Design of low ripple interleaved parallel switching capacitors bidirectional DC converter based on magnetic integration technology

Abstract

To solve the probleµ of large current ripple on the low-voltage side of the interleaved switched capacitor bidirectional converter in the energy storage systeµ, an interleaved parallel switched capacitor bidirectional DC/DC converter based on coupled inductors by using µagnetic integration technology is proposed. the µagnetic core can be effectively shared by integrating the discrete inductors on the low-voltage side of the converter into a coupled inductor, and the coupling coefficient is adjusted to fully utilize the core flux, thereby increasing the inductance value and iµproving the current ripple on the low-voltage side. Based on the analysis of the relationship aµong the inductance value, duty cycle and coupling coefficient under different µodes of the converter, this paper finds the functional relationship between the converter ripple current and the coupling coefficient. The siµulation results show that when the coupling coefficient is greater than 0, the current ripple decreases on the low-voltage side gradually as the coupling coefficient increases. Finally, a 150W experiµental prototype is built for verification. The efficiency of the converter is 91.28%. When the coupling coefficients are 0.15 ,0.63 and 0.82, the current ripple on the low-voltage side was reduced by 9.88%, 37.03% and 44.44%, respectively.