Harmonic current characteristic analysis for wind turbines

This paper analyzes the harmonic current characteristic of wind turbines. Field measurement, data sorting, and analysis are conducted for wind turbine. Most wind turbines at present use a power converter and are equipped with harmonic filters, the control results of these equipments will become highly stochastic as wind speed changes. Even if there is a slight difference in the wind speed, harmonic output of wind turbine will be quite different. If harmonic currents are segmented and the probability density distributions are calculated, then different viewpoints as can be observed. Although harmonic currents of the wind turbine are stochastic, the probability density distributions are close to normal distribution. A stochastic harmonic current predictor is then proposed in this paper based on the probability density distributions of harmonic current. Test results show that the harmonic currents of a wind turbine in long-term operation can be effectively analyzed by the established probability density distributions.