###### Abstract
Reference [26] introduced ADRC into the inverted pendulum system, achieving dual stable control of the swing angle and the position of the trolley. Reference [28] improves the current quality of the input grid of the photovoltaic three-phase grid connected inverter by applying ADRC. Reference [29] uses ADRC to ensure the displacement tracking accuracy of the robot's robotic arm. Reference [30] utilizes ADRC control to reduce the impact of amplitude disturbance on hydraulic motor systems. The engineering applications of ADRC in different control objects fully demonstrate the superiority of its control performance, which is of great reference significance for further research on ADRC in optimizing the voltage regulation performance of CCM flyback converters. This paper proposes a second-order LADRC strategy based on the output voltage to optimize the dynamic anti-interference performance of a CCM flyback converter. First, establish a small-signal model for the controlled object CCM flyback converter. Then, the basic framework of second-order LADRC is constructed, equivalent to a two-degree-of-freedom system. The controller parameter design method was constructed by analyzing the Bode diagram of its equivalent transfer function. A simulation model was built using MATLAB R2022b software, and it was compared with the PID control algorithm. Finally, a prototype of a 72 W flyback converter was constructed, and further comparative experiments were conducted using the dSPACE semi-physical simulation platform. The experimental results showed that the second-order LADRC strategy based on output voltage proposed in this paper effectively improves the anti-interference and robustness of the CCM flyback converter. The main contributions of this article are as follows:(1) A second-order linear active disturbance rejection control method is proposed for the anti-interference performance of the output voltage of CCM flyback power converter. (2) The proposed control scheme includes equating the controller to a two degree of freedom system and establishing a parameter tuning method for designing controller parameters by analyzing the Bode diagram of its equivalent transfer function, reducing the parameter trial work of engineers when applying the control algorithm. (3) In order to validate the proposed design method, the LADRC-CCM flyback converter system was simulated in Simscape Electrical of MATLAB and compared with the traditional PID scheme. (4) This article provides a detailed introduction on how to combine the hardware of power electronic converters with the dSPACE semi physical simulation platform for experiments, reducing the time for physical construction, accelerating the experimental process, and providing reference for other researchers in experimental methods. (5) Compared with the traditional control algorithm PID, the proposed second-order LADRC outperforms the traditional PID controller in terms of load disturbance and other aspects in the designed situation. (6) The research results provide important references for the promotion and design of ADRC in power electronic converters, and also provide a necessary theoretical basis for further optimizing the control methods of CCM flyback converters. The rest of this article is organized as follows: The mathematical model of the CCM flyback converter is obtained in Section 2. Section 3 provides an overview of the LADRC controller. This section also elaborates on the method of controller parameter tuning. Section 4 introduces the simulation and experiment of the designed control algorithm applied in the converter, and compares and analyzes the results. Finally, the conclusion is drawn in Section 5.