| Whether the hydroelectric generating set can operate efficiently and provide high-quality power mainly depends on the working stability for the pilot valve of the hydraulic turbine governor.However,the working stability of the pilot valve depends on the driving performance of the pilot valve driving device.At present,the pilot valve driving device in the governor is mostly drived by electromagnetism,having the characteristics of simple structure and easy control,but it has also some disadvantages such as low control precision,difficult control of the driving force size and poor resistance to external magnetic field interference.Piezoelectric stack is widely used in the field of micro-drive by virtue of its high control accuracy and output displacement resolution,strong resistance to magnetic field interference,accurate driving force control and other advantages.Therefore,this paper uses piezoelectric stack as driving source for the design of pilot valve driving device to improve the deficiencies of existing pilot valve driving device.Taking the design of pilot valve driving device as core,based on the analysis on the application and research status of the pilot valve driving device at home and abroad,this paper proposes a kind of pilot valve driving device of hydraulic turbine governor based on the piezoelectric stack;it studies the piezoelectric effect and the piezoelectric equation of the piezoelectric material,the piezoelectric stack structure and the inherent characteristics of the piezoelectric stack,designing displacement amplifying structure to realize the amplification for the output displacement of the piezoelectric stack and meet the travel requirements of the driving device,and uses ANSYS simulation software to simulate and optimize the amplification mechanism designed;finally,the test prototype is processed and the test platform is set up,to conduct experimental test and analysis on driving device prototype designed. |
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