A novel uninterruptible power supply system with active power factor correction

This paper presents a simplified sinusoidal uninterruptible power supply (UPS) system. The proposed scheme includes features such as high power factor, low total harmonic distortion and good dynamic response at the AC output voltage. In addition, the scheme has the desirable characteristics, of high efficiency, simple circuit and low cost compared with a traditional standalone multiple stages UPS with power factor correction. The paper also presents the circuit operation, the analysis and, experimental results of the proposed UPS scheme. The proposed UPS approach is a good solution in low. power applications (/spl les/500 W).