Switched LQ controllers for DC motor speed and current control: a comparison with cascade control

Abstract

That paper presents a methodic approach based on switched quadratic regulators for designing an efficient dcmotor speed controller. This alternative control strategy is compared with two cascade control design methods in terms of performances, robustness and complexity. Experimental results are given for each controller.

Model reference controlled separately excited DC motor

“…Several control techniques using conventional controllers have been reported for the control of SEDM [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. The learning ability, self-adapting capability, super fast computing features of artificial intelligence (AI) technology has brought a new challenge to electrical engineers who are struggling with complex, fast advancing, and interdisciplinary areas of technology.…”

Optimal State Space Control of DC Motor

“…The outer speed and inner current control loops are designed as PD or PI controllers. However, the cascaded control structure assumes that the inner loop dynamics are substantially faster than the outer one (Chevrel et al (1996)). …”

“…Umeno and Hori (1991) describe a generalized speed control design technique of DC servomotors based on the parametrization of two-degrees-of-freedom controllers and apply the design method of a Butterworth filter to determine the controller parameter. Chevrel et al (1996) present a switched LQR speed controller, designed from the linear model of the DC motor, and compare its performance with a cascade control design in terms of accuracy, robustness and complexity. Rubaai and Kotaru (2000) propose an alternative way to identify and control DC motors by means of a nonlinear control law represented by an artificial neural network.…”

Speed Control of Separately Excited DC Motor

“…An open loop control system which can predict the dynamic behavior of systems involving mechanic and electronic modules has been successfully designed and implemented to control the speed of a DC motor [4] . Several other speed control techniques using conventional controllers have been reported in [5,17] . Recently, the superior performance of artificial intelligence (AI) based controllers urged power system and power electronic engineers to replace conventional speed control circuit with intelligent speed controllers [18]- [30] .…”