Comprehensive evaluation of operational energy efficiency for active distribution networks with high photovoltaic penetration considering probabilistic power flow

To accurately characterize the operational state of active distribution networks (ADNs) with high photovoltaic (PV) penetration, this paper proposes a comprehensive operational energy efficiency evaluation method for ADNs considering probabilistic power flow (PPF). Firstly, based on the semi-invariant method, a fuzzy characterization method for PPF distribution is proposed. By extracting key numerical characteristics of the probability distribution to construct triangular fuzzy numbers (TFNs), the PPF results are transformed into an input form suitable for evaluation index calculation, providing a data foundation that accounts for uncertainty for subsequent comprehensive evaluation. Secondly, a dynamic combined weight method considering the PV fluctuation rate is proposed. The Criteria Importance Through Intercriteria Correlation (CRITIC) method is improved through fuzzy number decoupling, and weight updates are triggered based on the real-time PV fluctuation rate, enabling the weights to dynamically respond to changes in the system operating state. On this basis, a utility function-based fuzzy Grey Relational Analysis (GRA)-Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) comprehensive evaluation method is proposed, and GRA-TOPSIS is extended to the fuzzy domain, achieving absolute quantitative evaluation of the operational energy efficiency for a single scenario. Finally, case studies based on the modified IEEE 33-node distribution system are conducted. Simulation results show that the proposed method can accurately quantify the comprehensive operational energy efficiency of ADNs under high PV penetration (HPP) scenarios. Compared with traditional comprehensive evaluation methods, this method can more effectively distinguish the advantages and disadvantages of different schemes. Furthermore, the evaluation results are validated from an economic perspective, which indicates that the ranking results of different operating scenarios obtained by the proposed comprehensive evaluation method are highly consistent with the economic performance of system operating costs, thereby providing an important reference for the planning and operational optimization of ADNs.