ABSTRACT
The interleaved inductors are designed to meet the requirement of high power factor over a wide range of AC line voltages. Two non-coupled inductors are used. The inductance value of inductors should be high enough to avoid Discontinuous Current Mode (DCM) operation of each boost leg and acquire high power factor, low Total Harmonic Distortion (THD), and low Electromagnetic Interference (EMI). As the inductance value of an inductor decreases at higher operating currents, the nominal value of inductance is designed at maximum operating current, corresponding to full load conditions (1 kW) at a lower line voltage (85 Vac). The inductance value is determined by the switching frequency, which is set at 80 kHz and the current ripple of each boost leg, which is selected to be equal to 20% (Δi) of the maximum AC current. The boost inductors (L1 and L2) are selected based on the maximum allowable input ripple current. In universal applications (e.g., 85 V to 265 V RMS input), the maximum input ripple current occurs at the peak of low line, and for this design, the maximum input ripple current was set to 30% of the peak nominal input current at low line.
