A simple and effective control strategy for improved operation of a current-fed push-pull converter

An active control law for a current fed push-pull converter used in photovoltaic applications is discussed in this paper. The proposed control law aims at avoiding magnetic flux saturation and eliminating the magnetic flux imbalance observed at both windings of the converter transformer. The most prominent advantages of operating without flux saturation are: a more effective magnetic core design; power switches and converter live endurance; less voltage switching stress. Detailed analysis including simulation and experimental results are used to demonstrate the effectiveness of the proposed active control law.