Preface
Power system instabilities are unacceptable to society. Indeed, recent major blackouts in North America and in Europe have vividly demonstrated that power interruptions, grid congestions, or blackouts significantly impact the economy and society. At present, stability analysis programs routinely used in utilities around the world are based mostly on ste
by-step numerical integrations of power system stability models to simulate system dynamic behaviors. This off-line practice is inadequate to deal with current operating environments and calls for online evaluations of changing overall system conditions.
Several significant benefits and potential applications are expected from the movement of transient stability analysis from the off-line mode to the online operating environment. However, this movement is a challenging task and requires several breakthroughs in measurement systems, analytical tools, computation methods, and control schemes. An alternate approach to transient stability analysis employing energy functions is called the direct method, or termed the energy function-based direct method. Direct methods offer several distinctive advantages. For example, they can determine transient stability without the time-consuming numerical integration of a (postfault) power system. In addition to their speed, direct methods can provide useful information regarding the derivation ...
