Small-signal Analysis of Novel Bidirectional Naturally Clamped Zero Current Switching Current-fed Half-bridge DC/DC Converter for Hybrid Energy System

Abstract

This article presents the small-signal analysis and controller design of a novel current-fed bidirectional DC/DC converter for a hybrid energy system. The converter achieves soft switching of all active switches at both sides. The switching sequence of the secondary side active switches naturally clamps the voltage across the primary switches. Thus, no additional clamping circuit is needed. Hence, this converter has high power density, high efficiency, and low device requirements. The dynamic analysis and small-signal modeling is carried out using a state-space averaging technique. The model takes into account the currents through inductances in each transition interval to accurately predict the dynamic behavior of the converter. The design of controller using two-loop average current control is illustrated. Bode plots using MATLAB (The MathWorks, Natick, Massachusetts, USA) are plotted to verify the stability of the complete system and the simulation results obtained using PSIM 9.0 (Powersim Inc., Rockville, Maryland, USA) are presented to verify the controller design and converter's transient performance with a step change in load. The simulation and experimental results show that the small-signal model has good controllability and anti-disturbance resistance.

Keywords:

• bidirectional converter
• current-fed DC/DC converter
• fuel cell vehicle
• high frequency
• soft switching

Additional information

Notes on contributors

Sudha Bansal

Sudha Bansal received her B.E. in electrical engineering from the Madhav Institute of Technology and Science (MITS) Gwalior and her M.Tech. in electrical engineering with specialization in power apparatus and electric drive from Indian Institute of Technology (IIT), Roorkee. She is presently working as a member of the faculty in the Department of Engineering, Ibri College of Technology. Her field of interest is power electronics and its applications in renewable energy systems.

Lalit Mohan Saini

Lalit Mohan Saini is working as a member of the faculty in the Electrical Engineering Department, National Institute of Technology, Kurukshetra, since 1988. He has been granted a patent on the detection and prevention of power theft on electrical power distribution lines. His areas of interest are power electronics and embedded systems applications in electrical engineering.