Abstract:
This work focuses on investigation and evaluation of the performance of a permanent
magnet brushless dc motor (BLDCM) drive, controlled by PID or fuzzy logic control
techniques. The mathematical models of brushless DC motor with sinusoidal back EMF
supplied from three-phase inverter operating at 180o conduction mode, and that with
trapezoidal back EMF supplied from three-phase inverter operating at 120o conduction
mode are given. In the simulation part the mathematical models are transferred to simulink
models for PID and fuzzy logic control techniques. The gate driving simulink models
for each control technique and for each mode of operation are designed and implemented.
The system speed responses under the influence of load changes and set speed changes
are presented. The three-phase currents, voltages, and electrical torque waveforms are
presented. An experimental setup was constructed and tested. It consists of BLDCM,
inverter, DC generator with variable resistive load and two personal computers .The
load is automatically changed during operation by switching on and off relay contacts
controlled by microprocessor. The fuzzy or PID control algorithms are implemented in
one of the used personal computers while the other computer is used for data logging
via a data acquisition card. In this study the system performance with PID controller and
fuzzy controller is investigated and tested to achieve speed control under different loads
and set speeds.