As the cornerstone of adjusting microgrid output, the electrical load interface unit is difficult to continuously output desired dynamics under various uncertainties. To handle the problem, a variable form linear active disturbance rejection control (VFLADRC) including extended state differential compensation is proposed for load interface unit according to the separating response. In this technology, the extended state differential is embedded in the linear extended state observer (LESO) to construct a modified LESO, alongside the control law is generated via a feedforward way. By doing this, the attenuation capability of generalized disturbance response in the system output is improved, thereby optimizing output dynamics. Additionally, the stability and output characteristics of the studied scheme are theoretically investigated. It is revealed that the electrical load interface unit with VFLADRC exhibits a higher level of robustness. Finally, comparative experiments are conducted on a 40-kW test platform, which validates correctness of the analysis and the superiority of the proposed approach.