Coordinating regulation and demand response in electric power grids: direct and price-based tracking using multirate economic model predictive control

Abstract

We propose a framework for reducing demand-supply imbalances in the grid, by jointly controlling both the supply-side electric power regulation together with the demand-side energy consumption by residential and commercial consumers’ demand response. We focus on performance improvements that arise from the complementary dynamics: regulation allows for frequent control updates but suffers from slower dynamics; demand response has faster dynamics but does not allow as frequent control updates. We propose a multi-rate model predictive control (MPC) approach for coordinating the two services, and we refer to this coordinator as an aggregator. Multi-rate MPC captures the varying dynamics and update rates, and nonlinearities due to saturation and ramp rate limits, and a total variation constraint limits the switching of the demand response signal. Our approach can operate with both direct reference or indirect market price-based imbalance signal. Numerical examples are presented to show the efficacy of this joint control approach.