi Firmware

Integrations OpenEVSE
1

Hi All,

I’ve discussed this briefly before, and coming into summer, I’m using the ECO mode (PV divert) function on emonevse.
My emonevse controller is running the 3phase firmware 8.2.0.3P and has 3 phase supply and 3 phase charge cable to 3 phase capable vehicle (i-pace). All works well in normal (non-divert) operation.

When I use single phase, PV Divert works well, matching the available current to the pilot superbly.

When in 3 phase mode, it all goes to pot.
I tell emonevse the grid wattage (all combined phases) and as discussed before this causes 2 problems

  1. The minimum power going to car is 18A (6 x3), therefore any solar under 4500W cannot be used. In single phase, I can utilise solar above 1500W.
  2. After charging starts, emonevse calculations for eco mode wattage and how it applies this to the pilot seem wrong (out by a factor of 3). For example if 3000W excess is available, it will adjust the pilot by 12Amps (12A x 250V) to use it. In 3 phase, this is actually 12x3x250 that the car will take - 9000W

Issue 2 causes constant crazy adjustments to the pilot as it swings between grid import and export wildly as the adjustments it expects to make are three times bigger.

Looking at the code for the wifi firmware, there is a config option ‘is_threephase’ which seems to default to false and no way to change this I can see. This config option would seem to be used in divert.cpp and current_shapper.cpp and seems to be used to perform a x3 multiplier on the voltage (which I believe would fix the problem, having looked at the calculations it makes).

Is there a way to set this option or is it only possible at compile time ?

Thanks
Alan

2

Hi

Please use UI2 version of firmware as there’s no threephase switch on the v1 gui.
You don’t need anymore 3phase Evse firmware but it change nothing

The 3x6A limit comes from the PP specs and doesn’t depend on OpenEvse.
Therefore I advice to use then only one phase when charging over solar.

The Threephase switch should be activated from the UI ( /configuration / Evse ) each time you switch from mono or 3phase or sum calculation + divert etc will be wrong

You can try dev build from wifi firmware, but there’s still a bug with timezone that hasn’t been merged yet. You can also try my build for now as it includes all latests fixes:

https://drive.google.com/file/d/1Fd57zn8BgoqmNZAf6iVM6x_DgyOdzsyo/view?usp=sharing

l

3

Thank you for this.

I agree on using single phase when using solar… until openevse has a real 3 phase implementation (measuring on each phase and auto detect if 3 phase or single phase vehicle).
I plan to add a feature when pv divert is active it triggers a GPIO to which I will add a relay to switch a contactor to disconnect L2 & L3. I will also change is_threephase dynamically.
This will make it more useful in PV Divert situations and I’m sure someone smarter than me could make this behaviour configurable for those with larger PV arrays.

Alan

4

Thanks again Kip, just put your build on with the new GUI (impressive btw) and I’ll see how this goes.

Alan

5

I plan to add a feature when pv divert is active it triggers a GPIO to which I will add a relay to switch a contactor to disconnect L2 & L3. I will also change is_threephase dynamically.

This is the way yes.
I guess you could use one spi pin from the big connector wifi module gpio for that.
There’s not much to add on the fw to trigger the relay when switching is_threephase

6

Thanks. Ultimately, I will replace the single 4 pole contactor with 2 x 2 pole contactors.
One of the 2P contactor will have L1+N , the other L2 + L3.
The plan is to engage L2+L3 only when in divert mode.

Just waiting to generate > 4500W from PV to test your code… but the sun is hiding today.