Evaluation of a communication-based fault ride-through scheme for offshore wind farms connected through high-voltage DC links based on voltage source converter

• Published in: IET renewable power generation Vol. 9; no. 8; pp. 882 - 891
• Main Authors: Nanou, Sotirios, Papathanassiou, Stavros
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.11.2015
• Subjects: chopper resistors; Choppers; choppers (circuits); communication delays; communication link; communication system latency; Communication systems; communication‐based fault ride‐through scheme; Control systems; DC chopper; de‐loading control strategy; Electric potential; electromagnetic transient type model; EMTP; expected FRT response; Faults; FRT capability; grid code requirements; high‐voltage DC links; HVDC power convertors; HVDC power transmission; interconnection ends; linearised small‐signal model; Links; offshore wind farm; offshore wind turbine; onshore grid fault; power generation control; power generation faults; power generation reliability; power grids; power imbalance handling; power system interconnection; Ratings; resistors; Special Issue: Selected Papers from the European Wind Energy Association 2014; time‐domain analysis; time‐domain simulations; Voltage; voltage source converter; VSC‐HVDC system; wind power plants; wind turbines; HVDC power convertors; choppers (circuits); EMTP; communication link; power generation control; communication-based fault ride-through scheme; high-voltage DC links; linearised small-signal model; HVDC power transmission; time-domain simulations; de-loading control strategy; DC chopper; interconnection ends; power system interconnection; grid code requirements; VSC-HVDC system; power generation faults; power grids; wind power plants; power imbalance handling; expected FRT response; power generation reliability; voltage source converter; communication system latency; electromagnetic transient type model; time-domain analysis; offshore wind turbine; offshore wind farm; resistors; onshore grid fault; FRT capability; wind turbines; chopper resistors; communication delays
• ISSN: 1752-1416; 1752-1424; 1752-1424
• DOI: 10.1049/iet-rpg.2015.0017

Offshore wind farms connected to the mainland through high-voltage DC links based on voltage source converters (VSC-HVDC) are subject to grid code requirements, such as fault ride-through (FRT) capability and dynamic voltage support. To address the challenge of FRT capability, sophisticated control strategies are required, capable of handling the power imbalance between the two interconnection ends during onshore grid faults. Τhis study proposes an FRT method which combines a de-loading control strategy for the offshore wind turbines, utilising the communication infrastructure of the VSC-HVDC system, with a DC chopper to dissipate the power surplus that cannot be effectively curtailed via the communication link. The impact of communication system latency on the expected FRT response and the required rating of the DC chopper is investigated using a linearised small-signal model introduced in this study, whose results are validated against time-domain simulations using detailed electromagnetic transient-type models for the entire system. It is concluded that the required rating of chopper resistors can be substantially reduced when existing communication capabilities are exploited, even in the presence of relatively high communication delays.