Quantitative Evaluation of the Impact of Repetitive Voltage Sags on Low-Voltage Loads

Automatic reclosing is a typical protection method to clear temporary faults in power distribution systems. However, it has a weakness in regards to voltage sags because it produces repetitive voltage sags. In this paper, we explored the repetitive impacts of voltage sags due to the automatic reclosing of power distribution systems. The actual tests of low voltage loads were carried out for obtaining the susceptibility of voltage sags. The final results of the tests yielded the power acceptability curves of voltage sag, and the curves was transformed the 3-D Computer Business Equipment Manufacturer Association (CBEMA) format. For the quantitative evaluation of the impact of repetitive voltage sags, an assessment formulation using the voltage sag contour was proposed. The proposed formulation was tested by using the voltage sag contour data of IEEE standard and the results of the test. Through the case studies, we verified that the proposed method can be effectively used to evaluate the actual impact of repetitive voltage sags.