glenn schrooyenandClaude Opus 5
147456c2a2
A Belgian P1 meter publishes two UNSIGNED registers, not one signed figure. Until now the add-on asked the installer to bridge that gap with a template sensor, which put the sign convention of the whole control loop in a text box. This moves it into the EMS: net = import - export, derived once, in one place, with a test that fails if anyone inverts it. Two transports behind one contract, chosen by `meter_source`: the HA WebSocket subscribing to the DSMR integration's entities, and MQTT on a configurable topic. Everything downstream reads P1Ingest, so switching is a config edit. `meter_source: off` is the default and keeps the existing meter_entity path, so no installed system changes until it opts in. The other half is the timestamp. Every accepted sample is stamped at ingest with a monotonic clock, `meter_max_age_s` is applied to it, and the age is published as sensor.p1_sample_age_s for the ESP32's stale-input watchdog. That entity is recomputed against the clock every second rather than only when a telegram lands, because HA pushes state only on change: a meter frozen at a constant reading emits nothing and looks, to anything watching the value, exactly like a meter that has died. The age tells them apart. Deliberately absent: any fallback to an inverter-side power figure. The inverter's own AC power correlates 0.998 with battery power and 0.09 with the real meter, so failing over to it means regulating against your own output. A gap stays a gap - a reconnect emits no synthetic sample, and a rejected telegram never resolves to 0 W or refreshes the timestamp. Quarter-hour averages are time-weighted over clock-aligned blocks rather than a mean of samples, so a cadence change cannot bias the capacity-tariff figure, and only offtake is accumulated so a quarter of pure export averages to 0 kW. Per-phase import is kept separately: on an unbalanced three-phase load the phase sum and the connection net are different numbers, and only one of them is billed. test_p1.py: 99 checks, runnable with a bare interpreter and no meter. Includes an end-to-end run of the HA transport against a fake Home Assistant websocket. Stacked on SAFETY-04; nothing here touches control.py. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Du77usMj8XNKNFZGmUiWDa
192 lines
8.8 KiB
Markdown
192 lines
8.8 KiB
Markdown
# GoodWe RS485 Controller
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Drives a GoodWe ES/BP battery inverter over its RS485 meter bus: holds net grid
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exchange at zero, and runs a monthly battery maintenance cycle so the BMS can
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balance cells and recalibrate its coulomb counter.
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Installers: read `FIELD-GUIDE.md` in the repository. It is not optional reading —
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it contains the commissioning gates and the failure modes.
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## Before you start
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You need:
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- A GoodWe **ES / BP family** inverter (AA55 / RS485 meter-bus generation)
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- The vendor's meter-emulating controller **disconnected** from the bus
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- A T-CAN485 (ESP32) flashed with `firmware/goodwe-master.yaml`
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- A grid-power sensor already working in Home Assistant, updating every ~5–10 s
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## The safety model, in short
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The inverter **holds its last command forever** — it has no meter-timeout. So:
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- The ESP32 commands 0 W if this add-on stops refreshing for ~30 s, and keeps
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commanding it.
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- This add-on commands 0 W when its inputs go missing, when you stop control,
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and when it shuts down.
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- The **optional RS485 e-stop** is the only thing that covers this machine
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dying. Without it, a failed host leaves the battery latched at its last
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command until someone intervenes.
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**If anything looks wrong: stop the add-on.** That commands 0 W and the
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hardware holds it there.
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## Configuration
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### Sources
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| option | required | meaning |
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|---|---|---|
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| `meter_entity` | yes | Net grid power. **Positive must mean importing** |
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| `meter_invert` | | Flip the sign if the meter reports the other way |
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| `soc_entity` | yes | Battery state of charge — use the **ESP32's own read** |
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| `batt_entity` | yes | Battery power — again the ESP32's read, `+` = discharging |
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| `batt_invert` | | Flip if needed |
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| `setpoint_entity` | yes | The ESPHome `number.*_goodwe_setpoint_w` |
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Use the ESP32's readings rather than the inverter's cloud or dongle sensors:
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those serve cached values, and a stale reading here ends the maintenance charge
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phase having charged nothing.
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### P1 meter ingestion
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`meter_entity` above expects one signed sensor, which usually means a template
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someone wrote by hand. A Belgian P1 meter does not publish one: it publishes two
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**unsigned** registers, consumption and injection. Setting `meter_source` moves
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that subtraction into the add-on, where it is done once and tested, and replaces
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`meter_entity` entirely.
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| option | default | meaning |
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| `meter_source` | `off` | `off` keeps `meter_entity`. `ha_dsmr` subscribes to the DSMR integration over the HA WebSocket; `mqtt_p1` reads a topic |
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| `meter_phases` | 1 | 1 or 3. Must match the telegram, or every telegram is rejected and logged |
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| `meter_max_age_s` | 30 | Beyond this the reading is stale: grid power reads as *missing*, and the existing failsafe commands 0 W |
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| `meter_mqtt_topic` | | `mqtt_p1` only |
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| `p1_import_entity` | | The **unsigned** consumption sensor. Do not point this at a signed template |
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| `p1_export_entity` | | The **unsigned** injection sensor |
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| `p1_phase_import_entities` | `[]` | L1..L3, in order. Needed for the capacity-tariff peak on a three-phase connection |
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| `p1_phase_export_entities` | `[]` | L1..L3, in order |
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There is **no fallback to an inverter-side power figure**, deliberately. The
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inverter's own AC power tracks its battery almost perfectly and the real meter
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hardly at all, so a controller that failed over to it would be regulating
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against its own output while looking healthy.
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The `mqtt_p1` payload is one JSON object per telegram, and the schema is strict —
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a key it does not recognise is a telegram from something other than what was
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tested, and guessing a key here means guessing a kilowatt:
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```json
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{"import_w": 1234.0,
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"export_w": 0.0,
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"phases": [{"import_w": 500, "export_w": 0},
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{"import_w": 400, "export_w": 0},
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{"import_w": 334, "export_w": 0}],
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"timestamp": "2026-08-24T18:00:05+02:00"}
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```
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`phases` and `timestamp` are optional; `timestamp` must carry a UTC offset. Where
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it is present it is used for the age, which is what stops a retained message
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replayed on reconnect from presenting a ten-minute-old reading as current.
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#### `sensor.p1_sample_age_s`
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Published over MQTT discovery whenever a broker is available: **seconds since the
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newest accepted telegram**, refreshed every second rather than only when a
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telegram lands. The ESP32's stale-input watchdog subscribes to this exact entity
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id, so do not rename it.
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The reason it is recomputed against the clock is that Home Assistant only pushes
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a state when the state *changes*. A meter sitting at a genuinely constant reading
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emits nothing, which is indistinguishable — to anything watching the value — from
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a meter that has died. Watching the age instead separates the two: it climbs when
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telegrams stop and resets when they arrive, whatever the reading says.
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### Control
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| option | default | meaning |
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| `max_w` | 2000 | Hard limit on what may be commanded. Start low, raise after commissioning |
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| `gain` | 0.6 | Correction per cycle. **At the limit — do not raise** |
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| `slew_w` | 1000 | Maximum change per cycle |
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| `deadband_w` | 15 | Ignore errors smaller than this |
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| `target_grid_w` | -10 | What the meter should rest at. Negative = a slight export |
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| `step_w` | 10 | Quantisation |
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| `saturation_w` | 500 | Divergence that counts as "the inverter is at a limit" |
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| `saturation_cycles` | 3 | How many consecutive cycles before freezing. **Do not set to 1** |
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| `integrator_max_w` | 3000 | Bound on the loop's accumulator, separate from `max_w`. Caps how much stale error can be waiting to unwind when the sign flips. **Keep it above `max_w`, and do not set it equal to `max_w`** |
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| `heartbeat_s` | 10 | Refresh interval; must stay well under the firmware watchdog |
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| `stale_input_s` | 15 | How long inputs may be missing before commanding 0 W |
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| `auto_start` | false | Start controlling on boot (only after commissioning) |
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#### Why `target_grid_w` is not zero
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The deadband is a one-way ratchet: any resting point inside it holds until
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something disturbs it. Import and export are **separate registers on the
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meter**, so a rest point of +14 W is billed for every second it holds and no
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amount of export cancels it - 14 W all day is 0.34 kWh.
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Biasing the target below zero moves that residue into the export register,
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which is not billed. The resting band becomes `target ± deadband`, so:
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| `target_grid_w` | resting band | worst billed leak | export given away |
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| 0 | -15 … +15 W | ~15 W (0.35 kWh/day) | none |
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| **-10** | -25 … +5 W | ~5 W (0.12 kWh/day) | ~10 W |
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| -15 | -30 … 0 W | none | ~15 W (0.36 kWh/day) |
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Set it to `-deadband_w` if injection is worth nothing to you and you would
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rather give the energy away than buy it back. Set it to `0` if you are paid
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properly for export, or if you are debugging and want the loop centred.
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⚠️ This is a **billing** knob, not a speed knob. If import is arriving in
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bursts rather than as a trickle, the cause is tracking lag, and this will not
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help - see "Why the tuning is what it is".
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### Maintenance
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| option | default | meaning |
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| `maintenance_enabled` | false | Enable the monthly cycle |
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| `maintenance_interval_days` | 28 | Minimum gap between cycles |
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| `maintenance_start_hour` | 10 | Hour of day a due cycle begins |
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| `maintenance_discharge_w` | 2500 | Drain rate (exports the surplus) |
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| `maintenance_charge_w` | 2500 | Charge ceiling, capped again by peak headroom |
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| `maintenance_soc_floor` | 11 | Drain target — stay just above the inverter's own floor |
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| `maintenance_soc_target` | 99 | Charge target |
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| `maintenance_hold_min` | 120 | Hold at full so the BMS can balance |
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### Tariff (all optional)
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| option | meaning |
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| `peak_forecast_entity` | Quarter-hour demand forecast, for capacity-tariff markets. Empty = no cap |
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| `peak_cap_w` | The site's capacity-tariff target |
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| `price_now_entity`, `price_avg_entity` | Dynamic tariff. Empty = never force a paid grid top-up |
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On a capacity-tariff site the maintenance charge is capped by the headroom left
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under `peak_cap_w`, and if the forecast goes over the cap the charge-only clamp
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is dropped so the battery can shave the peak instead. Money outranks the
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maintenance schedule.
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### Site
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| option | meaning |
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| `estop_fitted` | Whether the RS485 e-stop is installed. Drives the warning banner |
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| `log_level` | `trace`/`debug`/`info`/`warning`/`error` |
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## The Web UI
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The ingress panel shows live values, why the controller is commanding what it
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is, and a **Commissioning** checklist that names any problem in words. It also
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carries the three buttons: start/stop control, force a maintenance cycle, and
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abort one.
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## Status entities
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If an MQTT broker is available the add-on publishes setpoint, grid power,
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battery power, state of charge, maintenance phase and controller status by MQTT
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discovery. This is observability only — the controller works fine without a
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broker, and MQTT problems can never affect control.
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