Patent ID: 8338984

Claim:
An uninterruptible power supply supporting active loads, comprising: a charge and discharge module having a battery set and a charger charging the battery set with an input power; a switch circuit having at least two active switches connected to the battery set; a dynamic PWM control module connected with each of the active switches of the switch circuit, alternately outputting duty cycles, wherein each duty cycle has a plurality of low-frequency square waves and hi frequency square waves in a first high-frequency zone, a low-frequency zone, and a second high-frequency zone, widths of the square waves in the first high-frequency zone increase progressively, and widths of the square waves in the second high-frequency zone decrease progressively, and alternately controlling each of the active switches to turn on or off; and a transformer having a primary side connected with the switch circuit and a secondary side whose two terminals are connected with an output capacitor generating a filtering function in collaboration with a leakage inductance in the secondary side of the transformer.