08-12-2012, 05:12 PM
SLIDING MODE SPEED CONTROL OF A D.C MOTOR
SLIDING MODE SPEED.pptx (Size: 113.49 KB / Downloads: 41)
Abstract
This paper presents a separately excited DC motor speed control scheme using sliding mode control
technique. The mathematical model suitable for sliding mode control is derived. A straight-line
switching surface is proposed, and a controller is designed to guarantee that the operation on sliding
surface is reached and sustained. The simulation results and experimental results are presented. The
performance of the proposed controller is evaluated under various operating conditions and compared
with conventional PI controller.
The performance of the proposed controller is evaluated under various operating conditions and compared
with conventional PI controller.
Introduction
1.d.C motor have occupied a wide spectrum of application for variable speed drive.
2.In these method, the state estimation and parameter identification are based on and limited to linear model.
3.Sliding mode controling is one of the effective and robust means of controling the non linear system.
4.There are many excellent properties in sliding mode control,such as, insencitivity to parameter variation and distrubances.
5.The feature of the switching surface is that when the rotor speed response reaches its steady state value. The swiching surface become linear.
Experimental result
To verify the proposed concept a laboratory setup
was made with a DC motor drive. It was found
that step changes of speed for PI controller where
speed change gradually for sliding mode controller
conclusion
A new switching surface is proposed for a DC
motor speed control system. The simulation and
experimental results show that the sliding mode
controller has the fast speed response, determined
by the switching surface, and is obtained without
overshoot. By applying random speed disturbance
up to ± 3%, the speed response of PI controller is
slightly oscillatory, whereas the speed response of
sliding mode controller is perfectly smooth. The
control system is insensitive to the motor parameter
variation and load torque disturbances.