Study Of On-line Monitoring System Based On Wireless Communication For Insulators

Outdoor insulators on transmission lines tend to be defective or zero early under the combined affect of electric, heat and internal stress. The defective insulators may lead to flashover and tripping of the electric transmission line. Heavily contaminated insulators even can cause power fail accident in the big area, bring great threat to power distribution reliability. Although the replacement of the insulators is an effectively method, it is unreasonable on the economy. It need to find a suitable and effective method to monitor the insulators.The paper firstly introduces the recent development of the live-line monitoring of insulators. Both the merits and demerits of the electric and non-electric methods are described.Then the rule of voltage distribution on insulators is theoretically analysized, as well as digital emulation. When there are faulty insulators in a string, the voltage across the fault insulators obviously become lower, making health insulators bear higher voltage than normal value. It can be the theory basis of the on-line monitoring system.Chapter 3 mainly introduces the whole design of an insultor detecting system and its hardware. A wireless communication based on-line monitoring system based is put foward. The whole detecting system consists of the data collecting unit, wireless communication unit and control diagnosis unit. The data collecting unit collects the electric voltage signal by use of a resistive voltage divider. The wireless transmission unit adopts a nRF401 as the wireless transceiver module. The serial communication between MCU and PC through chip MAX232 is also introduced. Then some possible sources of interference as well as the countermeasure in hardware are analysized.Chapter 4 describes the software design. Firstly, The basic principle of serial communication of computer system is described, then the realization of the serial communication between PC and MCU by use of API function is introduce in detail. The aim of wireless communication, the design principle for the protocol, and structure of the protocol are discussed . The paper then introduces the design of the frame, the program structure of the superior unit and the inferior unit and its realization. In the end, the visible display of the system is introduced as well as the test of the wireless communication protocol.