Describe the current behavior

The targetV of a generator is the target voltage by a local or remote regulating terminal. No local targetV can be defined for the generator.

Describe the expected behavior

A generator has a localBackupTargetV available, that can be null or set by the user for a local regulating control.

Describe the motivation

Be able to get a set local targetV of a generator besides the targetV that can be set for remote regulation.

Extra Information

The generator has a new attribute localBackupTargetV in IIDM that can be null or set. If set, when passing from remote to local regulation, the targetV should be updated with the localBackupTargetV if present.
When creating the generator it is possible to:

• set the target V like before: setTargetV(v) => set the targetV and set localBackupTargetV to NaN
• set both targets: setTargetV(v, vLocaleBackup) => set the targetV and localBackupTargetV

It is not wanted to be able to set only the localBackupTargetV: no method setLocalBackupTargetV()