One of the big concerns when planning the expansion of power distribution systems (PDS) is reliability. This is defined as the ability to continuously meet the load demand of consumers in terms of quantity and quality. In a scenario in which consumers increasingly demand high supply quality, including few interruptions and continuity, it becomes essential to consider reliability indices in models used to plan PDS. The inclusion of reliability in optimization models is a challenge, given the need to estimate failure rates for the network and devices. Such failure rates depend on the specific characteristics of a feeder. In this context, this paper discusses the main reliability indices, followed by a comprehensive survey of the methods and models used to solve the optimal expansion planning of PDS considering reliability criteria. Emphasis is also placed on comparing the main features and contributions of each article, aiming to provide a handy resource for researchers. The comparison includes the decision variables and reliability indices considered in each reviewed article, which can be used as a guide to applying the most suitable method according to the requisites of the system. In addition, each paper is classified according to the optimization method, objective type (single or multiobjective), and the number of stages. Finally, we discuss future research trends concerning the inclusion of reliability in PDS expansion planning.

We propose a comprehensive framework for the optimal day-ahead scheduling of power distribution systems (PDS), based on a mixed-integer linear programming (MILP) model. The interaction between transmission system operator (TSO) and distribution system operator (DSO) is considered, where TSO informs DSO of the day-ahead forecast concerning the expected power flow (PF) commitment at the TSO-DSO interconnection points and the violation costs. We propose a MILP model to determine the optimal voltage and power settings of distributed energy resources (DERs) such as dispatchable distributed generators and energy storage units and optimal adjustments of capacitor banks controlled by current. The objective function includes the minimization of energy losses, voltage violations, power curtailment of DERs using volt-watt strategy, and violation of TSO-DSO interconnection PF commitment. Furthermore, we propose a method to estimate the degree of uncertainty in the PF commitment. Therefore, the proposed method can help achieve an optimal operation of the distribution system; in addition, the TSO can best model uncertainty at TSO-DSO interface points and thereby procure reduced amounts of resources to address these uncertainties. Numerical results obtained for a system based on real data highlight the several potential applications of the proposed framework.

The quality of electricity is one of the most discussed issues in the regulatory context, structured by guidelines that allow the assessment of efficiency in electricity supply. Regarding electricity distribution systems, it is essential to highlight the aspects associated with the definition of continuity indicators to measure the service provided by the utilities. The parameters used to calculate the indicators are set by specific agencies in each country based on studies and their characteristics. With the growth in demand for electricity, debates associated with reducing greenhouse gas emissions in the atmosphere, and the increase in Distributed Energy Resources (DERs) connected to the grid, a new trend related to the energy supply is verified. Given these new scenarios, this paper presents a literature review in the regulatory field of existing distribution systems in South American countries. The research proposes to analyze, compare, and expose the current models to evaluate their methods and indicators, including a complete case study in Brazil. This paper seeks to illustrate and point out perspectives, challenges, and future perspectives through the collected and analyzed data.

Two important short-term voltage variation monitoring standards have recently been updated: IEEE 1564 and Distribution Procedures Module 8 (PRODIST) of the Brazilian National Regulatory Agency (ANEEL). The present work deals with a comparative analysis of both regulatory procedures, within the scope of the indices and reference standards implemented for the case of voltage sags. In order to achieve such a comparison, case studies of voltage sags are studied. Thus, in addition to showing the main updates and differences between the standardizations, the limitations on the classification of events by each case study case are also highlighted.

The increasing adoption of rooftop solar photovoltaic (PV) generation in power distribution systems (PDS) requires innovative methods to estimate behind-the-meter (BTM) energy consumption and generation, given the widespread use of net metering. Existing approaches often rely on extensive historical data, advanced measurement infrastructure (AMI), or smart metering. In contrast, we propose a practical energy disaggregation method that operates solely on monthly net energy imports and exports, estimating hourly gross data and leveraging reference generation profiles and typical load curves for residential, commercial, and industrial consumers. A clustering algorithm is used to generate probabilistic power generation for consumer groups within a region, while the sum of the differences between registered and estimated net monthly data is minimized through an iterative process. Validated with synthetic consumers across thirteen different classifications, the proposed method effectively estimates BTM energy consumption and generation. Thus, the method provides utilities with a valuable tool for assessing prosumer behavior and understanding self-consumption patterns, helping to prevent the underestimation of actual demand during PV generation periods while supporting grid operation and planning.