Abstract
Reliability of the transmission system in the Hsinchu Science Based Industrial Park is of utmost importance to the economic development of Taiwan. However, due to the composite and complex transmission network structure of this area (loop plus radial), the protection scheme design of this network presents a very challenging task. Take the loop protection design as an example. There are two kinds of loop in this area: single loop and double loop. Protection scheme design for the single loop is always characterized by the complex relationships between the main and backup protections for each of the nodes while that for the double loop must additionally take into consideration the uneven distribution of fault currents between the parallel feeders. As far as the protection scheme for the radial feeders are concerned, the pickup time for relays should be shortened as much as possible due to fact that radial feeders in this area are highly susceptible to lightning and flashovers due to salt depositions. As such, this thesis performs a detailed analysis on the protection scheme for the 69KV transmission network in the Hsinchu Science Based Industrial Park. Simulation result shows that existing relay settings for the loop feeders can not meet the protection requirement under certain instances while the pickup time for the radial feeder relays can be further shortened to reduce the fault duration occurring on the radial feeders. Strategies for improving present relay settings to meet the protection requirement are also proposed and evaluated numerically the thesis.