Research On Control Strategy Of Doubly Fed Linear Motor Based On Stator Flux Oriented

With the development of urban rail transit system, According to the advantage of small turning radius, direct drive, good climbing ability.urban rail transit train driven by linear motor has been more and more attentioned. Linear motor in urban rail transit system is a linear synchronous motor and linear induction motor are widely used, double feeder machine has the characteristics of the linear synchronous motor and linear induction motor, it can realize asynchronous, synchronous and doubly-fed operation mode, so it is of great significance, Based on the study of doubly-fed linear motor,its control is the first,and then analyzed to derive its use in urban rail lines in different times and matching speed, in consideration of the case of reactive power, the best match of control mode is found.Firstly, according to the rotary motor, the working principle of double-fed linear motors are described in more detail by use the knowledge of motors unified theory, and an equivalent mathematical model in the d-q coordinate system is established.the d-axis stator flux oriented frame is selected, based on the rotational speed of the outer ring and the outer ring speed outer flux reactive outer ring were derived and theoretical contrast, the double-fed linear motor stator flux oriented dual-loop control system is designed; the both conditions in the use of theoretically are analysised, and their own vector control block diagram are established.voltage feedforward compensation design method is designed for incomplete decoupling stator flux mover outer side of the current,voltage feed-forward compensation before the fast dynamic response simulation shows better decoupling use;flux differential feedback method is designed for the magnetic flux orientation chain oscillation problem, and it is analysised and researched,parallel simulation is contrasted that differential flux effectively suppresses flux oscillations. By comparing the flux and reactive outer ring outer ring, both in steady-state performance on a par, but the response rate, the reactive flux faster than the outer ring outer ring.Secondly,the problem doubly-fed linear motor’s energy is analyzed under different conditions,the energy of the rotor and the stator outer side of the flux control is quantitative analysised and calculated,then according to the rotor side energy issues,the energy formula is gived,and the doubly-fed linear motor rotor side energy conservation formula derivated.based on the relationship between energy consumption and the length of time is got at different speeds matching.and matching problems are derived.. By changeing the double-fed linear motor’s additional parameters to verify the accuracy of the formula. And the line length inequality and super-synchronous and secondary synchronization time inequality are obtained, the critical point of these three issues are solved.Finally, according to the reactive power analysis, the best match in terms of speed and time line of the doubly-fed linear motor matching is established, By controlling the stator frequencyin order the energy in meeting the conditions for the train running as far as possible in the frequency of the synchronization condition for a long time relationship.