A contingency is considered a reportable disturbance if it is what percent of the MSSC?

A contingency is considered a reportable disturbance when it reaches a threshold of 80% of the Maximum System Voltage Stability Capability (MSSC). This threshold is significant because it indicates a level of disturbance that has the potential to impact system reliability significantly. If a contingency exceeds this percentage, it suggests a substantial deviation from expected operating conditions, which can lead to stability issues or other reliability concerns within the electrical grid.

This definition plays a crucial role in operational standards as it helps ensure that operators maintain awareness of the system's performance and facilitate necessary actions to mitigate risks. Reporting such disturbances is essential for fostering communication and taking preventive measures to protect the reliability of the power system.