Technique Of Photoelectric Sensor Applied In Smart Grid

Measuring equipments are very important in Smart Grid, which needs to measure the real-time voltage and current value accurately in power line. Active fiber current sensor measures the current value using Electromagnetic induction effect, and recently it is well developed because it can not only use mature technique of traditional transducer but also adopt advanced fiber communication techniques. Also, under the high-tech development of laser and optoelectronics, passive fiber current sensor draws people`s attention. Based on Faraday effect, it introduces magneto-optical materials in high voltage side to sense the magnetic field, so as to obtain the current value indirectly. Passive fiber current sensor is the final development of current sensor.At the beginning, this thesis describes the classification and progress of fiber current sensor in Smart Grid, analyzes fiber current sensor system based on Yttrium Iron Garnet (YIG) using Jones Matrix, and explains the function of adding magnetic device around the sensor head. Then, two designs of sensor head based on magneto-optical materials are proposed. We fabricate and test one of the sensor heads, and it turns out to be effective in high voltage measuring. However, it can`t be practically used because of the measuring range limitation resulted from the material characteristics.Then this thesis analyzes all fiber current sensor using Jones Matrix, puts forward a reciprocal-compensated all fiber current sensor and do experiments to test this system. It shows to be feasible to some extent, especially introduced twisted fiber in the sensor head to restrain fiber birefringence. This work establishes certain foundation for further research on all fiber current sensor.It also shows research on photovoltaic power converter (PPC) used in active fiber current sensor. PPC is actually a single-junction photovoltaic cell. This thesis analyzes the theory of photovoltaic cell, proposes wafer design and the whole structure of the semiconductor device. It then describes PPC`s technique fabrication process and gives the results of sample testing. The conversion efficiency can get 20.7% under the condition when the input light power is 200mW.Finally, the thesis puts forward a design of a dispersive solar cell based on concentrator. Its main idea is to deflect light with different wavelengths in the sunlight into different emerging angles and utilize single-junction photovoltaic cells, each has a different wavelength of maximum absorption, to absorb the dispersive sunlight. This idea is potential since it`s easy to fabricate and improve performance of single-junction photovoltaic cells...