Paper Title
Speed Observer and Motion Controller Design for Permanent Magnet Synchronous Motors
Abstract
Permanent magnet synchronous motor’s (PMSM) three phase stator currents are decomposed into flux generating
current and torque generating current using mathematical Park and Clarke transformations and decoupling methods, so that
PMSM is controlled like DC motor with high efficiency and with high performance. PMSM is controlled cascaded control
structure consisting of three main control loops which are current, speed and position control loops and current loop consists of
two loops which are d current, related with flux, and q current, related with torque. One of the most important criteria whil e
designing cascaded control loops is bandwidth. Control loop with higher bandwidth means, lower settling time that defines
how fast control is occur. While designing control loops with desired bandwidth, small overshoot is acceptable for current
loop; However, overshoot and steady state error for position control loop and for speed control loop are undesirable. Moreover,
for low speed application speed observer is necessary, since incremental encoder resolution is decreased in low speed control.
According to mentioned problems and design criteria, in that paper it is described that current loop with state feedback
decoupling, PID controller with pseudo feedback derivative current controller design, speed control loop with approximate
first order transfer function using PI controller with no overshoot and no steady state error, proportional (P) position controller
guaranteeing no overshoot in desired bandwidth and that PID liked full order speed observer with approximated first order
transfer function.Controllers and observer designs are simulated in Matlab Simulink
Keywords- PMSM, Motion Control, Cascaded Control, Pseudo Derivative Feedback, State Feedback Decoupling,
Bandwidth, Speed observer, Speed Control with no overshoot.