Investigating the frequent burnout of 33 KV/433 V distribution transformers of ECG

Abstract

Transformers are one of the important devices in electric power transmission and distribution systems. These devices are used to control voltage and current levels on an electrical network by either stepping it up for transmission or stepping it down for utilisation. A distribution transformer provides the final voltage transformation in an electric power distribution system. Transformers, like many electrical devices, are prone to faults. These faults, regardless of their intensity can result in high financial implications. Failures of in-service distribution transformers not only limit system performance and reliability, but also have a serious social impact because of unscheduled outages of the electricity supply. The research focus on eliminating the lightning arrester leads length, which contributes to the total discharge voltage that is incident on a transformer during lightning surges. MATLAB Simulink (SimPowerSystems) is used to model the existing system and various simulations are performed to assess the effect of different lightning arrester configurations. The results indicate that when the lead length of the lightning arrester is reduced or eliminated, there is a higher margin of protection on the transformer, which implies that the frequent burnout of distribution transformers can be mitigated with the introduction of the Zero Lead Length configuration.