A novel current controller for active power filter based on optimal voltage space vector

In this paper, a novel hysteresis current controller for active power filter based on the optimal voltage space vectors is suggested. The controller jointly utilizes two sets of inter-phase current difference comparators to determine the location region of the reference voltage space vector and the current error space vector respectively. When the system reference voltage space vector is changing rapidly and randomly which makes its location region difficult to be estimated, the novel controller can quickly detect its correct location region by one trial-and-error process which is essential to the performance improvement of the active power filter. The related concept and formulation are presented. Computer simulation is conducted on a test system and the results show that the controller can quickly determine the optimal voltage space vector, therefore current tracking error is reduced effectively. So the voltage source inverter (VSI) switching frequency can be reduced and the efficiency of active power filter (APF) can be improved apparently under the same control accuracy