Standard IEC Research Articles

STUDI KERJA PROTEKSI RELAI OCR DAN GFR PADA PENYULANG ULUWATU SETELAH REKONFIGURASI

PT. PLN (Persero) South Bali Area built the Pecatu GIS to level the load, improve serviceand reliability of the electricity distribution system. The transfer of electrical loads to the PecatuGIS changes the configuration of the Pecatu feeder to the Uluwatu feeder and the Labuan Saitfeeder. Changes in load current and network impedance have an impact on short-circuit faultcurrents. The calculation of short-circuit fault current becomes the basis for determining theworking time of the OCR and GFR relays between the recloser and the feeder base PMT. Therelay working time based of the PLN regulation setting protection at 0,1 seconds to eliminatefault currents and IEC 60255 standard take 0,3 seconds to eliminate fault currents. The resultsof the study showed that the time value of PLN's regulation Tms was 0,076 SI and 0,033 SI.The results of the calculation of (Tms) standard IEC 60255 obtained time (Tms) 0,23 SI and0,09 SI. The simulation results of the PLN regulation relay settings and IEC 60255 work wellwith a grading time value of 0,2 – 0,4 seconds.

Performance based assessment of transmission lines to seismic events

Typical transmission line steel lattice towers are not designed for seismic excitations, based on the assumption that their ultimate limit state is governed by climatic actions (wind and ice). However, it is not unusual for line inspection reports to indicate the observation of moderate to severe structural damages after intense ground motions, which can ultimately reduce the capacity of tower elements. Performance-Based Earthquake Engineering (PBEE) assessment is a modern technique to earthquake resistant design frequently adopted for building frame structures, but not yet employed in the design of transmission line supports, to the best of the authors’ knowledge. The present article evaluates the seismic performance of two typical 230kV transmission towers in a PBEE framework, considering artificial and actual ground motions based on Chilean seismicity. Time-domain nonlinear dynamic analysis is employed to numerically obtain tower responses considering distinct earthquake loading scenarios according to two model configurations: stand-alone and tower-line section. Significant structural damage was detected even for moderate ground motions, which might reduce the tower capacity to future climatic events. The estimated failure probability for the ultimate limit state was found greater than the recommended values in the standard IEC 60826 (2017).

SCADA-Based Message Generator for Multi-Vendor Smart Grids: Distributed Integration and Verification of TASE.2.

Recent developments in massive machine-type communication (mMTC) scenarios have given rise to never-seen requirements, which triggered the Industry 4.0 revolution. The new scenarios bring even more pressure to comply with the reliability and communication security and enable flawless functionality of the critical infrastructure, e.g., smart grid infrastructure. We discuss typical network grid architecture, communication strategies, and methods for building scalable and high-speed data processing and storage platform. This paper focuses on the data transmissions using the sets of standards IEC 60870-6 (ICCP/TASE.2). The main goal is to introduce the TASE.2 traffic generator and the data collection back-end with the implemented load balancing functionality to understand the limits of current protocols used in the smart grids. To this end, the assessment framework enabling generating and collecting TASE.2 communication with long-term data storage providing high availability and load balancing capabilities was developed. The designed proof-of-concept supports complete cryptographic security and allows users to perform the complex testing and verification of the TASE.2 network nodes configuration. Implemented components were tested in a cloud-based Microsoft Azure environment in four geographically separated locations. The findings from the testing indicate the high performance and scalability of the proposed platform, allowing the proposed generator to be also used for high-speed load testing purposes. The load-balancing performance shows the CPU usage of the load-balancer below 15% while processing 5000 messages per second. This makes it possible to achieve up to a 7-fold improvement of performance resulting in processing up to 35,000 messages per second.

Multi-Mode Voltage Sag/Swell Generator Based on Three-Phase Inverter Circuit

The voltage ride through capability of the major auxiliary variable-frequency drive (VFD) in large thermal power plants is the key technical issue of power grid and source coordination. In order to test the high voltage ride through (HVRT) and low voltage ride through (LVRT) capability of the auxiliary VFD, it is necessary to develop a power supply to simulate different grid voltage sag and swell accurately. In this paper, a generator (VSSG) based on the common three-phase inverter circuit that can simulate multi-mode voltage sag/swell is proposed. The designed main circuit consisting of transformer, rectifier, DC split capacitors, three-phase inverter, and LC-filter can generate single-phase and three-phase voltage sag, swell, and phase angle jumping flexibly. The developed control strategies composed of the double closed-loop control and the neutral voltage balance control achieve accurate output, fast dynamic response, and step-less adjustment. Simulation and experiment results verify the multi-mode voltage simulation performances of the proposed VSSG, which can be effectively used to emulate power grid voltage sag and swell phenomena under the IEEE 1159 and IEC standards.

Investigation of photobiological safety of blue light of LED image projector of household use

Abstract
 Light emitted in the wavelength range of 400–500 nm causes a very significant photochemical effect on the retina. At certain doses of blue light energy can cause damage to the retina, so the study of the safety of blue light projectors used in domestic conditions is an urgent task. The aim of this work is to study the photobiological safety of light image projectors with light emitting diodes. The paper analyzes the requirements for photobiological safety of tube systems and methods for assessing the danger of blue light of projectors that use LED light sources. The information is provided on the equipment for measurement of spectroradiometric and photometric parameters of beams of projectors, as well as features of radiance and irradiance measurement of lamp systems in which lens optics is used.
 The results of research of photobiological danger levels of blue light of image projectors intended for use in household conditions are presented. It is shown that at a distance of 1 m from the projector (the distance for which the level of photobiological safety of blue light is normalized), the investigated type of projector belongs to the risk group RG1 (insignificant risk). When the distance is reduced to 0.5 m and 0.2 m, the risk of blue light increases to the RG2 group (medium risk).
 The features of the requirements for photobiological safety of blue light of image projectors used in everyday life, educational institutions and in other conditions are analyzed. In particular, the risk group at a distance of 1 m from the collimator lens should not exceed RG1, and it is recommended to put an additional label on the projector indicating the risk group RG1 and mark this information in the user manual.
 Conclusions are made on the compliance of the studied low-power image projectors with the safety conditions of blue light, established by the international standard IEC 62471-5 (Photobiological Safety of Lamps and Lamp Systems – Part 5 Image Projectors).

Hybrid test bench for high repetition rate radial shock wave measurement

Abstract Radial shock wave therapy is used for different therapeutic indications. In order to assess the effect on the treated tissue, it is important to know the sound field parameters. However, it is challenging to measure the pressure curves of ballistic devices, especially at high pulse repetition rates. In the new standard IEC 63045:2020 two possibilities for sound field measurements of non-focusing devices are described, a wet and a dry test bench. The whole sound field can be characterised using a wet test bench, but the process is cumbersome and cavitation is likely to occur at high pulse repetition rates. This effect is avoided using a dry test bench where the measurement position is limited to a single spot. Therefore, a hybrid test bench was developed combining the dry bench’s device mounting and coupling with a small water basin. The ballistic device was coupled to the basin filled with degassed ultrapure water using a latex membrane covered with ultrasound gel and the contact pressure was applied with a spring. A fibre optic probe hydrophone was used for the sound field measurements. The pressure curves of every 10th shot were measured on the beam axis in a distance of 1mm to the membrane. The device was analysed at 3.5 bar with different pulse repetition rates (1 Hz, 10 Hz, 20 Hz). The test setup enables an easy handling and reproducible results at all pulse repetition rates. The ballistic device provides constant peak pressures over different frequencies. The small water basin has the advantage that the water quality is easy to control and the measuring process is fast and uncomplicated. Cavitation suppression requires a clean water basin filled with degassed ultrapure water kept at a constant, low temperature. The hybrid test bench can be used to easily study shock wave parameters of ballistic devices at high repetition rates.

Design and operation of a versatile, low-cost, high-flux solar simulator for automated CPV cell and module testing

Solar power generation plays an increasingly important role in the context of the energy revolution. Apart from the widely used crystalline silicon photovoltaic (c-Si PV) cells and flat plate vacuum solar thermal collectors for decentralized energy generation, concentrating solar power systems are on the rise due to their ability to reach high process temperatures and/or high photovoltaic (PV) efficiencies. In order to push technological advancements in this field, high-flux solar simulators are required for development and testing of components and modules under reproducible conditions. This paper describes the design process, manufacturing and commissioning of a versatile, low-cost, high-flux solar simulator for the investigation of concentrator photovoltaic (CPV) cells or other parts and modules used in concentrating solar systems. The design and development process of the solar simulator is described in detail, starting with the compilation of the requirement list, followed by the selection of the correct light source, all the way to the measurement technology and graphic user interface. The solar simulator is also characterized based on IEC and ASTM standards regarding spectral mismatch, concentration factor, temporal stability, as well as adjustability for a variety of measurement tasks. It can reach adjustable concentration factors of more than 200 suns in an area of 50 x 50 mm and the cost was kept below 5000 €. Finally, exemplary test results of an Azurspace 3C44 multi-junction cell under different concentration factors are presented.

Evaluation of humidity retention in refrigerator storage systems by application of a food simulant

Vegetables lose quality after harvest mainly due to water-related weight loss. In households, vegetables are usually stored in refrigerators, typically providing temperatures from 0 – 14°C and relative humidity ranges from 20 – 100 %. Weight loss is related to the storage humidity conditions. As a consequence, storage systems providing humidity-controlled conditions are decisive for the evaluation of the freshness performance of refrigerators. To evaluate the impact of storage zones on the fresh weight loss of stored goods, the international standard IEC 63169:2020 “Electrical household and similar cooling and freezing appliances – Food preservation” has been released. It uses a cellulose based food simulant, overcoming influences of cultivar and post-harvest handling conditions of real vegetables. This publication compares the weight loss of spinach and the food simulant in chilled storage conditions at three ranges of relative humidity. Different cultivars and pre-handling modifications of the spinach were used to determine the impact of product parameters on weight loss. A round robin test was performed to analyse the applicability of the IEC 63169:2020. The results prove the applicability of the standard to analyse the impact of humidity controlled storage on weight loss: It is shown that pre-handling has an impact on spinach's weight loss, which is overcome by the food simulant. For all tested conditions, the weight loss behaviour from spinach and the food simulant is correlating in test durations up to 72 h. The round robin test shows that the test method of IEC 63169:2020 provides repeatable and reproducible results.

Design and Implementation of Multifunction Relay Based on Microcontroller

The power systems are exposed to many abnormal conditions, so an advanced protection system must be provided to stand up to these challenges. Protection devices evolved continuously with the development of power systems. The accuracy, high response, reliability, and speed of fault detection are required in the operating mode of multi-function protective relays. A Multifunction Relay has been designed and implemented, which consists of three types of relays: over current relay OCR, over/under voltage relay OVR/UVR, and differential relay DFR. The relays OCR, OVR/UVR, and DFR are designed according to the standards IEC 60255, IEEE 1159, and IEEE C37.91, respectively, based on Arduino MEGA. The multi-function relay was implemented to work on a single phase.
 The setting of the multi-function relay configuration done using a new design based on the MATLAB GUI environment. Furthermore, the results obtained after each test appear on it and LCD screen. The multi-function relay which is designed can work as (OCR, OVR/UVR, DFR) in the case of a single-phase source.
 The experiential results show that the proposed multi-function relay is accurate, fast response, reliable, selective, good performance, low cost, and sensitivity when used to protect the power system equipment under different operating conditions.

Induced radiofrequency fields in patients undergoing MR examinations: insights for risk assessment

Purpose. To characterize and quantify the induced radiofrequency (RF) electric (E)-fields and B 1+rms fields in patients undergoing magnetic resonance (MR) examinations; to provide guidance on aspects of RF heating risks for patients with and without implants; and to discuss some strengths and limitations of safety assessments in current ISO, IEC, and ASTM standards to determine the RF heating risks for patients with and without implants. Methods. Induced E-fields and B 1+rms fields during 1.5 T and 3 T MR examinations were numerically estimated for high-resolution patient models of the Virtual Population exposed to ten two-port birdcage RF coils from head to feet imaging landmarks over the full polarization space, as well as in surrogate ASTM phantoms. Results. Worst-case B 1+rms exposure greater than 3.5 μT (1.5 T) and 2 μT (3 T) must be considered for all MR examinations at the Normal Operating Mode limit. Representative induced E-field and specific absorption rate distributions under different clinical scenarios allow quick estimation of clinical factors of high and reduced exposure. B 1 shimming can cause +6 dB enhancements to E-fields along implant trajectories. The distribution and magnitude of induced E-fields in the ASTM phantom differ from clinical exposures and are not always conservative for typical implant locations. Conclusions. Field distributions in patient models are condensed, visualized for quick estimation of risks, and compared to those induced in the ASTM phantom. Induced E-fields in patient models can significantly exceed those in the surrogate ASTM phantom in some cases. In the recent 19 ε2 revision of the ASTM F2182 standard, the major shortcomings of previous versions have been addressed by requiring that the relationship between ASTM test conditions and in vivo tangential E-fields be established, e.g. numerically. With this requirement, the principal methods defined in the ASTM standard for passive implants are reconciled with those of the ISO 10974 standard for active implantable medical devices.

La logoaudiometría en Gallego

Se presenta el material fonético necesario para la determinación del umbral de recepción verbal y la discriminación en adultos y listas de palabras infantiles para la discriminación en niños, recopilado en disco compacto digital para la realización de la logoaudiometría. Material y método.- Seguimos los criterios expuestos en 1952 por Hirsch, Davis y Silverman (6): igual dificultad entre una palabra y otra en el material para umbral de recepción verbal y para el material de discriminación, composición fonética de cada lista, curvas y parámetros de referencia preliminares, grabación correcta del material seleccionado, método de calibraje de la grabación; y los criterios recogidos por Mª Rosa de Cárdenas y Victoria Marrero (4) para confeccionar y grabar las listas de palabras (polisí- labas para el umbral y ponderadas para discriminación) en castellano y en disco digital. Para el idioma Gallego seguimos las listas de la Dra Isabel Alvaro (5) en su tesis doctoral, modificadas y ampliadas por nosotros. Utilizamos un audiómetro Belton 2000 de dos canales y un reproductor de discos compactos, aplicando las normativas IEC de 1979 y la ISO 8253-3 de 1992. Resultados.- Presentamos en DC las listas de palabras en Gallego de la siguiente forma: Pista 1 de calibrado, pistas 2 y 3 listas de palabras para la determinación del umbral de recepción verbal, pistas 4 a 13 listas de palabras para la discriminación, pistas 14 al 19 listas de palabras infantiles para la discriminación. Conclusiones.- Presentamos un material fonético en Gallego no existente hasta la actualidad editado en disco compacto para la realización de la logoaudiometría de forma estable, reproducible y con la ventaja de ser una grabación digital.

Enhancement of the Flickermeter for Grid-Connected Wind Turbines

Distributed generators connected to the power system usually produce voltage fluctuations. For wind turbines connected to a grid, large changes in wind speed can cause voltage flicker at the point of common coupling. The measurement of voltage flicker caused only by wind turbines is difficult. The wind turbine under test is usually connected to a medium voltage point, in which other fluctuating loads may produce significant voltage disturbances at the wind turbine terminal where the measurement is made. Although the IEC 61400-21-1 standard specifies a method to evaluate voltage flicker caused by wind turbines, because of the complex algorithm and process of the IEC standard, there is currently a lack of measurement equipment that meets the IEC standard. In addition, some countries that use other voltage flicker standards, such as ΔV10, do not have suitable flicker measurements for wind turbines. Therefore, this study proposes an enhanced version of the IEC 61400-21-1 standard, which integrates the ΔV10 method, so that the proposed measurement system complies with the IEC and ΔV10 standards. In this study, the voltage flicker measurement system is successfully implemented, which can help engineers to predict the voltage flicker by wind turbines and assess whether a region or grid is suitable for installing wind turbines. Therefore, it can provide wind turbine companies with a quick assessment of voltage flicker to comply with the certification process.

Overcoming non‐idealities in electric vehicle charging management

The inconvenient nature of non-ideal charging characteristics is demonstrated from a power system point of view. A new adaptive charging algorithm that accounts for non-ideal charging characteristics is introduced. The proposed algorithm increases the local network capacity utilization rate and reduces charging times. The first unique element of the charging algorithm is exploitation of the measured charging currents instead of ideal or predefined values. The second novelty is the introduction of a short-term memory called expected charging currents. This makes the algorithm capable of adapting to the unique charging characteristics of each vehicle individually without the necessity to obtain any information from the vehicle or the user. The proposed algorithm caters to various non-idealities, such as phase unbalances or the offset between the current set point and the real charging current but is still relatively simple and computationally light. The algorithm is compatible with charging standard IEC 61851 and is validated under different test cases with commercial electric vehicles.

A Brief Introduction in the Mitigation of Conducted Electromagnetic Interference lssues

This paper deals with the mitigation of the influence of electromagnetic conducted emissions in low voltage grids, which can be performed using different filtering methods. Due to the relatively young age of the electromagnetic compatibility domain, the specific terminology is not yet fully consecrated. That is why the specific literature abounds in a bunch of definitions and notions, incomplete, redundant, or worse, even contradictory. Therefore, all over this paper, the terminology from the successive issues of the standard IEC 60050-161 International Electrotechnical Vocabulary, is used. The introductory section presents generalities regarding the broader context of electromagnetic compatibility in which the paper fit. Section II is devoted to measurement techniques and measuring equipment used in conducted electromagnetic interference tests, specifically for electromagnetic emissions that flow in/from the equipment under test through power lines in the standardized frequency range from 100 kHz to 30 MHz. These measurement techniques and equipment are further used in the next section which presents electromagnetic interference experiments, performed on an induction motor driven by a frequency converter. To mitigate the conducted electromagnetic emissions to fit into the standard limits, a cascade of two EMI filtering cells has been designed and implemented. This demonstrated the usefulness and effectiveness of mains EMI filters in low voltage power applications. The experiment also demonstrated that in some cases it would be necessary to retrofit more than one filtering cell

Determination of DQE as a quantitative assessment of detectors in digital mammography: Measurements and calculation in practice

Abstract Introduction: Advances in digital detector technology and methods of image presentation in digital mammography now offer the possibility of implementing mathematical assessment methods to quantitative image analysis. The aim of this work was to develop new software to simplify the application of the existing international standard for DQE in digital mammography and show in detail how it can be applied, using a Siemens Mammomat Inspiration as a model. Material and methods: Consistent with the IEC standard a 2 mm Al filter at the tube exit and images in DICOM format as raw data, without applying any additional post-processing were used. Measurements were performed for W/Rh anode/filter combination and different tube voltage values (26 ÷ 34 kV) without any anti-scatter grid. To verify new software doses ranging from 20-600 µGy were used in measurements. Exposure (air kerma) was measured using a calibrated radiation meter (Piranha Black 457, RTI Electronics AB, Sweden). MTF was determined, using an edge test device constructed specifically for this work. Results: It has been demonstrated that with the new software the DQE can be measured with the accuracy required by the international standard IEC 62220-1-2. DQE has been presented as a function of spatial frequency for W/Rh anode/filter combination and different tube voltage. Conclusions: New software was used successfully to analyze image quality parameters for the Siemens Mammomat Inspiration detector. This was done on the basis of an internationally accepted methodology. In the next step, mammographs with different detector types can be compared.

Augmented Markov Model for Enhancing Hazard Rate Result of Safety Critical Systems Possessing Diverse Redundant Architecture

Safety-critical systems in various industries such as transportation or nuclear energy have been paid more attention with the development of societies due to increased attachment of importance to the life of human, their property, and nature. While developing such systems, detailed availability and safety characteristics are to be taken into account in parallel with architectural design decisions such as synchronization between different computing units or real-time task management. For fulfilling top-level requirements in international standards, ambitious quantitative targets like 0.012 FIT for HW units are to be reached where the industry has difficulties to achieve it. In this paper, this problem is handled by proposing an augmented Markov model for diverse architectures that is superior to the formulas provided in the main safety standard IEC 61508 and previous studies. With the proposed method it is possible to cover all safety-relevant states, which leads to more accuracy and lower hazard rates helping to reach these ambitious quantitative targets. Besides, the reliability parameters are investigated and optimized to increase safety performance. Consequently, the proposed novel model including enhanced reliability parameters is used for an industry application, namely safety-critical computer used for unmanned metro and high-speed rail transportation. The result obtained by the proposed model is compared with the results obtained using state of art models in literature and using the formulas in IEC 61508. As domain independent references IEC 61508 and Markovian approach are used in the paper, this study is applicable to other safety critical areas such as automotive or avionic industry.

Poly (butyl acrylate- methyl methacrylateacrylamide)/ bentone 34 nano composites for electrical insulation

Poly (butyl acrylate- methyl methacrylate-acrylamide)/nano bentone 34 composites were prepared through bulk polymerization in presence of BPO (benzoyl peroxide) as initiator. The (BA/MMA/AAm) terpolymer/nano bentone 34 composite sheets were molded at 180°C prior subjecting to the specific mechanical and electrical characterization. Structural, physical and thermal validations were conducted through GPC, FT-IR, HRTEM and TGA classified techniques. The results of the electrical resistivity and mechanical properties aptitudes signpost step towards a new generation of insulators for electrical cables according to IEC and BS standards.

Speed of sound in the IEC tissue-mimicking material and its maintenance solution as a function of temperature

Tissue-Mimicking Material (TMM) is defined on IEC International Standards and applied in assessing ultrasonic diagnostic and therapeutic equipment's basic safety and essential performance. One of the TMM that fits IEC standards specification has its recipe described at IEC 60601-2-37, and it is fabricated using glycerol (11.21 %), deionized water (82.95%), benzalkonium chloride (0.47 %), silicon carbide (0.53 %), aluminum oxide 0.3 μm (0.88%), aluminum oxide 3.0 μm (0.94 %), and agar (3.08 %). Glycerol is the component responsible for adjusting the TMM's speed of sound. Moreover, it is recommended to store TMM in a closed container immersed in a mixture of water (88.1 %)/glycerol (11.9 %) to prevent it from drying out and avoiding air contact. The literature points out TMM measurements underwater can alter the speed of sound property as TMM tends to lose glycerol. Herein, the authors proposed to assess the viability of measuring the TMM speed of sound in the water/glycerol maintenance solution. First, the authors characterized the maintenance solution's speed of sound for a temperature range of 20 °C to 45 °C. Then, the group velocity of a set of TMM was measured underwater and in the maintenance solution for the same temperature range. The respective group velocity expanded uncertainty was calculated. The results indicate it is feasible to measure TMM in the maintenance solution, achieving group velocity values with no statistical difference from the ones measured underwater in the temperature range of 20 °C to 40 °C.

State‐of‐art design aspects of wearable, mobile, and flexible antennas for modern communication wireless systems

SummaryIn this present contemporary epoch, wireless communication appliances exemplified meteoric progression in technology. These systems entail an antenna in every strand of communication. Depending upon the recent expansions in generations, the antennas become more compact, lightweight, portable, wearable, cost‐effective, and conformal while maintaining essential performance characteristics like impedance bandwidth, efficiency, gain, SAR, etc. This review is envisioned to unveil state‐of‐art in conventional and unconventional antenna technologies in recent times and offers knowledge to readers about a large regime of antenna designs suitable for different wireless communication system applications like GSM, GPS, Wi‐Fi, WLAN, bluetooth, 4G, and 5G under a single head. It is unambiguously worth stating that recent 5G antenna designs will unleash new breaks in leapfrogging all outmoded blockades in developments. Intended wireless communication systems take in mobiles, laptops, smart wears, tablets, etc., while antenna technologies cover wearable models, conformal structures, MIMO configurations, microstrip and planar monopole antennas. This study draws attention towards multi‐band and wide‐band accomplishment techniques, SAR analysis, bending and twisting effects of conformal or wearable antennas, effect of human body and wireless appliances on antenna performance. As per the study, FCC set a standard value of SAR as equal or below to 1.6 W/kg for 1 g of body tissue. IEC standards regulated a limit on SAR value as 2 W/kg, which is average value over 10 g of body tissue. Also, envelope correlation coefficient (ECC) of below 0.05, diversity gain of less than 10 dB and a maximum channel capacity of 0.4 bit/s/Hz are necessary for MIMO systems.

Electric Field and Temperature Simulations of High-Voltage Direct Current Cables Considering the Soil Environment

For long distance electric power transport, high-voltage direct current (HVDC) cable systems are a commonly used solution. Space charges accumulate in the HVDC cable insulations due to the applied voltage and the nonlinear electric conductivity of the insulation material. The resulting electric field depends on the material parameters of the surrounding soil environment that may differ locally and have an influence on the temperature distribution in the cable and the environment. To use the radial symmetry of the cable geometry, typical electric field simulations neglect the influence of the surrounding soil, due to different dimensions of the cable and the environment and the resulting high computational effort. Here, the environment and its effect on the resulting electric field is considered and the assumption of a possible radial symmetric temperature within the insulation is analyzed. To reduce the computation time, weakly coupled simulations are performed to compute the temperature and the electric field inside the cable insulation, neglecting insulation losses. The results of a weakly coupled simulation are compared against those of a full transient simulation, considering the insulation losses for two common cable insulations with different maximum operation temperatures. Due to the buried depth of HV cables, an approximately radial symmetric temperature distribution within the insulation is obtained for a single cable and cable pairs when, considering a metallic sheath. Furthermore, the simulations show a temperature increase of the earth–air interface above the buried cable that needs to be considered when computing the cable conductor temperature, using the IEC standards.