Comparative Performance Analysis of PID and Sliding Mode Controllers in Speed Control of Induction Motor Drives with Intermittent Loading
Isemin Stephen Etim *
Department of Elect/Elect Engineering, Akwa Ibom State University, Ikot Akpaden, Nigeria.
Anyanime Tim Umoette
Department of Elect/Elect Engineering, Akwa Ibom State University, Ikot Akpaden, Nigeria.
Ubong S. Ukommi
Department of Elect/Elect Engineering, Akwa Ibom State University, Ikot Akpaden, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Induction motor (IM) is the most used AC machine, and it is a constant speed device. If induction motion must be used in variable speed applications, its speed must be controlled. Speed control of a squirrel cage induction motor (SCIM) using a control algorithm with proportional integral derivative (PID) and sliding mode controller (SMC) was designed, simulated, and analyzed in this paper. Three-phase SCIM was considered, MATLAB software was used for both design and simulation and decoupling of the flux and torque-producing components for separate control was done for the actual control of the SCIM drive. The motor drive was used in driving a constant load of 0% (0 Nm), 28% (4 Nm), and 62% (12 Nm) of the rated torque with a variable speed of 0 rad/s, 10 rad/s, and 25 rad/s. It is observed that SMC gave the best speed performance compared to other controllers. The steady-state error, rise time, settling time, and overshoot of the SMC model were 0.1%, 0.01 sec, 0.05 sec, and 4%, respectively while that if PID were respectively 2 %, 0.02 sec, 0.2 sec, and 16 %, when driving 4Nm under intermittent speed. The improved speed performance of the proposed SM controller can be used in robotics where high precision speed performance is required.
Keywords: Induction motor, proportional integral derivative, sliding mode controller, vector control