A Voltage Harmonic Self-Suppression Strategy of Single-Phase UPS

Under nonlinear load disturbances, the output voltage of single-phase uninterruptible power supply (UPS) easily distorts. To address this issue, this article proposes a voltage harmonic self-suppression strategy, which can automatically suppress wideband harmonics without using any harmonic extraction filter. According to the theoretical analysis, the optimized UPS has a smaller impedance and is more like an ideal voltage source, which can achieve stable control of voltage even under nonlinear load disturbances. Finally, a single-phase experimental platform is constructed in the laboratory and the experimental results verify that the proposed strategy can achieve the output voltage robust control of UPS.