Effects of Power Distribution Feeder Monitoring and Service Restoration through Cloud Computing on System Efficiency Improvement

摘要

The electrical power network as a whole consists of critical infrastructures which needcontinuous process of technological improvements for higher efficiency in terms of functions, reliability, andvalue. Nowadays, electric power systems (up to transmission level) are being upgraded with sophisticatedcommunication and control technologies to enhance the system reliability, however poor monitoring gives riseto instabilities on the distribution portion of the total power system. These instabilities affect the overallavailability and efficiency of the system. Therefore, it is essential to develop models and methods to improvemonitoring and protection of the distribution system through which could improve availability of the entirepower system.The methods of power distribution network improvement were studied with a view of developing an intelligentsystem capable of improving network’s efficiency through availability improvement without putting thosecritical power infrastructures at a higher risk of instability. This research evaluated the rates of failure ofcritical infrastructure in conventional distribution networks through gathering and analysis of reliability data.The load on medium voltage feeders and distribution transformers were monitored remotely to detect the healthconditions of the system after which faults were isolated thereby restoring normalcy. The impact of servicerestoration following fault conditions on distribution system availability without a complex Supervisory Controland Data Acquisition system on future power distribution systems was considered by comparing the systemefficiency before and after monitoring. The automatic system which remotely monitors the state of the feedersand transformers continuously to determine the state of the network was designed. Abnormal conditions wereautomatically addressed through automatic sensors, isolators and switches which open or close depending onthe status of individual feeder as detected by the sensing circuits. These circuits utilize sensors through remoteoperations for processing of data and actionable outputs in a virtual control room for automatic restoration,thereby reducing the system total downtime while improving the system availability.The distribution system test bed showed that the technical losses on the system are high leading to poorefficiency and reliability, however, after monitoring the availability and efficiency of the network improved byabout 70%. Therefore the designed network improved and stabilized the system delivery factor from 0.7635 to0.9470. In the end, the over one hundred and thirty-eight million naira monthly reduction in the revenue lossafter monitoring also reflects the milestone achieved in improving the technical and economic stability of powerdistribution networks.The designed and developed system therefore improved the network’s operational availability through thereduction of the total outage time and service restoration time.