An active coordination approach for thermal household appliances — Local communication and calculation tasks in the household

In this paper, an approach to the coordinated operation of a multitude of household appliances with thermal inertia is presented, which can be used for power system control tasks. Appliances under consideration are cooling and heating devices, e.g. refrigerators, freezers, or electric water boilers, which are characterized by an intermittent (duty cycle) operation. A recently developed coordination algorithm for a large group of these thermostat-controlled appliances equipped with a two-way communication interface uses centrally computed switching impulses based on an ”offer to be switched for a certain price” from the appliances. The price calculation on the local level requires an accurate prediction of the next switching instant triggered by the thermostat. This paper develops a framework for the communication within the household and to the outside, modeling and prediction approaches for the appliance duty cycles, and a switching price calculation method. Furthermore, the impact of the coordinated control on the appliances and requirements on the in-house communication system are discussed.