Study On Leak Detection And Location In Network Based On Urban Water Supply SCADA System

Water supply pipe1ine leak detection has always puzzled water supply industry. At present, many enterprises and sci-tech research institutes are studying pipe1ine 1eak detection technology, whereas encounter difficu1ties of high investment, complex computing, low precision and low benefit.The situation of nowadays leak-detecting, the history of SCADA system's research and development on the world are reviewed at first in this paper, and the shortage,inproved measurements and direction of development hereafter are indicated. In this paper, the function,compositions and build of the urban water supply SCADA system are elaborated in full.It is important to collect data accurately from water supply system for SCADA system attemper correctly, which not only relate whether water supply system's running atate are real-time known and monitored by SCADA, but also affect a certain extent the capitalize cost and running reliability and zalidity of SCADA system. Therefore, optimized laying of monitoring stations in urban water supply SCADA system is an emphasis in the first part of this paper. In the aspect of optimized location of water pressure monitoring stations in the water supply network, one way of laying measuring stations is holdup, which based on reflecting the change of pipeline leakage in the network, and then validate the effect by network simulation.In the second part of this paper, discussing the importance of the urban water-supply SCADA system and introducing the characteristic and methods of the wavelet transform de-noising. The experiments which de-noised from the hydraulic pressure signals of SCADA system proved that wavelet transformation got better effect to de-noise, then could reflect the true hydraulic state.In the third part, this paper proposed a methodology for fault diagnosis of a water distribution system by monitoring the water pressure on-line at nodes in the water distribution system. A neural network-based inverse anaylsis method was established to detect the location and extent of the fault and affected area based on the variation of water pressure. At the same time, it was shown through an example that the methodology is effective and practical.At last, if pressure monitors have been equipped at both ends of the pipe on which there are leakage points, negative pressure wave method can be used to more precisely confirm the leakage station. The paper establishes a structure of locating the leakage nodes, which is of the guiding significance to practical work.