Investigating delays in frequency-dependent load control

Increased penetration of renewables will require significant regulating reserves, so there is a need to re-think the traditional operating paradigm: supply follows demand. Recent work has expanded the role of flexible and controllable energy resources, such as energy storage and dispatchable demand, to regulate power imbalances and stabilize grid frequency. However, as shown in this paper, the large-scale deployment of dispatchable (i.e., controllable) loads needs to carefully consider the existing regulation schemes in power systems, i.e., generator droop control. That is, this paper illustrates with a standard linearized model, the complex nature of system-wide frequency stability from time-delays in actuation of dispatchable loads and the effect of different network topologies. Interestingly, we show that delay-induced instability can be stabilized by injecting additional delay into load controller.