Aiming at the problem that the expert judgment method is easily influenced by subjective factors in the process of determining the index weight for power supply reliability evaluation of mid-voltage distribution network

an evaluation method based on principal component analysis is proposed. The evaluation index system of power supply reliability for mid-voltage distribution network is established

and the evaluation index matrix of the objects to be evaluated is constructed

which is successively converted to the normalized index matrix and standardized index matrix. The principal components playing the leading role are determined according to the principal component analysis of standardized index matrix

and the weights of each reliability index of the comprehensive evaluation function are calculated. The comprehensive evaluation function is then established to obtain the reliability evaluation value of the objects to be evaluated. Combined with the weights of each index and its normalized index value

the quadrant diagrams of satisfaction and importance for each index are drawn

which provides a quantitative and intuitive scientific tool for the reconstruction of mid-voltage distribution network with higher reliability. The validity and practicality of the proposed method are verified by an engineering example.