TY - JOUR
T1 - Fault current control of MMC in HVDC-connected offshore wind farm
T2 - A coordinated perspective with current differential protection
AU - Gao, Guoqing
AU - Wu, Heng
AU - Blaabjerg, Frede
AU - Wang, Xiongfei
PY - 2023/6
Y1 - 2023/6
N2 - The modular multilevel converter (MMC) based high-voltage dc (HVDC)-connected offshore wind farm (OWF) is power electronic converter dominated power system, where the conventional current differential protection may not operate effectively. Based on the basic operation principle of the current differential relay, this paper points out that the phase difference (ϕdiff) of fault currents from MMC and OWF should be limited within a specific range, i.e. (-ϕdiffmax, ϕdiffmax), to guarantee the reliable tripping of the current differential relay. Yet, the highly control-dependent fault currents from the MMC and OWF could yield an arbitrary ϕdiff that might beyond (-ϕdiffmax, ϕdiffmax), which leads to the possible malfunction of the current differential relay. To tackle this challenge, the coordinated control method of MMC is proposed to align the phase angle of its fault current with that of the OWF, such that ϕdiff ∈ (-ϕdiffmax, ϕdiffmax) can be always guaranteed, so as the reliable operation of the current differential relay. Finally, the proposed coordinated control is verified by the electromagnetic transient (EMT) simulations in PSCAD and the real-time digital simulator (RTDS).
AB - The modular multilevel converter (MMC) based high-voltage dc (HVDC)-connected offshore wind farm (OWF) is power electronic converter dominated power system, where the conventional current differential protection may not operate effectively. Based on the basic operation principle of the current differential relay, this paper points out that the phase difference (ϕdiff) of fault currents from MMC and OWF should be limited within a specific range, i.e. (-ϕdiffmax, ϕdiffmax), to guarantee the reliable tripping of the current differential relay. Yet, the highly control-dependent fault currents from the MMC and OWF could yield an arbitrary ϕdiff that might beyond (-ϕdiffmax, ϕdiffmax), which leads to the possible malfunction of the current differential relay. To tackle this challenge, the coordinated control method of MMC is proposed to align the phase angle of its fault current with that of the OWF, such that ϕdiff ∈ (-ϕdiffmax, ϕdiffmax) can be always guaranteed, so as the reliable operation of the current differential relay. Finally, the proposed coordinated control is verified by the electromagnetic transient (EMT) simulations in PSCAD and the real-time digital simulator (RTDS).
KW - Current differential protection
KW - Offshore wind farm
KW - Coordinated control
KW - Short-circuit fault
KW - MMC
UR - http://www.scopus.com/inward/record.url?scp=85146422544&partnerID=8YFLogxK
U2 - 10.1016/j.ijepes.2023.108952
DO - 10.1016/j.ijepes.2023.108952
M3 - Journal article
SN - 0142-0615
VL - 148
SP - 1
EP - 13
JO - International Journal of Electrical Power & Energy Systems
JF - International Journal of Electrical Power & Energy Systems
M1 - 108952
ER -