Decoupling Control Strategy for Multi-function-form Realization of Medium-voltage AC Port of Electric Energy Router

The medium voltage AC port(MVAC) of electric energy router(EER) requires multiple functional forms such as active power following, reactive power compensation and active filtering, and the multi-form control has strong coupling characteristics. In this paper, two-dimensional analysis of power and current were used. From the power dimension, the instantaneous active power is decomposed under the dq frames. By injecting negative-sequence current and adjusting the active power deviation, the imbalance control problem was solved. From the current dimension, a control scheme was proposed to adjust the unified component of fundamental positive-sequence and higher harmonics in the positive- sequence dq frame, and to adjust the fundamental negative- sequence component in the negative-sequence dq frame. The notch filter(NF) of different center frequencies is reasonably combined to achieve accurate extraction of voltage and current. The "proportional integral(PI) + vector PI(VPI)" regulator was used for fundamental positive-sequence and high-order harmonics. In addition, the parameter design process of each control link was elaborated. Finally, experiments performed on the laboratory prototype verified the effectiveness of the proposed control strategy and the correctness of the parameter design. © 2022 Chin. Soc. for Elec. Eng.