For the randomness and dynamics problem of condition information and evaluation level boundary in the cable joint, an insulation state evaluation method of cable intermediate joint based on variable weight and interval number-set pair analysis theory is proposed. The partial discharge characteristic parameters of cable joint are extracted as the state evaluation index, and the index data are expressed in intervals. The variance and standard deviation are introduced to measure the volatility of the interval data of each index, and then the objective weight of the index is given. For the problem of unbalanced deterioration of partial discharge indicators, the corresponding state variable weight function is constructed to obtain the variable weight by comprehensively considering the deterioration degree and trend parameters of the indicators. Finally, the coupling method of interval number and set pair analysis is applied to obtain the state level of cable joint according to the expectation of comprehensive connection. By analyzing the online monitoring data of a 10 kV cable intermediate joint, the validity and feasibility of the state evaluation method are verified.

The widespread integration of user-side renewable energy and shared energy storage has outpaced the flexibility of existing operational models and led to unreasonable allocations of energy-sharing benefits. This study aimed to develop an optimized operational model for community microgrid alliances that accommodated diverse service demands and power exchange. First, a system framework for the coordinated operation of shared energy storage and community microgrid alliances was established. Second, based on a Stackelberg game balancing the interests of both the shared energy storage operator and community microgrid alliances, a nested RIME algorithm integrated with the Gurobi solver was employed to determine day-ahead scheduling decisions, community operating costs, energy storage pricing decisions, and operational revenues. Third, in the day-ahead scheduling stage, power exchange among communities was considered by computing allocation coefficients from the similarity between community renewable generation outputs and load profiles, the magnitude of power exchange, and their correlation; these coefficients were then used in a weighted-contribution method to reallocate day-ahead operating costs among communities. Finally, case-study simulations validate the effectiveness and applicability of the proposed model.

The large-scale integration of distributed photovoltaics poses challenges to the economy and reliability of the distribution network. To address this, a coordinated planning approach of "source-grid-load-storage" considering reliability has been proposed. Firstly, a bi-level coordination planning model of "source-network-charge-storage" with reliability is established. The upper-level is established to minimize the cost and maximize the revenue of reliability, and the lower-level is established to minimize the cost of operation and voltage quality. The weighted coefficient method is used to transform the multi-objective into a single-objective in the upper and lower level. And the model considers constraints such as power balance, power flow, and configuration capacity of system. Next, Crisscross optimization algorithm is used to solve the model with gurobi solver jointly. Finally, IEEE 33-node system is utilized to verify the effectiveness and practicality of the proposed method. The results show that the joint planning model of "source-network-load-storage" which considers the reliability can minimize the cost while improve the reliability and voltage quality.