New trends and requirements for dynamic security assessment

Power system security can be defined as the art and science of the "survival" of power systems. In order to ensure their survival, power systems are operated within certain power transfer limits, commonly referred to as security limits. If such limits depend on steady state feasibility or adequacy criteria, they are called steady-state or static security limits; otherwise, if such limits depend on transient or long-term stability criteria, these are referred to as dynamic security limits.