Titel: DC Connected Wind Farm – Evaluation of Dynamic Performance, Elforsk rapport 08:44
Författare: Andreas Petersson, Massimo Bongiorno
Utgivare: Elforsk, Vindforsk
Årtal: 2008
Ämnesord: infrastruktur
Sökord/keywords: HVDC, transmission, VSC
Rapport
Sammanfattning/Abstract: Modern variable-speed wind turbines (WTs) which are connected to the grid by a voltage-source converter high-voltage direct current (VSC-HVDC) system may require several power-electronic components (PECs). Within the variablespeed turbines, there are normally PECs in order to control the turbine speed
and torque while the VSC-HVDC introduces additional conversions in order to achieve the grid connection. In this report, the possibility to the VSC-HVDC in order to control the WTs is studied, thus eliminating some of the PECs within the turbines. This means that there is a possibility to use simpler and cheaper types of WTs with less power-electronic equipment.
It has been found that a wind farm utilizing a VSC-HVDC rectifier in order to control the rotor speed of the wind turbine can utilize simper and cheaper type fixed-speed WTs and still produce the same amount of power. One drawback with these simpler type fixed-speed WTs is that they produce excess power, i.e., power above the rated. It is essential to determine the amount of excess power that can be expected from the WTs, since this will have an impact of the system design. However, these power variations will be less significant with the number of installed WTs in the wind farm.
Design of the control system of the wind-farm side VSC-HVDC must be done with care, since it is importance to ensure that the overall system is sufficiently damped at all critical frequencies.