An approach to the design of energy storage reactors for DC-to-DC switching power converters using ferrite structures

The method for the design of energy storage reactors for dc-to-dc power converters is outlined. With the dynamic equations of the power converter and the calculations of the total power losses in the reactor as a starting point, the approximate expression describing the required volume of the core is derived, and the optimal geometry of the magnetic circuit is found analytically. The method, for a given power stage specification and constant coefficients of the geometry of a normalized core series, uses a designer-selected value of the difference between the operating temperature of the reactor´s external surface and the ambient temperature as a major design constraint. The design procedure makes use of a family of core-loss characteristics. The boost type of power regulator is used as an example, yet the design technique may be applied to each of nine different dc-to-dc power converters and is applicable to most core shapes and most modern magnetic materials.