Uninterruptible power supply systems using a quasi-resonant technique in a dual converter mode

This paper investigates the application of resonant techniques for building uninterruptible power supply (UPS) systems incorporating a dual power converter. The magnetic circuit of the dual power converter consists of a high frequency transformer with two primary and one secondary windings. The two primary windings are supplied from the mains and a standby power source. The major contribution of the proposed approach is that all the windings operate at high frequency in a quasi-resonant mode; parasitic leakage inductance being used as part of the resonant circuits. The paper outlines the basic principle of a 700 kHz system together with the analysis, design and experimental results including simulation results obtained using PSpice