High voltage lines are one of the main components of the electrical power system. The maximum transmission capacity depends on numerous factors at all times. First of all these factors are the technical parameters, which are determined during design and construction periods of the line. On the other hand we have to take the real-time circumstances into consideration. The instantaneous weather condition plays significant role as well. The exact value of the possible peak load cannot be simply calculated because of the aforementioned factors are of a wide range and significant volatility.
By using different devices (such as on-line sensors and weather stations) the system operator can have complete, real-time information about the state of the conductors. From this data a suitable algorithm can calculate the highest current which is safely transmittable.
This thesis aims to compare and summarize the various sensors available in the market according to coherent aspects. Categorizing the devices considering their power supply, communication and the additional hardware tools is also a basic task. It is as well important to examine the frequency and method of setting these devices in order to get a full picture of the condition of the line. It helps to create a system of sensors that is capable of providing input for the above mentioned algorithm with adequate delay and necessary sampling rate.