Power Quality Issues on Wind Power Installations in Denmark

Abstract

This paper introduces the power quality issues of wind power installations in a historic perspective, as the development from a few small wind turbines connected directly to the low voltage grid, to the present system with high penetration on the medium voltage distribution grids and two large offshore wind farms connected at transmission level. In this perspective, the power quality issues are divided into local issues particularly related to the voltage quality in the distribution systems and global issues related to the power system control and stability. Power quality characteristics of wind turbines and wind farms are described according to national and international standards, and measurements from wind farms are presented.

Power Quality in Grid-Connected Wind Turbines

“…There are not too many works assessing the power quality in wind farms according to the IEC 61400-21 standard (Foussekis et al, 2003;Srensen, 2001;Srensen et al, 2007). This section shows the results of measurements performed on two wind turbines with different constructive characteristics and located in an experimental wind farm in the northwest of Spain 1 .…”

Grid integration impacts on wind turbine design and development

“…Various wind turbine manufactures have also been challenged to initiate research activities directed towards connection and optimised integration of large wind farms within the electrical power grid. Risø-DTU National Laboratory has developed a dynamic simulation model for wind farms [1], [3], [6], including both wind farm controllers, individual wind turbine controllers and the dynamics of the wind turbines themselves. In the following, different aspects of the grid integration impacts on the wind turbine design and development are briefly discussed.…”

“…At that time, the main power quality concern was to ensure that the voltage in the distribution grid was kept within an acceptable range -i.e. local power quality issue [1].…”

“…For such large wind farms the focus in the power quality is drawn toward large power system and wind power integration problem, where the power system control and stability issues are addressed -i.e. global power quality issue [1].…”

Study on grid adaptability testing methodology for wind turbines

“…In particular, testing theories and methodologies have been developing rapidly, and a large number of papers have been published [2][3][4][5][6][7][8][9][10]. For example, [2] analyzed the basic principles and influencing factors of grid-connected wind turbine power quality problems, and conclusions were validated by simulation.…”