Voltage Stability Research Articles

Initial Characteristics of Submillimeter Metal Particles in GIS under Impact Vibration

As a critical component within power systems, Gas Insulated Switchgear (GIS) is notably susceptible to insulation degradation due to submillimeter metal particles, compromising its operational safety and stability. Moreover, impact vibrations induced by circuit breaker operations can dislodge particles that typically adhere to the interior walls, causing them to become airborne and thereby intensifying their movement and discharge activities. To investigate this phenomenon, this study establishes a testing platform where alternating current (AC) voltage is superimposed with impact vibration. A camera system, interfaced with an upper computer, is used to capture the real-time motion behavior of the particles. This study focuses on characterizing the initial movement of submillimeter metal particles of varying sizes under the influence of impact vibration by analyzing critical voltages, such as the initial lift-off voltage, stable jumping voltage, and extinction voltage. Furthermore, the effects of introducing large, centimeter-scale spherical metal and rubber particles on these initial characteristics are examined. The findings provide crucial insights into the initial behavior of submillimeter metal particles in GIS, particularly in relation to circuit breaker operations.

Mitigating Intraphase Catalytic-Domain Transfer via CO2 Laser for Enhanced Nitrate-to-Ammonia Electroconversion and Zn-Nitrate Battery Behavior.

Developing sustainable energy solutions is critical for addressing the dual challenges of energy demand and environmental impact. In this study, a zinc-nitrate (Zn-NO3 -) battery system was designed for the simultaneous production of ammonia (NH3) via the electrocatalytic NO3 - reduction reaction (NO3RR) and electricity generation. Continuous wave CO2 laser irradiation yielded precisely controlled CoFe2O4@nitrogen-doped carbon (CoFe2O4@NC) hollow nanocubes from CoFe Prussian blue analogs (CoFe-PBA) as the integral electrocatalyst for NO3RR in 1.0 M KOH, achieving a remarkable NH4 + production rate of 10.9 mg h-1 cm-2 at -0.47 V versus Reversible Hydrogen Electrode with exceptional stability. In situ and ex situ methods revealed that the CoFe2O4@NC surface transformed into high-valent Fe/CoOOH active species, optimizing the adsorption energy of NO3RR (*NO2 and *NO species) intermediates. Furthermore, density functional theory calculations validated the possible NO3RR pathway on CoFe2O4@NC starting with NO3 - conversion to *NO2 intermediates, followed by reduction to *NO. Subsequent protonation forms the *NH and *NH2 species, leading to NH3 formation via final protonation. The Zn-NO3 - battery utilizing the CoFe2O4@NC cathode exhibits dual functionality by generating electricity with a stable open-circuit voltage of 1.38 V versus Zn/Zn2+ and producing NH3. This study highlights the innovative use of CO2 laser irradiation to transform Prussian blue analogs into cost-effective catalysts with hierarchical structures for NO3RR-to-NH3 conversion, positioning the Zn-NO3 - battery as a promising technology for industrial applications.

Hunter–Prey Optimization Algorithm for Optimal Allocation of PV, DSTATCOM, and EVCS in Radial Distribution Systems

ABSTRACTThis research article instigates a seminal approach for optimizing reactive power in renewable energy sources (RES) and electric vehicles (EVs) coalescing distribution systems, using the innovative Hunter–Prey Optimization (HPO) algorithm in conjunction with DSTATCOM as a reactive power compensator. The proposed methodology aims to minimize losses, enhance voltage stability, and improve overall system performance by simultaneously optimizing reactive power flows in photovoltaic RES (PV_DG), EV charging stations (EVCS), and DSTATCOMs within the distribution system. Simulations carried on IEEE‐33, IEEE‐69, and IEEE‐118 test bus systems in MATLAB environment demonstrate that the HPO‐based approach achieves a 91.47% and 96.61% reduction in real power losses and an improvement in voltage profile with a minimum voltage value of 0.991 and 0.994 p.u. (respectively for IEEE‐33 and 69 bus systems), compared to traditional algorithms. These results highlight the lofty performance of the HPO method, effectively addressing the challenges posed by the integration of RES and EVs along with DSTATCOM.

Coordination of smart inverter-enabled distributed energy resources for optimal PV-BESS integration and voltage stability in modern power distribution networks: A systematic review and bibliometric analysis

Integrating photovoltaic (PV) and battery energy storage systems (BESS) in modern power distribution networks presents opportunities and challenges, particularly in maintaining voltage stability and optimizing energy resources. This systematic review and bibliometric analysis investigates the coordination of smart inverter-enabled distributed energy resources (DERs) for enhancing PV-BESS integration and ensuring voltage stability. The study synthesizes recent advancements in smart inverter technologies, which provide grid support functions such as Volt/VAr control, and their applications in DER coordination. A comprehensive review of the literature is conducted to identify prevailing trends, research gaps, and emerging techniques in the field. Bibliometric analysis is employed to quantify the research landscape, highlighting key publications, citations, publications per country, and collaborative networks. The findings reveal that smart inverters play a crucial role in mitigating voltage violations and improving the hosting capacity of PV systems in distribution networks. Furthermore, optimal inverter settings, strategic placement of PV-BESS, and advanced control algorithms are identified as critical factors for effective DER integration. The study concludes by proposing future research directions, including the exploration of smart inverter interactions with legacy grid management systems and the development of robust algorithms for dynamic and adaptive DER coordination. This review serves as a valuable resource for researchers and practitioners aiming to enhance the stability and efficiency of power distribution networks through advanced DER management strategies.

Design and implementation of a control system for multifunctional applications of a Battery Energy Storage System (BESS) in a power system network

This work proposes a design and implementation of a control system for the multifunctional applications of a Battery Energy Storage System in an electric network. Simulation results revealed that through the suggested control approach, a frequency support of 50.24 Hz for the 53-bus system during a load decrease contingency of 350MW was achieved. Without the control system, the frequency was 50 .38Hz. Such a high frequency if not addressed, may result in a loss of synchronization among interconnected synchronous machines which could result in a decrease in voltage stability of the studied network. Besides, a reduction of about 2.05 MW in the active power losses was accomplished and a reactive power support of 3.63Mvar was realised. Thus, through the proposed strategy, Battery energy storage system has been enabled for frequency regulation, power loss minimization and voltage deviation mitigation resulting in an overall enhancement of the power quality of the electric power delivered in the studied networks.

Research on the Flicker Effect in Modern Light Sources Powered by an Electrical Network

Disruptions in power quality have a negative impact on many energy consumers. These include lighting, where interference manifests itself, among others, in the form of light flickering. The article presents phenomena accompanying the operation of modern light sources against the background of exemplary results of studies on the flicker of conventional light sources, such as incandescent or fluorescent lamps. The flickering effect of light generated in modern lamps can occur under stable voltage conditions in the supply network. The main subjects of the conducted research were solid-state light sources—light-emitting diode (LED) lamps, currently available on the lighting market. To assess the effects of these phenomena, it is necessary to use measures other than those traditionally used. The method used allows for the measurement of flicker resulting from both power supply disturbances and the properties of modern light sources. Using the developed measurement system, it is possible to record temporal changes in flicker coefficients resulting from, for example, changing supply voltage conditions. Due to the possibility of flickering light from sources offered by different manufacturers, as shown by research, it is advisable to carry out measurements at the place of use of the lighting.

Advanced smart grid controller: a next-gen alternative to Fuzzy-logic for UPFC

A very valuable component of flexible AC transmission systems (FACTs) is the Unified Power Flow Controller (UPFC). By simultaneously regulating both active and reactive power on transmission lines, it maintains voltage stability on linked buses. This study devised a thorough control strategy for the Unitary Power Flow Controller (UPFC), combining traditional and artificial intelligence (AI)-based methods. To see how the system would react in different situations and how well artificial intelligence control worked compared to more traditional proportional-integral power control, we ran a lot of simulations. The study found that the control strategy based on artificial intelligence (AI) was better than the proportional-integral (PI) control at managing power flow, keeping the voltage stable, and responding to changes in the environment. The results of this study emphasize the capacity of artificial intelligence methods to improve the performance and stability of FACT components such as the UPFC. The research provides important insights into power system control and optimization, indicating that strategies based on artificial intelligence could greatly enhance power generation. In order to enhance the AI control strategy, future research should focus on its practical application in actual power systems.

Reducing noble metal content in water electrolysis catalysts: A study on high-entropy oxides

This study presents the development of high-entropy oxide (HEO) catalysts based on Iridium-Ruthenium oxides (IrRuOx) for the oxygen evolution reaction (OER) in proton exchange membrane water electrolyzers (PEMWEs). By incorporating 3d transition metals such as Fe, Co, and Ni, we achieved catalysts with enhanced performance and stability. Using density functional theory (DFT) calculations, we predicted that HEOs possess a more favorable electronic structure for catalytic reactions. The synthesized rutile-type HEO catalyst (RuIrFeCoNi)O2, created via a molten salt oxidation method, exhibited a low overpotential of 261 mV and excellent cycling stability, maintaining a stable voltage of 1.73 V at 1 A cm−2 over 100 hours of electrolysis. This innovative approach not only reduces noble metal content but also leverages multimetallic synergistic effects to optimize the catalytic performance and stability, offering a promising avenue for the industrial application of acidic water electrolysis in PEMWEs.

A Novel Approach for Power Quality Improvement Using D-STATCOM in Wind Integrated Distribution System

Objectives: The major goal of the proposed article is to enhance the power quality of a wind-integrated radial distribution network utilizing D-STATCOM. It is done by the appropriate allocation of wind turbine-based DGs and D-STATCOM. Methods: The multi-objective optimization problem is implemented using a novel and effective Prairie Dog Optimization (PDO) to attain the best-compromised solutions. This optimization tool is well suited for solving complex, non-linear voltage stability problems. The proposed approach is validated for the modified IEEE-13 bus highly unbalanced system using MATLAB. Findings: The findings indicate enhancements in the voltage profile, system losses, and total harmonic distortion (THD). The THD for the load current is 18%, while the THD for the source current is 2.54% for nonlinear loads using the proposed methodology. The voltage profile of 3.25% is enhanced as compared with the existing method, which is 2.15% better than the other obtainable method. Novelty: Prairie Dog Optimization (PDO) was chosen over traditional algorithms for its nature-inspired approach, simplicity, and efficacy in exploring complicated search fields. Its robust exploration and exploitation skills make it excellent for multi-modal optimization challenges. Keywords: Radial distribution system (RDS), D-STATCOM, Power quality, Prairie Dog Optimization, THD

A Molten Alkali Approach to Tailor Hydroxyl Groups of Hexaazatrinaphthalene Toward High-Capacity and Low-Potential Anode of Aqueous Proton Batteries.

Hexaazatrinaphthalene (HATN) has attracted a lot of attention in aqueous proton batteries (APBs). However, its redox potential as an anode is insufficiently negative. The introduction of electron-donating substituent groups, such as hydroxyl groups, is considered as a good approach to reduce the redox potential of HATN. Nevertheless, manufacturing hydroxyl-substituted HATN (HATN-OH) requires either expensive precursors or multi-step process, limiting their research. Herein, a straightforward strategy is proposed to synthesize HATN-OH based on the nucleophilic substitution reaction of halogenated HATN in a molten alkali. The redox potential of 1,2,7,8,13,14-hexahydroxy-5,6,11,12,17,18-hexaazatrinaphthalene (34-HATN-6OH) electrode may be lowered by 0.15V in comparison to HATN, and exhibits a high specific capacity, low redox potential, remarkable rate capability, and outstanding long-term cycling performance. The electrochemical redox kinetics is significantly enhanced owing to the formation of rapid proton transport channels created by intermolecular hydrogen bond network. The assembled MnO2||34-HATN-6OH full battery delivers a high discharge voltage (1.16V) and cycling stability (74% capacity retention after 5000 cycles). This study provides a general cost-effective molten alkali approach for the synthesis of hydroxyl-substituted conjugated small molecules from their halogenated counterparts and further enriches the regulation means of electro-chemical performances of organic electrodes for enabling high-capacity and high-voltage APBs.

Influence of a new controlled voltage regulator on the current and voltage non-sinusoidality of a power supply system

This work evaluates the influence of a new controlled voltage regulator on the current and voltage non-sinusoidality in different sections of a power supply system during smooth (discrete) voltage regulation on the high-voltage side of a shop transformer. The MatLab software application was used to develop a block-modular model for a transformer substation with the proposed controlled voltage regulator and measurement modules. The developed model was used to investigate the current and voltage non-sinusoidality in different parts of a power supply system when stabilizing the voltage at the consumer end at a given level. The study was carried out using a shop transformer with a capacity of 1 MV∙A and a voltage of 6/0.4 kV under an active-inductive character of the load with the load current phase angle of φ=45 deg. The obtained results confirm that, due to the extended functional capabilities of the proposed technical solution, the voltage at consumers is maintained at a given level under high technical and economic performance. When the network voltage is reduced by 5% and the activeinductive load current is increased by 35%, the proposed device was shown to create voltage non-sinusoidality. The voltage non-sinusoidality value does not exceed the permissible domestic and international norms. In addition, the proposed device is capable of maintaining the voltage at the consumer end at a given level. The obtained integral characteristic of voltage stabilization shows that the application of the proposed technical solution instead of the existing mechanical voltage regulator of the “switching without excitation” type allows the nominal voltage at the busbar of the switchgear to be retained. Further research will investigate voltage stabilization at consumers with simultaneous compensation of reactive power for complex improvement of technical and economic indicators of power supply systems under the conditions of unstable supply voltage and load current.

Electricity production and nutrient recovery from waste activated sludge via microbial fuel cell and subsequent struvite crystallization: Effect of low temperature thermo-alkaline pretreatment

Microbial fuel cell (MFC) and subsequent struvite crystallization are available low-carbon environmental- friendly techniques for resource utilization of waste activated sludge (WAS). In this study, low temperature thermo-alkaline pretreatment (LTTAP) was innovatively proposed for enhancing MFC electricity generation and subsequent struvite crystallization from WAS. The results indicated that LTTAP at 75 °C and pH 10 not only substantially shortened the start-up time of MFC to 3–4 days, but also significantly increased maximum power density to 5.38 W/m3. Moreover, thermo-alkaline pretreated WAS effectively exhibited stable and high output voltage over long period, compared to unpretreated WAS. Furthermore, pretreated WAS can provide an effective pH buffering function for MFC operation. In addition, about 90 % of phosphate in the pretreated WAS supernatant was recovered by struvite crystallization. The findings herein provided a new route for enhancing electricity production and nutrient recovery from WAS, which can realize the full-scale applicationof WAS resource utilization.

Improved body and interface properties of EPDM insulation for HVDC cable accessory by grafted voltage stabilizer

As a key component in HVDC cable accessory, EPDM insulation is prone to breakdown both in body and along interface. To improve the comprehensive electrical strength of EPDM, voltage stabilizer 2-propenyl-4,6-dibenzoylresorcinol (ADR) was simultaneously grafted onto macromolecules through free radical reaction on its vinyl during crosslinking of EPDM. After modification, the mechanical strength and thermal stability of EPDM are improved. In terms of body properties, the injection and rapid transfer of space charge under normal electric field are weakened, the volume conductivity is reduced, the breakdown strength is improved and the growth of electrical tree is suppressed. In terms of interface properties, the normal electric field at the EPDM/XLPE interface is weakened, hence reduced potential risk of deterioration initiated from interface. Moreover, the surface conductivity of EPDM is reduced, the charge accumulation and migration along the EPDM/XLPE interface are suppressed, and the interface breakdown strengths under different interface pressures are significantly increased under tangential electric field. Molecular simulations and UV absorption characteristics indicate that the grafted ADR molecules not only introduce charge traps into EPDM, but also absorb the high energy from trapped electrons and consume it through multiple excitations, thus preventing the electron avalanche and subsequent degradation of EPDM.

Robust distribution networks reconfiguration considering the improvement of network resilience considering renewable energy resources

The integration of renewable energy sources into smart distribution grids poses substantial challenges in maintaining grid stability, efficiency, and reliability due to their inherent variability and intermittency. This study addresses these challenges by proposing a novel two-level optimization model aimed at enhancing operational efficiency and robustness in smart distribution grids. The model synergistically integrates renewable energy sources, energy storage systems, electric vehicles, and demand-side management through a dynamic reconfiguration approach. It employs a robust optimization framework combined with a two-stage second-order cone optimization model to manage real-time operations and strategic grid reconfiguration. Key findings from simulations on the IEEE 33 and 69-bus networks underscore the model’s effectiveness. In the 33-bus system, implementing the demand response program led to a significant reduction in power losses, from 0.64 MW to 0.52 MW, and improved voltage stability, with the minimum voltage increasing from 0.970 to 0.980 p.u. Similarly, in the 69-bus system, power losses decreased from 0.85 MW to 0.79 MW, and voltage stability improved, with the minimum voltage rising from 0.962 to 0.972 p.u. The model also demonstrated reduced energy procurement needs, showcasing its impact on enhancing grid efficiency and reliability. These results highlight the model’s potential for advancing smart grid management strategies, offering significant improvements in operational performance and stability under varying demand conditions.

Transient voltage stability assessment and margin calculation based on disturbance signal energy feature learning

With the increasing variation of the network topology and the high complexity of the processing measurement data, the transient voltage stability assessment of the new power system is facing significant challenges in low accuracy and high time costs. To address the shortcomings of the existing method and apply it to online assessment, this paper proposes an assessment method based on feature learning for disturbance signal energy (DSE) from bus voltages. Firstly, the relationship between DSE and system transient voltage stability is established, and the calculation of DSE from bus voltage time series is detailed. Subsequently, a transient voltage stability assessment method based on the ID3 Decision Tree algorithm and DSE is proposed. Finally, by employing the Support Vector Machine (SVM) to construct the optimal boundary in the feature space formed by the key buses, the transient voltage stability margin (TVSM) for specific scenarios is proposed. Simulation results on the IEEE 39-bus system demonstrate that the proposed method can rapidly and accurately assess the transient voltage stability of the system and calculate the stability margin, providing intuitive and interpretable results with high engineering application value.

Stochastic optimal power flow framework with incorporation of wind turbines and solar PVs using improved liver cancer algorithm

AbstractThe present study introduces a nature inspired improved liver cancer algorithm (ILCA) for solving the non‐convex engineering optimization issues. The traditional LCA (t‐LCA) inspires from the conduct of liver tumours and integrates biological ethics during the optimization procedure. However, t‐LCA facing stagnation issues and may trap into local optima. To avoid such issues and provide the optimal solution, there are some modifications are implemented into the internal structure of t‐LCA based on Weibull flight operator, mutation‐based approach, quasi‐opposite‐based learning and gorilla troops exploitation‐based mechanisms to enhance the overall strength of the algorithm to obtain the global solution. For validation of ILCA, the non‐parametric and the statistical analysis are performed using benchmark standard functions. Moreover, ILCA is applied to resolve the stochastic renewable‐based (wind turbines + PVs) optimal power flow problem using a modified RER‐based IEEE 57‐bus. The objective of this work is to obtain the minimum predicted power losses and enhance the predicted voltage stability. By incorporation of renewable resources into the modified IEEE57‐bus network can help the system to reduce the power losses from 5.6622 to 3.8142 MW, while the voltage stability is enhanced from 0.1700 to 0.1164 p.u.

Low-Temperature Drift Bandgap Reference Based on Exponential Compensation Design

Abstract In analogue and mixed-signal systems, a stable and accurate reference voltage source is essential to ensure system performance. In this paper, a high-precision bandgap reference (BGR) with a high power supply ripple rejection ratio (PSRR) and lowtemperature drift is proposed, which mainly consists of a core circuit, an exponential temperature compensation circuit, a PSRR enhancement circuit and a start-up circuit. The PSRR is improved by using a PSRR enhancement circuit and a low-pass filter. An exponential compensation circuit is used to reduce the temperature drift coefficient of the bandgap reference. Based on a 0.18 μm BCD process for design and simulation, the output reference voltage is 1.203 V with a temperature drift coefficient of 2.635 ppm/°C over the temperature range of −40°C to 125°C. The PSRR is −144.4 dB at a frequency of 10 Hz, and −43.8 dB at a frequency of 1 MHz, and the layout area is 316 μm × 156 μm.

Gd3Ga5O12: a wide bandgap semiconductor electrolyte for ceramic fuel cells, effective at temperatures below 500 °C

Searching for compatible electrolytes with Ni0.8Co0.15Al0.05LiO2 (NCAL) electrodes with high ionic conductivity at low operational temperatures (<550 °C) is essential for the research on ceramics fuel cells (CFCs). In this work, the experimental and theoretical analyses demonstrate that the highly stable single-phase Gd3Ga5O12 (GGO) garnet structure, composed of Gd-O octahedrons and Ga-O tetrahedrons, provides more active sites for ion transport, resulting in enhanced peak power density (PPD) and stable open circuit voltage (OCV) at low operational temperature. The unique internal garnet structure effectively reduces the interfacial impedance of the prepared fuel cell device, provides many active sites at triple-phase boundaries and increases the electrochemical stability. As a result, the constructed cell can deliver a superior peak power density of 770 mW/cm2 at 490 °C. In addition, X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy and theoretical calculations further demonstrate electrolyte effectiveness of GGO, enabling stable OCV even at a low temperature of 370 °C under a H2/air environment. This work can help in improving the understanding of the underlying mechanisms of a single-layer fuel cell device, which is essential to further develop this potential energy technology even at a very low temperature of 370 °C.

Voltage Stability Assessment and Power Regulation of Solar PV Based DC Microgrid

Voltage Stability Assessment and Power Regulation of Solar PV Based DC Microgrid

Reactive Load Pre-measurement for Large Industrial Users Based on Improved GBDT Regression Algorithm

Abstract With the development of intelligence and marketization of power system, reactive load prediction is the key technology applied to the intelligent technical means of power grid. For large industrial users, the management of reactive power is one of the key factors to maintain the voltage stability. Therefore, the accurate prediction of the reactive load of large industrial users is of great significance to optimize the operation of the power system and reduce energy waste. To this end, this paper realizes the prediction set date based on the improved gradient lifting tree (Gradient Boosting Decision Tree, GBDT) regression algorithm, selects the whole data as the historical data for training, and compares the data with the traditional prediction method. The experiments show that the improved GBDT regression algorithm is 28.9% more accurate than the time series algorithm MA, which predicts only from historical data.