The Application of Real-Time Monitoring and Rating Equipment to HPOF Pipe Cable Systems

The Boston Edison Company has installed realtime monitoring and rating systems on two independent pairs of 115 KV HPOF pipe-type cables. This paper describes these installations and gives some results of their operation. These circuits exhibited large increases in short time emergency ratings because they normally operate at relatively low temperatures. The identification of effective earth parameters in real-time generally results in increased long term and normal ratings because of the conservative assumptions that must be made at the design stage. The real-time systems are remotely located at cable terminal locations so that critical data inputs can be hard-wired to the computing processor. Real-time information is made available via analog SCADA connections and also by IBM-PC´s equipped with MODEMs which can call the remote systems to view real-time conditions or unload historical data. A PC Software package compliments the real-time system and gives Planners, System Operators, and Cable Engineers the ability to simulate cable system operation in an off-line environment.