Investigation of Frequency Dependency of Residential Loads in Modern Power Systems: An Experimental Approach

The increasing penetration of power electronic-based or -interfaced resources and loads leads to a reduction in the overall system inertia. As a result, the modern power network can experience faster and larger frequency changes under power imbalances. This highlights the importance of a better assessment of network parameters, such as the frequency dependency of loads and active resources. So far, studies on load behavior have mainly focused on voltage dependency, and very few have investigated frequency dependency. The frequency dependency parameters used in recent publications are still mainly results obtained between 1940 and 1980. Load technology has changed since. Therefore, this paper focuses on the identification of the frequency dependency of modern passive residential loads and active resources through experiments on real appliances. For this purpose, the perturbation-based identification method is used: an apartment-like laboratory is supplied by a three-phase voltage amplifier to create artificial frequency variations. The frequency dependency is then calculated from the recorded power responses.