Performance analysis of interior permanent magnet synchronous motor (IPMSM) drive system using different speed controllers

Abstract

The present research is indicating that the Permanent magnet motor drive could
become serious competitor to the induction motor drive for servo application. Further, with
the evolution of permanent magnet materials and control technology, the Permanent Magnet
Synchronous Motor (PMSM) has become a pronounced choice for low and mid power
applications such as computer peripheral equipments, robotics, adjustable speed drives and
electric vehicles due to its special features like high power density, high torque/inertia ratio,
high operating efficiency, variable speed operation, reliability, and low cost etc. Here we
deals with the detailed modeling of an IPMSM drive system with Hybrid PI-Fuzzy logic
controller (PI-FLC) as speed controller and Adaptive Hysteresis Current Controller as torque
controller by controlling the current components of torque.In this thesis we deals with a simulation for speed control and improvement in the
performance of a closed loop vector controlled IPMSM drive which employ two loops for
better speed tracking and fast dynamic response during transient as well as steady state
conditions by controlling the torque component of current. The outer loop employ Hybrid PIFuzzy
logic controller (PI-FLC) while inner loop as Adaptive Hysteresis Band Current
Controller (AHBCC) designed to reduce the torque ripple. Despite proportional plus Integral
(PI) controller are usually preferred as speed controller due to its fixed gain (Kp) and Integral
time constant (Ki), the performance of PI controller are affected by parameters variations,
speed change and load disturbances in PMSM, due to which it results to unsatisfied operation
under transient conditions. The drawbacks of PI controller are minimized using fuzzy logic
controller (FLC). So for this a fuzzy control technique is also designed using mamdani type,
triangular based 5x5 MFs and selecting the superior functionalities of PI and FLC, a Hybrid
PI-FLC designed for effective speed control under transient and steady state condition.The complete viability of above mentioned integrated control strategy is implemented
and tested in the MATLAB/Simulink environment and a performance comparison of
proposed drive system with conventional PI, fuzzy logic controller and Hybrid PI-Fuzzy
Logic Controller integrated separately as speed controller in terms of steady state and
transient analysis with fixed step, variable step load and variable speed condition has been
presented. Beside this a detailed comparative study of AHBCC is also done with
Conventional Hysteresis Current Control(CHCC) scheme. The simulation circuits parameters
for IPMSM, inverter, speed and current controllers of the drive system are given in
Appendix-A.