Vladimir Sousa Santos

Economic dispatch in grid-connected microgrids is challenged by the variability of renewable generation, the uncertainty of demand, and the need to simultaneously satisfy technical and economic constraints under different operating conditions. This study proposes an integrated predictive economic dispatch strategy for power grids with interconnected microgrids, structured as a unified optimization framework. The approach integrates nodal electrical modeling, Optimal Power Flow (OPF)-based optimization, multi-scenario analysis, and post-optimization feasibility verification based on performance indicators within a single decision-support structure. The methodology is applied to a modified 14-node power grid interconnected with a microgrid, where simulations are conducted under three representative load scenarios (100%, 70%, and 40%) and two operational configurations (hybrid and renewable-only), enabling a comprehensive assessment of system behavior. Results show that the hybrid configuration consistently outperforms the renewable-only case, achieving loss reductions of up to 7.3 MW, increases in spinning reserve exceeding 50 MW, and a transition from net power import to export of approximately 50 MW under high demand. Additionally, the microgrid plays an active operational role, dynamically switching between import and export modes based on load levels and the generation mix. The proposed framework enables identification of operationally efficient and technically feasible configurations by incorporating bidirectional power exchange, electrical constraints, and reserve requirements. The main contribution lies in integrating technical, operational, and interaction variables within a single deterministic Optimal Power Flow (OPF)-based assessment scheme to support decision-making in interconnected microgrid-based power grids.

Tidal energy assessment in tropical estuaries is constrained by low current velocities and high spatial variability, which limit conventional evaluation approaches. This study proposes a methodological framework adapted to velocity-constrained environments. The framework integrates ADCP-calibrated hydrodynamic modeling, velocity-exceedance-based site selection, low cut-in tidal turbine compatibility analysis, and a localized Levelized Cost of Energy evaluation within a unified decision-support structure. The methodology is applied to Buenaventura Bay, Colombia, where numerical simulations reproduce the mixed tidal regime with errors of approximately 0.30 m in water levels and 0.022 m/s in current velocities, enabling consistent characterization under low-flow conditions. Results at three locations indicate average available power densities of 64 W/m² at La Bocana, 19 W/m² at Buoy 29, and negligible values at Aguadulce, supporting the identification of marginal and non-viable sites based on velocity distributions. Under a low-velocity turbine configuration (10 m rotor diameter, 0.4 m/s cut-in speed), annual energy production is about 18 MWh per unit, while a 300-turbine array would generate approximately 5.4 GWh per year. The results indicate that annual energy production and capital expenditure are the main drivers of techno-economic feasibility in low-energy estuarine systems.

This paper studies the harnessing of tidal energy in a low-energy tropical estuary. The research uses Buenaventura Bay, on the Colombian Pacific coast, as a case study. The study develops and applies a step-by-step method for these environments that integrates data-driven hydrodynamic modeling, resource identification, site selection, low-speed turbine analysis, pilot-set configuration, and local cost analysis. The simulations match the mixed tidal pattern, with errors of approximately 0.30 m in water levels and 0.022 m/s in water velocities. This allows for reliable energy estimates even at low velocities. Results from three points in the bay showed that the average available power densities are approximately 64 W/m² at La Bocana, 19 W/m² at Buoy 29, and are low at Aguadulce. A horizontal-axis turbine, designed for low speeds (10 m rotor diameter and a start-up speed of 0.4 m/s), was proposed and is expected to produce approximately 18 MWh per unit per year. A pilot park of 300 turbines (approximately 1.1 MW total) would produce approximately 5.4 GWh per year. The base case yields a Levelized Cost of Energy (LCOE) of approximately USD 663/MWh and a negative Net Present Value (NPV). Although tidal power generation in Buenaventura Bay is not currently profitable, the study demonstrated that annual energy production is the most important factor, followed by initial costs. In contrast, interest rates and operating costs have a minor impact. Based on these results, the study provides quantitative and procedural guidance for marine energy development under resource-constrained conditions.

This paper analyzes trends in electrical power quality (PQ) in industrial systems through a bibliometric approach to identify key topics, prominent authors, and patterns of international collaboration that may guide future research. PQ disturbances can significantly affect operational continuity, energy efficiency, and equipment lifespan in industrial electrical systems (IES), making it essential to map the research landscape to support technological and strategic responses. The study reviews 103 articles from the Scopus database for the period 2016–2024, applying relevance and currency criteria. VOSviewer® was used to conduct the analysis, employing keyword co-occurrence networks and bibliographic coupling to visualize thematic, collaborative, and citation relationships. Results indicate a strong research focus on harmonic distortion, voltage disturbances, and artificial intelligence applications for diagnosis and mitigation. India leads in scientific production, while IEEE Access is the most influential source. Despite growing interest, the study identifies limited international collaboration and thematic fragmentation, which may hinder comprehensive solutions. The findings highlight the need to expand collaboration networks, standardize methodologies, and integrate underexplored topics into mainstream PQ studies, strengthening the ability of industrial systems to address emerging challenges and improve performance, resilience, and reliability.

This paper evaluates the power quality in a residential photovoltaic system in Colombia. Power quality parameters were monitored in a residence in Barranquilla with a 4.44 kW system connected to the grid, analyzing its behavior over time and comparing it with regulatory limits. Graphical and statistical analysis tools were used to identify deviations and problems in the network based on current regulations. The results show a voltage unbalance reaching 9.84% and a current unbalance of up to 147.7%, with a total demand distortion of up to 17.1% and a k-factor >70%. These results show high unbalance and harmonics in the supply source, affecting network stability, efficiency, and equipment life. The research confirms that the injection of energy from photovoltaic systems can affect power quality in low-voltage networks, highlighting the need for mitigation strategies. The implementation of advanced controls in inverters, active filters, and FACTS devices is proposed, along with strengthening the regulation of harmonic distortion and load balancing in residential networks. Given the accelerated growth of photovoltaic generation in Colombia, it is essential to evaluate its long-term impact to ensure the stability of the electrical system and maximize the benefits of distributed generation in the country.

This study evaluates and compares centralized and distributed reactive power compensation strategies using Static Var Compensators (SVCs) to enhance the performance of a high-voltage transmission system in the Caribbean region of Colombia. The methodology comprises four stages: system characterization, assessment of the uncompensated condition under peak demand, definition of four SVC-based scenarios, and steady-state analysis through power flow simulations using DIgSILENT PowerFactory. SVCs were modeled as Thyristor-Controlled Devices (“SVC Type 1”) operating as PV nodes for voltage regulation. The evaluated scenarios include centralized SVCs at the Slack node, node N4, and node N20, as well as a distributed scheme across load nodes N51 to N55. Node selection was guided by power flow analysis, identifying voltage drops below 0.9 pu and overloads above 125%. Technically, the distributed strategy outperformed the centralized alternatives, reducing active power losses by 37.5%, reactive power exchange by 46.1%, and improving node voltages from 0.71 pu to values above 0.92 pu while requiring only 437 MVAr of compensation compared to 600 MVAr in centralized cases. Economically, the distributed configuration achieved the highest annual energy savings (36 GWh), the greatest financial return (USD 5.94 M/year), and the shortest payback period (7.4 years), highlighting its cost-effectiveness. This study’s novelty lies in its system-level comparison of SVC deployment strategies under real operating constraints. The results demonstrate that distributed compensation not only improves technical performance but also provides a financially viable solution for enhancing grid reliability in infrastructure-limited transmission systems.

This article evaluates energy quality in individual circuits within an industrial electrical system and its impact on common connection point parameters. The research is crucial due to rising challenges in power quality arising from increased nonlinear electrical loads in industrial processes. The study involves sequential steps, covering the industrial electrical system´s description, power quality parameters analysis, and issue identification. A comprehensive assessment was conducted on a 3,000 kVA, 13.8 kV/460 V point of common coupling (PCC) transformer, and 10 transformers (10 to 250 kVA) supplying individual circuits. Findings indicated load factors below 70% in all transformers and a power factor below 0.9 in eight. Issues like voltage variation, current imbalance, and harmonic distortion were identified in nine transformers supplying individual circuits, while the PCC exhibited no power quality problems. The research emphasizes the importance of including individual circuits in power quality assessments, as compliance with regulatory limits at the PCC may not guarantee the absence of power quality issues in individual circuits, affecting equipment lifespan and increasing energy losses.

This paper compares concentrated and distributed reactive power compensation to improve the power factor at the point of common connection (PCC) of an industrial electrical system (IES) with harmonics. The electrical system under study has a low power factor, voltage variation, and harmonics caused by motors operating at low loads and powered by variable-speed drives. The designed compensation system mitigates harmonics and reduces electrical losses with the shortest payback period. Four solutions were compared, considering concentrated and distributed compensation with capacitor banks and harmonic filters. Although the cost of investment in concentrated compensation is lower than that of distributed compensation, a higher reduction in electrical losses and a lower payback period are obtained with distributed compensation. Although the lowest payback period was obtained with distributed compensation with capacitor banks (0.4 years), it is not recommended in the presence of harmonics because the effects of current harmonics significantly reduce the useful life of these elements. For this reason, distributed compensation with harmonic filters obtained a payback period of 0.6 years, and it was proposed as the best solution. These results should be considered in projects aimed at power factor compensation in IESs with harmonics. The concentrated compensation of the capacitor bank at the PCC is proposed because of the lower investment cost and ease of installation. However, the advantages of distributed compensation with harmonic filters have not been evaluated. An energy efficiency approach is used to analyze the impact of the location methods of the power factor compensation equipment on the electrical losses of the IES.

This study aims to determine the energy efficiency of three-phase induction motors (TIM) powered when operated with photovoltaic systems (PVS). The environmental advantages of photovoltaic systems (PVS) are very well known. However, there are still challenges related to energy quality, electricity generation instability, failure in frequency regulation, instability in reactive power, and harmonics generation. However, the impact of PVS on TIM efficiency has not been thoroughly explored. This research compares a TIM's electromechanical characteristics and efficiency when powered by a conventional electrical grid versus a PVS. Experimental studies revealed that when powered by the PVS, the TIM experienced increased voltage and higher voltage and current harmonics compared to grid power. These electrical difficulties, attributed to the PVS inverter, resulted in a 2.7% decrease in TIM efficiency compared to grid power. Modeling conducted under actual load variation conditions demonstrated a 2.6% increase in energy consumption when powered by the PVS compared to grid power. Based on these findings, PVS installers are advised to consider the energy quality provided by these systems, as it may affect the efficient operation of TIM, leading to increased energy consumption.