Study on Alternative Communication Technology for Pilot Cable Communication for SCADA System in TNB Distribution

SCADA (Supervisory Control and Data Acquisition) system is crucial in Tenaga Nasional Berhad (TNB) as power utility to perform remote control and restore supply quickly by providing accurate information on failure points, in the event of an unscheduled power supply. In order to achieve high reliability in SCADA system, TNB Distribution Network (DN) uses several communication mediums: fibre optics, copper wire/pilot wire, UHF, leased-line, satellite, and General Packet Radio Services (GPRS). Copper wire, widely known as pilot wire, is highly used for SCADA communication in primary substation, not to mention fibre optic. The simplicity in establishing the communication on top of robustness has led to the high utilisation of pilot wires in SCADA system. However, the communication over pilot wires suffers from electrical noise of power cables that are laid together underground. Currently, the communication modem used for pilot wires is not dedicated to operating over induced voltage environments. Hence, most communication under high induced voltage experiences intermittent issues, thus deteriorating the service performance of SCADA system. Therefore, this report discusses the Power Line Carrier application as an alternative technology to serve as an optimum solution for intermittent Remote Terminal Unit (RTU) communication over high induced voltage environments and other long-distance issues communication (over 10km) and unknown failure. Three sites with different pilot wire issues are selected to test PLC modem performance. Overall, RTU communication under high induced voltage is achievable using PLC modem technology.