Simulation analysis of two-level and three-level (NPC) converter based SAPF for different current control schemes

Use of non-linear power electronics equipment create power quality issues by introducing harmonics and reactive power in the utility system. Shunt Active Power Filters (SAPF) are a common solution for mitigation of current harmonics in the system. This paper presents evaluation of fixed-band hysteresis current controller based two-level converter used as a SAPF. Hysteresis current control scheme is preferable because of ease of implementation, robustness against parameter variations and fast dynamic response. Because of the inherent advantages associated, this paper emphasizes to extend the same control strategy to multilevel converters as well. This paper presents advanced multiband hysteresis modulation scheme for three-level Neutral Point Clamped (NPC) converter based SAPF application. Detailed analysis of the proposed control scheme is presented and the claimed performance of both SAPF configurations are validated from results obtained by carrying out extensive simulations in MATLAB/Simulink environment.