Remote Monitoring Of High Voltage Transmission Line Study

This paper gave a result that the majority faults of HV overhead transmission lines focus on cable junction by analyzing the causes of the damage of electric power cable. A new method for judging the running state of HV overhead transmission lines was put forward according to the temperature parameter of power cable junction. The temperature data could be acquired at any time we wanted by using the character of optical fiber temperature sensor, the anti-jamming to surrounding electromagnetism and the endurance to high voltage. Then the data could be transmitted to a distance by using the new technique of communications that is called wireless optical communication. Thus a temperature monitoring system on-line for power cable junction has been achieved .The problem about communications under the situations that require high maneuverability and that implement difficulty for wired communication has been solved. It could also be easy to communicate in special environment. The system will be easy to set up and the communication frequency is free. The efficiency for patrolling of the high voltage lines and the veracity for fault forecast were improved remarkablely. The powerful basis for preventive maintenance of transmission lines was also provided.In this paper, the basic model, the principle as well as the development and the application conditions about wireless optical communication system have been outlined. One kind of simple wireless optical communication system was proposed and the structure, the code, the modulation, the demodulation were presented along with the correspondence protocol based on the model and the principle. The essential technology has been solved and the facility installment has been established. The function has been tested in laboratory. It was the innovation spot of this paper that the optical fiber temperature sensor and the wireless optical communication were combined to realize remote monitor on-line for high voltage transmission lines. This plan could apply to other equipment control and monitor with long-distance by slightly modifying. It was very valuable to promote widely.In the article, taking the simple wireless optical communication system as the research core, influence of the atmospheric channel to the optical communication system was briefly introduced. Design for the Communication Terminal mainly revolved the choice for the photo source and the wave length, the laser design, the laser drive circuit design, the optical system design, the power design and so on. The detail was introduced, which included the work principle of PIN detector, the pre-amplifier and the host amplifier design, the filter design for miscellaneous lights and background lights, the anti-electronic circuit design, and the implementation methods. The performance of the direct detection system about the noise,SNR, NEP and the sensitivity was analyzed carefully. The method for designing threshold value was proposed.The C8051F series MCU were chosen for designing the system hardware of the receiver and the transmitter. The correspondence came true between the receiver and the transmitter by the wireless optical communication. The system can communicate with PC through the USB interface. The application program for PC used VC++ 6.0 while the slave systems' procedures developed based on the Keil C51. It was proved that all designed parameters meet the request we wanted and there was a good result at the bit...