A universal custom power conditioner (UCPC) with selective harmonic voltage compensation

This paper presents an integrated series/shunt active filter combination (termed a universal custom power conditioner or UCPC) which uses a range of control strategies to achieve improved voltage harmonic compensation capabilities and to fully exploit the potential functionality of the topology without requiring tuned passive harmonic filters. The series active filter uses a DVR type controller for voltage regulation and dip compensation, together with an array of resonant harmonic controllers to provide selective mitigation of supply voltage harmonics as seen by the load. The shunt active filter regulates the DC link voltage and compensates for load unbalance and load current harmonics. Experimental results show that the proposed system can regulate the load voltage, compensating for both source voltage dips and voltage harmonics, while simultaneously eliminating load current harmonics as seen by the source. For radial distribution applications, the proposed scheme achieves minimal load voltage error even under wide variations of supply voltages and load currents. The control principle can be used for both singleand three-phase systems, and is implemented with a delta-operator-based infinite impulse response (IIR) filter to achieve high performance using only 16 bit fixed-point DSP based controllers.