Comparison of Battery Reliability for Offshore Remote Telemetry Unit

Abstract

Remote telemetry unit (RTU) is a vital equipment, especially for real monitoring, remote command, also safety shutdown system. In order to achieve its function, this unit required strong power reliability for operating in twenty-four hours, seven days. In practically power feeder to supply RTU consist of normal supply and backup supply. Application in offshore area normal supply could be fed from Diesel Engine Generator, Closed Cycle Vapor Turbogenerator (CCVT), also Thermal Electric Generator (THEG), each type was backup by batteries unit. To maintain backup power system, it required discharge autonomy test periodically. This maintenance will be useful whenever unexpected shutdown occurred. Application on site already use various type of batteries, recently Nickel Cadmium was chosen for long life time power consumption source instead of Lead Acid also Lithium Acid. Generally, power consumptions in RTU are; power amplifier, switch modules, channels with its discrete input-output and analog input-output, also antenna power feeder. Determining of battery type considers discharge capacity, RTU was liable to capacitive load which majority of component inside consist of electronic parts, tend to long period and stable discharge. This condition was opposite with batteries of engine starter which has high rush current but short period. Maintenance treatment was absolutely different between each other included charging, floating and high rate mode.