Power-imbalance allocation control of power systems — A frequency bound for time-varying loads

For secondary frequency control of power systems with lossless networks, we proposed a method named Power-Imbalance Allocation Control (PIAC) to restore the nominal frequency after a disturbance. PIAC has shown a good transient performance where under a constant power imbalance, the overshoot problem and unnecessary oscillations of frequencies are eliminated. In this paper, we evaluate the performance of PIAC on power systems with time-varying power imbalance, which is more realistic since the power supply and load are continuously changing. Analysis and numerical simulations show that PIAC is able to closely track the power imbalance and effectively controls the global frequency to a desired range for slowly changing and Lipschitz-continuous power imbalance.