Add a new component category for precharge modules

Precharging involves gradually ramping up the DC voltage to prevent any
potential damage to sensitive electrical components like capacitors.
While many inverters and batteries come equipped with in-built precharging
mechanisms, some may lack this feature. In such cases, we need to use
external precharging modules.

Signed-off-by: Tiyash Basu <[email protected]>

Author: tiyash-basu-frequenz

RELEASE_NOTES.md

@@ -16,6 +16,9 @@
 * Added a new variant `COMPONENT_CATEGORY_RELAY` to the `ComponentCategory`
   enum.
 
+* Added a new variant `COMPONENT_CATEGORY_PRECHARGE_MODULE` to the
+  `ComponentCategory` enum.
+
 ## Bug Fixes
 
 <!-- Here goes notable bug fixes that are worth a special mention or explanation -->

proto/frequenz/api/common/components.proto

@@ -51,6 +51,14 @@ enum ComponentCategory {
   // They are generally placed in front of a component, e.g., an inverter, to
   // control whether the component is connected to the grid or not.
   COMPONENT_CATEGORY_RELAY = 11;
+
+  // A precharge module.
+  // Precharging involves gradually ramping up the DC voltage to prevent any
+  // potential damage to sensitive electrical components like capacitors.
+  // While many inverters and batteries come equipped with in-built precharging
+  // mechanisms, some may lack this feature. In such cases, we need to use
+  // external precharging modules.
+  COMPONENT_CATEGORY_PRECHARGE_MODULE = 12;
 }
 
 // Enumerated battery types.