Specification of minimum short circuit capacity for three-phase unbalance evaluation of high-speed railway power system

In the paper, firstly, we present an efficient computational algorithm to evaluate the short circuit capacity distribution at a substation bus, and on the basis of this distribution to specify the minimum short circuit capacity for the year under evaluation. Secondly, we estimate the maximum traction load at seven 161 kV substations of Taiwan high-speed railway system which is now under planning. Thirdly, using the maximum traction load and the minimum short circuit capacity derived, we estimate the maximum unbalance of the 3/spl phi/ voltage at these seven 161 kV substations, and compare our results with that by Taipower to demonstrate the effectiveness of our proposed algorithm.