Research On Adaptive Control Of Permanent Magnet Synchronous Motor

As the actuating equipment of the servo system, permanent magnet synchronousmotors have become the main stream of servo driving system by possessing a variety ofadvantages such as small size, low noise, low inertia, high efficiency, high power factor andhigh torque-current ratio, widely used in different areas of production.In this paper, the adaptive control algorithm for PMSM has been researched and verifiedby simulation. As a major branch of the adaptive method, model reference adaptive controlhas been widely used and very mature for application. For the time being, the research onmodel reference adaptive control of permanent magnet synchronous motor is also verycommon at home and abroad, but most of them have adopted continuous control scheme thatis not suitable for the application by using digital chip in a discrete way. This paper uses thediscrete model reference adaptive scheme and does research on adaptive control of PMSMbased on vector control system. Make a brief introduction to the basic principles of one-stepahead prediction and control, analyze model reference adaptive control method combinedwith least squares parameter identification, and the method is applied to the design of thespeed controller for PMSM. Simulation study has shown that the speed controller has a goodcontrol performance. Based on that, kalman filter is used in place of the least squares methodfor parameter estimation to further improve the performance of system at low speed.Because of the dead time effect, the waveform of inverter's output voltage andcurrent are distorted which results in a direct bad impact on the performance of permanentmagnet synchronous motor. Based on analyzing the dead time effect, according to thevector-controlled PMSM model, the relationship between dq-axis compensation voltage and aaverage dead time compensation time is investigated. The q-axis disturbance voltages areconsidered as disturbance variables in the state equation. Then using an adaptive observer, theaverage dead-time compensation time is calculated on line. At last, compensate the voltagesource inverter in the dq-axis by coordinate transformation, matlab simulation results provethat the proposed method is simple and effective.