Currently, it is becoming common practice for underground transmission projects to use distributed temperature-sensing systems based on fiber-optic technology to monitor cable temperature all over the run. To supplement this technology, CYME's CYMCAP/RTTR dynamic or real-time temperature cable rating system extends the monitoring functionality and forecasts the behavior of the installation under emergency situations.
CYMCAP/RTTR is designed to provide both steady-state and transient thermal analysis. It is based on IEC standards 60287 and 60853 or finite elements. By looking into the future, this function allows the user to be ready when an emergency situation arises. Given the operating temperature and the applied (over) load, the RTTR software predicts the temperature of the cable in the future; given the operating temperature and the applied (over) load, the RTTR gives the time it will take for the cable to reach a specified emergency temperature; and given the operating temperature and a time frame for an over load, the RTTR computes the maximum current that the circuit can carry to reach certain emergency temperature.
The RTTR based on CYMCAP has two modes of operation: estimating the conductor temperature from the fiber-measured temperature and performing emergency ratings with the transient engine. Virtually every cable construction in the market can be modeled with CYMCAP, as well as several installation types.