Versatile current controller suitable for two-level as well as three-level converters of shunt active power filters: part 1

摘要

Current control strategy dominates shunt active power filter (SAPF) performance. Versatile current error space phasor (CESP)-based hysteresis controller (HC) for SAPF is presented. Controller keeps CESP within hexagon shaped boundary by selecting appropriate SAPF voltage vector. Optimal voltage vector switching is ensured unlike non-optimum selection in conventional HC based SAPFs. Proposed SAPF generates compensating currents by coordinating sector changeovers and supply frequency. Two different sector change detection schemes are presented. The concept is simulated and implemented using digital signal processor (DSP) TMS320LF2407A. Experimental results depicting steady-state and transient performance are presented. Effect of hysteresis band variation on SAPF performance is also reported. Adequate compensation by SAPF is evident from presented results. However, complex voltage space phasor structure of multi-level converter (MLC) limits proposed controller's sector change detection ability. For application of proposed controller to MLC-based SAPF a versatile controller using outer hysteresis band is described in part-2 of this paper.