Current control schemes for three-phase fourwire shunt active power filters: a comparative study

this paper discusses the performance of different current control schemes used in three- phase four-wire shunt active power filters (apf). the control schemes are based on: delta modulation (dm), dead-beat control and pi regulator. the feasibility of the three control schemes have been tested with different waveform and the results are compared through the instantaneous error and the root mean square error between the current of the active power filter and its reference. finally, the best controller is applied in an experimental setup designed for mitigating harmonics generated by a nonlinear load.