Capacitive Voltage Substations Ferroresonance Prevention Using Power Electronic Devices

Abstract

This paper describes the underlying theory and model of capacitive voltage substations and its assosiated problems. This system is intended to supply electricity to rural communities directly from high voltage transmission lines. This technique leads to important cost reductions when compared with conventional alternatives. However, in several transient cases, some problems such as ferroresonance and overvoltages can occur in these substations. These transient cases are simulated in this paper and a new technique is proposed for damping of dangerous overvoltages due to ferroresonance. In this technique, by using power electronic devices, a damping resistance is switched to secondary side of the system transformer, when necessary. Several computer simulation tests are presented in the paper to highlight the usefulness of this technique. The simulation results present that overvoltages are adequately limited.