Oscillating setpoint in Export mode when BOTH solar production and grid powers are published via MQTT #901
Description
Hello, first and foremost thanks for this GREAT project, both the hardware and the software are fantastic!
It seems that there is an issue in the divert control system, where the current setpoint keeps going up and down without settling. This happens when both solar power production AND grid import/export values are reported through MQTT.
I'm latest firmware (5.2.0). My current set-up is as follows (screenshots below):
- Self production: enabled
- Mode: Export
- Feed: +Import/-Export power from Home Assistant
I was also experimenting with Production mode, which is set up this way:
- Mode: Production
- Feed: PV production feed from the inverters via Home Assistant
But note that my currently selected mode is: Export.
In this scenario, the setpoint oscillates. I have compiled the firmware in debug mode (target openevse_wifi_tft_v1_dev) with the -D ENABLE_DEBUG_DIVERT option enabled. See an example trace and walkthrough below:
{"amp":19360,"voltage":233.5,"power":4520.56}
voltage = 233.50
Igrid_ie = -12.87
amps = 19.36
Igrid_ie = -32.23
reserve = 1.28
_available_current = 30.94
_smoothed_available_current = 33.07
_charge_rate = 30
min_charge_time_remaining = 0
{"claims_version":1}
{"divert_update":0,"grid_ie":-3004,"divert_active":true,"charge_rate":30,"trigger_current":6,"voltage":233.5,"available_current":30.94029979,"smoothed_available_current":33.0734289,"pilot":21,"min_charge_end":0}
{"pilot":30}
{"amp":19360,"voltage":233.5,"power":4520.56}
{"evse_connected":1,"amp":19360,"voltage":233.5,"power":4520.56,"pilot":30,"max_current":33,"temp":355,"temp_max":355,"temp1":false,"temp2":355,"temp3":false,"temp4":false,"state":3,"status":"active","flags":1344,"vehicle":1,"colour":6,"manual_override":0,"freeram":113556,"divertmode":2,"srssi":-63,"time":"2024-08-31T11:32:40Z","local_time":"2024-08-31T13:32:40+0200","offset":"+0200","uptime":228263,"session_elapsed":2249,"session_energy":2766.183585,"total_energy":627.4020846,"total_day":2.766183585,"total_week":14.66208464,"total_month":14.66208464,"total_year":14.66208464,"total_switches":50,"elapsed":2249,"wattsec":9958260.906,"watthour":627402.0846}
{"amp":19360,"voltage":233.5,"power":4520.56}
{"session_elapsed":2251,"session_energy":2769.037816,"total_energy":627.4049388,"total_day":2.769037816,"total_week":14.66493888,"total_month":14.66493888,"total_year":14.66493888,"total_switches":50}
{"amp":21780,"voltage":233.5,"power":5085.63}
{"amp":21780,"voltage":233.5,"power":5085.63}
voltage = 233.50
Igrid_ie = -12.87
amps = 21.78
Igrid_ie = -34.65
reserve = 1.28
_available_current = 33.36
_smoothed_available_current = 33.09
_charge_rate = 33
min_charge_time_remaining = 0
{"claims_version":2}
{"divert_update":0,"grid_ie":-3004,"divert_active":true,"charge_rate":33,"trigger_current":6,"voltage":233.5,"available_current":33.36029979,"smoothed_available_current":33.09193007,"pilot":30,"min_charge_end":0}
{"pilot":33}
{"amp":25300,"voltage":233.5,"power":5907.55}
{"amp":25300,"voltage":233.5,"power":5907.55}
{"amp":28820,"voltage":233.5,"power":6729.47}
{"voltage":232}
voltage = 232.00
Igrid_ie = 7.02
amps = 28.82
Igrid_ie = -21.80
reserve = 1.29
_available_current = 20.51
_smoothed_available_current = 33.03
_charge_rate = 20
min_charge_time_remaining = 0
{"claims_version":3}
{"divert_update":0,"grid_ie":1628,"divert_active":true,"charge_rate":20,"trigger_current":6,"voltage":232,"available_current":20.50965517,"smoothed_available_current":33.02917571,"pilot":33,"min_charge_end":0}
_pause_timer = 0
{"pilot":20}
{"session_elapsed":2257,"session_energy":2778.093795,"total_energy":627.4139948,"total_day":2.778093795,"total_week":14.67399486,"total_month":14.67399486,"total_year":14.67399486,"total_switches":50}
{"amp":25960,"voltage":232,"power":6022.72}
{"amp":25960,"voltage":232,"power":6022.72}
{"amp":18260,"voltage":232,"power":4236.32}
Walking through the trace:
- The trace starts out while the car it's charging at 19.36A
- A new +I/-E report comes via MQTT: -12.87A
- Car amps are subtracted from grid amps (-12.87 - 19.36 = -32.23), 1.28 amps are reserved, 30.94 available, thus new setpoint is: 30. So far so good.
- A new PV production report comes via MQTT, doesn't matter its value as it's not used because we are in
Exportmode. However, and I believe here is where the bug lies, the setpoint calculation code is called again here. - Car amps (21.78), which are on its way to ramping up to their current setpoint (30), are subtracted from the OLD grid amps, which hasn't updated yet (-12.87 - 21.78 = -34.65), 1.28 amps are reserved, 33.36 are available and new setpoint is 33.
- A new +I/-E report comes via MQTT: +7.02A as the previous setpoint overshot the actual available current.
- Car amps are subtracted from grid amps (7.02 - 28.82 = -21.8), 1.29 are reserved, 20.51 available thus the new setpoint is 20A.
This over-shooting / under-shooting the setpoint (30 -> 33 -> 20) keeps going on forever.
If I stop reporting PV production from Home Assistant, the issue resolves.
However, that would prevent me from using the Production mode.
I believe the solution should be to not call divert.update_state(); from MQTT callback if topic_string == mqtt_solar and we're in Export mode but I'm not aware of other implications.
I can raise a PR with a suggested solution for review.
Thanks again!
Export mode config screenshot
Production mode config screenshot
