CM voltage compensation in AC/DC/AC interfaces for smart grids

2011 ◽  
Vol 59 (4) ◽  
pp. 513-523 ◽  
Author(s):  
R. Smoleński ◽  
M. Jarnut ◽  
G. Benysek ◽  
A. Kempski
Keyword(s):  
Side Effects ◽  
Smart Grids ◽  
Low Voltage ◽  
Common Mode ◽  
Medium Voltage ◽  
Frequency Converters ◽  
Voltage Compensation ◽  
Four Quadrant

CM voltage compensation in AC/DC/AC interfaces for smart grids In this paper the results of research connected with common mode (CM) interference generated by four-quadrant frequency converters and effective methods of CM voltage compensation are presented. The obtained results show that conducted CM interference generated by these converters in a low voltage (LV) grid can be transferred by means of parasitic couplings into a medium voltage (MV) network and can be observed at distant points under overhead MV lines. The compensation of the CM voltage sources on both the input and the output sides of the AC/DC/AC converter using proposed arrangement of compensators significantly reduces unwanted, EMC related, side effects accompanying the application of AC/DC/AC interfaces in Smart Grids.

scholarly journals Incremental Heuristic Approach for Meter Placement in Radial Distribution Systems

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3917 ◽  
Author(s):  
Giovanni Artale ◽  
Antonio Cataliotti ◽  
Valentina Cosentino ◽  
Dario Di Cara ◽  
Salvatore Guaiana ◽  
...  
Keyword(s):  
Radial Distribution ◽  
Power Distribution ◽  
Smart Grids ◽  
Distribution Systems ◽  
Low Voltage ◽  
Distribution Network ◽  
Load Flow ◽  
State Variables ◽  
Medium Voltage ◽  
Meter Placement

The evolution of modern power distribution systems into smart grids requires the development of dedicated state estimation (SE) algorithms for real-time identification of the overall system state variables. This paper proposes a strategy to evaluate the minimum number and best position of power injection meters in radial distribution systems for SE purposes. Measurement points are identified with the aim of reducing uncertainty in branch power flow estimations. An incremental heuristic meter placement (IHMP) approach is proposed to select the locations and total number of power measurements. The meter placement procedure was implemented for a backward/forward load flow algorithm proposed by the authors, which allows the evaluation of medium-voltage power flows starting from low-voltage load measurements. This allows the reduction of the overall costs of measurement equipment and setup. The IHMP method was tested in the real 25-bus medium-voltage (MV) radial distribution network of the Island of Ustica (Mediterranean Sea). The proposed method is useful both for finding the best measurement configuration in a new distribution network and also for implementing an incremental enhancement of an existing measurement configuration, reaching a good tradeoff between instrumentation costs and measurement uncertainty.

scholarly journals DESIGN OF UNIVERSAL CONTROL SYSTEM FOR H-BRIDGE MULTILEVEL CONVERTER

2021 ◽  
Author(s):  
Andrey Chepiga ◽  
Aleksey Anuchin
Keyword(s):  
Response Time ◽  
Single Cell ◽  
Low Voltage ◽  
Current Loop ◽  
Switching Frequency ◽  
Unequal Distribution ◽  
Medium Voltage ◽  
Frequency Converters ◽  
Switching Losses ◽  
Cell Topology

The medium voltage frequency converters mostly utilize the low-voltage multi-cell topology. However, available PWM techniques have some drawbacks, such as time delayed operation, which limits current loop response time, need reinitialization of the PWM carriers in case of cell failure, or have unequal distribution of losses. To solve the set of these problems the PWM strategy, which utilize PWM in a single cell with sequential cell switching, was introduced. This PWM strategy can operate in case of partial inverter failures, provides maximum available voltage to the load and has low response time due to operation at high PWM frequency of a single cell, while the average switching frequency is limited. The proposed PWM technique was examined using a model, where the switching losses distribution and high quality of the output voltage were confirmed.

scholarly journals Characterization of Narrowband Noise and Channel Capacity for Powerline Communication in France

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3022 ◽  
Author(s):  
Imène Elfeki ◽  
Sébastien Jacques ◽  
Ismail Aouichak ◽  
Thierry Doligez ◽  
Yves Raingeaud ◽  
...  
Keyword(s):  
Channel Capacity ◽  
Smart Grids ◽  
Low Voltage ◽  
Powerline Communication ◽  
Medium Voltage ◽  
Time Frequency ◽  
Frequency Representation ◽  
Major Interest ◽  
Capacity Calculation ◽  
Advanced Metering

Narrowband powerline communication (NB-PLC) systems represent a key step for the real development of smart grids’ applications in the medium voltage (MV) and low voltage (LV) networks. This article sums up the results of a complete experimental measurement campaign aimed at investigating the low voltage NB-PLC channel in the frequency range from 9 to 500 kHz in various sites (i.e., rural, urban etc.) located in France. The noise features in time-frequency representation are studied at five different sites between the transformer substation and the smart electricity meter. The main contribution of this study consists in estimating the theoretical channel capacity which constitutes a major interest for the users and actors of the electrical system. The channel capacity calculation shows reliable results in the US Federal Communications Commission (FCC) band (a few Mbits/s). The quality of the communication in the FCC band enables to integrate new smart grids’ applications and services based on the existing NB-PLC communication for advanced metering infrastructure (AMI).

Reduction of the Low Voltage Substation Constraints by Inserting Photovoltaic Systems in Underserved Areas

2019 ◽  
Vol 12 (2) ◽  
pp. 105-112
Author(s):  
Benbouza Naima ◽  
Benfarhi Louiza ◽  
Azoui Boubekeur
Keyword(s):  
Low Voltage ◽  
Voltage Drop ◽  
Electrical Energy ◽  
Utilization Rate ◽  
Photovoltaic Systems ◽  
Voltage Distribution ◽  
Medium Voltage ◽  
Pv Systems ◽  
Transformer Substation ◽  
Load Pattern

Background: The improvement of the voltage in power lines and the respect of the low voltage distribution transformer substations constraints (Transformer utilization rate and Voltage drop) are possible by several means: reinforcement of conductor sections, installation of new MV / LV substations (Medium Voltage (MV), Low Voltage (LV)), etc. Methods: Connection of mini-photovoltaic systems (PV) to the network, or to consumers in underserved areas, is a well-adopted solution to solve the problem of voltage drop and lighten the substation transformer, and at the same time provide clean electrical energy. PV systems can therefore contribute to this solution since they produce energy at the deficit site. Results: This paper presents the improvement of transformer substation constraints, supplying an end of low voltage electrical line, by inserting photovoltaic systems at underserved subscribers. Conclusion: This study is applied to a typical load pattern, specified to the consumers region.

scholarly journals Machine Learning and GIS Approach for Electrical Load Assessment to Increase Distribution Networks Resilience

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4133
Author(s):  
Alessandro Bosisio ◽  
Matteo Moncecchi ◽  
Andrea Morotti ◽  
Marco Merlo
Keyword(s):  
Machine Learning ◽  
Distribution System ◽  
Low Voltage ◽  
Regression Tree ◽  
Distribution Networks ◽  
Machine Learning Algorithms ◽  
Extreme Weather Events ◽  
Medium Voltage ◽  
Weather Events ◽  
Building Area

Currently, distribution system operators (DSOs) are asked to operate distribution grids, managing the rise of the distributed generators (DGs), the rise of the load correlated to heat pump and e-mobility, etc. Nevertheless, they are asked to minimize investments in new sensors and telecommunication links and, consequently, several nodes of the grid are still not monitored and tele-controlled. At the same time, DSOs are asked to improve the network’s resilience, looking for a reduction in the frequency and impact of power outages caused by extreme weather events. The paper presents a machine learning GIS-based approach to estimate a secondary substation’s load profiles, even in those cases where monitoring sensors are not deployed. For this purpose, a large amount of data from different sources has been collected and integrated to describe secondary substation load profiles adequately. Based on real measurements of some secondary substations (medium-voltage to low-voltage interface) given by Unareti, the DSO of Milan, and georeferenced data gathered from open-source databases, unknown secondary substations load profiles are estimated. Three types of machine learning algorithms, regression tree, boosting, and random forest, as well as geographic information system (GIS) information, such as secondary substation locations, building area, types of occupants, etc., are considered to find the most effective approach.

scholarly journals Insulation Life Span of Low-Voltage Electric Motors—A Survey

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1738
Author(s):  
Vanessa Neves Höpner ◽  
Volmir Eugênio Wilhelm
Keyword(s):  
Life Span ◽  
Electric Motor ◽  
Low Voltage ◽  
Frequency Converter ◽  
Rate Of Change ◽  
High Rate ◽  
Switching Frequency ◽  
Electric Motors ◽  
Frequency Converters ◽  
High Switching Frequency

The use of static frequency converters, which have a high switching frequency, generates voltage pulses with a high rate of change over time. In combination with cable and motor impedance, this generates repetitive overvoltage at the motor terminals, influencing the occurrence of partial discharges between conductors, causing degradation of the insulation of electric motors. Understanding the effects resulting from the frequency converter–electric motor interaction is essential for developing and implementing insulation systems with characteristics that support the most diverse applications, have an operating life under economically viable conditions, and promote energy efficiency. With this objective, a search was carried out in three recognized databases. Duplicate articles were eliminated, resulting in 1069 articles, which were systematically categorized and reviewed, resulting in 481 articles discussing the causes of degradation in the insulation of electric motors powered by frequency converters. A bibliographic portfolio was built and evaluated, with 230 articles that present results on the factors that can be used in estimating the life span of electric motor insulation. In this structure, the historical evolution of the collected information, the authors who conducted the most research on the theme, and the relevance of the knowledge presented in the works were considered.

scholarly journals Time Synchronized Low-voltage Measurements for Smart Grids

2015 ◽  
Vol 100 ◽  
pp. 1389-1395 ◽  
Author(s):  
Ladislav Stastny ◽  
Lesek Franek ◽  
Zdenek Bradac
Keyword(s):  
Smart Grids ◽  
Low Voltage
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