Distributed frequency control via demand response in smart grids

Frequency control is essential to maintain the stability and reliability of power grids. For decades, generation side controllers, e.g., isochoronous governors and automatic generation controllers, have been used to stabilize the frequency of power systems, which, however, incur high operational costs. In smart grids, demand response can be used to control frequency and thus reduce the grids´ dependency on expensive controllers. Despite of its economic advantages, the synchronization problem, which is due to the simultaneous responses of smart appliances, becomes the main barrier to implementing frequency responsive demand control in reality. In this paper, we propose a distributed control algorithm for smart appliances, based on the randomized frequency monitoring and a baseline hysteresis algorithm, to solve the synchronization problem. We provide analytical results to characterize the influence of distributed demand response on the system frequency dynamics. Finally, we validate our analysis and demonstrate the effectiveness of our proposed algorithm via simulations on the Ireland power system.