The Design Of Subsection Moving-phase Six-phase Permanent Magnet Linear Servo Motor Control System

With the development of modern advanced numerical control (NC) machines, the performance of the linear servo system is more and more important and the research of direct drive of permanent magnet linear servo motor (PMLSM) is meaningful. The reasons of thrust ripple of PMLSM are analyzed, and because the large thrust PMLSM used for NC machine has the characteristic of short primary, long secondary and flexibility of installation with several motors'parallel drive, the PMLSM's design method of moving phases is introduced. The mechanism which reduce the thrust ripple caused by the ending effect of PMLSM is analyzed from the view of motor design, and subsection moving-phase six-phase PMLSM control system is designed from the view of control based on this mechanism. By choosing control strategy properly, other disturbances which can cause the thrust ripple of PMLSM possibly are restrained effectively so that the thrust ripple can be reduced further. At the same time, the robustness, the disturbance rejection, the steady-state performances and the dynamic performances are improved.The end effect is the main reason for thrust ripple of PMLSM, and the thrust ripple caused by the end effect is more serious for large thrust and several motors'parallel drive. For reducing the thrust ripple of PMLSM, the paper uses the method of subsection moving-phase to two-module PMLSM of permeability modulation, so that second harmonic components playing the leading role in thrust ripples caused by end effects in the two-module motor can cancel out to achieve the purpose of weakening end effect thrust ripple.Except that the end effect and cogging effect can produce thrust ripple, load disturbance, system's nonliner and coupling, mover quality and the changes of viscous friction coefficient, permanent magnet's magnetization inhomogeneity, motor electromagnetic parameter changes caused by ambient temperature and humidity and time-delay perturbation can also produce thrust ripples inevitablely. In response to these factors, different control system's simulations are conducted basing on three controllers which are PI, standard ADRC and new simplified ADRC, and the system designs weaken the thrust ripple further and improve the system's robustness, disturbance rejection, steady-state and dynamic-state performance at the same time.Subsection moving-phase six-phase PMLSM control system contains many advantages, including multiphase system's high reliability, reducing of magnetomotive harmonic losses, achieving high-power using low-voltage devices, high efficiency and eliminating 4 n±2 harmonic components in thrust rippling caused by end effect. Taking vector control as the core of the system, the hardware platform and software framework are constructed basing on TMS320F2812 DSP, and the effectiveness of the system is verified by means of experiments and simulations. The results provide the possibility for the development of more advanced control algorithm for the future.