Objectives

11.1 Role of wide area protection (WAPS)

11.2 Achievements with WAPS on power systems

11.3 Power system phenomena with possible WAPS solutions

11.4 Classification of WAPS

11.5 Detailed description of various WAPS

11.6 Voltage stability assessment (VSA) guidelines

11.7 On-line VSA execution modes

11.8 On-line VSA requirements

11.9 Interfaces requirements

11.10 The implementation of wide area protection

11.11 References

Power systems are planned, built and operated in such a manner that customers should not be affected, within given limits, by possible contingencies. However it may be affected by more severe disturbances resulting from multiple and simultaneous outages with possible conjunction of protection and regulation failures leading to 

• stability problems,
• voltage collapse and
• large frequency deviation.

The result may be a system collapse for the whole network or large part of it.

The objective of this section is to explain what preventive and  curative measures should be foreseen in terms of defense plans and WAPS initiated control actions  to prevent major incidents to occur or to limit their consequences.