A Family of High Frequency Isolated Impedance Source DC-DC Converters for Distributed Power Generation Systems

This paper proposes a new family of high frequency isolated Z-source dc-dc converters (ZSDCs) intended for distributed power generation systems. The proposed converters employs high frequency isolation between the load and the source and provides a wide range of buck and boost functions with improved reliability and good efficiency. The proposed converters can increase the output voltage by either adjusting the duty cycle, turns ratio of the coupled inductors (n), or by changing the high frequency transformer turn ratio (m) giving more flexibility in modifying the gain. It is expected that the benefits of proposed converters makes them a practical candidate for distributed power generation systems that can convert a varying low dc-input voltage into required stabilized output voltage with essential galvanic isolation. In this paper, several isolated ZSDC are presented, and an example isolated improved Γ-ZSDC is shown and discussed in detail with theoretical analysis followed up by verifications through simulations.