Design of new technology for generator guard ring expansion and its automatic control system
NI Hongqi
WU Baosheng
YANG Bing
SHAO Mingang
Abstract：[Objective]To produce high-quality generator guard rings with straight busbars,minimal machining allowance,and low residual stress,a new process was proposed to reinforce the guard rings through the linkage of a hydraulic press and an ultra-high-pressure pump.[Methods]The mold was pressed down on the guard ring by a hydraulic press.An ultra-high-pressure liquid was injected into the interior of the guard ring by using an ultra-high-pressure pump to cause plastic deformation.The deformation shape of the guard ring was controlled by precisely controlling the pressure of the hydraulic press and the ultra-high-pressure liquid injected by the ultra-high-pressure pump.When the guard ring deformed to a certain extent,due to the increase in deformation resistance,the mold needed to be replaced to continue expansion until the expected forming size was reached.Compared to the traditional hydraulic expansion process for generator guard rings,the new process used equipment with a lower cost and a higher efficiency.The material used in the manufacturing of the generator guard ring was 50Mn18Cr5.Using the analysis function of ANSYS Workbench,a finite element analysis was conducted on the changes of the outer diameter and stress of the guard ring during the expansion process.At the same time,according to the requirements of the automatic control system,the automatic control program and human-machine interface(HMI)configuration interface were designed,with a programmable logic controller(PLC)used to control the production process of the generator guard ring.Various parameters such as the diameter change,deformation speed,system pressure,and temperature of the guard ring during the expansion process were displayed on the HMI configuration interface.By detecting the diameter changes of the guard ring during the expansion process,the pressure of the hydraulic press and the ultra-high-pressure pump was precisely controlled to ensure the smooth progress of hydraulic expansion.At the same time,if both the hydraulic press and the ultra-high-pressure pump failed,the automatic control system would also issue an automatic alarm,which can protect the safety of workers and avoid major safety accidents.[Results]The finite element analysis shows that the maximum error between the change in the outer diameter of the guard ring during the hydraulic expansion process and the actual production result is only 2.312 mm,which proves the feasibility of the new process.The intuitive presentation of the working status and parameters of the equipment through the HMI configuration interface not only ensures the production quality and efficiency of the generator guard ring but also makes the operation more convenient.[Conclusion]The new process that utilizes the linkage between a hydraulic press and an ultra-high-pressure pump can effectively produce high-quality generator guard rings with straight busbars,minimal machining allowance,and low residual stress,providing an efficient and low-cost technical solution for guard ring manufacturing.
Keywords：generator guard ringlinkage between hydraulic press and ultra-high-pressure pumpguard ring reinforcement deviceautomatic control systemfinite element analysisconfiguration interfacecold deformation strengthening
Publication Date：2025-03-31
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 223-230 )