Reduction of Current Harmonics in Data Center Power System using Single-Phase Shunt Active Power Filter.

With the significant increase of nonlinear loads in data center power systems, the losses due to the injection of current harmonics have also increased significantly. In order to reduce current harmonics, the use of Shunt Active Power Filters (SAPF) has become widespread. These filters use active components such as IGBT or MOSFET as well as R,L and C passive components. The SAPF power stage consists of a voltage source inverter (VSI) and an LCL filter, which is used to filter the signal at the switching frequency. The paper presents two simulatons of SAPF. The first simulation refers to a filter used only to reduce the current harmonics, while the second simulation uses a filter that also acts on the current reactive component. The control loop consists of a current controller and a PWM. In the first simulation, the grid side current and the converter side current are used as the current feedback signal. In the second simulation, only the grid side current is used as the current feedback signal. The results of two SAPF simulations are compared and the results show the influence of the control methods on the total current distortion as well as on the current ripple.