The Research Of Protection And Fault Location New Technique Based On Microprocessor For Extra High Voltage Transmission Line

The scale of electric power system in china become larger and larger, and HV/UHV transmission lines have been developed quickly, which leads to higher requests for protective relaying and fault location sets for HV/UHV transmission lines. With the progresses of computer, communication and correlative technique, It is of great necessity to develop more advanced microprocessor based protective relaying and fault location set for HV transmission line. This paper just focuses on this task.At first this paper introduced the history of protective relaying and the new directions on microprocessor based protective relaying and fault location, summarized the techniques of protective relaying and fault location respectively. Then this paper researched and analyzed the process of a perfect protective relaying device for UHV transmission line according to the needs of UHV transmission line, focus on the scheme principle and realization of protective relaying device foe UHV transmission line. The scheme included much different protective principles and these protective principles can be assembled neatly. The protective programme is designed based on protection logic diagram. The protective relaying device can reliably protect the transmission line at any state. The protective relaying device provided convenient manager system and analysis system to users, this paper analyzed the software design and its realization, introduced the functions and communication protocol.After the design of protective relaying device for UHV line, the static and dynamic simulation experiments for the UHV transmission line protection system is introduced. The results of the experiments and some detail problems were analyzed and show that the performance of the protection device has achieved the system design goals.The fault location of UHV transmission lines is an important part of protection. This paper summarized the fault location method based on PMU, and introduced a new fault location for parallel transmission lines, the simulate result show that this method has high location precision and is applicable for any fault types. The fault location based travelling wave is a new field in fault location for transmission line. The paper analyzed the recorded data from power system and brought forward a new module of capacitance voltage transformer. The result of frequency response and alternating response were provided, the result show that the module taken into account the stray and coupling capacitances of capacitance voltage transformer is more accurate and the voltage travelling wave from capacitance voltage transformer can be used to fault locate based travelling wave.