This article presents a novel load frequency control (LFC) method using an adaptive internal model of a power system, where model predictive control (MPC) technique is applied to the internal model, which is being updated on‐line. The proposed method will improve the LFC performance by reducing model identification error and by handling the disturbance effectively. Novelty lies in the combination of MPC and the effective use of the internal model to meet the response time of real world LFC control, which is typically equivalent to generation dispatch control cycle. The effectiveness of the proposed control is confirmed by simulations using a three‐area power system model. The results show that the proposed method can accurately identify the target plant and successfully handle disturbances to realize a reliable LFC. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.