Comparison of the space vector current controls for shunt active power filters

In this paper, a new space vector current control scheme for shunt active power filters is introduced with a three-level neutral point-clamped voltage source inverter as well as a standard two-level voltage source inverter. Then, the proposed control is compared with the other space vector current control method to evaluate inherent advantages and drawbacks of the control schemes. The proposed control can selectively choose harmonic current components by real time Fast Fourier Transform (FFT) to generate the compensation current. The proposed current control utilizes a rotating coordinate system processing the information of the actual position of the grid-voltage space vector which is remarkably important in active power filter application, and chooses switching states from the switching table implemented in a Field Programmable Gate Array (FPGA). With the proposed control, the total harmonic distortion of the compensated grid current, the average switching frequency, and switching power loss are significantly reduced.