Linear active disturbance rejection control for the LCL-type grid-connected inverter based on improved bandwidth method

With the increase of distributed generation penetration, the inertia of the new power system decreases significantly. In order to reduce the effects of network disturbance, variable coupling and model mismatch, a linear active disturbance rejection control strategy based on improved bandwidth method is proposed. First, a first-order linear active disturbance rejection controller is designed for the LCL grid-connected inverter. Secondly, the bandwidth method is improved to solve problems such as the difficulty in selecting the initial value of the linear active disturbance rejection controller and the imperfect parameter tuning process. The regulation rules of bandwidth ratio and bandwidth center are introduced. At the same time, combined with the D division method of S domain, the appropriate parameters are selected according to the stable region, which improves the design efficiency and rationality of the parameters of the linear active disturbance rejection controller. Finally, the simulation and experiment verify the effectiveness of the method.