TY - JOUR
T1 - A High power, medium voltage, series-resonant converter for DC wind turbines
AU - Dincan, Catalin Gabriel
AU - Kjær, Philip Carne
AU - Chen, Yu-Hsing
AU - Munk-Nielsen, Stig
AU - Bak, Claus Leth
PY - 2018/9
Y1 - 2018/9
N2 - A new modulation scheme is introduced for a single-phase series-resonant converter, which permits continuous regulation of power from nominal level to zero, in presence of variable input and output dc voltage levels. Rearranging the circuit to locate the resonant LC tank on the rectifier side of the high turns-ratio transformer combined with frequency control and phase-shifted inverter modulation keep transformer flux constant from nominal frequency down to DC, always in sub-resonant continuous or discontinuous conduction mode. This overcomes the principal deficit of series-resonant converters, and the resulting compact and efficient transformer, and soft-commutated inverter, present particular advantages in high-power, high-voltage applications, like DC offshore wind turbines. With transformer excitation frequency in hundreds of Hz range, line-frequency diodes can be employed in the high-voltage rectifier valve. Circuit operation and conduction modes, governing equations and sample waveforms are presented, together with experiments from a scaled demonstrator.
AB - A new modulation scheme is introduced for a single-phase series-resonant converter, which permits continuous regulation of power from nominal level to zero, in presence of variable input and output dc voltage levels. Rearranging the circuit to locate the resonant LC tank on the rectifier side of the high turns-ratio transformer combined with frequency control and phase-shifted inverter modulation keep transformer flux constant from nominal frequency down to DC, always in sub-resonant continuous or discontinuous conduction mode. This overcomes the principal deficit of series-resonant converters, and the resulting compact and efficient transformer, and soft-commutated inverter, present particular advantages in high-power, high-voltage applications, like DC offshore wind turbines. With transformer excitation frequency in hundreds of Hz range, line-frequency diodes can be employed in the high-voltage rectifier valve. Circuit operation and conduction modes, governing equations and sample waveforms are presented, together with experiments from a scaled demonstrator.
KW - High-voltage converter
KW - medium frequency transformer
KW - medium-voltage dc (MVdc)
KW - offshore wind farm
KW - phaseshifted modulation
KW - resonant converter
UR - http://www.scopus.com/inward/record.url?scp=85033680479&partnerID=8YFLogxK
U2 - 10.1109/TPEL.2017.2770220
DO - 10.1109/TPEL.2017.2770220
M3 - Journal article
SN - 0885-8993
VL - 33
SP - 7455
EP - 7465
JO - I E E E Transactions on Power Electronics
JF - I E E E Transactions on Power Electronics
IS - 9
ER -