Abstract

Development and analysis of non linear controllers for enhanced speed performance in induction motor (IM) is the main focus of this research. IM is a constant speed machine, this makes it not suitable for variable applications except the speed is controlled appropriately. 2.2 kW squirrel cage three phase induction motor was used as a sample motor for this work and it was modeled in Ansys rotating Machinery Expert (RMxprt)  and Ansys Maxwell 2D . The data for software modeling of the motor was extracted from laboratory experiment on 2.2kW squirrel cage induction motor. No load test, block rotor test and the load test was carried out on  2.2 kW induction motor, and some data were extracted to verify that the experimented motor and the simulated motor are the same. On the load test, the effect of load on the speed value of both the experimented and simulated motor had a negligible difference, also the core loss of the simulated motor was 44.0W while the experimented motor gave a core loss of 44.4W, hence, the simulated motor and the experimented motor are the same. Steady state behavior was gotten from RMxprt platform where the rated performances and the rated parameters were generated. The dynamic performance of the motor was analyzed in Maxwell 2D platform, where the behavior of the motor on different loading condition was studied. The parameters generated form RMxprt were extracted and used for conventional modeling of the 2.2kW induction motor in MATLAB/Simulink, and this model was used for developing an induction motor vector control drive for speed control. The dynamic behavior of the motor was further assessed on the different loading condition using the conventional model without controller. The controllers used for this work include Proportional integral derivation controller, Fuzzy logic controller, hybrid FLC-PID controllers, Genetic Algorithm hybrid controller (FLC-PID-GA) particle swarm optimization hybrid controller (FLC-PID-PSO) and these controllers were designed in MATLAB/Simulink. The performance of the induction motor with these controllers using vector speed control technique in variable speed operating condition were analyzed and compared in terms of steady state error, overshoot, undershoot, rise time and settling time. The operating conditions considered were constant speed on constant load, constant speed on intermittent loads, varying speed on constant load, and varying speed on intermittent load. Non-linear load was also tested on the induction motor. It is observed from the simulation results that FLC-PID and FLC-PID-PSO controllers on driving the induction motor with the reference speed of 30rad/s on constant load, the percentage peak overshoots were 9.7501% and 1.374%, and steady state error were 2.45% and 0.183% respectively. Also the speed reaches its desired set value at 0.072 second in FLC-PID-PSO and 0.13 Sec in FLC-PID. While in varying speed and intermittent load condition,  FLC-PID and  FLC-PID-PSO controllers have percentage peak overshoots of 8.32 % and 0.64%, and steady state error of 0.313% and 0.28% respectively. The reduction in the steady state error and overshoots in the induction motor regulated speed at the stated operating operations has shown the effectiveness of FLC-PID-PSO controller. From the results, it is established that FLC-PID-PSO controller has produced the best speed  performance on the operating conditions considered, and the errors realized with FLC-PID-PSO controller is negligible that it can be comfortably used in the most  applications such as Mixers, Cranes and submarine robotic  divers that have high speed precision requirement.