Improved Battery Models of an Aggregation of Thermostatically Controlled Loads for Frequency Regulation

TL;DR

This paper enhances battery models for aggregations of thermostatically controlled loads (TCLs) used in frequency regulation by optimizing clustering and analyzing ramping constraints, supported by theoretical and simulation results.

Contribution

It introduces an improved stochastic battery model for TCL aggregations by optimal clustering and analyzes the effects of no-short-cycling constraints on regulation performance.

Findings

Optimal dissipation parameter improves clustering efficiency.

Imposing no-short-cycling constraints affects ramping capabilities.

Simulation results validate the theoretical models.

Abstract

Recently it has been shown that an aggregation of Thermostatically Controlled Loads (TCLs) can be utilized to provide fast regulating reserve service for power grids and the behavior of the aggregation can be captured by a stochastic battery with dissipation. In this paper, we address two practical issues associated with the proposed battery model. First, we address clustering of a heterogeneous collection and show that by finding the optimal dissipation parameter for a given collection, one can divide these units into few clusters and improve the overall battery model. Second, we analytically characterize the impact of imposing a no-short-cycling requirement on TCLs as constraints on the ramping rate of the regulation signal. We support our theorems by providing simulation results.