Comments on “Impact of Load Frequency Dependence on the NDZ and Performance of the SFS Islanding Detection Method”

We read with interest an article by Zeineldin and Salama, published in the IEEE Transactions on Industrial Electronics (vol. 58, no. 1, pp. 139-146, Jan. 2011) and tried to reproduce the results of this article for the needs of our own research. Unfortunately, we were led to think that the load model equations used by the authors contained an inconspicuous but significant mathematical error, leading to erroneous results and conclusion. This letter brings corrections to some figures and their analysis as well as the paper conclusion. The new results show that the load's frequency dependence has actually no significant impact on the NDZ of the SFS method.