Compensation of irregular currents with active filters

Compensation of irregular currents such as those associated with arc furnaces, transient disturbances, and power electronic converters is presented. The compensation is based on a well-defined nonactive current definition. The basic concepts required in the definition of nonactive current are presented and illustrated by compensation simulations for a variety of different types of nonperiodic currents found in distribution electrical systems, including disturbance, subharmonic, and stochastic currents. Further, based on the compensation objectives for different types of load waveforms, the specifications such as current ratings or capacitance requirements of the active filter are also presented.