Improved wind gust stability for wind diesel generator systems

With a sudden wind gust, a wind-diesel system with a large wind turbine penetration can suffer from power system instability, even though it may be stable under steady-state conditions at the same wind speeds. This suggests that the wind-diesel system should be investigated for better frequency and power stability. In this paper, a concept has been presented to improve the stability of the wind-diesel system in high wind gust condition, by placing the wind turbines in such a way that the wind turbines experience the wind gust at different times. A 1.25 MVA Caterpillar diesel generator with six NORDEX 150 turbines has been modelled using MATLAB, and it has been found that when all the wind turbines experience a sufficiently large wind gust simultaneously, frequency and power control is lost. However, if the turbines are located so that they experience the wind gust at staggered times, the power system is found to remain stable for the same gust conditions. The potential stability benefits of this approach have been demonstrated for an area with a known predominant wind front movement direction