A novel two-phase interleaved parallel bi-directional DC/DC converter

Abstract

The energy storage system (ESS) is an important way to improve the power quality of renewable energy sources (such as solar energy and wind energy). A bi-directional DC/DC converter is an essential part of the ESS to achieve bi-directional energy transfer. According to the characteristics of the low-voltage gain and high-voltage stress of switches in the existing bi-directional DC/DC converter, this study proposes a novel two-phase interleaved parallel bi-directional DC/DC converter. The converter can effectively combine the advantages of a Z-source network and interleaved parallel structure. The working principle, the boost mode and buck mode of the converter are analyzed in detail. In addition, the voltage conversion ratios under the two modes are deduced. The control strategy of the two-phase interleaved parallel bi-directional DC/DC converter is introduced in detail. Furthermore, the main working waveforms of the system under each working mode are verified by building a simulation experiment model using MATLAB/Simulink. The simulation results show that the system has advantages of high-voltage gain, low-voltage stress of switches and automatic current sharing between inductors.

Keywords

• bi-directional dc/dc converter
• energy storage system
• interleaved parallel structure
• voltage stress
• z-source network