TY - JOUR
T1 - A hierarchical coordinative control strategy for solid state transformer based DC microgrids
AU - Li, Zheng
AU - Zheng, Tao
AU - Wang, Yani
AU - Yang, Chang
N1 - Funding Information:
Funding: This research was funded by the Key Research and Development Program of Shaanxi Province, grant number 2019ZDLGY18-06.
Funding Information:
This research was funded by the Key Research and Development Program of Shaanxi Province, grant number 2019ZDLGY18-06.
Publisher Copyright:
© 2020 by the authors.
PY - 2020/10/1
Y1 - 2020/10/1
N2 - A solid state transformer (SST), as a kind of energy router in the Energy Internet, provides a unified access point for AC or DC distributed power subjects. However, the DC-link capacitors inside the SST will suffer huge voltage fluctuations when the output power of the microgrid changes dramatically. With respect to this problem, caused by the random and intermittent characteristics of distributed generation (DG), a hierarchical coordinative control strategy is proposed. Compared with the common independent control, the proposed method not only makes full use of the regulation capacity of super capacitors, but also enhances the dynamic power tracking speed and reduces the speed difference between different stages of an SST. The dynamic voltage response under the proposed method is analyzed in frequency domain and compared with the independent control. To validate the effectiveness of the coordinative control strategy, a simulation model of an SST-based grid-connected DC microgrid system is established, and the topology of the SST is improved. The voltage stability of the DC bus is compared under different control strategies, and the coordinative control strategy is also verified, effectively under transition conditions.
AB - A solid state transformer (SST), as a kind of energy router in the Energy Internet, provides a unified access point for AC or DC distributed power subjects. However, the DC-link capacitors inside the SST will suffer huge voltage fluctuations when the output power of the microgrid changes dramatically. With respect to this problem, caused by the random and intermittent characteristics of distributed generation (DG), a hierarchical coordinative control strategy is proposed. Compared with the common independent control, the proposed method not only makes full use of the regulation capacity of super capacitors, but also enhances the dynamic power tracking speed and reduces the speed difference between different stages of an SST. The dynamic voltage response under the proposed method is analyzed in frequency domain and compared with the independent control. To validate the effectiveness of the coordinative control strategy, a simulation model of an SST-based grid-connected DC microgrid system is established, and the topology of the SST is improved. The voltage stability of the DC bus is compared under different control strategies, and the coordinative control strategy is also verified, effectively under transition conditions.
KW - Hierarchical coordinative control strategy
KW - Microgrid
KW - Solid state transformer (SST)
KW - Voltage stability
UR - http://www.scopus.com/inward/record.url?scp=85092634246&partnerID=8YFLogxK
U2 - 10.3390/app10196853
DO - 10.3390/app10196853
M3 - Article
AN - SCOPUS:85092634246
VL - 10
JO - Applied Sciences (Switzerland)
JF - Applied Sciences (Switzerland)
SN - 2076-3417
IS - 19
M1 - 6680
ER -