MILP model for reliability assessment of active distribution networks with microgrids

• MILP model for reliability assessment of active distribution networks. • Network topology optimization via microgrid formation and tie-lines. • Linear reward-penalty scheme for reliability cost quantification. • Reliability diagnosis tool supporting operation and planning. We propose a mixed-integer linear programming (MILP) model for assessing the reliability of active distribution networks under both normal and contingency conditions. The objective function combines system operation costs with reliability costs. The model integrates self-healing mechanisms, including topology adjustments, system restoration via microgrids, and tie lines. Additionally, a linear formulation is developed to represent reward-penalty schemes and assess reliability costs. To demonstrate the applicability of the proposed model, tests are conducted on a 12-node system and a 136-node system, the latter based on real data. The results illustrate that the model provides a reliable diagnosis of the network and supports operators in decision-making to enhance network performance under various operational scenarios. A sensitivity analysis considering different failure rates, distributed generation capacities, and reward–penalty scheme coefficients is also presented, providing insights into their impact on system reliability and operational performance.