| The guide vane is an important part of the turbine,and it is the main component of the turbine to regulate the flow.The guide vane is generally evenly arranged on the periphery of the runner.Its role is to guide the water flow into the runner evenly,and to adjust the opening of the guide vane to change the turbine's performance.Flow to meet the requirements of generator load adjustment changes.After two years of use,the guide vanes are abraded by the water flow containing sediment,especially in rivers with a large amount of sediment,the abrasion of the flow passages such as the guide vanes of the hydro turbine unit is more serious.The current repair of the abraded parts of the guide vanes of hydraulic turbines is mainly manual surfacing,especially in Xinjiang,where hydroturbine units with large river sediment content are frequently overhauled,backward manual surfacing welding has a large workload,low efficiency and long maintenance time.Due to the increase in the time of production shutdown and maintenance,the cost is high and the benefit is low.In this paper,the guide vane of the hydraulic turbine abraded by water flow is taken as the research object,and its structure and worn parts are analyzed,so that the worn parts are divided into two types on the guide vane shaft and the guide vane.Combined with the characteristics of PLC stepper motor positioning control,PID fuzzy controller was used to adaptively adjust the repair and stable speed of the guide vane shaft,and PLC was used to control the stepper motor to complete the surfacing repair of the guide vane arc transition section.By using Simulink simulation software to adjust the parameters of the PID controller,the response speed and stability of the system are increased.The system combines the characteristics of PLC stepping motor positioning control,and uses PLC linear interpolation and arc interpolation to realize the spatial curve movement of the welding gun to complete the automatic surfacing repair of the arc transition section of the guide vane.The main research contents of this article are as follows:1.The overall scheme design of the control system of the automatic overlay welding device for the repair of the turbine guide vanes and the proposal of the overall mechanical structure.Based on the analysis of the structural characteristics of the guide vane and the wear parts,the automatic surfacing welding process of guide vane shaft abrasion spiral surfacing repair,the repair of the space curve of the arc transition section of the guide vane,and the linear reciprocating repair of the guide vane water stop surface are proposed.2.The design and parameter setting of PID controller for automatic surfacing welding of guide vane shaft and the realization of PLC stepper motor positioning control to realize the curve movement of repair space of guide vane circular arc transition.By studying the principle of fuzzy PID control,combined with Simulink simulation software,a PID fuzzy controller is designed and its parameters are adjusted to obtain the optimal solution,so that the actual speed of the turbine vane is always stable at the set value.The system combines the characteristics of PLC stepping motor positioning control,and uses PLC linear interpolation and arc interpolation to realize the spatial curve movement of the welding gun to complete theautomatic surfacing repair of the arc transition section of the guide vane.3.The host computer control interface configuration of the system,the software writing of the lower computer controller and the key hardware selection.Using the configuration software,a set of control interface suitable for guide vane repair and automatic overlay welding is designed,and a manual hardware button control box is set up to back up with the HMI.4.Debugging of the control system of the automatic overlay welding device for the repair of the turbine guide vanes.The logic of the system control program was tested using the ladder diagram offline simulation software,and the touch screen terminal and hardware buttons were used to manually control the box to start,stop and forward / reverse jog control of the variable frequency motor and stepper motor connection.The key parameters such as voltage,current,wire feeding speed,and shielding gas flow of the welding machine were determined through automatic repair welding tests of different guide vanes.Tests show that the system meets the control requirements for automatic surfacing of turbine guide vane repairs.The control system of the hydraulic turbine guide vane repair automatic overlay welding device designed in this paper has high positioning accuracy,stable operation and easy implementation.It provides technical support for the automatic transformation of the repair of the turbine guide vanes,improves the efficiency for the enterprise,and has high practical and promotional value. |
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