TY - JOUR
T1 - An Improved Zero-Sequence Circulating Current Suppression Based Method in Parallel Three-Level T-Type Grid-Connected Inverters
AU - Xing, Xiangyang
AU - Chen, Alian
AU - Zhang, Zicheng
AU - Pan, Yiwei
AU - Du, Chunshui
AU - Zhang, Chenghui
PY - 2017/7/20
Y1 - 2017/7/20
N2 - Module parallel three-level T-type inverters (3LT2Is) can increase power rating and efficiency of systems. However, the topology of transformerless inverters with common dc-link would cause the zero-sequence circulating current (ZSCC) problem. Previous papers have proven that the ZSCC can be suppressed by adjusting the time of the zero-sequence component. However, the performance would be deteriorated without considering the disturbance caused by differences in currents. An averaged model of ZSCC was analyzed in detailed. A small vector feed-forward control method with the PI controller was proposed to reject disturbance in zero-axis current systems. Moreover, a double sampling method was employed to expand the bandwidth of the zero-axis current system. Therefore, the ZSCC can be suppressed satisfactorily when output currents are different by applying the proposed scheme. The effectiveness of the proposed method is verified by the experimental results.
AB - Module parallel three-level T-type inverters (3LT2Is) can increase power rating and efficiency of systems. However, the topology of transformerless inverters with common dc-link would cause the zero-sequence circulating current (ZSCC) problem. Previous papers have proven that the ZSCC can be suppressed by adjusting the time of the zero-sequence component. However, the performance would be deteriorated without considering the disturbance caused by differences in currents. An averaged model of ZSCC was analyzed in detailed. A small vector feed-forward control method with the PI controller was proposed to reject disturbance in zero-axis current systems. Moreover, a double sampling method was employed to expand the bandwidth of the zero-axis current system. Therefore, the ZSCC can be suppressed satisfactorily when output currents are different by applying the proposed scheme. The effectiveness of the proposed method is verified by the experimental results.
KW - Double sampling method
KW - Small vectors feed-forward control
KW - Three-level T-type inverter (3LTI)
KW - Zero-sequence circulating current (ZSCC)
UR - http://www.scopus.com/inward/record.url?scp=85028976216&partnerID=8YFLogxK
U2 - 10.13334/j.0258-8013.pcsee.160819
DO - 10.13334/j.0258-8013.pcsee.160819
M3 - Journal article
AN - SCOPUS:85028976216
SN - 0258-8013
VL - 37
SP - 4165
EP - 4174
JO - Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering
JF - Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering
IS - 14
ER -