Disturbance observer based generalized wind/solar/battery consistent control strategy for AC microgrids

Although the distributed renewable energy source is an advisable solution for ac microgrids to reduce fuel consumption and CO₂ emission, the fluctuation and uncertainty of renewable energy source also brings significant problem to the safe and stable operation. Based on this, a disturbance observer method based on generalized wind/solar/battery consistent model is proposed in the primary control level. Firstly, it is through establishing the analogy model between the interface wind rectifier circuit and the interface solar/battery boost circuit that the equivalent model of the isomorphic solar/wind/battery with single input and single output (SISO) is first proposed in this article. With this effort, the wind, solar, and battery can achieve the consistency of the generalized model, which reduces the design complexity of the following control strategy. Furthermore, in order to solve the fluctuation and uncertainty problems, a continuous-time disturbance observer is introduced to control the equivalent generalized SISO model, which can achieve quick response, stable operation, and no-difference adjustment under disturbance. Finally, the effectiveness of the proposed method is verified by simulation results.