There are complicated or mixed uncertain properties in the evaluation of equipment sensitivity to voltage sags thereby making it difficult to use the point-value based assessment method to evaluate the impact of voltage sags on sensitive equipment, especially in the case of a small sample size. Considering the multi-valued nature of the equipment operation status during voltage sag, the voltage tolerance level of sensitive equipment is characterized by an interval numeral. After the interval probability of the abnormal operation status is obtained, the concept of hybrid entropy is introduced to measure the complicated uncertainty of the equipment voltage tolerance referring randomness and fuzziness. A novel method based on the maximum hybrid entropy principle is used to obtain the point-value of equipment failure probability. The proposed method is demonstrated on personal computers (PCs) and adjustable speed drives (ASDs) and the simulation results show that the proposed method is correct and adaptive.
展开▼
