Minimization of system harmonics using facts controllers to enhance controllability and increase power transfer capability

Abstract

Power electronic loads introduce harmonic currents into the utility power system. This work presents harmonic reduction techniques, which satisfy the current harmonic limits. The techniques which are considered here, are active filter, hybrid filter and zig-zag transformer rectifier as FACTS controllers. According to rectifying or inverting operation of HVDC converters, reactive power is absorbed from the bus in which the converter is connected. In either case of operation reactive power compensation in AC side of converters is quite necessary. In addition to reactive power compensation, due to nonlinear behavior of power electronics converters. The characterized and uncharacterized harmonics are produced in both sides of links and often they are filtered by passive and active filters. There has been a great growth in application of AC/DC links and therefore the harmonic reduction and reactive power compensation method should be improved but this increases the complexity in hardware and control strategies and also increases the total cost of links. In this work the new switching patterns of capacitance for achieving continuously controlled compensation and reduction of harmonics produced by HVDC converters are described. This method has a simple structure and easier switching control strategies compared to active filter configuration alone. newlineThis work presents Minimization of harmonics using power active filters, which satisfy the current harmonic suppression for the improvement in power quality. The techniques considered include here is the shunt and series power active filters. Modern high-speed rail traction systems exert heavy and complex loadings on supply grids. Usually, power is taken between two phases, thereby causing substantial unbalance between phases in networks originally not at all built for this kind of operation. Unless remedied, the result will be deterioration of power quality, not only harmful to the traction system itself, but also prone to spreading through the supply grid, disturbing other users o