In October 2019, we completed a power cable temperature monitoring system in Company L's underground utility tunnel.

The monitored facilities comprise two extra-high-voltage circuits leading to the 154 kV receiving substation. Fiber optic sensing cables were installed between the R and S phases and between the S and T phases to measure temperatures.

The system panel is installed in the receiving substation, and the HMI is available on a wallboard in the central control room.

All power cables are monitored at one-meter intervals. If the temperature exceeds an operator-defined threshold, or its rate of increase exceeds the configured limit, the system issues an alarm, notifies the operator and reports to the higher-level DCS.