The increase in the number of consumers who produce part of their own electricity through photovoltaic distributed generation (PVDG) led to the need for studies on how the power system is affected. As the distribution systems were not designed to integrate PVDG, it is important for regulatory agencies and utilities to identify technical problems in the grid associated with the levels of photovoltaic penetration. In this regard, this study presents a method with indicators that quantify the technical impacts that PVDG growth causes to an actual utility that contains hundreds of feeders with different topologies, load types, and densities. Real solar irradiance and temperature values over a year, and photovoltaic system locations varying based on the Monte Carlo method were also considered in the computational simulations. This study helps the utilities to plan preventive measures to strengthen the grid, and regulatory agencies to enhance policies to support PVDG. We analyzed the impacts on voltage magnitudes, technical losses and peak demand arising from the PVDG integration. The results show that, even at low penetration levels (2%), one-third of feeders required modification in the distribution system to allow photovoltaic integration. For over 60% of feeders, penetration levels of up to 20% reduced technical losses and voltage problems, with practically no effect on peak demand. Feeders in residential and commercial/industrial areas presented increases in technical losses and voltage levels for high penetration levels. Rural areas presented reductions in these parameters for all levels of PVDG integration.

Optimizing the placement of capacitors in conventional and modern electric power systems offers a highly effective means of minimizing energy losses, particularly in distribution systems where power losses surpass those in transmission. The dynamic nature of load levels within such networks significantly impacts the magnitude of energy losses, making the load profile a pivotal factor in determining both the extent of power losses and the ideal locations for shunt capacitors in radial feeders. Nevertheless, incorporating load variability into the capacitor placement problem can significantly increase computational complexity and processing time. Conversely, disregarding it can result in inaccurate calculations of energy losses and, subsequently, suboptimal locations for capacitor banks. Consequently, many specialized studies have opted to omit load variations from their capacitor placement models due to concerns about computational demands and processing time. In this context, present study aims to assess the influence of consumption patterns on capacitor placement plans in modern and conventional networks. The objective is to shed light on the critical importance of considering load variability when striving to reduce power losses cost and reactive power expenditure through optimally placing capacitor banks in the presence and the absence of renewable and distributed energy sources and mobile energy storage systems (MESSs). The analysis is conducted using mathematical programming techniques across a range of distribution systems with and without considering distributed energy resources, renewable energy sources (RESs), and MESS units. Accordingly, the variable nature of RESs and optimal operation of MESSs are coordinated with the capacitor placement plan in the modern system scenario.

Many unbalanced voltage conditions, which produce different effects on electric equipment, are associated with the same voltage unbalance factor. This fact hinders the precise association between the values of this index and the effects of voltage unbalance. In the present study, an alternative methodology for quantifying voltage unbalance based on the effects of this phenomenon on the temperature and efficiency of three-phase induction motors is proposed. The application of the suggested methodology results in an index that contemplates the combined effects of the modules and angles of the positive and negative sequence voltages. Aiming to apply this methodology and evaluate its performance, we selected a comprehensive set of balanced and unbalanced voltage conditions and used it on a three-phase induction motor. The results show that the index obtained, when compared to the traditional voltage unbalance factors, reduces the uncertainties inherent to the quantification process of this phenomenon. In other words, it allows a better association between the values and effects of the voltage unbalance. For these reasons, this index is considered as a potential alternative that can be employed in industrial utilities and standards that deal with voltage unbalance.

Utilities apply an additional fee for medium and large customers with low power factors. However, unfair financial charges may occur in installations subjected to voltage unbalance and harmonic distortion. The objective of this paper is to determine the fairest PF definitions and their corresponding measurement algorithms in the case in which a constant impedance load or an induction motor is supplied with unbalanced and nonsinusoidal voltages. Fairness is defined considering that the meter (built based on a particular definition and measurement method) under nonideal supply should lead to very close values as if it was submitted to an ideal balanced sinusoidal supply. We performed computational simulations to emulate several conditions in which a balanced customer (modeled as a constant impedance load or an induction motor) is charged due to a voltage supply no longer balanced and sinusoidal. We also performed experimental tests with an induction motor subjected to a wide range of unbalanced nonsinusoidal supply conditions to ratify the conclusions drawn from the simulations. Based on the simulation results and the experimental tests, we indicate some power factor definitions and measurement methods that are not significantly affected by voltage unbalance and harmonic distortions. These indicated PF definitions provide the fairest billing for conditions with unbalanced nonsinusoidal voltages.

This study assesses the technical and financial impacts on voltage levels, peak demand, and technical losses of distribution systems due to the integration of battery energy storage systems (BESSs) associated with photovoltaic distributed generation (PVDG). It assumes that the BESS features (location and storage capacity) are chosen by consumers individually, aiming to directly benefit themselves according to self-consumption and price arbitrage uncoordinated control strategies. Computational simulations of several PVDG/BESS penetration levels in residential feeders of a Brazilian utility were performed via OpenDSS, employing real data of the load (consumption and load profiles) and photovoltaic generation (irradiance and temperature). We address the PVDG/BESS locations and the selection of solar irradiance, temperature, and load profile based on the Monte Carlo method. As the impacts on voltage levels, peak demand, and technical losses are expressed in different units, they were stochastically converted into monetary amounts to identify the control strategy that enhances the technical benefits in the distribution system. The results show that BESS installation with location, size, and control strategy defined by consumers creates technical benefits for the distribution system. The risk analysis allows us to conclude that price arbitrage should be prioritized in deciding incentives for penetration levels of up to 60%. Above these levels, self-consumption should be prioritized as an incentive. However, it is worth mentioning that the two strategies could be encouraged regardless of the penetration levels, as both create technical benefits for the distribution networks. The proposed method can support policy proposals to encourage BESS integration in distribution systems.