Fix PV inverters power distribution (#1028)

To exclude PV inverters that haven't sent any data since startup. The
power distributor crashed because it tried to get data from a component
that had no data.

Note that this is port of a patch-fix that was released in v1.0.0-rc602,
but I have slightly changed some log messages as this was done in a
rush.

Author: daniel-zullo-frequenz

RELEASE_NOTES.md

@@ -7,17 +7,17 @@
 ## Upgrading
 
 - The `frequenz.sdk.microgrid.*_pool` methods has been renamed to `new_*_pool`, to make it explicit that they create new instances of the pool classes.
-  + `battery_pool` -> `new_battery_pool`
-  + `ev_charger_pool` -> `new_ev_charger_pool`
-  + `pv_pool` -> `new_pv_pool`
+  - `battery_pool` -> `new_battery_pool`
+  - `ev_charger_pool` -> `new_ev_charger_pool`
+  - `pv_pool` -> `new_pv_pool`
 
 - The following component metric streams have been renamed to clarify that they stream per-phase values:
-  + `frequenz.sdk.microgrid.`
-    * `voltage` -> `voltage_per_phase`
-    * `grid.current` -> `grid.current_per_phase`
-    * `ev_charger_pool.current` -> `ev_charger_pool.current_per_phase`
+  - `frequenz.sdk.microgrid.`
+    - `voltage` -> `voltage_per_phase`
+    - `grid.current` -> `grid.current_per_phase`
+    - `ev_charger_pool.current` -> `ev_charger_pool.current_per_phase`
 
-* Passing a `request_timeout` in calls to `*_pool.propose_power` is no longer supported.  It may be specified at application startup, through the new optional `api_power_request_timeout` parameter in the `microgrid.initialize()` method.
+- Passing a `request_timeout` in calls to `*_pool.propose_power` is no longer supported.  It may be specified at application startup, through the new optional `api_power_request_timeout` parameter in the `microgrid.initialize()` method.
 
 - Power distribution results are no longer available through the `power_status` streams in the `*Pool`s.    They can now be accessed as a stream from a separate property `power_distribution_results`, which is available from all the `*Pool`s.
 
@@ -42,3 +42,4 @@
 - Fixed typing ambiguities when building composite formulas on streaming data.
 - Fixed a bug that was causing the `PowerDistributor` to exit if power requests to PV inverters or EV chargers timeout.
 - Fix handling of cancelled tasks in the data sourcing and resampling actor.
+- Fix PV power distribution excluding inverters that haven't sent any data since startup.

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

@@ -121,11 +121,19 @@ 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(
+                    "Excluding PV inverter %s from power distribution due to "
+                    "lack of data since 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
@@ -138,6 +146,10 @@ async def distribute_power(self, request: Request) -> None:
         )
 
         num_components = len(working_components)
+        if num_components == 0:
+            _logger.error("No PV 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 or equal to 0.0, we can stop allocating further, and set 0