Maximum Hybrid Entropy Interval Probability Assessment of Equipment Failure Due to Voltage Sags

There is complex uncertainty involved in evaluation of equipment sensitivity to voltage sags, and that makes it difficult for the point-valued assessment method to evaluate the impact of voltage sags on the sensitive equipment, especially in the case of small sample size. Considering the multi-valued nature of equipment status during the voltage sags, the voltage tolerance level of sensitive equipment is characterized by interval data, so as to derive interval probabilities of equipment operation status. Meanwhile, hybrid entropy is then used to measure the uncertainty of randomness and fuzziness in equipment voltage tolerance level. It develops one novel model by transforming the interval probability into point-valued probability based on maximum hybrid entropy model. By the help of personal computers, the proposed model is finally verified in a test distribution system.