Robust Control of Variable Speed Refrigeration System by Simplified Model Reference Adaptive Control Applying Pre-filter

Abstract

This paper aims to design a simplified model reference adaptive controller (S-MRAC) with pre-filters for robust, high-precision control of a variable-speed refrigeration system (VSRS) amidst model uncertainty and disturbances. The S-MRAC is based on the MIT rule, utilizing parameters that minimize a cost function. It features a simple structure and optimized design parameters. Simulations and experiments demonstrate the S-MRAC's robust control performance against VSRS model uncertainties and disturbances. Compared to a conventional PI (Proportional-Integral) controller, the S-MRAC exhibits a faster settling time, less undershoot, and reduced steady-state error, enabling more precise and robust control. Consequently, the S-MRAC provides robust control that fundamentally eliminates the need for controller maintenance, even with environmental changes affecting the VSRS over time.