Search Results (155)

As power systems evolve rapidly, cables, essential for electric power transmission, demand accurate and timely fault diagnosis to ensure grid safety and stability. However, current cable fault diagnosis technologies often struggle with incomplete feature extraction from complex fault signals and inefficient parameter tuning in diagnostic models, hindering efficient and precise fault detection in modern power systems. To address these, this paper proposes a data-driven strategy for cable fault diagnosis in substation secondary circuits, enhanced by effective parameter optimization. Initially, wavelet packet decomposition is employed to finely divide collected cable fault current signals into multiple levels and bands, effectively extracting fault feature vectors. To tackle the challenge of selecting penalty and kernel parameters in Support Vector Machine (SVM) models, an improved Golden Jackal Optimization (GJO) algorithm is introduced. This algorithm simulates the predatory behavior of golden jackals in nature, enabling efficient global optimization of SVM parameters and significantly improving the classification accuracy and generalization capability of the fault diagnosis model. Simulation verification using real cable fault cases confirms that the proposed method outperforms traditional techniques in fault recognition accuracy, diagnostic speed, and robustness, proving its effectiveness and feasibility. This study offers a novel and efficient solution for cable fault diagnosis. Full article

Maintenance techniques are fundamental in the context of the safe operation of continuous process installations, especially in electrical energy-transmission and/or -distribution substations. The operating conditions of power transformers are fundamental for the safe functioning of the electrical power system. Predictive maintenance consists of periodically monitoring the asset in use, in order to anticipate critical situations. This article proposes a methodology based on data science, machine learning and the Internet of Things (IoT), to track operational conditions over time and evaluate transformer aging. This characteristic is achieved with the development of a synchronization method for different databases and the construction of a model for estimating ambient temperatures using k-Nearest Neighbors. In this way, a history assessment is carried out with more consistency, given the environmental conditions faced by the equipment. The work evaluated data from three power transformers in different geographic locations, demonstrating the initial applicability of the method in identifying equipment aging. Transformer TR1 showed aging of $3.24\times {10}^{-3}\%$, followed by TR2 with $8.565\times {10}^{-3}\%$ and TR3 showing $294.17\times {10}^{-6}\%$ in the evaluated period of time. Full article

This study explores modernization strategies for existing district heating (DH) networks to enhance their efficiency and sustainability, focusing on achieving net-zero emissions in urban heating systems. Building upon a literature review and expert interviews, we developed a strategic decision-support framework that outlines distinct strategies for retrofitting district heating grids and includes a portfolio analysis. This framework serves as a tool to guide DH operators and stakeholders in selecting well-founded modernization pathways by considering technical, economic, and social dimensions. The review identifies several promising measures, such as reducing operational temperatures at substations, implementing optimized substations, integrating renewable and waste heat sources, implementing thermal energy storage (TES), deploying smart metering and monitoring infrastructure, and expanding networks while addressing public concerns. Additionally, the review highlights the importance of stakeholder engagement and policy support in successfully implementing these strategies. The developed strategic decision-support framework helps practitioners select a tailored modernization strategy aligned with the local context. Furthermore, the findings show the necessity of adopting a comprehensive approach that combines technical upgrades with robust stakeholder involvement and supportive policy measures to facilitate the transition to sustainable urban heating solutions. For example, the development of decision-support tools enables stakeholders to systematically evaluate and select grid modernization strategies, directly helping to reduce transmission losses and lower greenhouse gas (GHG) emissions contributing to climate goals and enhancing energy security. Indeed, as shown in the reviewed literature, retrofitting high-temperature district heating networks with low-temperature distribution and integrating renewables can lead to near-complete decarbonization of the supplied heat. Additionally, integrating advanced digital technologies, such as smart grid systems, can enhance grid efficiency and enable a greater share of variable renewable energy thus supporting national decarbonization targets. Further investigation could point to the most determining context factors for best choices to improve the sustainability and efficiency of existing DH systems. Full article

In order to solve the problem that the system parameters will be offset during the detection process of the pulsed eddy current receiving coil, this paper first analyzes the response signal of the receiving system and the deconvolution process of the response signal, and discusses the influence of various system parameters on the deconvolution accuracy. A method is proposed to change the system response characteristics and apply a step signal through the excitation coil to realize parameter identification through the response of the receiving coil system. The error of feature extraction under the change in each parameter is discussed, and the influence of increasing the matching resistance and switching the capacitor in parallel on the identification accuracy is analyzed and compared. It is proposed to realize the accurate identification of the receiving system through the Newton method. It is proved from both simulation and experiment that the method proposed in this paper can realize the identification of the receiving coil parameters efficiently, conveniently, and accurately, and can improve the inversion accuracy of the pulsed eddy current detection signal and improve the detection accuracy. Full article

This paper presents a novel method for assessing the technical condition of devices in the high-voltage (HV) switching bay of a substation, focusing on circuit breakers, disconnectors, and instrument transformers. These devices are typically maintained using a condition-based maintenance approach. The proposed method integrates data from individual maintenance tasks into a comprehensive assessment of each device’s technical condition. Traditionally, the technical condition and health index assessments rely solely on additive criteria. This study introduces an advanced assessment method that incorporates both additive and multiplicative criteria to enhance the prioritization of maintenance tasks. A data model is developed to extract the maintenance task data from device maintenance databases, enabling an automated assessment process. The proposed approach facilitates the generation of a c-curve throughout a device’s operational life. A comparison using real transmission system operator maintenance data demonstrates that the proposed method, which assesses device conditions using both additive and multiplicative criteria, outperforms the conventional approach that relies solely on additive criteria. Full article

The growing scale of offshore wind farms and increasing transmission distances has driven the demand for optimized offshore substation (OSS) configurations. This study proposes a comprehensive techno-economic framework to minimize the total lifecycle cost (LCC) of an OSS by determining the optimal number of OSSs and transformers considering wind farm capacity and transmission distance. The methodology incorporates three cost models: capital expenditure (CAPEX), operational expenditure (OPEX), and expected energy not supplied (EENS). CAPEX considers transformer costs, topside structural mass effects, and nonlinear installation costs. OPEX accounts for substation maintenance and vessel operating expenses, and EENS is calculated using transformer failure probability models and redundancy configurations. The optimization is performed through scenario-based simulations and a net present value (NPV)-based comparative analysis to determine the cost-effective configurations. The quantitative analysis demonstrates that for small- to medium-scale wind farms (500–1000 MW), configurations using 1–2 substations and 3–4 transformers achieve minimal LCC regardless of the transmission distance. In contrast, large-scale wind farms (≥1500 MW) require additional substations to mitigate transmission losses and disruption risks, particularly over long distances. These results demonstrate that OSS design should holistically balance initial investment costs, operational reliability, and supply security, providing practical insights for cost-effective planning of next-generation offshore wind projects. Full article

Swift urbanization and technical progress in Cambodia, specifically in Phnom Penh, require underground transmission lines (UGTL) as a viable substitute for overhead transmission lines (OHTL). However, the substantial cost of UGTL has prevented its extensive integration. In this respect, we identified the most cost-effective technological route for an underground transmission line between substations. Using geographic information system (GIS) data, we generated algorithms to define the optimal route for the installation of a UGTL and minimize the costs of the material and labor required. The research results presented an automated tool for route optimization which simplifies the planning of energy projects and partially relieves the financial burden of UGTL integration. The proposed method radically changes the planning of urban energy infrastructure, as it provides a technology-based, cost-efficient, and environmentally favorable decision for UGTL routing. It also fosters the development of sustainable and resilient urban energy systems in similar urban locations. Full article

The management of power supply and distribution is becoming increasingly challenging because of the significant increase in energy demand brought on by global population growth. Buildings are estimated to be accountable for 40% of the worldwide use of energy, which underlines how important accurate demand estimation is for the design and construction of electrical infrastructure. In this respect, transmission and distribution network planning must be adjusted to ensure a smooth transition to the National Interconnected System (NIS). A technical and analytical scientific approach to a modern neighbourhood in Ecuador called “the Nuevo Samborondón” case study (NSCS) is laid out in this article. Collecting geo-referenced data, evaluating the current electrical infrastructure, and forecasting energy demand constitute the first stages in this research procedure. The sector’s energy behaviour is accurately modelled using advanced programs such as 3D design software for modelling and drawing urban architecture along with a whole building energy simulation program and geographical information systems (GIS). For the purpose of recreating several operational situations and building the distribution infrastructure while giving priority to the current urban planning, an electrical system model is subsequently developed using power system analysis software at both levels of transmission and distribution. Furthermore, seamless digital substations are suggested as a component of the nation’s electrical infrastructure upgrade to provide redundancy and zero downtime. According to our findings, installing a 69 kV ring is a crucial step in electrifying NSCS and aligning electrical network innovations with urban planning. The system’s capacity to adjust and optimize power distribution would be strengthened provided the algorithms were given the freedom to react dynamically to changes or disruptions brought about by distributed generation sources. Full article

Building-energy consumption constitutes a pivotal component of global energy systems, with the heating and cooling loads during the operational phase being particularly significant. Substation building, as nodes in the transmission and transformation network, deserve attention for their building-operating loads. This study investigates heating and cooling loads during substation operation in severe cold climates. By integrating energy consumption simulations with one-factor-at-a-time and orthogonal multivariate analyses, optimization strategies under key influencing factors are systematically explored. The impact analysis identifies the following order of influence magnitude on substation total loads: indoor equipment heat generation, ventilation rate, roof U-value, exterior wall U-value, and window U-value. The heating- and cooling-load characteristics exhibit distinct patterns depending on indoor equipment heat generation. The total building load can be reduced by 61.23 per cent under multifactor optimal de-sign conditions, highlighting the critical role of systemic design coordination. This study provides a case study reference for energy efficient design of heating and cooling loads in substations, especially where significant changes in equipment heat occur, and highlights the importance of controlling indoor heat sources to achieve optimal energy efficiency. Full article

In the current context of sustainability management and energy insecurity, amplified by the military instability determined by the war between Russia and Ukraine, and the increasingly frequent occurrence of a series of plausible scenarios for disasters or energy blackouts worldwide, this work is a real and applicable model for regional states that would like to critically analyze the situation of their energy security through identifying all the plausible risk scenarios targeting the energy critical infrastructures. The study has identified and assessed two of the most plausible risk scenarios (a natural disaster and a terrorist attack) in the case of a strategic power substation of 220 kV, 400 kV, or 750 kV undergoing a blackout effect. After having assessed the risks, the safety strategy for Romania’s national power system has been elaborated together with the safety strategy for the European Power system-ENTSO-E (European Network of Transmission System Operators for Electricity). The results of the study match other specialized works from different European countries and might represent a model for other types of energy safety risk assessments and for other types of critical infrastructures that are vital for the modern European society and for sustainability management. Full article

High-voltage transmission and substation projects at high altitudes are pivotal in realizing the objective of universal electricity access. However, the reduced air density at elevated heights facilitates the formation and propagation of discharges, posing more stringent challenges to the external insulation of these projects compared to their counterparts in plains areas. Furthermore, considering the influence of meteorological conditions such as rainfall, it is imperative to conduct comprehensive experimental studies on the insulation properties of air gaps to inform the design and maintenance of engineered external insulation. This paper presents the results of rod–plane gap discharge tests conducted under dripping conditions at an actual high-altitude location of 2500 m. The employed test methodology effectively simulates the impact of rainfall on the insulation characteristics of the gap. Based on the experimental findings, a detailed analysis is conducted on the effects of gap distance, dripping flow rate, and conductivity on the gap breakdown voltage. Additionally, the discharge paths and underlying mechanisms under water-dripping conditions on rod electrodes are briefly discussed. The acquired data and conclusions contribute to a deeper understanding of the mechanisms governing rainfall effects on gap discharges and provide valuable insights for the design of external insulation in high-altitude HVDC transmission projects. Full article

In this paper, the particle swarm optimization (PSO) technique is used to optimally allocate phasor measurement units (PMUs) within standard test systems and a real-world power system. PMUs are allocated at system substations in a manner that ensures complete system observability while minimizing installation costs. This study considers IEEE 14-, 30-, and 57-bus standard test systems, along with the Jordanian national high-voltage grid. The optimal allocation was performed separately on the 132 kV and 400 kV buses of the Jordanian grid. Additionally, a novel technique for further minimization of measurement units, considering electric grid planning, is investigated. The results demonstrate that the proposed approach successfully reduces the required number of PMUs while maintaining full system observability. For instance, the IEEE 14-bus system achieved complete observability with only four PMUs, while the IEEE 30-bus and 57-bus systems required ten and seventeen PMUs, respectively. For the Jordanian transmission network, the 400 kV system required only three PMUs, and the 132 kV system required twenty-six PMUs. Furthermore, it was found that integrating power system planning and grid expansion strategies into the PMU placement problem may further reduce installation costs. The results emphasize the effectiveness of the proposed approach in enhancing situational awareness, improving state estimation accuracy, and facilitating reliable protection, control, and monitoring schemes. This study concludes that an optimal PMU allocation strategy shall be incorporated into power system planning studies to maximize cost efficiency while ensuring full observability. Full article

Power transmission lines transfer energy between power plants and substations by means of a linear chain of towers. These towers are often situated over extensive distances, sometimes in regions that are difficult to access. Wireless sensor networks present a viable solution for monitoring these long chains of towers due to their wide coverage, ease of installation and cost-effectiveness. The proposed LoRaBUS approach implements and analyses the benefits of a linear topology using a mixture of LoRa and LoRaWAN protocols. This approach is designed to enable automatic detection of nearby nodes, optimise energy consumption and provide a prioritised transmission mode in emergency situations. On remote, hard-to-reach towers, a prototype fire protection system was implemented and tested. The results demonstrate that LoRaBUS creates a self-configurable linear topology which proves advantageous for installation processes, node maintenance and troubleshooting node failures. The discovery process collects data from a neighbourhood to construct the network and to save energy. The network’s autonomous configuration can be completed within approximately 2 min. In addition, energy consumption is effectively reduced 25% by dynamically adjusting the transmission power based on the detected channel quality and the distance to the nearest neighbour nodes. Full article

A low-voltage distribution substation is the last link before electricity transmission from the high-voltage grid to end-users. It is responsible for converting high-voltage electricity into low-voltage electricity suitable for domestic and commercial use and plays a central and critical role in the power system. The traditional modeling method is difficult to directly observe and solve the complete safety boundary expression in the high-dimensional state space, so the solution efficiency is greatly reduced. To address the above problems, this paper proposes a low-voltage distribution substation station safety domain (LVDS-SR) modeling method based on the high-dimensional safety domain definition method. In this paper, the concepts of safety work point, safety boundary, and safety domain are first defined. Then, the general mathematical model, edge points, and safety boundaries of the substation system are solved accurately by the high-dimensional safety domain definition and solution method, to obtain the safety domain model. The validity of the model and method is verified by arithmetic examples. Comparison with existing studies shows that the complete analytical formulation of the high-dimensional security domain is obtained for the first time in this paper, and the linearization method is used to improve the solution efficiency at the same time. This study provides a new analytical tool for the reliable and stable operation of low-voltage distribution substations, which has important theoretical and practical application value for the security assessment and optimization of power systems. Full article

In complex electromagnetic environments, such as substations, converter stations in power systems, and the compartments of aircraft, trains, and automobiles, electromagnetic immunity testing is crucial. It requires that the electric field sensor has features such as a large dynamic measurement range (amplitude from hundreds of V/m to tens of kV/m), a fast response speed (response time in the order of nanoseconds or sub-nanoseconds), a wide test bandwidth (DC to 1 GHz even above), miniaturization, and robustness to strong electromagnetic interference. This paper introduces a multi-channel, ultra-wideband transient electric field measurement system. The system’s analog bandwidth covers the spectrum from DC and a power frequency of 50 Hz to partial discharge signals, from DC to 1.65 GHz, with a storage depth of 2 GB (expandable). It overcomes issues related to the instability, insufficient bandwidth, and lack of accuracy of optical fibers in analog signal transmission by using front-end digital sampling based on field-programmable gate array (FPGA) technology and transmitting digital signals via optical fibers. This approach is effectively applicable to measurements in strong electromagnetic environments. Additionally, the system can simultaneously access four channels of signals, with synchronization timing reaching 300 picoseconds, can be connected to voltage and current sensors simultaneously, and the front-end sensor can be flexibly replaced. The performance of the system is verified by means of a disconnect switch operation and steady state test in an HVDC converter station. It is effectively applicable in scenarios such as the online monitoring of transient electromagnetic environments in high-voltage power equipment, fault diagnosis, and the precise localization of radiation sources such as partial discharge or intentional electromagnetic interference (IEMI). Full article