A Stability Analysis of Thermostatically Controlled Loads for Power System Frequency Control

Figure 7

Illustration of the three types of cycling behaviour of two groups relative to one another, based on simulations. Arrows indicate the occurrence of many cycles and the central illustrations are snapshots of the cycling behaviour between the start and the final behaviour. Synchronisation occurs in cases (a) and (b), while in case (c) each group tends towards a fixed phase difference apart.