Uncertainty Measure Evaluation Method of Voltage Sag Severity to Industrial Equipment

An uncertainty measure method based on hybrid entropy is introduced to evaluate voltage sag severity to sensitive industrial equipment. Voltage sag severity, usually a qualitative concept, is complex uncertain. The complex uncertainty includes random, fuzzy and their cross uncertain properties. In order to evaluate voltage sag severity to sensitive industrial equipment, hybrid entropy is used to describe the complex uncertainty contained in voltage sag severity and maximum hybrid entropy principle is introduced to determine the complex uncertainty. The equipment failure rate can be calculated using the obtained hybrid entropy. As a case study, the personal computer (PC), widely used in many industries, is evaluated and compared with existing methods. The results have shown that the proposed method is correct and feasible. It can overcome the disadvantages of over- and under-evaluation in current methods.