NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October ANALYSIS OF THE PLC SYSTEMS FOR JEBBA-SHIRORO TRANSMISSION LINE 1 A. Abdulkarim & 2 Y.A. Adediran Department. Of Electrical & Electronics Engineering University of Ilorin, Ilorin 1 2

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October INTRODUCTION Power line communication (PLC): a communication network technology using pre-installed power lines which provide the electricity to the household or the building used to provide services such as Internet access, automatic meter reading (AMR) and home networking

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October INTRODUCTION PLC technology could let the power transmission companies open lucrative revenue streams, – by integrating electricity supply with broadband telecommunication access – by providing high speed and reliable communication traffic including Internet access

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October INTRODUCTION PLC’s other applications: both industrial control and home automation over power lines with economical and reliable solutions long-distance monitoring of alarms and air- conditioning systems, comfortable control of intelligent household appliances, and off-site reading of electricity meters via the power grid

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October INTRODUCTION Aim of paper: Reliability analysis of PLC systems connected to the Jebba-Shiroro transmission line. Reliability: probability that a device or system will perform its prescribed function adequately, for the period of time intended, under specified operating conditions.

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October Phase-to-Earth Coupling Circuits PHCN uses Phase-to-Earth Coupling Circuits as one of the media of communication between different parts of the grid series reliability block diagram (RBD) assumed as failure of any component in system leads to total system failure Relevant failure data obtained from NCC, Oshogbo

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October Phase-to-Earth Coupling The general reliability of the power line communication phase-to-earth coupling circuit is given by Subscripts: RT=receiver/transmitter unit, CO=coax cable unit, MX=matching transformer, CF= coupling filter, CC=coupling capacitor, PU=protection unit, LT=line trap, XL=transmission line

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October Phase-to-Earth Coupling Substituting the components` failure rates, the general reliability equation of the power line communication phase-to-earth coupling circuit is λ=failure rate, t=operating time

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October Phase-to-Earth Coupling Jebba-Shiroro 330 kV network reliability plot:

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October PLC Contribution to the Communication Network Failure PHCN uses other means of communication apart from PLC; these include: GSM, Fibre optics and VSAT But, PLC is the major means of communication with different parts in the Nigerian grid

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October PLC Contribution to the Communication Network Failure

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October PLC Contribution to the Communication Network Failure :decrease in %-age of PLC contribution to communication systems’ failures due to introduction of other communication media like GSM and NITEL : rapid increase as a result of NITEL problem which makes PLC to contribute the highest to system failure 2009: recorded highest communication network percentage failure b/c the PLC network was upgraded by removing some aged equipment such as the line trap unit that had been in operation since 1976, thus the decrease observed in year 2010.

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October COMPONENTS’ IMPORTANCE ANALYSIS (CIA) Purpose: to identify the weakness(es) in a system and to quantify the impact of component failures to identify the components that should be modified, improved, or replaced with higher quality ones indicates the improvement of the system reliability when the component under consideration has been replaced by a perfect component. results therefrom are key contributors to the system design, tuning, and maintenance activities

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October Components’ Importance Analysis (CIA) Birnbaum’s component importance used: = reliability importance of the k-th component for B-th coupling circuit. R S (t) and F S (t) are the system reliability and unreliability respectively at time t

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October Components’ Importance Analysis (CIA)

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October Components’ Importance Analysis (CIA) Observations: – protection unit has the highest reliability importance – i.e. the protection unit has the highest influence on the system reliability; – it contributes most to system failure; – transmitter/receiver unit, coaxial cable, coupling capacitor units, matching transmitter and line trap follow in that order.

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October CONCLUSION AND RECOMMENDATIONS Reliability figures for the phase-to-earth coupling connected to the Nigerian grid for the last 11 years are very low when compared to the expected reliability figures obtained using RBD model. transmission line distance has little effect on the reliability figures of the PLC system most of transmission line failures are as a result of vandalism.

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October Conclusion and Recommendations most of the PLC network failures are from the protection unit and the receiver/transmitter unit during the 11 years under investigation It is therefore recommended that these units should more often be replaced and with higher reliability components for increased availability of the overall system

NSE Industrial Division Intn'l Conf. & AGM, Lagos, 4-6 October THANK YOU ALL