Title :
A new PWM control strategy for the buck converter
Author :
Wu, Chao-Cheng ; Young, Chung-Ming
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ. of Sci. & Technol., Taipei, Taiwan
fDate :
6/21/1905 12:00:00 AM
Abstract :
A new PWM control strategy for the buck converters is presented. The proposed control strategy is based on the switching converter large signal average model linearization and use modern control theory to achieve the control laws for the expected response. Therefore, a new nonlinear PWM controller is made to implement the control law. The new nonlinear PWM controller development is based on the error between the switched variable and the control reference of expected system response to zero each cycle. As a result, the system transfer functions are derived as a function of the desired closed loop poles. Simplifying the design procedure and bringing forward all the important characteristics of the closed loop system. From a conventional control point of view: first, the proposed PWM control strategy such uses an observer approach both to reconstruct an inductor current state and to control the converter based on a current mode technique. Second, this technique also a method of indirectly implementing the sliding-mode control law. The proposed control strategy has significant advantages over conventional current mode control techniques in noise susceptibility, dynamic response and without inductor current sensing. Finally, the simulation results confirm the theory
Keywords :
DC-DC power convertors; PWM power convertors; control system analysis; control system synthesis; dynamic response; electric current control; linearisation techniques; observers; switching circuits; variable structure systems; PWM control strategy; buck converter; closed loop poles; control design; control laws; control simulation; design procedure; dynamic response; large signal average model linearization; modern control theory; noise susceptibility; nonlinear PWM controller; observer approach; sliding-mode control law; switching converter; transfer functions; Buck converters; Control systems; Control theory; Error correction; Inductors; Nonlinear control systems; Pulse width modulation; Pulse width modulation converters; Sliding mode control; Switching converters;
Conference_Titel :
Industrial Electronics Society, 1999. IECON '99 Proceedings. The 25th Annual Conference of the IEEE
Conference_Location :
San Jose, CA
Print_ISBN :
0-7803-5735-3
DOI :
10.1109/IECON.1999.822189