Economic MPC of Nonlinear Systems with Non-Monotonic Lyapunov Functions and Its Application to HVAC Control

TL;DR

This paper introduces a Lyapunov-based economic MPC method for nonlinear systems with non-monotonic Lyapunov functions, improving energy efficiency in HVAC control while ensuring stability and convergence.

Contribution

It presents a novel MPC scheme that relaxes Lyapunov constraints for better economic performance in nonlinear systems, with proven stability and applicability to HVAC systems.

Findings

Enhanced energy efficiency in HVAC control demonstrated

Guaranteed stability and convergence of the control scheme

Effective temperature tracking in a simulated building environment

Abstract

This paper proposes a Lyapunov-based economic MPC scheme for nonlinear sytems with non-monotonic Lyapunov functions. Relaxed Lyapunov-based constraints are used in the MPC formulation to improve the economic performance. These constraints will enforce a Lyapunov decrease after every few steps. Recursive feasibility and asymptotical convergence to the steady state can be achieved using Lyapunov-like stability analysis. The proposed economic MPC can be applied to minimize energy consumption in HVAC control of commercial buildings. The Lyapunov-based constraints in the online MPC problem enable the tracking of the desired set-point temperature. The performance is demonstrated by a virtual building composed of two adjacent zones.