Safe Protocol for Controlling Power Consumption by a Heterogeneous Population of Loads

TL;DR

This paper introduces a 'safe protocol' for adjusting thermostatically-controlled loads' set points to change aggregate power consumption quickly while avoiding oscillations, enhancing control and energy management.

Contribution

It proposes a novel 'safe shift' method for set point adjustments that prevents power oscillations and is analytically and numerically validated.

Findings

Safe set point shifts change power within TCL cycle durations

The method avoids undesirable power oscillations

Potential to mitigate abnormal energy generation impacts

Abstract

Recent studies on control of aggregate power of an ensemble of thermostatically-controlled-loads (TCLs) have been concentrated on shifting the temperature set points of each TCL in the population. A sudden shift in the set point, however, is known to be associated with undesirable power oscillations which require closed-loop control strategies to regulate the aggregate power consumption of the population. In this article, we propose a new approach which we term as a "safe protocol" to implement the shift in temperature set point. It is shown analytically and verified numerically that by shifting the set point "safely" the aggregate power consumption can be changed to a different value within a time frame of the order of a TCL's cycle duration and avoid the undesired oscillations seen otherwise in a "sudden" shift. We discuss how the excess aggregate energy transferred under a safe shift in the set point could potentially mitigate the burden due to abnormal energy generation within a short time span.