A new wide area protection system

As a result of recent developments in power markets, power utilities are forced to increase the reliability and profitability of their power systems. Their networks have to be operated closer to limits, which may lead to frequent outages due to unreliable assessment of stability limits. A new wide area protection system is introduced to extend the system operational limits, i.e. operate the system closer to the physical limits, without any investments in high voltage equipment. The system protects the entire power system against blackouts due to several kinds of instabilities. With dynamic supervision of the system´s stability and the optimization of transmission capability, it is a cost-effective system that complements installed protection and control systems. Phasor measurement information is transmitted to a system protection center, where snapshots of the transient system status are online available. This dynamic system´s view opens up new applications to assess and actively remain system´s stability in case of voltage or angle instability and oscillations. After the introduction of the system setup of the new wide area protection system, a new voltage stability prediction algorithm for transient system states and cascaded contingencies is presented. The applicability of the algorithm is shown with the example of a test system and a real power system