一种小水电电能质量灰色模糊综合评价模型

A Synthetic Power Quality Evaluation Model of Small Hydropower Based on Gray and Fuzzy Theory

针对小水电易出现电压过高和欠发无功的特点,结合国家电能质量标准及国网对小水电电能质量的要求,提出了一种主客观组合赋权的电能质量模糊综合评估模型。综合考虑小水电电能质量各项指标,运用熵值法和层次分析法组合赋权确定电能质量评价指标的综合权重。基于灰色关联系数构造模糊评价关系矩阵,并结合求得的综合权重向量实现电能质量的模糊综合评价。这种方法既能够对数据样本的电能质量进行整体评价,又可以对同一等级的电能质量进行精细的评价,还能够反映电能质量各分项指标的优劣情况,对小水电站的调整与改进提供参考。通过实际算例验证了该模型的有效性和可行性。

According to the characteristics that over-voltage and lack of reactive power are easy to occur in small hydropower stations, combining requirements of national power quality standards and state grid, a new synthetic power quality evaluation model based on gray and fuzzy theory is proposed. Taking all the elements into account, the synthetic weighting is obtained by using analytic hierar- chy process and entropy method. A relation matrix of the fuzzy synthetic evaluation is constructed based on grey relational coeffi- cient. Finally, the synthetic evaluation of power quality is achieved. This method can not only perform synthetic assessment, but al- so evaluate power quality difference more precisely within the same power quality grade. Besides, it reflects the pros and cons of each sub-index, which provides a reference for the adjustment and improvement of small hydropower stations. The feasibility and validity of the proposed model are demonstrated with the results of the practical examples.