Three-phase three-wire three-level APF based on vector mode one-cycle control

To break the power limit of APF(Active Power Filter) caused by the smaller capability of switching devices,the three-phase three-wire three-level APF based on vector mode one-cycle control is presented.The diode-clamp three-level topology is used in its main circuit and the one-cycle control strategy of vector mode within 0°~360° is employed to reduce APF switching stress and loss and to enhance APF power rating with low-voltage switching devices.The equivalent switching model and average model of proposed APF are analyzed and the unified control object equation is deduced,based on which the system simulation model is established.The system stability and PI regulator design are analyzed in detail.Simulations are carried out for both balanced and unbalanced three-phase power supply.Simulation results show that the proposed APF can compensate the system harmonics and reactive currents effectively and improve the power factor and transmission efficiency of transmission lines,which verify its feasibility and validity.