Long distance AC transmission is often subject to stability problems , which limits the transmission capability.Large interconnected power systems often suffer from weakly damped swings between synchronous generators and subsystems.This paper presents two methods , based on the use of nonlinear system model , to improve transient stability and damping of power swings using UPFC. A statevariable...

In developing countries, a pressure associated with economical and environmental constraints has forced the power utilities to meet the future demand by fully utilizing the existing resource of transmission facilities without building new lines. Flexible alternating current transmission systems (FACTS) devices are used to control the phase angle, voltage and impedance of high voltage AC lines. ...

Power systems form one of the largest and most complex technical systems. Changes of load parameters may lead to so called bifurcations, resulting in nonlinear phenomena like voltage collapse or interarea oscillations. Special software tools are able to simulate these systems and to identify bifurcations. This paper presents a systematic approach to determine gain factors of Flexible AC Transmi...

This paper describes how multi-agent system technology can be used as the underpinning platform for voltage control in power systems. In this study, some FACTS (flexible AC transmission systems) devices are properly designed to coordinate their decisions and actions in order to provide a coordinated secondary voltage control mechanism based on multi-agent theory. Each device here is modeled as ...

In this paper power quality of 3-bus solar-based hybrid system has been presented (where one or more than distribution generator unit is connected to the grid). The injection solar into grid-connected systems creates problems such as current consistency, electrical fluctuations, and inefficient demand. A control strategy based on a real-time self-regulation method for autonomous microgrid opera...

With the increasing electric power demand, power systems can face to stressed conditions, the operation of power system becomes more complex, and power system will become less secure. Moreover, because of restructuring, the problem of power system security has become a matter of concern in deregulated power industry. Better utilization of available power system capacities by Flexible AC Transmi...

Flexible AC transmission system; Static synchronous compensator (STATCOM); Optimal reactive power dispatch (ORPD); Chemical reaction optimization (CRO); Transmission loss Abstract Optimal reactive power dispatch (ORPD) problem has a significant influence on optimal operation of power systems. However, getting optimal solution of ORPD problem is a strenuous task for the researchers. The inclusio...

Flexible ac Transmission Systems (FACTS) devices have emerged in power system because of the development of power electronics components for high voltage and power. The FACTS devices provide higher controllability in power systems by means of power electronic devices. Several FACTS equipments have been already introduced for various applications worldwide, and new types of FACTS are in the stag...