Reflections on stability technology for reducing risk of system collapse due to cascading outages

This paper aims at putting forward viewpoints regarding the use of stability technology to prevent and control cascading outages by examining recent blackout events. Based on the inquiry reports of the 2011 Southwest America blackout and the 2012 India power blackouts, event evolution features are first summarized from a stability perspective. Then a comparative analysis is conducted so as to propose suggestions of effective measures, either preventive or emergency, which could have avoided the blackouts. It is shown that applications of several mature technologies can create opportunities of preventing or interrupting the cascading development. These include offline dynamic simulation, online stability analysis and preventive control, real-time situational awareness and automatic emergency control. Further R & D directions are given to address the challenges of modern power systems as well. They cover system fault identification criterion of protection and control devices, verification of adaptability of control effect to system operating conditions, real-time operational management of emergency control measures and improvement of simulation accuracy.