Electromechanical Dynamics Analysis Of A Single Stand In Flexible Roll-Die Forming Machine With Load Factors

Variable cross-section roll forming products are lightweight,and the reason why they can meet the requirements for use is that they have excellent cross-section characteristic.The component whose cross-section changes in height direction can be manufactured in the flexible roll-die forming machine,and whether it turns out to be good or not is directly determined by the machine's dynamic mechanical variation.In this paper,a coupling problem of electromechanical system has been studied in the flexible roll-die forming machine.In order to obtain the mechanical variation of a single stand in flexible roll-die forming machine,the Lagrange-Max well method is used to establish its electromechanical system dynamics equation,then to solve it by numerical method.This paper's main contents are as followed:To study the electromechanical system of the flexible roll-die forming machine,physical model of permanent magnet synchronous motor(PMSM)is abstracted according to its structure.Based on the coordinate system and reasonable assumptions,the Lagrange-Maxwell equation of permanent magnet synchronous motor is established under three-phase stator coordinate system.For the purpose of removing the calculation difficulties caused by rotor's electrical angle,Park coordinate transformation is used to transform the equation into a two-phase rotor coordinate system.According to three-phase voltage inverter,it is described in this paper that what is voltage space vector pulse width modulation(SVPWM)control algorithm and how to use it.The second stand of the flexible roll-die forming machine is studied after analyzing its mechanical structure.The stator electric charge of Z-direction&roll drive servo motor and rotation angle of the roll are selected as the generalized coordinates of the electromechanical system.Lagrange-Maxwell electromechanical system dynamics equation of the second stand in the flexible roll-die forming machine is established in the same way as PMSM's mathematic modeling.And Park coordinate transformation is used to simplify it.The classical Runge-Kutta method(RK4)is used to solve the electromechanical dynamics equation.Id=0 vector control strategy which is based on SVPWM is proposed.Then,we can get mechanical variation of two motor's d-q axis current,roll's rotation angle,velocity and acceleration.By analyzing these results,it can be obtained that load has a great influence on two motors' current variation while it has a little effect on the roll rotation velocity.This shows that the electromechanical system dynamics equation is established correctly and the control strategy is reasonable and effective.