Evaluation of reliability of power distribution components: A case study of Sagamu Substation, Ogun State

Power system especially the distribution system which is the closest to the consumer is very fundamental and important to a nation’s economy development and that was the reason this study titled “Evaluation of reliability of power system distribution components, a case study of Sagamu Substation, Ogun State” was carried out in response to the yawning of the consumer for reliable and stable power supply. It is indispensable to find means of shaping which component failure contributes most to the unavailability, outage or interruption of the distribution system, and how this unavailability essentially affects the customers. A year power outages data that caused as a result of failure on each of these components such as Switch gears, Supply lines (11Kv),Busbar, circuit breakers, Fuses, Switches, Outgoings feeders, Over current relays, Earth fault relays, Surge arresters, transformers e.t.c. were collected from Ibadan Electricity Distribution company (IBDEC), Sagamu Substation Zone, Ogun State and were typified in Table 1-11.The failure rate (f/yr) (λ) of transformer, switch gear, supply line (incoming),bus bars, circuit breakers, fuses, switches, outgoing feeder, over current relay, earth fault relay and surge arrester were evaluated as follows 0.0059, 0.0044, 0.0011, 0.6667, 0.0007, 0.0082, 0.0000, 0.0039, 0.0003, 0.0001 and 0.0000 respectively and others such as average outages time (hours) ,outages time hours and other basic reliability indices were calculated and illustrated in Table 12. Some of these failures were also represented in bar chart. This method relates reliability theory with the experience gained from statistics and practical knowledge of components failures and maintenance. The findings from this work revealed that fuses had the highest failure followed by transformers and the least was surge arresters and it was also discovered that the outages time was reduced during the December period. This approach can be applied to rural and urban distribution systems. This submission made reliability theory a powerful tool to assist distribution Engineers in solving difficult and complicated problems.

Earth fault detection in distributed power systems on the basis of artificial neural networks approach

Nowadays, the advancement of microgrids promises numerous economic and environmental advantages of renewable energies to nations and societies. The presence of decentralized energy units, however, makes serious technical challenges; for instance, criteria and procedure of fault recognition and diagnosis in this condition is entirely changing. This article, therefore, proposed a novel accurate and fast technique based on Artificial Neural Networks (ANN) for earth fault detection. A sample distributed power system considered for the proposed technique and different earth faults applied to this system consist of one phase, two phases and three phases faults. Also, any alteration of current and voltage signals of all phases is investigated at the fault occurrence moment. Analysis of simulation results demonstrates how the proposed technique could make faster responses and improve the reliability of the distributed power system by more accurate fault recognition in comparison with the other traditional methods such as the Wavelet Transformation technique. The proposed technique is likely to enhance the growth of renewable energy sources usage by decreasing operational risk factors and fault recognition delays.

OVERVOLTAGE DURING ARC SINGLE-PHASE EARTH FAILURES IN 35 KV ELECTRICAL NETWORKS

The results of the study of overvoltages during arc single-phase earth faults of intermittent nature in the 35 kV electric network with isolated neutral are presented. Computer simulations of transients in the electrical network have obtained the maximum multiplicities of overvoltages at the point of occurrence of single-phase arc earth faults, which exceed theoretically expected according to known theories of the occurrence and development of overvoltages. The change of the overvoltage level on the 35 kV busbars of the network substations, electrically connected to the place of occurrence of the single-phase earth fault, and the influence of the cable line on the overvoltage multiplicity are shown. Ref. 12, fig. 3, table.

Development of Smart Earth Leakage Circuit Breaker Using IoT and Power Electronics

The Smart Earth Leakage Circuit Breaker research is based on IoT& power electronics-based protective switchgear for domestic consumers for the protection against earth leakage faults. In this paper, we have shown how to create a custom web server using HTML and CSS language and hosting this webserver to ESP module using Serial Peripheral Flash File System (SPIFFS). Along with protection against earth fault it provides, controlling of tripping current or fault current, monitoring voltage, power, current, power factor parameters of the connected load, monitoring fault parameters, Indicating the device status whether the ELCB is on or off, and the condition of ELCB it is in faulty condition or healthy condition and to let the user set the value of the tripping current on the webserver at which the ELCB must trip.