The Ln-least method is commonly used to estimate the Weibull parameters from the observed wind speed data. In previous studies, the bin method has been used to calculate the cumulative frequency distribution for the Ln-least method. The purpose of this study is to obtain better performance in the Ln-least method by applying probability plotting position(PPP) instead of the bin method. Two types of the wind speed data were used for the analysis. One was the observed wind speed data taken from three sites with different topographical conditions. The other was the virtual wind speed data which were statistically generated by a random variable with known Weibull parameters. Also, ten types of PPP formulas were applied which were Hazen, California, Weibull, Blom, Gringorten, Chegodayev, Cunnane, Tukey, Beard and Median. In addition, in order to suggest the most suitable PPP formula for estimating Weibull parameters, two accuracy tests, the root mean square error(RMSE) and R2 tests, were performed. As a result, all of PPPs showed better performances than the bin method and the best PPP was the Hazen formula. In the RMSE test, compared with the bin method, the Hazen formula increased estimation performance by 38.2% for the observed wind speed data and by 37.0% for the virtual wind speed data. For the R2 test, the Hazen formula improved the performance by 1.2% and 2.7%, respectively. In addition, the performance of the PPP depended on the frequency of low wind speeds and wind speed variability.
- Ko, K. N., Kim, K. B., and Huh J. C., Characteristics of Wind Energy for Long-term Period (10 years) at Seoguang Site on Jeju Island, Journal of the Korean Solar Energy Society, Vol. 28, No. 3, pp. 45-52, 2008.
- Song, H. S., and Kwon, S. D., Assessing Goodness-of-Fit of Weibull Distributions for Wind Resource Prediction, Spring Conference of the Korean Solar Energy Society, pp. 63-65, 2014.
- Mathew, S., Wind Energy: Fundamentals, Resource Analysis and Economics, Springer, pp. 68-78, 2006.
- Seguro, J. V., and Lambert, T. W., Modern estimation of the parameters of the Weibull wind speed distribution for wind energy analysis, Journal of Wind Engineering and Industrial Aerodynamics, Vol. 85, No. 1, pp. 75-84, 2000.
- Chang, T. P., Performance Comparison of Six Numerical Methods in Estimating Weibull Parameters for Wind Energy Application, Applied Energy, Vol. 88, No. 1, pp. 272-282, 2011.
- Yahaya, A.S., Chong, S.Y., Ramli, N.A., and Ahmad, F., Determination of the Best Probability Plotting Position for Predicting Parameters of the Weibull Distribution, International Journal of Applied Science and Technology, Vol. 2, No. 3, pp. 106-111, 2012.
- Huh, M., Lee, S., Cha, G., Park, J., and Yoo J., R&statistic Computation, Parkyeongsa, pp. 149-154, 2011.
- Kang, D., Ko, K., and Huh, J., Comparative Study of Different Methods for Estimating Weibull Parameters: A Case Study on Jeju Island, South Korea, Energies, Vol. 11, No. 2, 2018.
- Costa Rocha, P. A., de Sousa, R. C., de Andrade, C. F., and da Silva, M. E. V., Comparison of Seven Numerical Methods for Determining Weibull Parameters for Wind Energy Generation in the Northeast Region of Brazil, Applied Energy, Vol. 89, No. 1, pp. 395-400, 2012.
- Ross, R., Graphical Methods for Plotting and Evaluating Weibull Distributed Data, Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials, Vol. 1, pp. 250-253, 1994.
- Deaves, D. M. and Lines, I. G., On the Fitting of Low Mean Windspeed Data to the Weibull Distribution, Journal of Wind Engineering and Industrial Aerodynamics, Vol. 66, No. 3, pp. 169-178, 1997.
- Lun, I. Y. F. and Lam, J. C., A Study of Weibull Parameters Using Long-term Wind Observations, Renewable Energy, Vol. 20, No. 2, pp. 145-153, 2000.
- Yahaya, A. S., Nor, N. M., Jali, N. R. M., Ramli, N. A., Ahmad, F., and Ul-Saufie, A. Z., Determination of the Probability Plotting Position for Type I Extreme Value Distribution, Journal of Applied Sciences, Vol. 12, No. 14, pp. 1501-1506 , 2012.
- Makkonen, L., Plotting Positions in Extreme Value Analysis, Journal of Applied Meteorology and Climatology, Vol. 45, No. 2, pp. 334-340, 2006.
- Kang, D. B. and Ko, K. N., A Comparative Study on the Probability Plotting Positions to Estimate Weibull Parameters, Spring Conference of the Korean Solar Energy Society, pp. 102, 2018.