Abstract
AbstractBecause of the large power capacity of Taiwan High Speed Railway (HSR) train and the large as well as instantaneous power variation very short during the running of trains, the power consumption of Taiwan’s HSR could thus have significant impact on the power quality of Taiwan system. The thesis presents methodologies and results of numerical evaluation on the power quality of 7 main substations of HSR at the duty points, which includes that to examine whether the evaluated power quality could conform to the regulation.Two important premises for the analysis of power quality are the calculation of short-circuit capacity (SCC) at duty points and the estimation of time-variational traction load at main substations of HSR. The simulations are based on the planned Taipower 2006 transmission network and the route parameters as well as the planned train timetable of Taiwan HSR. Having obtained the SCC’s and the dynamic loads at 7 substations, this thesis then presents the methodologies and results of four different types of power quality.The three phase unbalance studies are comprised of three parts. In the first part, the thesis presents formulas for calculation of the three-phase voltage unbalance factor under the Scott connected transformer. By the formulas, the three-phase voltage unbalances at duty points are then evaluated under both normal and load transfer conditions. The letter refers to the condition when a HSR substation is outaged. In the second part, the thesis presents a method to estimate the negative sequence current injection into the utility generators by means of evaluation on the negative-sequence current distribution from HSR substation to the utility generators. Thirdly, the thesis presents an efficient way to estimate substation’s three-phase voltage unbalance which accounts for the influence of unbalance load from the remaining HSR substations.In voltage fluctuation analysis, the thesis presents formulas for the estimation of voltage fluctuation factor under the Scott connected transformer. Also the voltage fluctuation factors at HSR substations are evaluated under both normal and load transfer conditions.In harmonic analysis, the thesis calculates the amount of harmonic current injection into the Taipower system at HSR substations, and compares the amount of injection with the regulation, also on basis of the SCC and load at 7 substations.As to the power factor analysis, the thesis presents methodology for the estimation of power factor under Scott connected transformer. By the formula, the power factor at 7 substations are calculated under both normal and load trnsfer conditions.