Suspended Optical Fiber Voltage Sensor Based On All Polarization Detection

ABSTRACT:With the construction of the smart grid and the continuous improvement of the voltage level, traditional voltage sensor can no longer meet the development needs of modern power systems. We urgently need a new type of high-quality voltage sensor instead. The optical fiber voltage sensor overcomes many shortcomings of the traditional voltage sensor, and it has broad application prospects in future electricity system. After decades of development, it has formed a set of related theory, but it still exists some problems of development and improvement.On the basis of a comprehensive analysis and review of the current development of the Optical fiber voltage sensor, a new structure of suspended optical fiber voltage sensor based on all polarization state detection without polarizer and analyzer is proposed. It is aimed at some problems of existing optical fiber voltage sensors, such as complex structure, adjustment difficulties, poo r temperature stability, optical power loss and voltage introduced inconvenience. The sensor only contains three main elements, which are a self-focusing lens, a BGO crystal and a total reflection mirror. It has a few devices, a simple structure and it is easy to align. All polarization state detection system is described. It uses division-of-amplitude method and has fast response and simple algorithm. Some formulas about polarization state, electric field and the measured voltage are deduced. An experiment of measuring the high voltage by suspending the sensor is demonstrated in the first time. The sensor has no electrode and without ground, not only eliminates the need for expensive insulators, and increases the range of the sensor. The test results show that sensor has a good linearity at room temperature in the range of0～10kV AC voltage at power-frequency, that proves the feasibility of the structure.