A new space-vector-based control method for UPS systems powering nonlinearand unbalanced loads

In this paper, a new real-time space-vector-based control strategy is prese nted for three-phase uninterruptible power supply systems powering nonlinea r and unbalanced loads. The proposed control strategy generates the inverte r reference and gating signals in closed loop and guarantees high-quality o utput voltages at the load terminals. The approach, which is implemented on a digital signal processor, adapts to a wide variation of nonlinear and un balanced load conditions without specific knowledge of the output filter (L -C) component values, Analysis and experimental results on a 10-kVA prototy pe are presented. The results show that the output voltage is restored at h eavy nonlinear and unbalanced load.