scholarly journals High-Efficiency Bi-Directional Single-Phase AC/DC Converter Design and Field Application for LVDC Distribution

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2191 ◽  
Author(s):  
Juyong Kim ◽  
Hongjoo Kim ◽  
Jintae Cho ◽  
Youngpyo Cho
Keyword(s):  
Distribution System ◽  
Single Phase ◽  
High Efficiency ◽  
Low Voltage ◽  
Control Function ◽  
High Reliability ◽  
Power Converter ◽  
Field Application ◽  
Distribution Grid ◽  
Demonstration Site

This paper describes the design and field application of a high-efficiency single-phase AC/DC converter that is suitable for distribution lines. First, an appropriate AC/DC converter was designed in consideration of the environment of the application system. In order to ensure high efficiency and high reliability, we designed an optimum switching element and capacitor suitable for the converter, and the protection element of the AC/DC converter was designed based on these elements. The control function for the power converter suitable for an LVDC distribution system is proposed for highly reliable operation. The AC/DC converter was manufactured based on the design and its performance was verified during application in an actual low-voltage DC (LVDC) distribution grid through tests at the demonstration site. The application to a DC distribution system in an actual grid is very rare and it is expected that it will contribute to the expansion of LVDC distribution.

scholarly journals Control of Single-Phase Electrolytic Capacitor-Less Isolated Converter for DC Low Voltage Residential Networks

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1401
Author(s):  
Nelson Santos ◽  
J. Fernando Silva ◽  
Vasco Soares
Keyword(s):  
Single Phase ◽  
High Efficiency ◽  
Low Voltage ◽  
Sliding Mode ◽  
Residential Buildings ◽  
Direct Method ◽  
Electrical Energy ◽  
Power Converter ◽  
Electrolytic Capacitor ◽  
Dc Power

In recent years, there has been a desire to improve electricity generation and consumption, to reach sustainability. Technological solutions today allow a rational use of electricity with good overall performance. Traditionally, from production to distribution, electrical energy is AC-supported for compatibility reasons and easy voltage level transformation. However, nowadays most electric loads need DC power to work properly. A single high-efficiency central AC-DC power converter may be advantageous in eliminating several less efficient AC-DC embedded converters, distributed all over a residential area. This paper presents a new single-phase AC-DC converter using one active bridge (most isolated topologies are based on the dual active bridge concept) and a high-frequency isolation transformer with low-value non-electrolytic capacitors, together with its control system design. The converter can be introduced into future low-voltage DC microgrids for residential buildings, as an alternative to several embedded AC-DC converters. Non-linear control techniques (sliding mode control and the Lyapunov direct method) are employed to guarantee stability in the output DC low voltage with near unity power factor compensation in the AC grid. The designed converter and controllers were simulated using Matlab/Simulink and tested in a lab experimental prototype using digital signal processing (DSP) to evaluate system performance.

scholarly journals An Overview of Bidirectional AC-DC Grid Connected Converter Topologies for Low Voltage Battery Integration

2018 ◽  
Vol 9 (3) ◽  
pp. 1223 ◽  
Author(s):  
Kaspars Kroics ◽  
Oleksandr Husev ◽  
Kostiantyn Tytelmaier ◽  
Janis Zakis ◽  
Oleksandr Veligorskyi
Keyword(s):  
Energy Storage ◽  
High Efficiency ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Storage System ◽  
Distribution Grid ◽  
Battery Energy Storage ◽  
Battery Energy Storage Systems ◽  
Converter Topologies ◽  
Battery Energy

<p>Battery energy storage systems are becoming more and more popular solution in the household applications, especially, in combination with renewable energy sources. The bidirectional AC-DC power electronic converter have great impact to the overall efficiency, size, mass and reliability of the storage system. This paper reviews the literature that deals with high efficiency converter technologies for connecting low voltage battery energy storage to an AC distribution grid. Due to low voltage of the battery isolated bidirectional AC-DC converter or a dedicated topology of the non isolated converter is required. Review on single stage, two stage power converters and integrated solutions are done in the paper.</p>

scholarly journals A Single-Phase Buck-Boost Matrix Converter with Low Switching Stresses

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Naveed Ashraf ◽  
Tahir Izhar ◽  
Ghulam Abbas
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Single Phase ◽  
Low Voltage ◽  
Sliding Mode ◽  
Low Frequency ◽  
Matrix Converter ◽  
Power Distribution System ◽  
Selective Approach ◽  
Switching Devices

The suggested single-phase ac-to-ac matrix converter operated with inverting and noninverting characteristics may solve the grid voltage swell and sag problem in power distribution system, respectively. It is also employed as a direct frequency changer for domestic induction heating. The output voltage is regulated through duty cycle control of high frequency direct PWM (DPWM) and indirect PWM (IDPWM) switching devices. The DPWM control switches control the switching states of IDPWM switching devices. The inverting and noninverting characteristics are achieved with low voltage stresses and hence low dv/dt across the high and low frequency-controlled switches. This reduces their voltage rating and losses. The high voltage overshoot problem in frequency step-up operation is also analyzed. The sliding mode (SM) controller is employed to solve this problem. Pulse selective approach determines the power quality of load voltage. The validity of the mathematically computed values is carried out by modelling the proposed topology in MATLAB/Simulink environment and through hardware results.

Maintenance of Three-phase Load Voltage during Single Phase Auto Reclosing in Medium Voltage Radial Distribution Lines

2011 ◽  
Vol 12 (4) ◽  
Author(s):  
Kartik Prasad Basu ◽  
Moley Kutty George
Keyword(s):  
Radial Distribution ◽  
Distribution System ◽  
Single Phase ◽  
Dead Time ◽  
Low Voltage ◽  
Radial Distribution System ◽  
Load Voltage ◽  
Medium Voltage ◽  
Distribution Lines ◽  
Three Phase

Most faults in medium voltage (MV) distribution lines are temporary line to ground (LG) faults. Three-phase auto reclosing (TPAR) is commonly used to remove this fault with temporary disconnection of all the phases. Multi-shot single-phase auto reclosing (SPAR) may also be used to remove the LG fault. But it produces highly unbalanced and low voltage across the load during the reclosure dead time. It is proposed to connect a zigzag winding grounding transformer at the load bus to maintain the 3-phase load voltage when one phase opens during the SPAR. With low value of grounding resistance the 3-phase voltage during the SPAR dead time becomes approximately balanced. Directional over current relays may be used for the protection. Analysis of a MV radial distribution system having a zigzag transformer connected to the remotest load bus is presented with the computation of voltages during the dead time of SPAR.

scholarly journals Smart Meter Traffic in a Real LV Distribution Network

Energies ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 1156 ◽  
Author(s):  
Nikoleta Andreadou ◽  
Evangelos Kotsakis ◽  
Marcelo Masera
Keyword(s):  
Distribution System ◽  
Low Voltage ◽  
Distribution Network ◽  
Distribution Networks ◽  
Smart Meter ◽  
Advanced Metering Infrastructure ◽  
Distribution Grid ◽  
Message Size ◽  
Real Distribution ◽  
Advanced Metering

The modernization of the distribution grid requires a huge amount of data to be transmitted and handled by the network. The deployment of Advanced Metering Infrastructure systems results in an increased traffic generated by smart meters. In this work, we examine the smart meter traffic that needs to be accommodated by a real distribution system. Parameters such as the message size and the message transmission frequency are examined and their effect on traffic is showed. Limitations of the system are presented, such as the buffer capacity needs and the maximum message size that can be communicated. For this scope, we have used the parameters of a real distribution network, based on a survey at which the European Distribution System Operators (DSOs) have participated. For the smart meter traffic, we have used two popular specifications, namely the G3-PLC–“G3 Power Line communication” and PRIME–acronym for “PoweRline Intelligent Metering Evolution”, to simulate the characteristics of a system that is widely used in practice. The results can be an insight for further development of the Information and Communication Technology (ICT) systems that control and monitor the Low Voltage (LV) distribution grid. The paper presents an analysis towards identifying the needs of distribution networks with respect to telecommunication data as well as the main parameters that can affect the Inverse Fast Fourier Transform (IFFT) system performance. Identifying such parameters is consequently beneficial to designing more efficient ICT systems for Advanced Metering Infrastructure.

The Research on Main Circuit Parameters and its Control Law of TCR Single-Phase to Three-Phase Power Converter

2015 ◽  
Vol 740 ◽  
pp. 359-363
Author(s):  
Shi Long Chen ◽  
Lu Luo ◽  
Yan Wu Wang
Keyword(s):  
Power Factor ◽  
Single Phase ◽  
High Reliability ◽  
Power Converter ◽  
Control Law ◽  
Configuration Theory ◽  
Three Phase ◽  
Railway System ◽  
Electrified Railway ◽  
And Control

The TCR single-phase to three-phase power converter has been widely used in electrified railway system as its simple control raw and high reliability. The research on main circuit parameters and its control law is necessary to design suitable TCR single phase to three phase power converter. This paper analyses the main circuit of TCR single phase to three phase power converter, and acquires the parameters configuration theory of each element in main circuit and control law of converter when the power factor varies from 0.7 to 0.9.

scholarly journals Experimental Validation and Deployment of Observability Applications for Monitoring of Low-Voltage Distribution Grids

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5770 ◽  
Author(s):  
Karthikeyan Nainar ◽  
Catalin Iosif Ciontea ◽  
Kamal Shahid ◽  
Florin Iov ◽  
Rasmus Løvenstein Olsen ◽  
...  
Keyword(s):  
Real Time ◽  
Data Storage ◽  
Distribution System ◽  
Low Voltage ◽  
Experimental Studies ◽  
Distribution Grid ◽  
Grid Voltage ◽  
Laboratory Setup ◽  
Field Deployment ◽  
Distribution Grids

Future distribution grids will be subjected to fluctuations in voltages and power flows due to the presence of renewable sources with intermittent power generation. The advanced smart metering infrastructure (AMI) enables the distribution system operators (DSOs) to measure and analyze electrical quantities such as voltages, currents and power at each customer connection point. Various smart grid applications can make use of the AMI data either in offline or close to real-time mode to assess the grid voltage conditions and estimate losses in the lines/cables. The outputs of these applications can enable DSOs to take corrective action and make a proper plan for grid upgrades. In this paper, the process of development and deployment of applications for improving the observability of distributions grids is described, which consists of the novel deployment framework that encompasses the proposition of data collection, communication to the servers, data storage, and data visualization. This paper discussed the development of two observability applications for grid monitoring and loss calculation, their validation in a laboratory setup, and their field deployment. A representative distribution grid in Denmark is chosen for the study using an OPAL-RT real-time simulator. The results of the experimental studies show that the proposed applications have high accuracy in estimating grid voltage magnitudes and active energy losses. Further, the field deployment of the applications prove that DSOs can gain insightful information about their grids and use them for planning purposes.

scholarly journals Unified Power Flow Controller Based on Autotransformer Structure

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1542
Author(s):  
Hyun-Jun Lee ◽  
Dae-Shik Lee ◽  
Young-Doo Yoon
Keyword(s):  
Power Flow ◽  
Single Phase ◽  
Low Voltage ◽  
Power Converter ◽  
Unified Power Flow Controller ◽  
Phase System ◽  
Three Phase ◽  
Flow Controller ◽  
And Control ◽  
Power Flow Controller

This paper proposes a new unified power flow controller (UPFC) topology. A single phase of them system with the proposed topology consists of an N:2 transformer with a center tap at the low-voltage side and a power converter module comprising full- and half-bridge converters. A three-phase system can be implemented with three devices. While the conventional UPFC topology uses two three-phase transformers, which are called series and parallel transformers, the proposed topology utilizes three single-phase transformers to implement a three-phase UPFC system. By using an autotransformer structure, the power rating of the transformers and the voltage rating of switches in the power converter module can be significantly decreased. As a result, it is possible to reduce the installation spaces and costs compared with the conventional UPFC topology. In addition, by adopting a full- and half-bridge converter structure, the proposed topology can be easily implemented with conventional power devices and control techniques. The techniques used to control the proposed topology are described in this paper. The results obtained from simulations and experiments verify the effectiveness of the proposed UPFC topology.

scholarly journals Demonstration Study of Voltage Control of DC Grid Using Energy Management System Based DC Applications

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4551
Author(s):  
Juyong Kim ◽  
Hongjoo Kim ◽  
Jintae Cho ◽  
Youngpyo Cho ◽  
Yoonsung Cho ◽  
...  
Keyword(s):  
Real Time ◽  
Energy Management ◽  
Distribution System ◽  
Management System ◽  
Low Voltage ◽  
Voltage Control ◽  
Energy Management System ◽  
Test Scenario ◽  
Demonstration Site ◽  
Power Testing

This paper is about the development of the real-time direct current (DC) network analysis applications for the operation of DC power systems. The applications are located in the central energy management system (EMS) and provide the operator with the optimal solution for operation in real time. Developed DC applications are not limited by voltage level. Applications can be used at all DC voltage levels such as low voltage, medium voltage and high voltage. A program configuration and sequence for analyzing the DC distribution system are suggested. Algorithms of each program are presented and the differences when compared with the processes of the applications of the existing alternating current (AC) systems are analyzed. The DC grid demonstration site at the Korea Electric Power Corporation (KEPCO) power testing center is introduced. The details of EMS and applications installation are described. The developed DC applications were installed in the EMS of the demonstration site and verification tests have been carried out. The configuration of the test scenario for testing the voltage control of the DC network is described. The voltage control result is analyzed and the measured data and the results of the applications are verified for compatibility by comparing them with the results of an off-line simulation tool. Finally, the future direction of the development of technology for the operation of the DC grid is introduced.

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