Performance Analysis and Digital Implementation of Two-Level and Three-Level Converter based Active Power Filter (APF) for Different Control Schemes

Abstract

Extensive use of power electronics based converters in industrial as well as domestic applications has resulted into degradation of power quality. This is because; these power electronics based converters serve as non-linear loads thereby introducing current harmonics into the system. From the viewpoint of a utility supply system, presence of current harmonics in the system cause operational and life expectancy problems for other equipments connected to the same system but owned or operated by some other party. Therefore, it becomes essential to ask consumers to rectify harmonics injected into mains from their side by using devices such as filters. As a result, Active Power Filters (APFs) were proposed by researchers as a solution to above mentioned problems. Two-level and Three-level converters based shunt active power filter (SAPF) used different control schemes. The control scheme employed for two-level SAPF is hysteresis current control. Two different control techniques are employed for three- level converter based SAPF. The first technique employed is multi-carrier PWM control scheme. The second technique is a multiband hysteresis modulation control scheme. Multiband hysteresis modulation control technique is applied to a Three-level NPC converter. The performance of the Shunt Active Filter is evaluated through MATLAB / SIMULINK environment using Simpower Systems toolbox. For hardware implementation Programming on ARM Cortex is to be performed by initialization of various peripherals.