Study On Fast Positioning Method And Positioning System For Mobile Workers In Digital Substation

The work of workers in substation plays a very big role in the normal operation ofthe substation. The work is related to the normal operation of the grid and the safety oflife and property. However, there is no technology with high quality and low cost tosupervise and manage the work of the workers in substation in real time. For this reason,the paper introduced the emerging ZigBee technology for locating mobile workers insubstation. The ZigBee positioning technology is based on signal propagationattenuation for ranging. The technology wins the favor of many scholars with its lowlatency, low power consumption, low cost and low positioning algorithm complexity.But it has so low anti-interference ability that it will cause low positioning accuracywhen it is used in substation. In this paper, a fuzzy reasoning algorithm for the ZigBeepositioning system was proposed to replace its existing traditional ranging algorithm,and the superiority of the new proposed algorithm was verified by simulation andexperiment. In addition, new positioning software was developed to replace the originalpositioning software. The new software can monitor the workers more directly andconveniently.In this paper, the main research work and results show that:(1) The propagation ofelectromagnetic wave in free space was simulated by FDTD, and an attenuation formulawas obtained by fitting. The formula is almost the same with the theoretical formula. Itshows that the result is right.(2) The influence of the cement towers on positioningresults was simulated by FDTD, and the result shows that the reference nodes aresuitable for being fixed between the two towers instead of on the tower. The resultprovides a basis for the practical application of the positioning system. The diffractiontheory of electromagnetic wave was also described (3) The new positioning methodbased on fuzzy reasoning and the traditional ranging positioning method was simulatedseparately. The comparison result shows that the new proposed algorithm can improvepositioning accuracy and stability significantly without any additional hardware.(4) Thepositioning experiments show that the new algorithm is better than the conventionalalgorithm in positioning performance, but it is worse than the positioning result ofsimulation. It is indicated that the new algorithm needs to be improved.(5) Thepositioning software developed can be modeled for substation and monitor workers insubstation conveniently, and it has playback function for route of the workers.