Predictive control of active filter system with LCL coupling circuit

The paper presents the novel control system for a shunt active power filter (APF) connected to an electrical grid via LCL circuit. Such a circuit constitutes 3^rd order low pass filter and almost completely attenuates current ripples from PWM, which are the major drawback of APF connected via inductors. Such a solution requires control that overcomes LCL resonance problem and, at the same time, maximizes control dynamics. The proposed control system is fully predictive and provides control dynamics which is limited only by circuit parameters. The control has been implemented in high power, 1.2 MVA APF system. The paper includes both simulations and experimental results.