Issue with HDVC AC computation when output terminal is disconnected

[vidaldid-rte]

Describe the current behavior

The Pull Request #957 contains a minimal test that reproduces the issue (ACHvdcTest)

Basically when a line is disconnected from the output terminal of an HVDC station, the HVDC still delivers atcive power to that dandling terminal (and consumes it from upward).

Expected result; No electricity flow to the dandling terminal (no current, no active power, no reactive power).

Describe the expected behavior

No response

Describe the steps

No response

Environment

No response

Relevant Log Output

No response

Extra Information

No response

[vidaldid-rte]

Fixed for VSC HVDC during security analysis and sensi analysis by #961

Proposal for HVDC in N_situation (disconnect in the IIDM network) in #965

[annetill]

Still missing: Lccs after contingency or remedial action management.