TY - JOUR
T1 - Model predictive control methods of leakage current elimination for a three-level T-type transformerless PV inverter
AU - Wang, Xiaodong
AU - Zou, Jianxiao
AU - Ma, Lan
AU - Zhao, Jiancheng
AU - Xie, Chuan
AU - Li, Kai
AU - Meng, Lexuan
AU - Guerrero, Josep M.
PY - 2018/7
Y1 - 2018/7
N2 - This study presents finite control set model predictive control (FCS-MPC) methods to eliminate leakage current for a three-level T-type transformerless photovoltaic (PV) inverter without any modification on topology or any hardware changes. The proposed FCS-MPC methods are capable of eliminating the leakage current in the transformerless PV system by applying the defined candidate voltage vector (VV) combinations with only six medium and one zero VVs (6MV1Z) or three large and three small VVs, which generate constant common-mode voltage to perform the optimisation in every control period. With fewer VVs used for the optimisation, the computational burden can be significantly reduced. Furthermore, comparative analysis is performed to show that among these proposed methods, the 6MV1Z method can achieve satisfactory performances in both grid current tracking and neutral point potentials balance control even with less number of candidate VVs, which exhibits the FCS-MPC as an alternative control strategy to be used in the grid-connected transformerless PV system. Finally, experiments are performed to validate the analysis and the effectiveness of the proposed methods.
AB - This study presents finite control set model predictive control (FCS-MPC) methods to eliminate leakage current for a three-level T-type transformerless photovoltaic (PV) inverter without any modification on topology or any hardware changes. The proposed FCS-MPC methods are capable of eliminating the leakage current in the transformerless PV system by applying the defined candidate voltage vector (VV) combinations with only six medium and one zero VVs (6MV1Z) or three large and three small VVs, which generate constant common-mode voltage to perform the optimisation in every control period. With fewer VVs used for the optimisation, the computational burden can be significantly reduced. Furthermore, comparative analysis is performed to show that among these proposed methods, the 6MV1Z method can achieve satisfactory performances in both grid current tracking and neutral point potentials balance control even with less number of candidate VVs, which exhibits the FCS-MPC as an alternative control strategy to be used in the grid-connected transformerless PV system. Finally, experiments are performed to validate the analysis and the effectiveness of the proposed methods.
UR - http://www.scopus.com/inward/record.url?scp=85048730421&partnerID=8YFLogxK
U2 - 10.1049/iet-pel.2017.0762
DO - 10.1049/iet-pel.2017.0762
M3 - Journal article
AN - SCOPUS:85048730421
SN - 1755-4535
VL - 11
SP - 1492
EP - 1498
JO - IET Power Electronics
JF - IET Power Electronics
IS - 8
ER -