Patent ID: 8232779

Claim:
A method for selecting an optimum number of phases for a converter, comprising: selecting a duty range using an input voltage and an output voltage; obtaining ripple values for multiple phases within the selected duty range, wherein obtaining ripple values for multiple phases within the selected duty range comprises obtaining an input current ripple value for each phase, and wherein the obtaining the input current ripple value for each phase includes calculating the input current ripple values by the following equation, Δ ⁢ ⁢ I i ⁢ ⁢ n = V o L ⁢ ( N onsw - ND ) ⁢ T N ⁢ d , where V o denotes the output voltage, L denotes inductance, N onsw denotes a number of turned-on switches, N denotes a number of phases, D denotes a duty, T denotes a switching period of one phase, and d denotes a short period; and obtaining the optimum number of phases based upon the obtained ripple values by selecting one or more phases in the duty range and selecting the phases having a minimum ripple value in a rated duty among the selected one or more phases, wherein the selecting one or more phases in the duty range comprises integrating the equation calculated for the respective phases in the obtaining the input current ripple value for each phase, selecting the phase numbers corresponding to a minimum integrated value among integrated values obtained for the respective phases, and selecting the phase numbers within a specified range from the phase numbers corresponding to the minimum integrated value.