Fuzzy Logic based Speed Controllers for Vector Controlled Induction Motor Drive

Optimal gain tuning of PI speed controller in induction motor drives using particle swarm optimization

“…Fuzzy rules of this controller are shown in Figure 3 [8,15] where the fuzzy variables: NB stands for negative-big, NM for negative-medium, NS for negative-small, ZE for zero, PB for positive-big, PM for positive-medium and PS for positive-small.…”

“…To take over the advantages present in both PI (zero steady-state error) and FL (negligible overshoot and undershoot) controllers, a hybridization of PI and FL controllers, called fuzzy pre-compensated PI (FPPI) controller, is done and is used as a single controller. In this by on July 14, 2010 controller, FL is used for pre-compensation [8,10,13,15,16] of reference speed, which means that the reference speed signal (ω * r ) is altered in advance in accordance with the rotor speed (ω r ), so that a new reference speed signal (ω * r1 ) is obtained and the main control action is performed by PI controller. Some specific features such as overshoot and undershoot occurring in the speed response, which are obtained with PI controller can be eliminated [15] and this controller is much useful to mine hoist load where torque/speed of the motor varies time to time.…”

Design of Tuning Mechanism of PID Controller for Application in three Phase Induction Motor Speed Control

“…Instability is caused by excess gain, particularly in the presence of significant lag [1]. Generally, stabilization of response is required and the process must not oscillate for any combination of process conditions and setpoints, though sometimes marginal stability (bounded oscillation) is acceptable or desired [1]. Mathematically, the origins of instability can be seen in the Laplace domain.…”

“…However, if the PID controller parameters are chosen incorrectly, the controlled process input can be unstable, i.e., its output diverges, with or without oscillation, and is limited only by saturation or mechanical breakage. Instability is caused by excess gain, particularly in the presence of significant lag [1]. Generally, stabilization of response is required and the process must not oscillate for any combination of process conditions and setpoints, though sometimes marginal stability (bounded oscillation) is acceptable or desired [1].…”

“…The induction motor is made up of two distinct parts, stator which is a stationary part and rotor (also called armature core windings) which is the rotary part. Induction motor is an alternating current electric machine which by excitation, produces a torque [1]. The torque result from an electromagnetic induction from the magnetic flux due to the stator core windings as a result of rotation about a fixed position in the stator core windings [2].…”