Modular DC-DC Converter with Adaptable Fast Controller for Supercapacitor Energy Storage Integration into DC Microgrid
Electronics 2025
Kaspars Kroičs, Kristiāns Gaspersons, Mariusz Zdanowski

Supercapacitors are well suited for braking energy recovery in electrical drive applications and for voltage sag compensation. For voltage-sensitive devices, only a small voltage deviation can be acceptable, and therefore the voltage controller should be fast. This paper analyzes the design of such a controller for DC bus voltage stabilization considering a GaN transistor-based converter with a 400 kHz switching frequency. Inner and outer loop controller design considering delays caused by the digital nature of the controllers has been analyzed in the paper. This paper proposes to use adaptable controller for the outer voltage loop, thus increasing the stability and reducing the calculation time. The 2p2z controller has been developed for the current loop, achieving a 20 kHz bandwidth and a response time of less than 0.2 ms. A 2p2z controller with adaptable coefficients has been developed for the outer voltage loop, achieving a 2 kHz bandwidth and a response time of 2 ms. Voltage controller digital implementation is split into two switching cycles, thus decreasing the required time for current and voltage control loops implementation from 2.1 µs to 1.5 µs. This allows calculating three current control loops for three-phase interleaved converter control. By combining such three-phase converters in parallel, it is possible to develop modular six-, nine-, or even more-phase interleaved DC-DC converters for high-current applications.


Keywords
bidirectional converter; Bode plot analysis; DC microgrid; DC-DC converter; digital control; energy storage; fast response; GaN transistors
DOI
10.3390/electronics14040700
Hyperlink
https://www.mdpi.com/1996-1073/18/2/336

Kroičs, K., Gaspersons, K., Zdanowski, M. Modular DC-DC Converter with Adaptable Fast Controller for Supercapacitor Energy Storage Integration into DC Microgrid. Electronics, 2025, Vol. 14, No. 4, Article number 700. e-ISSN 2079-9292. Pieejams: doi:10.3390/electronics14040700

Publication language
English (en)
The Scientific Library of the Riga Technical University.
E-mail: uzzinas@rtu.lv; Phone: +371 28399196