scholarly journals Modeling Capacitive Low-Power Voltage Transformer Behavior over Temperature and Frequency

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1719
Author(s):  
Alessandro Mingotti ◽  
Federica Costa ◽  
Gaetano Pasini ◽  
Lorenzo Peretto ◽  
Roberto Tinarelli
Keyword(s):  
High Frequency ◽  
Renewable Energy Sources ◽  
Electronic Devices ◽  
Measurement Instruments ◽  
Voltage Measurement ◽  
Voltage Transformer ◽  
Medium Voltage ◽  
Wide Range ◽  
Power Frequency ◽  
Intelligent Electronic Devices

The use of capacitive dividers (CDs) in medium-voltage (MV) networks started as simple voltage detectors and as rough voltage measurement instruments for protective purposes. Now, with the spread of intelligent electronic devices and renewable energy sources at the distribution level, capacitive dividers are designed and installed to perform accurate voltage measurements. Such a requirement is mandatory when the power quality has to be assessed. Therefore, CDs are currently being used either for power frequency or for high-frequency (supraharmonic- or partial-discharge-level) measurements. In this paper, typical off-the-shelf CDs are studied and modeled to understand how they behave in a wide range of frequencies and when the temperature varies. To this purpose, specific setups and tests have been developed and performed. From the results, it is clear that with proper modeling of CDs, it is possible to exploit them for measuring phenomena in a wide range of frequencies, including the effects due to temperature variations and self-resonances.

scholarly journals New Sensor for Medium- and High-Voltage Measurement

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4654
Author(s):  
Andrzej Wetula ◽  
Andrzej Bień ◽  
Mrunal Parekh
Keyword(s):  
Finite Element Method ◽  
Electronic Devices ◽  
Finite Element Method Simulation ◽  
Laboratory Model ◽  
Power Electronic ◽  
Proof Of Concept ◽  
Voltage Measurement ◽  
Medium Voltage ◽  
Narrow Frequency Band ◽  
Further Development

Measurements of medium and high voltages in a power grid are normally performed with large and bulky voltage transformers or capacitive dividers. Besides installation problems, these devices operate in a relatively narrow frequency band, which limits their usability in modern systems that are saturated with power electronic devices. A sensor that can be installed directly on a wire and can operate without a galvanic connection to the ground may be used as an alternative voltage measurement device. This type of voltage sensor can complement current sensors installed on a wire, forming a complete power acquisition system. This paper presents such a sensor. Our sensor is built using two dielectric elements with different permeability coefficients. A finite element method simulation is used to estimate the parameters of a constructed sensor. Besides simulations, a laboratory model of a sensor was built and tested in a medium-voltage substation. Our results provide a proof of concept for the presented sensor. Some errors in voltage reconstruction have been traced to an oversimplified data acquisition and transmission system, which has to be improved during the further development of the sensor.

scholarly journals Sparse Voltage Measurement-Based Fault Location Using Intelligent Electronic Devices

2020 ◽  
Vol 11 (1) ◽  
pp. 48-60 ◽  
Author(s):  
Ke Jia ◽  
Bin Yang ◽  
Xiongying Dong ◽  
Tao Feng ◽  
Tianshu Bi ◽  
...  
Keyword(s):  
Fault Location ◽  
Electronic Devices ◽  
Voltage Measurement ◽  
Intelligent Electronic Devices

scholarly journals Optimization of IEDs Position in MV Smart Grids through Integer Linear Programming

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3346
Author(s):  
Francesco Bonavolontà ◽  
Vincenzo Caragallo ◽  
Alessandro Fatica ◽  
Annalisa Liccardo ◽  
Adriano Masone ◽  
...  
Keyword(s):  
Linear Programming ◽  
Integer Linear Programming ◽  
Smart Grids ◽  
Electronic Devices ◽  
Circuit Breaker ◽  
Computational Effort ◽  
Optimal Position ◽  
Medium Voltage ◽  
The One ◽  
Intelligent Electronic Devices

In the paper, an analytical method for determining the optimal positioning of intelligent electronic devices in medium voltage grids is proposed. Intelligent electronic devices are automated devices able to communicate one with each other and command the circuit breaker in order to localize and isolate a line fault as fast as possible. However, the number of intelligent electronic devices to install has to be limited, due to the relevant installation costs and the reduction in the transmission bandwidth caused by the increased number of exchanged messages. So, the electrical distributor has to carefully detect the nodes of the grid where the intelligent electronic devices have to be installed. The authors propose a method based on integer linear programming, which, given the number of intelligent electronic devices to install, finds their optimal position, i.e., the one that minimizes the penalties associated with the power down experienced by customers. In order to highlight the offered advantages in terms of computational effort, the proposed approach has been assessed with a real medium voltage grid.

scholarly journals A Comparative Analysis of Half-Bridge LLC Resonant Converters Using Si and SiC MOSFETs

2021 ◽  
Vol 12 (1) ◽  
pp. 43
Author(s):  
Hasaan Farooq ◽  
Hassan Abdullah Khalid ◽  
Waleed Ali ◽  
Ismail Shahid
Keyword(s):  
Silicon Carbide ◽  
Renewable Energy ◽  
High Frequency ◽  
High Efficiency ◽  
Low Voltage ◽  
Low Cost ◽  
Renewable Energy Sources ◽  
Input Voltage ◽  
Resonant Converters ◽  
Wide Range

With the expansion of renewable energy sources worldwide, the need for developing more economical and more efficient converters that can operate on a high frequency with minimal switching and conduction losses has been increased. In power electronic converters, achieving high efficiency is one of the most challenging targets to achieve. The utilization of wideband switches can achieve this goal but add additional cost to the system. LLC resonant converters are widely used in different applications of renewable energy systems, i.e., PV, wind, hydro and geothermal, etc. This type of converter has more benefits than the other converters such as high electrical isolation, high power density, low EMI, and high efficiency. In this paper, a comparison between silicon carbide (SiC) MOSFET and silicon (Si) MOSFET switches was made, by considering a 3KW half-bridge LLC converter with a wide range of input voltage. The switching losses and conduction losses were analyzed through mathematical calculations, and their authenticity was validated with the help of software simulations in PSIM. The results show that silicon carbide (SiC) MOSFETs can work more efficiently, as compared with silicon (Si) MOSFETs in high-frequency power applications. However, in low-voltage and low-power applications, Si MOSFETs are still preferable due to their low-cost advantage.

scholarly journals DAB Based DC-DC High Frequency Link PET for Interconnecting MVDC-LVDC Grids

2021 ◽  
Vol 7 (05) ◽  
pp. 165-171
Author(s):  
D.Srinivasa Rao & Dr. Anupama A. Deshpande
Keyword(s):  
High Frequency ◽  
Low Voltage ◽  
Short Circuit ◽  
Power Electronic ◽  
Distribution Grid ◽  
Medium Voltage ◽  
Electronic Transformer ◽  
Power Electronic Transformer ◽  
Wide Range ◽  
Medium Voltage Dc

This paper proposes dual active bridge (DAB) based high frequency power electronic transformer (PET) for interconnecting medium voltage dc (MVDC) and low voltage dc (LVDC) grids for dc power distribution. The above proposed concept works on dual active phase shift principle and square wave HF modulation technique for bidirectional power transfer. Compared to the traditional dc transformer scheme, The proposed power electronic transformer (PET) can disconnect from LVDC distribution grid effectively as a dc breaker when a short circuit fault occurs in the distribution grid. The isolated DC-DC PET topology with a wide range of voltage conversion ratio is useful for High Voltage DC tapping. The DAB based on switched capacitor is connected to the medium voltage DC side and acts as an inverter. The proposed topology has the ability to transfer higher power, and lower circulating power, lower high frequency link voltage, and RMS current and peak values with the same transmission power in the MVDC side. This paper analyzes the topology, voltage and power characterization, control strategy in detail. Increase in the intermediate AC frequency will reduce the size of the transformer and other passive elements significantly in the circuit. The theoretical analysis is supported by MATLAB simulation.

Measure Characteristic of UHV Power Frequency Voltage Ratio Standard

2011 ◽  
Vol 354-355 ◽  
pp. 1210-1215
Author(s):  
Feng Zhou ◽  
Min Lei ◽  
Xiao Dong Yin ◽  
Shu Han Zhang
Keyword(s):  
Measuring Method ◽  
Voltage Measurement ◽  
Voltage Transformer ◽  
Ratio Measurement ◽  
Measurement Traceability ◽  
Voltage Ratio ◽  
Voltage Coefficient ◽  
National Power ◽  
Power Frequency ◽  
Better Than

In order to meet the urgent needs of voltage measurement traceability and transfer in the construction of ultra-high voltage power grid, 1000kV series standard voltage transformer is developed as the standard instrument, and then its measurement characteristics is tested. According to the theory and construction of the series power frequency voltage ratio standard, semi-insulating transformer voltage summation is proposed to make the voltage ratio measurement of SSTV whose accuracy can reach the 0.02 level trace to the source of national power frequency ratio standard of 500kV successfully. The compatibility is better than compared to traditional voltage coefficient measuring method.

scholarly journals Characterization Procedure for Stand-Alone Merging Units Based on Hardware-in-the-Loop Technology

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1993
Author(s):  
Alessandro Mingotti ◽  
Federica Costa ◽  
Lorenzo Peretto ◽  
Roberto Tinarelli
Keyword(s):  
Distributed System ◽  
Electronic Devices ◽  
Hardware In The Loop ◽  
Medium Voltage ◽  
Merging Unit ◽  
Measurement Devices ◽  
Characterization Procedure ◽  
Power Measurements ◽  
Intelligent Electronic Devices ◽  
Metrological Performance

The digitalization of a medium voltage network requires huge efforts from distributed system operators and electric utilities. The main reason is attributed to the costs associated with the replacement or introduction of new intelligent electronic devices capable of collecting and digitalizing current and voltage measurements. To this purpose, this paper introduces a new idea of a stand-alone merging unit (SAMU), which features real-time and hardware-in-the-loop technology, completed with accurate voltage and current sensors. Furthermore, the characterization procedure that allows an evaluation of the metrological performance of a complex device, such as a SAMU, is fully described. From the results, it is highlighted that (i) the developed SAMU is capable of performing highly accurate voltage, current, and power measurements; (ii) the characterization procedure is simple and exploitable for all kinds of SAMUs and other synchronized measurement devices.

Design and Implementation of Digital Frequency Meter Based on SCM

2014 ◽  
Vol 687-691 ◽  
pp. 3466-3469
Author(s):  
Wei Qiang Zheng
Keyword(s):  
High Frequency ◽  
Electronic Devices ◽  
Digital Display ◽  
Accuracy Measurement ◽  
The Core ◽  
Digital Frequency ◽  
Wide Range ◽  
Gate Time ◽  
Frequency Meter ◽  
Strong Expansion

The digital frequency meter was a device to detect and display the frequency. In many design complexity, features a variety of electronic devices, the digital frequency meter was one of the essential equipment. It was widely used in various fields. The core of the frequency meter is AT89C51 microcontroller. It used SCM counting and timing functions to achieve the measurement pulse within a certain gate time, and it uses LED digital display tube displays the measured frequency. The device has a high frequency accuracy measurement, real time, and it has a simple, easy to carry, strong expansion capability, a wide range.

scholarly journals Low-Impact Current-Based Distributed Monitoring System for Medium Voltage Networks

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5308
Author(s):  
Alessandro Mingotti ◽  
Lorenzo Peretto ◽  
Roberto Tinarelli
Keyword(s):  
Monitoring System ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Distribution Networks ◽  
Distributed Monitoring ◽  
Power Networks ◽  
Medium Voltage ◽  
Intelligent Electronic Devices ◽  
A Current

Distribution networks are currently subject to a huge revolution in terms of assets being installed. In particular, the massive spread of renewable energy sources has drastically changed the way of approaching the grid. For example, renewables affected (i) the production of the legacy power plants, (ii) the quality of the supplied energy, decreasing it, (iii) the fault detection and location, etc. To mitigate the significant drawbacks of the renewables’ presence, several intelligent electronic devices have been (and are being) developed and installed among the grid. The aim is to increase grid monitoring and knowledge of its status. However, considering the significant number of nodes of the distribution network, compared to the transmission one, the process of installing new equipment is not effortless and is also quite expensive. This work aims at emphasizing a new concept of distributed monitoring systems, based on the phasor measurement unit’s current measurements, and a controlling algorithm to exploit it. The idea underneath the work is to avoid the out-of-service time needed and the costs associated with the installation of voltage sensors. Therefore, this paper describes an algorithm that exploits measurements from existing equipment and current measurements from PMUs to obtain information on the load and the node voltages. The algorithm is then tested on simulated power networks of increasing complexity and verified with an uncertainty evaluation. The results obtained from the simulation confirm the applicability and effectiveness of the algorithm and the benefits of a current-based monitoring system.

scholarly journals Voltage Optimization in MV Network with Distributed Generation Using Power Consumption Control in Electrolysis Installations

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 993
Author(s):  
Paweł Pijarski ◽  
Piotr Kacejko
Keyword(s):  
Control System ◽  
Power Consumption ◽  
Reactive Power ◽  
Low Voltage ◽  
Voltage Control ◽  
Active Power ◽  
Control Voltage ◽  
Voltage Transformer ◽  
Medium Voltage ◽  
Wide Range

Connecting a large number of distributed sources to the medium and low voltage grid poses many problems. The most important of these are the voltage changes inside the network, what can be observed when the power flow from these sources towards the HV/MV (High Voltage/Medium Voltage) transformer station. In particular, if the power consumption in nodes of the MV network is small and the distance between the place of installation of the source and the substation is large, increases and changes in voltage may be dangerous for the insulation of the network and burdensome for the consumers connected to it. The solution most frequently used to control voltage increases is the appropriate setting of the controller that affects the on-load tap changer of the MV/HV or even MV/LV (Medium Voltage/Low Voltage) transformer. It is also possible to regulate the reactive power of the sources and, of course, to limit their generated active power (curtailment of generation). The development of energy storage technology has made it possible to introduce consumers into the network, whose power can be controlled in a wide range. The article proposes the concept of an innovative voltage control system in the MV network, whose output values are three groups of parameters: HV/MV transformer ratio, reactive power of sources and active power of consumers connected in generation nodes. In the technological sense, it has been assumed that the loads are installations of electrolyzers used to produce “green hydrogen”, according to the P2G (Power to Gas) formula. The tests consisting in the execution of several hundred calculation cycles for the IEEE 37 test network, using the Monte Carlo simulation, have shown that the subordination of the hydrogen production process to the objectives of voltage control in the MV network clearly contributes to stabilizing its value, while meeting the technological requirements. The control variables of the proposed control system are the result of the optimization algorithm described in the article, the function of which is the quality of network voltage.

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