Design, Simulation and Digital Implementation of a Three-Phase Shunt Active Power Filter

Abstract

The non-linear loads like saturating devices like transformers, arc discharge and static power converters which are used in industry for applications like adjustable speed drives (ASD's), uninterruptible power supplies. The consequence of using this non-linear loads results in non-sinusoidal current due to which harmonic current will flow in the grid. These harmonic currents also lead to increased losses and heating in numerous electromagnetic devices (motors, transformers, etc.) to make the system free from harmonics pollution power filters are incorporated to mitigate the harmonics and major work has been carried out on Shunt Active Power Filter (SAPF), many control strategies such as Instantaneous Reactive Power Theory, Synchronous Frame d-q Theory, Synchronous Detection Method and many more method are pro- posed in literature. Majority of literature review suggests implementation using two level based SAPF. This report is focused on design, simulation and implementation of shunt active power filter based on three level inverter and compare the THD of supply side current using different control strategy. For medium voltage application, three level VSIs have proven to be more advantageous, however control of a three level inverter is more complicated then two-level inverter because of large number of switching states, and when use three level neutral point clamped (NPC) inverter dc-link capacitors voltage balancing is also to be maintained and simulation results proven the performance of the SAPF with THD of line current at PCC.