BigPatents India

A Novel Optimum filter design for an Off-line UPS is proposed in this study. The study is carried out to obtain an undistorted sinusoidal output. The inductance part of the filter is incorporated within the inverter transformer. This property is not seen in any of the conventional Off-line UPS. The inverter transformer, which is a Ferro resonant power transformer, is in a condition of persistent core saturation resulting in distortion of the sine wave shape. To overcome this effect, an inductance filter is introduced, forming a resonant circuit tuned to the supply frequency. This results in sinusoidal output.