Laguerre functions based model predictive frequency and voltage control of isolated micro-grid

摘要

PI controller forms the conventional way of controlling voltage and frequency of a micro-grid. Model predictive controller (MPC) is an alternative and effective approach for micro-grid frequency and voltage control as it predicts the future outputs from the present information of the system and generates the optimized controlled input signal at every sampling instant accordingly. However as the future prediction horizon increases, control horizon should also be increased for better transient performance and stability of the system. This increases the number of variables that are to be optimized at each sample causing more computational burden and slow response of the controller. To overcome this problem Laguerre functions based MPC is employed in this paper for frequency and voltage control of isolated micro-grid instead of conventional MPC. This greatly reduces the number of optimized variables at each sampling instant for the same frequency and voltage controlled response of the micro-grid obtained using conventional MPC. The performance of the Laguerre functions based MPC in the context of frequency and voltage control of an isolated micro-grid is tested using MATLAB software package. Performance of the controller is compared with conventional MPC and discrete-time linear quadratic regulator.