Extended Disturbance Observer Based Execution Adjustment Estimation Method of Dynamic Demand Response

Since Dynamic demand response (DDR) has the characteristics of large quantity and uncertainty, it is difficult to get accurate response power in real time. At the same time, it is very important to know the execution adjustment of DDR accurately and quickly for updating DDR control strategy and frequency regulation of power system. In this paper, we design an extended disturbance observer (EDO) to estimate the execution adjustment of DDR. Firstly, in order to facilitate the design of estimation scheme, a simplified load frequency control (LFC) model is obtained by using model fitting method. Then, by combining the load variation with tie-line power exchange as an extended disturbance, a reduced-order LFC model of power system is derived. Finally, based on the reduced-order LFC model, EDO can be designed by pole-assignment method. The execution adjustment of DDR can be obtained by subtracting the measured value of tie-line power from the estimated value of the observer. From the simulation results of a multi-area LFC control system, the effectiveness of the proposed scheme is demonstrated.