Shunt active power filtering algorithms for unbalanced, non-linear loads

[摘要] ENGLISH ABSTRACT:This thesis presents the design and implementation of shunt active power filtering algorithms forunbalanced, non-linear loads.A three-phase four-wire topology is developed in the dqO space. Based on this development an accuratedynamic system model, taking into account the effect of the neutral inductor is developed.The synchronous reference frame technique is expanded to enable the isolation of the zero sequencecurrent component into its instantaneous active and reactive current components. Additionally aprediction method is proposed that will enable the proper prediction of the reference currents in a threephasefour-wire system.Two categories of reference current signal tracking algorithms are investigated; namely the predictivecurrent controller and the sliding mode current controller. A compensating technique is proposed tocompensate for the effects that sampling and computational time delay have on the performance of thesystem. Additionally, an investigation is done into the effect that dead-time has on the performance of thesystem, and based on this investigation a dead-time compensating strategy is proposed.Finally simulation and practical results are provided to validate the discussed theories.

[发布机构] Stellenbosch University