Design and study of a switch reactor for Central Queensland SWER system

Abstract

Single wire earth return (SWER) systems are a widely applied, low cost electrification method used in many rural areas. In central queensland a single SWER system supplying approximately 100 kW may extend more than 300 km. Many SWER systems include shunt reactors to control the effects of the line charging capacitance. One effect, the Ferranti effect, causes the line voltage to rise with the distance. In three phase distribution systems this effect is not visible but in SWER systems, this effect makes it difficult to maintain the consumers supply within the acceptable regulation range. As the second effect, the loading of the SWER system supply transformer increases. Controllable shunt reactors are used as one solution to the aforementioned problems. Stanage Bay feeder in central queensland area has been chosen for the installation of the designed shunt reactor. Stange Bay feeder is supplied by an isolating transformer with the total capacity of 150 kVA and the voltage level of 22 kV. Using the Stanage Bay feeder, this paper details the process of design and simulation of a suitable switch reactor. This step has been carried out by firstly, the design of the switch reactor and secondly, the proper modelling of the designed reactor for the voltage regulation studies.