**3.3.4 Conclusions**

It has been shown that the proposed monitoring system for transmission line cables measurement of temperature and current provides reliable data. Since silica optical fiber cables are utilized in communications and power supply links, insulation between the sensor head and the user operation site is guaranteed, eliminating the use conventional copper cabling.

The measured values were compared with reference values, the latter being outfitted by commercial measurement laboratory instruments; and small errors were observed, for both current and temperature data. For an even more reliable study of the system accuracy, a calibration using tracked instruments must be carried out.

Future works include the system field installation, in Piracicaba TL, which requires the improvement of system mechanical robustness, and the addition of the sag monitoring subsystem. It is expected that the data collected, together with the sag information, will provide support for the development of an algorithm for the estimation of conductor-sag values.

#### **3.4 Optical high voltage sensor based in fiber Bragg grating and PZT piezoelectric ceramics**
