Research On The Key Technology Of Optical Current/Temperature-Sensing System

As the the application of the hybrid Optical Current Transformer (OCT) becomes more and more extensive, its shortcomings of complicated structure, huge consumption, high cost and the monopoly of the optical power supply are gradually exposed. To solve this problem, a new kind of optical current/temperature-sensing system is put forward. The power consumption of the scheme is low and micro optical power supply with the independent intellectual property is used. The scheme is also integrated with fiber Bragg grating to realize the real-time monitoring. It will be a new direction of the hybrid optical current transformer in the future.In the second chapter, the basic scheme of the optical current/temperature-sensing system is designed. The principle of the FVOA is analysed. The FVOA module based on photoelectric closed-loop is designed to correct the nonlinearity of the FVOA. The marhematical model of the system is established. The suppress of the optical fiber disturbance using interference correction strategy and the optical power supply based on Si based photodiode are proposed. The low-cost FBG temperature detection and superfluorescence fiber source are designed.In the third chapter, the prototype of the optical current/temperature-sensing system is developed. The photoelectric closed-loop based FVOA on the high-voltage terminal, the optical power supply module, the analog receiver and the digital receiver are designed. In the digital receiver, the bus current calculation algorithm, the CRC algorithm, the Manchester coding and the communication algorithm based on IEC60044-8 are designed. The FBG temperature detection system and the module of data processing are designed.The SFS based on erbium doped fiber, its driver and its constant temperature system are developed.In the fourth chapter, the experiment platform is set up to achieve the precision of the optical current/temperature-sensing system. The expermential results show that the precision of the optical current/temperature-sensing system is in accordance with the requirements of the 0.2 level of the GB/T 20840.8-2007 and the optical current/temperature-sensing system can communicate with the combiner. The output and the spectrum of the superfluorescence fiber source are constant with the simulation result. The precisions of the FBG are 1.1 centigrade and 0.9 centigrade.Finally, the fifth chapter summarizes the whole paper and gives the outlooks of the future development of the optical current/temperature-sensing system.