TY - GEN
T1 - A GaN based doubly grounded, reduced capacitance transformer-less split phase photovoltaic inverter with active power decoupling
AU - Xia, Yinglai
AU - Roy, Jinia
AU - Ayyanar, Raja
N1 - Publisher Copyright:
© 2017 IEEE.
PY - 2017/5/17
Y1 - 2017/5/17
N2 - Transformer-less PV inverters are gaining widespread applications with lower cost, reduced footprint, and improved efficiency. This paper proposes a topology that can eliminate the common mode leakage current which is a major challenge in transformer-less PV inverters. In addition, an active power decoupling strategy is implemented in this topology instead of using large energy storage element for double line frequency power decoupling which is a common problem in single phase inverters / rectifiers, thus achieving a smaller volume and replacing electrolytic capacitors with film capacitors to increase reliability. A constant input voltage with negligible double line frequency ripple component less than 2% ensuring high MPPT efficiency is achieved in this topology through control strategy. Compared with previous topology, the 120 Hz inductor current ripple in the boost stage is reduced significantly resulting in the decrease of the RMS current value by 14% and the peak current value by 41%. Also the RMS current in the input capacitor is decreased by 91%. The dc link capacitor volume is also decreased with the increase of the voltage level. Finally, a 1 kW, 100 kHz single-phase prototype with 200 V DC nominal input and 120 V/60 Hz AC output in split phase configuration using GaN FETs has been built to validate the theoretical analysis. The control strategy and modulation scheme are implemented in DSP TMS320F28335.
AB - Transformer-less PV inverters are gaining widespread applications with lower cost, reduced footprint, and improved efficiency. This paper proposes a topology that can eliminate the common mode leakage current which is a major challenge in transformer-less PV inverters. In addition, an active power decoupling strategy is implemented in this topology instead of using large energy storage element for double line frequency power decoupling which is a common problem in single phase inverters / rectifiers, thus achieving a smaller volume and replacing electrolytic capacitors with film capacitors to increase reliability. A constant input voltage with negligible double line frequency ripple component less than 2% ensuring high MPPT efficiency is achieved in this topology through control strategy. Compared with previous topology, the 120 Hz inductor current ripple in the boost stage is reduced significantly resulting in the decrease of the RMS current value by 14% and the peak current value by 41%. Also the RMS current in the input capacitor is decreased by 91%. The dc link capacitor volume is also decreased with the increase of the voltage level. Finally, a 1 kW, 100 kHz single-phase prototype with 200 V DC nominal input and 120 V/60 Hz AC output in split phase configuration using GaN FETs has been built to validate the theoretical analysis. The control strategy and modulation scheme are implemented in DSP TMS320F28335.
KW - Doubly grounded
KW - Leakage current
KW - PV inverter
KW - Power decoupling
KW - Split phase
UR - http://www.scopus.com/inward/record.url?scp=85020028779&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85020028779&partnerID=8YFLogxK
U2 - 10.1109/APEC.2017.7931121
DO - 10.1109/APEC.2017.7931121
M3 - Conference contribution
AN - SCOPUS:85020028779
T3 - Conference Proceedings - IEEE Applied Power Electronics Conference and Exposition - APEC
SP - 2983
EP - 2988
BT - 2017 IEEE Applied Power Electronics Conference and Exposition, APEC 2017
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 32nd Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2017
Y2 - 26 March 2017 through 30 March 2017
ER -