Extraction of Dynamic Frequency Response Characteristics and Modelling of Modern Air Conditioners

Modern inverter-based air-conditioners (IACs) are generally equipped with power-electronic components to achieve higher efficiency and more advanced controllability. Thus, their operating behaviours can be very different from the conventional air-conditioners with direct motor connections, and their new characteristics have not been adequately studied in the current literature. Thus, hardware experiments are conducted to extract the novel dynamic frequency response features of modern inverter-based air-conditioners under a range of different frequency disturbances. Then, a new IAC model with physical meanings is developed by accommodating the discovered new features such as time delays, load frequency relief and the minimum operating power limit. Further, this letter also demonstrates that the developed air-conditioner model can accurately represent the dynamics of the IACs under various frequency events. The extracted dynamic frequency response behaviours and the developed air-conditioner model will provide a solid foundation for the modern appliance modelling in a large scale and will assist to improve the accuracy of the inertia response representations of distribution network’s loads.