Comprehensive fiber optic sensor for photovoltaic panels parameters monitoring

The article proposes the concept of constructing a comprehensive fiber-optic sensor (CFOS) for simultaneous measurement of relative humidity and air temperature, as well as the temperature of a solar cell. The sensor is represented by a double structure, consisting of a two-stage Fabry-Perot interferometer for measuring relative humidity and air temperature and a two-component wave addressable fiber Bragg structure for measuring the temperature of a solar cell. The sensor is inserted orthogonally to the plane of the solar photovoltaic panel into the technological hole formed in it so that the distance between the addressable fiber Bragg structure(s) and the Fabry-Perot interferometer module allows simultaneous measurement of relative humidity and air temperature, as well as the temperature of the solar panel. A change in relative humidity affects only the refractive index of the outer interferometer, while a change in air temperature affects the refractive index of both interferometers. Changing the temperature of the solar cell only affects the central wavelength of the addressable fiber Bragg structure. By solving a system of equations using the specified parameters, relative humidity and air temperature, as well as the temperature of the solar battery, can be controlled simultaneously. The structure and design of an integrated fiber-optic sensor and the results of the first experiments are presented, which confirmed the possibility of simultaneous measurement of the parameters under consideration that affect the efficiency of solar panels.