TY - JOUR
T1 - Second Ripple Current Suppression by Two Bandpass Filters and Current Sharing Method for Energy Storage Converters in DC Microgrid
AU - Yang, Ling
AU - Chen, Yandong
AU - Luo, An
AU - Wu, Wenhua
AU - Huai, Kunshan
AU - Zhou, Xiaoping
AU - Zhou, Leming
AU - Xu, Qianming
AU - Guerrero, Josep M.
PY - 2017/9
Y1 - 2017/9
N2 - With the increasing of AC loads injected into DC microgird (MG) through the inverters, the second ripple current (SRC) in the front-end energy storage converter (ESC) and circulating current among the ESCs in DC MG become more and more serious. In this paper, the SRC suppression method by introducing two band-pass filters (BPFs) into the output voltage and inductance current feedback of the ESC is proposed. Compared with the traditional dual-loop control method, the proposed method effectively reduces the SRC and improves the dynamic performance in case of a lower cut-off frequency in the outer voltage loop. Simultaneously, an adaptive droop control method by introducing the fine tuning virtual resistances is adopted to reduce the output voltage deviation of parallel ESCs and improve the output current sharing among the ESCs. Considering the allowed range of the deviation between the output voltage and rated voltage for each ESC, the impacts of the line power loss and circulating current power loss caused by the introduced virtual resistances are analyzed in detail. While the sum of the line power loss and circulating current power loss reaches the minimum value, the appropriate control parameters are obtained. Simulation and experimental results verify the validity of the proposed method.
AB - With the increasing of AC loads injected into DC microgird (MG) through the inverters, the second ripple current (SRC) in the front-end energy storage converter (ESC) and circulating current among the ESCs in DC MG become more and more serious. In this paper, the SRC suppression method by introducing two band-pass filters (BPFs) into the output voltage and inductance current feedback of the ESC is proposed. Compared with the traditional dual-loop control method, the proposed method effectively reduces the SRC and improves the dynamic performance in case of a lower cut-off frequency in the outer voltage loop. Simultaneously, an adaptive droop control method by introducing the fine tuning virtual resistances is adopted to reduce the output voltage deviation of parallel ESCs and improve the output current sharing among the ESCs. Considering the allowed range of the deviation between the output voltage and rated voltage for each ESC, the impacts of the line power loss and circulating current power loss caused by the introduced virtual resistances are analyzed in detail. While the sum of the line power loss and circulating current power loss reaches the minimum value, the appropriate control parameters are obtained. Simulation and experimental results verify the validity of the proposed method.
KW - DC microgrid (MG)
KW - Energy storage converter (ESC)
KW - Second ripple current (SRC)
KW - Band-pass filter (BPF)
KW - Current sharing
KW - Virtual resistance
U2 - 10.1109/JESTPE.2016.2642399
DO - 10.1109/JESTPE.2016.2642399
M3 - Journal article
SN - 2168-6777
VL - 5
SP - 1031
EP - 1044
JO - I E E E Journal of Emerging and Selected Topics in Power Electronics
JF - I E E E Journal of Emerging and Selected Topics in Power Electronics
IS - 3
ER -