Automatic voltage regulator design by modified discrete integral variable structure model following control

In power systems, the automatic voltage regulator (AVR) is designed to make the terminal voltage to accurately track the deviation of the reference vo ltage. To achieve the desired requirements, this paper proposes the modifie d discrete integral variable structure model following control (MDIVSMFC) a pproach. The MDIVSMFC approach comprises a reference model part for specify ing the design requirements and a MDIVSC part for minimizing the errors bet ween the plant and model. The non-ideal sliding motion is introduced to tak e the place of the ideal sliding motion in discrete-time systems. Its exist ence conditions are used to adapt the proposed approach to the discrete sys tems. The application of MDIVSMFC to an AVR design is developed. Procedures for determining the control function, the coefficients of the sliding surf ace and the integral control gain are also proposed in detail. Simulation r esults are compared with the IEEE type-I voltage regulator to demonstrate t hat the proposed scheme can achieve fast and robust responses. (C) 1998 Els evier Science Ltd. All rights reserved.