In this paper, a novel neuro-fuzzy based method combined with a feature selection technique is proposed for online dynamic voltage stability status prediction of power system. This technique uses synchronized phasors measured by phasor measurement units (PMUs) in a wide-area measurement system. In order to minimize the number of neuro-fuzzy inputs, training time and complication of neuro-fuzzy ...

The voltage instability of power system often occurs when the active power on one or more weak branches exceeds its transfer capability. This paper presents a preventive control model for voltage stability using the active power transfer capabilities of weak branches as static voltage stability margin constraints. A local line-based voltage stability index is used to determine the critical cont...

This paper presents a voltage stability constrained optimal power flow that is expressed via a bilevel programming framework. The inner objective function is dedicated for maximizing voltage stability margin while the outer objective function is focused on minimization of total production cost of thermal units. The original two stage problem is converted to a single level optimization problem v...

Series of blackouts encountered in recent years in power system have been occurred because either of voltage or angle instability or both together was not detected within time and progressive voltage or angle instability further degraded the system condition, because of increase in loading. This paper presents the real-time assessment methodology of voltage stability using Phasor Measurement Un...

The voltage instability phenomena occur in both transmission systems and distribution systems. The weakening of voltage stability level will limit the growth of load served by distribution companies. Voltage instability in power distribution systems could lead to voltage collapse and thus power blackouts. The integration of distributed generation (DG) in the distribution system has increased to...

This paper provides a novel hierarchical control for VSI-based microgrids. The advantage of the provided control scheme is to maintain the frequency and voltage stability and load sharing against large-signal disturbances. A hierarchical control, consisting of three levels, is described. A new control loop based on PI controller, is presented. The new control loop has a great impact on increasi...

Abstract: Voltage instability is a major threat for security of power systems. Preserving voltage security margin at a certain limit is a vital requirement for today’s power systems. Assessment of voltage security margin is a challenging task demanding sophisticated indices. In this paper, for the purpose of on line voltage security assessment a new index based on the correlation characteristic...

On-line voltage stability monitoring based on the local phasor measurements is a very active branch of voltage stability assessment presently. It can be divided into local bus measurements based methods and local branch measurements based methods. The latter can be classified into three versions. They are voltage stability indices based on the feasible solution region of quadratic equation of r...