Theory And Application Of Optimal Maintenance For Hydro Turbine Governing System

The development of industrial production devices and automation systems, which are becoming large-scaled, efficiency and automation, is promoted by progress of modern technologies and development of productivity. It satisfies external demands of modern industry with a certain extent, and it gains large economic and social benefits, but meanwhile the demands of production put forward a higher request towards safety and credibility of the equipments and the systems. Hydropower is one of the foundational energy establishments of our country. With the development in past years, the automation of produce processing control and technical management, which are the two important parts in hydropower plants, have gradually become more and more mature, but because the limitation of the present maintenance system, the automatic level of maintenance is still very low. The cost of maintenance which once took a little proportion in the device lifecycle is increased sharply now. In the precondition of ensuring the reliability of device, how to reduce the maintenance cost is becoming the focus of current research. In this dissertation, based on entirely summarizing the present maintenance system of our country, the development direction of the maintenance of hydropower plant aimed to optimal maintenance is put forward as below: we suggest adopting the optimal maintenance method and reducing the frequency of schedule maintenance and avoid using the breakdown maintenance method as certain as possible. All of these maintenance methods have to be coexistent by now because of the technical limitation. The aim of maintenance method of hydropower plant is to use condition based maintenance. It analyzes the influence of devices maintenance methods to the reliability and economy of devices running synthetically in this dissertation. Based on summarizing the disadvantage and shortcoming of all kinds of the monitoring and diagnosis devices and systems, which are already existent in hydropower plants related to condition based maintenance, the idea of applying device optimal maintenance to the overhaul of hydro-turbine sets to realize the optimal maintenance of hydroelectric devices is put forward. The definition of the optimal maintenance of the hydroelectric devices is put forward in this dissertation. The classification and collection of the device information and its'validly expressive method is the foundation of implementing devices optimal maintenance. The theories about classification and collection of the device information and its'validly expressive method have been studied in this thesis, and the theories have something about theoretical significance and popular applying value. After completely summarizing the main contents of optimal maintenance system, theory methods of how to apply them have been studied, and they have the significance of methodology. Then, the relationship between the optimal maintenance system and the rising technology of CMMS is also analyzed in this dissertation. The essentiality of simulation and modeling to the devices diagnoses and optimal maintenance is analyzed in this article. From the process of the conception and implementation of optimal maintenance, the demands of optimal maintenance doing with simulation model are also discussed. Basing on the 3D dynamic simulation modeling method and the distributed physical graphic net modeling method, the conception of the device digitalization modeling method has been put forward, and its foundation, executive step, crucial technology and aim have been studied. According to the hydro turbine governing system, the methods and its executive steps of device digitalization modeling have been particularly described with an application example of the wobble gate main servomotor. Through introducing device digitalization models'application area in optimal maintenance system, it is pointed out that the implementation of device digitalization modeling is a great progress in course of device operation, maintenance and management. The status analysis and fault diagnosis are key technologies to the optimal maintenance of hydro turbine governing system. In this dissertation, the performance characters of hydro turbine governing system are classified and defined from the process of governing system implementing its design function. The classification and definition of device fault are made according to the fault occurrence and process of hydro turbine governing system. These classified and defined methods have common applicability to other industrial systems. According to condition monitoring characters and the data sources of hydro turbine governing optimal maintenance system, it is put forward that through data analysis, operating modes analysis, device analysis and event analysis to analyze the condition data of hydro turbine governor. The aim of it is to know the health condition and capability developing trend of governor devices. These analysis methods are studied with instances. At last, the conception of distributed fault diagnosis is put forward.From degree of the difficulties of system fault diagnosis, the faults of governor are divided into three administrative levels as simple fault, device fault and integrated fault. The diagnosis methods of each level have been studied with instances. Referring to the basic theories and methods of achievement of optimal maintenance system discussed in this paper, the framework of optimal maintenance information system is brought forwards to satisfy the demand of the development of Gezhouba power plant and governoring system device maintenance. And then, it is pointed out that the governor optimal maintenance system is one of the important parts of the optimal maintenance information system, and the hardware configuration of it is introduced. The governor of 19th hydro turbine unit in Gezhouba has been studied as a research object. The functional hierarchy of governoring optimal maintenance system has been summarized, and the functional distributed characters of governoring optimal maintenance system have been described. The governoring optimal maintenance system of Gezgouba Hydropower plant has been researched and designed according to the architecture of optimal maintenance information system. Now, the system has been installed and debugged, and it has put into industrial practice for several months. From the effect of operation and reflection of the users, the feasibility and applicability of theories of governoring optimal maintenance have been fully proved. But the application of the system is only at a primary stage, more tests for practical operation would be taken, and a lot of problems in the application would be further discussed.