From 0c4de4e5b92a36cdd11f603a4c229c31f58d91eb Mon Sep 17 00:00:00 2001
From: Dusan Vojacek <dusan.vojacek@direct.cz>
Date: Fri, 22 May 2026 16:09:11 +0200
Subject: [PATCH] fix infeasable na home-01

---
 backend/services/planning_engine.py          | 12 +++++-
 backend/tests/test_planning_dispatch_milp.py | 42 ++++++++++++++++++++
 docs/04-modules/planning.md                  |  2 +-
 3 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/backend/services/planning_engine.py b/backend/services/planning_engine.py
index c324123..6d6f967 100644
--- a/backend/services/planning_engine.py
+++ b/backend/services/planning_engine.py
@@ -1311,7 +1311,16 @@ def solve_dispatch(
                 prob += z_export[t] == 0
 
         # Ekonomické guardy: ceny v objective nestačí proti maskám / terminal SoC.
-        ref_buy_horizon = min(float(s.buy_price) for s in slots)
+        # Referenční buy jen z ne-záporných slotů: jinak jeden buy<0 v horizontu označí
+        # téměř všechny sloty jako „drahé“ (gi=0 pro dům) → Infeasible (home-01).
+        non_negative_buys = [
+            float(s.buy_price) for s in slots if float(s.buy_price) >= 0.0
+        ]
+        ref_buy_horizon = (
+            min(non_negative_buys)
+            if non_negative_buys
+            else min(float(s.buy_price) for s in slots)
+        )
         min_spread = float(degradation_cost_effective)
         for t in range(T):
             s = slots[t]
@@ -1339,6 +1348,7 @@ def solve_dispatch(
             skip_pv_store_block = (
                 float(s.pv_b_forecast_w) > 0
                 and not getattr(grid, "block_export_on_negative_sell", False)
+                and sell_t < 0
             )
             if (
                 not allow_pre_neg_pv_export
diff --git a/backend/tests/test_planning_dispatch_milp.py b/backend/tests/test_planning_dispatch_milp.py
index a2008ca..e725b44 100644
--- a/backend/tests/test_planning_dispatch_milp.py
+++ b/backend/tests/test_planning_dispatch_milp.py
@@ -1243,6 +1243,48 @@ class AutoPassiveSelfConsumptionTests(unittest.TestCase):
         )
         self.assertEqual(len(results), 2)
 
+    def test_negative_buy_in_horizon_does_not_block_all_grid_import(self) -> None:
+        """Jeden slot buy<0 nesmí z min(buy) udělat všechny sloty expensive_import (gi=0 pro dům)."""
+        base = datetime(2026, 5, 22, 13, 15, tzinfo=timezone.utc)
+        slots = [
+            PlanningSlot(
+                interval_start=base + timedelta(minutes=15 * i),
+                buy_price=-0.54 if i == 15 else (0.8 + i * 0.05),
+                sell_price=-0.06 if i < 3 else 2.0,
+                pv_a_forecast_w=0,
+                pv_b_forecast_w=max(0, 5000 - i * 100) if i < 25 else 0,
+                load_baseline_w=5316 if i < 10 else 3392,
+                ev1_connected=False,
+                ev2_connected=False,
+                allow_charge=(i == 15 or i < 3),
+                allow_discharge_export=False,
+                charge_acquisition_buy_czk_kwh=0.94,
+                future_sell_opportunity_czk_kwh=5.5,
+            )
+            for i in range(20)
+        ]
+        battery = _battery(uc_wh=64_000.0, min_pct=12.0, arb_pct=20.0)
+        battery.planner_terminal_soc_value_factor = 0.0
+        battery.planner_discharge_floor_percent = 5.0
+        hp = SimpleNamespace(rated_heating_power_w=0, tuv_min_temp_c=45.0, tuv_target_temp_c=55.0)
+        grid = SimpleNamespace(max_import_power_w=17_000, max_export_power_w=13_500)
+        vehicles = [
+            SimpleNamespace(max_charge_power_w=0, battery_capacity_kwh=1.0, default_target_soc_pct=80.0),
+            SimpleNamespace(max_charge_power_w=0, battery_capacity_kwh=1.0, default_target_soc_pct=80.0),
+        ]
+        results, _, _ = solve_dispatch(
+            slots,
+            battery,
+            hp,
+            grid,
+            [None, None],
+            vehicles,
+            float(battery.soc_max_wh),
+            50.0,
+            operating_mode="AUTO",
+        )
+        self.assertEqual(len(results), 20)
+
 
 class AutoPassiveNoLoadFollowingDischargeTests(unittest.TestCase):
     """AUTO bez allow_discharge_export: žádný export do sítě (Deye PASSIVE)."""
diff --git a/docs/04-modules/planning.md b/docs/04-modules/planning.md
index fad8aa9..181f593 100644
--- a/docs/04-modules/planning.md
+++ b/docs/04-modules/planning.md
@@ -17,7 +17,7 @@
   - **Load-first (Deye, AUTO):** proměnné `pv_ld` (PV → load+EV+TČ), `pv_sp` (přebytek), `bc_pv` / `bc_gi`. Plná bilance `pv_a + pv_b + gi + bd = load + ev + hp + bc + ge`; `bc_pv + ge_pv ≤ pv_sp`; `gi ≤ load + bc_gi`; mimo `allow_discharge_export`: `bd ≤ load − pv_ld` a **`pv_ld ≥ load − gi − bd`**. Snapshot: `load_first_enabled=true`. Test `LoadFirstDispatchTests`.
   - **Tvrdé výkonové limity site/baterie:** `gi ≤ site_grid_connection.max_import_power_w` (breaker); **`bc_pv + bc_gi ≤ asset_battery.max_charge_power_w`**; **`ge ≤ max_export_power_w`** (proměnná `ge`, platí `ge = ge_pv + ge_bat`); **`bd + ge_bat ≤ asset_battery.max_discharge_power_w`** (vybíjení do domu + export z baterie nesmí současně překročit BMS). Dříve LP dovoloval import+nabíjení a dvojnásobné nabíjení; u prodeje hrozilo současné `bd` a `ge_bat` až 2× max discharge — viz `SitePowerCapTests`.
   - **Hodnota FVE (PV store value):** `ge_pv = 0`, pokud `sell < future_sell_opportunity − degradation` (ne `charge_acquisition` — u fixního KV1 by jinak blokoval export při sell 2 Kč). **Před prvním `sell < 0` v horizontu:** při `sell ≥ 0` smí `ge_pv` až do `pv_sp` (strategie BA81: vyvézt přes poledne, pak nabít z FVE v záporném okně). Výjimka **nucený vent** jen plná baterie. Testy `Home01PvStoreValueTests`, `PreNegativeSellExportTests`.
-  - **Drahý nákup → vlastní spotřeba z baterie:** mimo `allow_charge` platí `bd + pv_ld ≥ load_baseline + hp[t]` a `gi ≤ EV + hp[t]` (ne `hp_rated` — jinak infeasible když TČ v slotu neběží). Platí při `buy > min(buy horizontu)` **nebo** `buy > charge_acquisition + degradace`. Testy `AutoPassiveSelfConsumptionTests`, `test_fixed_tariff_expensive_slot_discharges_not_grid_load`, `test_expensive_slot_uses_hp_variable_not_rated`.
+  - **Drahý nákup → vlastní spotřeba z baterie:** mimo `allow_charge` platí `bd + pv_ld ≥ load_baseline + hp[t]` a `gi ≤ EV + hp[t]` (ne `hp_rated` — jinak infeasible když TČ v slotu neběží). Referenční buy = **min buy ≥ 0** v horizontu (záporný OTE slot jinak označí všechny sloty jako drahé → `gi=0` pro dům → Infeasible na home-01). Platí při `buy > ref_buy + degradace` **nebo** `buy > charge_acquisition + degradace`. Testy `AutoPassiveSelfConsumptionTests`, `test_negative_buy_in_horizon_does_not_block_all_grid_import`, `test_expensive_slot_uses_hp_variable_not_rated`.
   - **Pole B při sell&lt;0 (home-01):** pokud `block_export_on_negative_sell = false`, LP nesmí vynutit `ge_pv = 0` (přebytek neriťitelného PV B). KV1 s `block_export = true` jen curtail A / nabíjení.
   - **`ref_buy_min` (brána exportu):** `min(buy_price)` horizontu — jen „existuje levný nákup?“, **ne** průměrná cena nabití přes hodiny. Export sloty: `sell > ref_buy_min + degradation` (spot). Viz [`planning-arbitrage-accounting.md`](planning-arbitrage-accounting.md).
   - Pokud `energy_to_fill <= 0` nebo `charge_slot_buffer = 0`: všechny sloty povoleny.