Transients in low voltage power systems (LVPS) in Sri Lanka under modern domestic environment

摘要

A life in modern society without safe and reliable supply of electricity is almost unimaginable, as it plays an indispensable role in human life. This reliability, essentially the balance is very important for safe operation of electronic appliances, but failures by transients become more prevalent due to their higher susceptibility of control circuits. Therefore either it should be reduced or eliminated in order to keep the mains safe and clean for other electrical appliances. Even though time duration that the electrical transients are present in the system is short, the components in the system are subjected to high-current and high-voltage peaks that can cause catastrophic damage. In order to identify this formidable menace, 1148 transient waveforms were recorded in LVPS in Sri Lanka under modern domestic environment. These recorded transients were due to induce over-voltages under lightning, switching, loading, energizing, etc. Through an empirical analyses carried out to extract the parameters of transients in LVPS in Sri Lanka, the highest positive peak of 472 V, negative peak of 448 V and the highest amplitude of 815 V were recorded. Burst width as high as 1.338 ms is also reported. Rise times are as short as 15 ns for impulsive transients and 0.1 us for oscillatory transients calculated. Results may be used to identify and understand the behavior of transients by correlating the major components in transients to the operated electrical appliance and to develop proper transient protection systems.