The tolerance improvement method for adjustable speed drive based on fuzzy field-weakening vector control under voltage sag

Abstract

Adjustable speed drive (ASD) has been widely used in modern industrial production process, however it is sensitive to voltage sags, resulting in the huge economic losses. Firstly, this paper researches on the response characteristics of DC link voltage, torque and speed of ASD under voltage sags and finds out the key parameters of control strategy which effect on the tolerance of ASD. Secondly, a fuzzy PI control method is proposed to adjust adaptively the control parameters of ASD in time to enhance the tolerance of ASD under voltage sags. Furthermore, this paper presents a field-weakening control method that reduces the reference flux value according to the residual voltage of voltage sag automatically, which ensures that ASD can operate within the acceptable range under the steady-state of voltage sag. Finally, this paper builds ASD simulation models based on MATLAB/Simulink and experimental platform in laboratory, to verify that the proposed fuzzy field-weakening vector control method. Both the simulation and experimental results show that ASD with the proposed method has better tolerance than with the traditional control method.© 2017 Elsevier Inc. All rights reserved.