Potentials and applications of coordinated groups of thermal household appliances for power system control purposes

Abstract

In this paper, a novel load management approach using thermal household appliances is presented, which provides extensive possibilities to support power system control tasks. A recently developed coordination algorithm for a high number of small thermostat-controlled appliances requires the connection of individual appliances to a central control entity through a twoway communication channel. The control method, which does not cause significant comfort losses for users, enables the group of appliances to act like a virtual distributed energy storage. While the coordination algorithm has been presented in detail before, the contribution of this paper lies in the analysis of the aggregated behavior of coordinated appliance groups. Apart from that, a methodology for estimating the coordinated load control potential in larger areas (e.g. countries) is presented. This is illustrated by exemplary considerations on the Swiss power system, which can also be adapted to other countries. Furthermore, different applications for the gained demand-side flexibility in a liberalized electricity market are discussed.

Enabling Micro-level Demand-Side Grid Flexiblity in Resource Constrained Environments

“…The theoretical approach to demand response has motivated a wide body of work that seeks to show that large aggregations of TCLs can be used both to bid into grid related ancillary service markets for profit as well as to maintain reliable power system operations [18][19] [20][21] [22]. Detailed end-use models explore associated uncertainties in aggregating TCLs, algorithmic bidding approaches toggle load switch controllers for managing wind forecast error and reducing external balancing penalties, and control and differential equation approaches for modeling the effect of broadcasting signals for TCL set point adjustments [17][23] [24] [25]. In general, room temperature, inside temperature (of a room, or inside a refrigerator, for example), power consumption, and TCL characteristics (resistance, capacitance, and wall thickness, for example) are all used for the design of a smart controller [20].…”

Mean field game based control of dispersed energy storage devices with constrained inputs

“…One strategy is direct load control and it relies on developing aggregate models to describe the evolution of the mass probability distribution of a large population of thermostatically controlled loads (TCL) and to control their aggregate power demand to balance the load and generation. Different types of TCLs have been explored in the literature, for example, air conditioners [Callaway, 2009;Koch et al, 2009] and water heaters [Gustafson et al, 1993;Ericson, 2009]. In general, the aggregate load dynamics are often described by coupled PDE's [Laurent et Malhamé, 1994;Malhamé et Chong, 1985].…”

Centralized and decentralized balance group optimization in electricity markets with demand response

“…1 BGs are virtual aggregations of market players for accounting and billing purposes only, i.e., loads and generators are not necessarily concentrated in the same region. Several BGs are subsumed in a control area which is supervised by a Transmission System Operator (TSO).…”

“…This will create a generation-load mismatch and eventually frequency deviation from 50 Hz. The TSO compensates for frequency 1 The BG concept is used in Switzerland but also in other European countries, although it might be given a different name. An example is Germany where the name Balancing Responsible Party (BRP) is used instead.…”

“…With this information, a particular BG can track its schedule in order to minimize balancing energy costs with either of the three following possibilities: (a) adjusting the setpoints of dispatchable power plants, (b) trading in intra-day markets, and (c) using Demand Response (DR) [1]. This paper focuses on (c) and proposes one centralized and one decentralized algorithm to enable BG optimization by exploiting the flexibility of large office buildings.…”