Active Power Filter DC Voltage Control Based on Capacitor Energetic Model

Active power filter (APF) is a common solution to suppress the influence of current harmonics in power systems in which the phase current compensation performance of an APF system is affected by the DC-link voltage control loop. In a conventional APF control scheme, the converter power losses are directly conducted from the voltage error by using a PI controller. Due to the lack of physical relationship between the DC voltage error and the converter losses, the conventional controller synthesis is often only based on strict mathematics of control theory. This paper proposes two novel methods to design the DC-link voltage controller taking into account the physical insight of the system model and control. The first method deduces the loss power reference through controlling the energetic model of the capacitor. In the second approach, the loss power is determined through multiplication of the measured DC voltage and current reference conducting from the regulation of the capacitor electrical model. To systematically deduce the control structure, we employ energetic macroscopic representation (EMR) and its associated inversion-based control scheme to organize the studied system. The studied system is simulated on MATLAB/Simulink and the results highlight the correctness and rationale of the proposed control design method.