Linear Active Disturbance Rejection Control Design for Single-Phase UPS Inverters

This paper presents a step-by-step analysis of the Linear Active Disturbance Rejection Control (LADRC) for single-phase Uninterruptible Power Supplies (UPS) application. In UPS application, the regulated output voltage with low Total Harmonic Distortion (THD) under different load conditions and disturbances is the desirable. To achieve this goal, LADRC is appropriate since it uses the state observer similar to the modern control theory. Also, this control method inherits the PID controller’s simplicity, it is not a model-based controller. Moreover, it is useful for experimental platforms since it can control the system even there was weakness in the modeling of the system. Finally, a 1kW single-phase UPS has been simulated in Matlab/Simulink to verify the theoretical analysis as well as the operation of the LADRC in this application.