A survey of current practices for transient voltage dip/sag criteria related to power system stability

Role of Induction Motors in Voltage Instability and Coordinated Reactive Power Planning

“…As far as the performance measure for dynamic stability phenomena is concerned, in [11] it is stated that the needs of the industry related to voltage dips/sags for power system stability fall under two main scenarios. One is the traditional transient angle stability where voltage "swing" during electromechanical oscillations is the concern.…”

“…For a large power system, this method requires computing integrals of a set of high dimension differential algebraic equations. An alternative to calculate the sensitivities is using numerical approximation [25], as shown by equation (11). This procedure of sensitivity calculation by numerical approximation requires repeated simulations of the system model for the SVC capacitive limits Bsvc and Bsvc+∆Bsvc.…”

“…The dynamic devices are more expensive power electronics based fastacting devices such as static VAR compensators (SVC), Static Synchronous Compensator (STATCOM), Unified Power Flow Controller (UPFCs) that exert continuous feedback control action and have better controllability and repeatability of operation. While MSCs are able to strengthen a power system against long term voltage instability issues [1], transient voltage dip and slow voltage recovery issues (influenced by electric load dynamics) is most effectively addressed by fast responding dynamic VAR sources [10,11,12]. While, past methods allocate static and dynamic VAR sources sequentially for one contingency at a time, the key to solving transmission system problems in the most cost-effective way will be to coordinate reactive power requirements simultaneously under many contingencies for both static and dynamic problems.…”

Derivation and application of sensitivities to assess transient voltage sags caused by rotor swings

“…Furthermore, the assessment addresses power quality issues and short-term voltage stability. In [7], the authors present a survey of current practices for transient voltage sag criteria related to power system stability.…”

Early prediction of transient voltage sags caused by rotor swings

“…In the recent publication [5], the authors developed a method for contingency filtering and ranking with respect to voltage dips using sensitivities. A survey of current practices for transient voltage sag criteria related to power system stability was presented in [6] In the present paper voltage sags are investigated with focus on system dynamics rather than power quality. The aim is to derive a method, which in real-time allows early and accurate prediction of voltage sags caused by angular separation.…”