State plane analysis of a resonant DC-DC converter incorporating integrated magnetics

The state-plane method of analysis of a parallel inductor transformer resonant DC-DC converter is developed. A key feature is the use of integrated magnetics to combine in a single magnetic structure the high-frequency output transformer, the resonant inductor, and an inductor for short-circuit protection. Use of integrated magnetics reduces the weight, size, and cost of the converter. The design of the magnetic structure is discussed, and design equations for leakage and magnetizing inductance control are derived. The effect of the leakage inductances on the shape of the equilibrium trajectories, converter derating, and available turn-off time are discussed.>