Fix PV power distribution (#1015)

To exclude PV inverters that didn't send any data. The power distributor
crashes because it tried to get data from a component that didn't send
any data since the application startup.

Author: daniel-zullo-frequenz

RELEASE_NOTES.md

@@ -2,4 +2,4 @@
 
 ## Bug Fixes
 
-- Fix getting reactive power from meters, inverters and EV chargers.
+- Fix PV power distribution excluding inverters that haven't sent any data since the application started.

src/frequenz/sdk/actor/power_distributing/_component_managers/_pv_inverter_manager/_pv_inverter_manager.py

@@ -113,11 +113,19 @@ async def distribute_power(self, request: Request) -> None:
             raise ValueError(
                 "Cannot distribute power to PV inverters without any inverters"
             )
-        working_components = list(
-            self._component_pool_status_tracker.get_working_components(
-                request.component_ids
-            )
-        )
+
+        working_components: list[int] = []
+        for inv_id in self._component_pool_status_tracker.get_working_components(
+            request.component_ids
+        ):
+            if self._component_data_caches[inv_id].has_value():
+                working_components.append(inv_id)
+            else:
+                _logger.warning(
+                    "Exclude inverter %s from distribution, because it didn't "
+                    "send any data since the application startup.",
+                    inv_id,
+                )
 
         # When sorting by lower bounds, which are negative for PV inverters, we have to
         # reverse the order, so that the inverters with the higher bounds i.e., the
@@ -130,13 +138,18 @@ async def distribute_power(self, request: Request) -> None:
         )
 
         num_components = len(working_components)
+        if num_components == 0:
+            _logger.error("No inverters available for power distribution. Aborting.")
+            return
+
         for idx, inv_id in enumerate(working_components):
             # Request powers are negative for PV inverters.  When remaining power is
             # greater than 0.0, we can stop allocating further.
             if remaining_power > Power.zero() or is_close_to_zero(
                 remaining_power.as_watts()
             ):
-                break
+                allocations[inv_id] = Power.zero()
+                continue
             distribution = remaining_power / float(num_components - idx)
             inv_data = self._component_data_caches[inv_id]
             if not inv_data.has_value():

tests/timeseries/_pv_pool/test_pv_pool_control_methods.py

@@ -131,7 +131,7 @@ async def _recv_reports_until(
             if check(report):
                 break
 
-    async def test_setting_power(
+    async def test_setting_power(  # pylint: disable=too-many-statements
         self,
         mocks: _Mocks,
         mocker: MockerFixture,
@@ -260,3 +260,24 @@ async def test_setting_power(
             mocker.call(inv_ids[2], -30000.0),
             mocker.call(inv_ids[3], -30000.0),
         ]
+
+        # Setting 0 power should set all inverters to 0
+        set_power.reset_mock()
+        await pv_pool.propose_power(Power.zero())
+        await self._recv_reports_until(
+            bounds_rx,
+            lambda x: x.target_power is not None and x.target_power.as_watts() == 0.0,
+        )
+        self._assert_report(
+            await bounds_rx.receive(), power=0.0, lower=-100000.0, upper=0.0
+        )
+        await asyncio.sleep(0.0)
+
+        assert set_power.call_count == 4
+        inv_ids = mocks.microgrid.pv_inverter_ids
+        assert sorted(set_power.call_args_list, key=lambda x: x.args[0]) == [
+            mocker.call(inv_ids[0], 0.0),
+            mocker.call(inv_ids[1], 0.0),
+            mocker.call(inv_ids[2], 0.0),
+            mocker.call(inv_ids[3], 0.0),
+        ]