Stabilty of Power Transmission Capability of HVDC system using facts controllers

The necessity to deliver cost effective energy in the power market has become a major concern in this emerging technology era. Therefore, establishing a desired power condition at the given points are best achieved using power controllers such as the well known High Voltage Direct Current (HVDC) and Flexible Alternating Current Transmission System (FACTS) devices. High Voltage Direct Current (HVDC) is used to transmit large amounts of power over long distances. The factors to be considered are Cost, Technical Performance and Reliability. A Flexible Alternating Current Transmission System (FACTS) is a system composed of static equipment used for the AC transmission of electrical energy. It is meant to enhance controllability and increase power transfer capability of the network. It is generally a power electronics-based system. A Unified Power Flow Controller (or UPFC) is a FACTS device for providing fast-acting reactive power compensation on high-voltage electricity transmission networks. The UPFC is a versatile controller which can be used to control active and reactive power flows in a transmission line. The focus of this paper is to identify the improved Power Transmission Capability through control scheme and comprehensive analysis for a Unified Power Flow Controller (UPFC) on the basis of theory, computer simulation. The conventional control scheme cannot attenuate the power fluctuation, and so the time constant of damping is independent of active- and reactive-power feedback gains integrated in its control circuit. The model was analyzed for different types of faults at different locations, keeping the location of UPFC fixed at the receiving end of the line, With the addition of UPFC, the magnitude of fault current and oscillations of excitation voltage reduces. Series and Shunt parts of UPFC provide series and shunt injected voltage at certain different angles.