Design And Realization Of Vibration Monitoring And Fault Diagnosis System For Hydropower Unit

With the rapid development of hydropower industry in China, the growing installation capacity of hydropower units and the increasing automatic operations make the conventional maintenance mode hardly meet the demand of development. The condition-based maintenance technique of hydropower units is capable of enhancing the rate of equipment utilization and reducing the maintenance cost, which has great significance in achieving safe and steady operation of units and improving the economic effect of hydropower plants.The condition-based maintenance techniques mainly include condition monitoring, trend prediction and fault diagnosis. This paper mainly focuses on the vibration state of hydropower unit. At first, the analysis processing for vibration signals including integer period sampling, signal preprocessing, FFT algorithm, window function, spectrum correction, etc., is discussed in detail. And the accuracy of spectrum analysis is verified via simulations. Next, with the utility of fuzzy mathematic method, the fuzzy relation matrices are built to implement the fuzzy diagnosis of operational faults in units according to the locations of vibration parts and the spectrum characteristics of vibration signals. Eventually, a vibration monitoring and fault analysis system for hydropower unit has been designed with adopting the idea of object-oriented programming and multithreading mechanism, taking C++ as the development platform and using digital signal processing technology and fuzzy diagnosis theory. Also, the function of each module of the system has been stated elaborately.This system, which has the capability of fast transmission of multiplex data using the Ethernet communication and supports a variety of graphics display including bar chart, spectrum map, axis locus diagram and three-dimensional hologram, is able to offer the real-time monitoring and accurate fault analysis to the operational conditions of hydropower unit. Furthermore, the system provides friendly man-machine interactive interfaces and is easy for operation and maintenance, which guarantees a promising application prospect.