Voltage regulation

Transient recovery voltage

Quantum mechanics

Control (management)

Direct current

Overvoltage

Voltage

Engineering

Geotechnical engineering

Marine engineering

Power (physics)

Computer science

Fault (geology)

Seismology

Geology

Physics

AC power

Submarine pipeline

Voltage drop

Electric power system

Automotive engineering

Environmental science

Artificial intelligence

Wind power

Dropout voltage

Control theory (sociology)

Offshore wind power

High-voltage direct current

Electrical engineering

IEEE Transactions on Power Systems

Modular Multilevel Converter based High Voltage Direct Current (MMC-HVDC) connected offshore wind farms could suffer serious challenges: DC overvoltage during a fault and post-fault DC voltage restoration. In this paper, to mitigate DC overvoltage, a two-stage voltage drop control scheme is proposed for offshore MMC to realize a fast active power reduction, by coordinating with a voltage-dependent active current control of individual wind turbines. The voltage drop depths are designed by considering the offshore de-loading efficiency and the stability of WTs. To improve the post-fault DC voltage recovery performance, an adaptive voltage rise control scheme is proposed to coordinate the recovery of onshore and offshore active power. The recovery trajectory of DC voltage is formulated and further employed to design the onshore active power ramp rate for uninterrupted operation of WTs. Case studies have been conducted on two test systems to validate the proposed method.

Enhanced FRT and Postfault Recovery Control for MMC-HVDC Connected Offshore Wind Farms