Three-Phase Unified Power Quality Conditioner in Open Delta With Shared Legs

This work proposes a ten-leg AC-DC-AC converter composed of two three-leg cells and a four-leg cell cascaded-connected in open delta. It is suitable for applications where the fundamental frequency of grid and load are the same. A space-vector pulse-width modulation (SVPWM) is presented. The DC-link voltage balance control was performed using the redundant states of the SVPWM and the converter operated with minimum number of switch commutations, with six of its legs clamped every pulse-with modulation (PWM) period. Converter model and control strategy are presented. Simulation and experimental results validate the feasibility of the system. Compared with the considered conventional solutions, the proposed converter presents reduced semiconductor losses both for an operation with fixed carriers frequency and fixed total harmonic distortion (THD) of grid currents.