Modular active power filtering approaches: Power splitting verses frequency splitting

Power-line active filtering is performed by injecting into the power line a current equal in magnitude, but opposite in sign, to the line current distortion. In high-power applications, the filtering job is conventionally split among several identical active filter modules (power splitting). An alternative approach is to split the filtering job among several active filter modules, each dedicated to take care of a specific harmonic (frequency splitting). In this paper, the two modular active filtering approaches are compared against each other from the installation and operating costs, as well as performance points view.