Design Of AC-AC Frequency Conversion Speed Regulation System For 1780mm Tungsten Molybdenum Alloy Hot Mill Main Drive

With the rapid development of aviation and aerospace industry,enterprises are increasingly demanding the quality and output of tungsten-molybdenum sheet products.At the same time,energy-saving,emission reduction,consumption reduction,and efficient lean production methods are increasingly becoming shortcuts for enterprises to improve their competitiveness.It is necessary to improve the quality of all aspects of actual production.The main drive system of the hot rolling mill,which is the key link in the production process of tungsten-molybdenum strip,plays an important role in the quality index of the two main products of the plate-shaped plate thickness.As a highly efficient AC drive,the synchronous motor's AC frequency conversion has been successfully applied to the main drive system in the production of strip and strip hot rolling mills.This paper focuses on the design of power supply system,controller hardware design and regulator algorithm application of the main drive synchronous motor of the tungsten-molybdenum sheet hot rolling mill.First of all,The production process of the 1780 tungsten-molybdenum sheet reversing hot rolling mill and the composition and working principle of the main production equipment were analyzed.According to the control performance index of the main rolling mill,the configuration scheme of the main circuit rectifier transformer and the three-phase thyristor rectifier of the stator circuit of the synchronous motor of the main rolling mill was designed,and the parameter calculation and selection were carried out.At the same time,the rated parameters of the excitation main loop rectifier transformer and the excitation thyristor converter are designed,and the selection and scheme configuration are carried out.Secondly,The main drive synchronous motor is designed based on the hardware configuration scheme of Siemens SL150 digital control system,and the data acquisition and monitoring system design is carried out.The structure and parameter selection of AC current regulator,DC current regulator,rotor excitation current regulator,flux regulator and speed regulator in synchronous motor vector control system are analyzed.The main mill load observer algorithm is designed and the load balance control scheme is studied.Finally,the designed main rolling mill synchronous motor is handed over to the variable frequency speed control system for debugging software and hardware preparation,actual value calibration,open loop control,intermittent current regulation,rotor position detection,excitation establishment,no-load debugging,HMI mode selection and Optimization in speed control mode and commissioning with load.The running curve verifies the feasibility of the designed system.