U-Quality

Effects of future low-voltage grid utilization cases and their mode of operation on voltage quality and its control.

The U-Quality project will be the first to investigate the effects of future low-voltage grid usage cases (photovoltaics, photovoltaic battery storage systems, electromobility and power-to-heat applications) and their operating mode on voltage quality. The results will help distribution grid operators to integrate these elements into the grid efficiently and cost-effectively. In addition, solutions are being investigated as to how the effects on voltage quality can be managed effectively, efficiently and cost-effectively.

Objective

The voltage quality in the distribution grid depends on the generators and consumers connected in the grid area. The current changes to these so-called grid usage cases as part of the energy, mobility and heating transition therefore have a major influence on the voltage quality. Maintaining this quality is one of the central and current tasks for distribution grid operators.
The U-Quality project aims to investigate the influence of the change in grid usage cases on voltage quality in distribution grids and which components, technologies and processes can contribute to ensuring this quality. In addition, the processes and components will be adapted and further developed in such a way that they improve the voltage quality not only with regard to static voltage stability, but also with regard to unbalance, flicker and harmonics, among other things. Recommendations for action for distribution grid operators and manufacturers as well as for the future revision of standards, application rules and test specifications will be developed.
A three-stage approach with simulations, laboratory tests and field tests is planned. In order to promote the evaluation of realistic scenarios, an initial measurement campaign is planned to record the current situation. The cooperation of innovative partners from industry and grid operation ensures a high degree of practical relevance and rapid implementation of the findings. Through the cooperation of the project partners in various standardization committees, the project results will be directly incorporated into future standards and guidelines.

Based on simulations, laboratory tests and field trials, the following questions will be examined in detail:

Which power quality parameters in the distribution grid have which effect?
Which future grid usage cases will result in poor voltage quality?
What requirements must be placed on the parameterization of a control method with regard to stability?
What are the economic expenses in this context?
What do valid verification procedures look like in order to ensure the broad implementation of voltage quality requirements in the distribution grids?

To achieve the objectives, simulations are carried out using meaningful sample networks. These will be validated in the research partners' laboratory environments and then transferred into practice in field tests. Economic analyses, the creation of a control prototype and the development of recommendations for action round off the project.

Schedule

The project consortium is made up of four research institutes, six distribution grid operators and four industrial partners, who give the institutes the opportunity to receive direct feedback on their results and test their simulations under real conditions. The U-Quality project is supported by the Federal Ministry for Economic Affairs and Energy. This and other projects are presented on Forschung-Stromnetze.info

Technische Universität Braunschweig - elenia Institut für Hochspannungstechnik und Energiesysteme (Projektkoordination)

Technische Universität Braunschweig - elenia Institute for High Voltage Technology and Energy Systems (Project Coordination)|The elenia Institute for High Voltage Technology and Energy Systems deals with the technical and economic challenges of electrical energy supply in the 21st century. As part of the research focus "Active distribution grid, electromobility and components of the energy supply", for example, the effects of decentralized generators on the operating states of medium and low-voltage grids were examined. As part of the project, elenia is responsible for project coordination as well as dynamic simulations, economic evaluation and the implementation of field tests.

RWTH Aachen - Institut für Hochspannungstechnik

The Institute of High Voltage Technology (IFHT) is divided into the research groups "Equipment and Diagnostics, Switchgear and DC Technologies, Sustainable Transmission Systems and Sustainable Distribution Systems". Among other things, protection systems for distribution grids were simulated and tested in this context and the use of controllable local grid transformers was researched. In the "U-Quality" project, the IFHT is determining the power quality generation of individual devices, simulating harmonics and carrying out a field measurement for power quality control. The laboratory-specific investigations and the field measurement are intended to verify the results of the controller and the simulations.

TU München, Fachgebiet Elektrische Energieversorgungsnetze

The Department of Electrical Energy Networks (EEN) at the Technical University of Munich is dedicated to modeling unbalanced loads on low-voltage grids. A field test is being carried out for this purpose. Within the project, the EEN is responsible for the development of model grids and project conventions and examines the effectiveness of the control of various voltage quality parameters. In addition, laboratory-specific investigations are being carried out to verify the results of the simulations.

FGH - Forschungsgemeinschaft für Elektrische Anlagen und Stromwirtschaft e.V.

The Forschungsgemeinschaft für Elektrische Anlagen und Stromwirtschaft e.V. (FGH e.V.) is a non-profit research organization of the electricity sector and electrical industry. Its areas of work include the grid integration of decentralized generation plants and information and communication technology in electrical grids. The task of the FGH e.V. in the project is the scenario development and simulation of grid utilization cases, the technical investigation of the regulation and the creation of technical recommendations for action.

RPT Ruhstrat Power Technology GmbH

RPT Ruhstrat Power Technology GmbH develops and produces electrical testing technology, voltage optimization systems and transformers. In the field of electrical testing technology, the company specializes in heating, motor and pump test benches as well as test systems for high-voltage cables (heat cycle test). Ruhstrat has over 80 years of experience in voltage optimization systems and offers modern systems for protection against voltage dips and for voltage stabilization. In-house transformer production for low and medium voltage with switch cabinet construction guarantees the consistently high quality of all electrotechnical components.

Associated partners

Netze BW GmbH

As the largest grid company for electricity, gas and water in Baden-Württemberg, Netze BW GmbH stands for secure, reliable, efficient and cost-effective supply and customer-oriented grid services. For more than three million households as well as commercial and industrial companies, we are the link between generation and the power socket. We operate, maintain and continuously expand around 100,000 kilometers of high-, medium- and low-voltage electricity grid. The grid integration of renewable energies plays an important role in this. Netze BW is supporting the project primarily with its practical experience in distribution grid operation and measurements of voltage quality.

Bayernwerk Netz GmbH

Bayernwerk Netz GmbH is one of the largest regional grid operators in Bavaria and is responsible for and operates a medium and low-voltage electricity grid with a length of around 153,000 kilometers as well as natural gas pipelines with a length of around 5,700 km. In addition to grid operation, the company is also active in the heating and water sectors. As one of the participating distribution grid operators, Bayernwerk Netz GmbH provides representative grids with a high feed-in from decentralized generation plants for field tests and supports the research institutes in the tests with the relevant experience, expertise and manpower.

Regionetz GmbH

As a wholly-owned subsidiary of Stadtwerke Aachen Aktiengesellschaft (STAWAG AG), Regionetz GmbH operates the electricity and gas grids and is also responsible for the water and heating network of STAWAG AG in Aachen, Simmerath and Monschau. As the third distribution network operator, Infrawest GmbH will also make an important contribution and, for example, support the parameterization of the systems or provide the corresponding measurement technology.

Stromnetz Hamburg GmbH

As the owner of the electricity distribution grid and a 100 percent municipal company, Stromnetz Hamburg GmbH ensures a secure and reliable supply of electricity in Hamburg. With 12.2 billion kilowatt hours of electricity per year, they supply around 1.1 million households and businesses. They take care of all current and future issues relating to grid connection and use. Stromnetz Hamburg GmbH supports the project in carrying out the field tests and is also available to provide advice.

Braunschweiger Netz GmbH

Braunschweiger Netz GmbH is the operator of the electricity, gas, water and district heating networks as well as street lighting in Braunschweig. It provides the supply network for the citizens of Braunschweig, trade and industry with electricity, gas, drinking water and district heating. In addition to maintaining the supply networks, its responsibilities also include the expansion and further development of the current distribution network. As an associated partner, Braunschweiger Netz GmbH supports the project in an advisory capacity during the project phase and by making selected network areas available for measurements and field tests.

Avacon Netz GmbH

Avacon Netz GmbH is a wholly owned subsidiary of Avacon AG. Our electricity grid, with a total length of over 60,000 kilometers, runs through Lower Saxony, Saxony-Anhalt, Hesse and North Rhine-Westphalia and brings energy to 16 million people. Our natural gas grid supplies energy to households in Lower Saxony, Saxony-Anhalt and Hesse. In 2018, generation plants with a total capacity of almost 12 GW were connected to our electricity grids. The green electricity quota amounted to around 170% of grid sales. We are contributing to the success of the energy transition by continuously expanding the grid and using innovative technologies. We will support the U-Quality research project with grid data and our experience in the field of distribution grids.

Phoenix Contact Electronics GmbH

Phoenix Contact is the global market leader for components, systems and solutions in the fields of electrical engineering, electronics and automation. The family-owned company currently employs around 17,400 people worldwide and generated sales of EUR 2.38 billion in 2018. The company is headquartered in Blomberg, Westphalia. The Phoenix Contact Group comprises fourteen companies in Germany and more than 55 of its own sales companies around the world. Its international presence is further strengthened by more than 40 agencies in Europe and overseas.

SMA Solar Technology AG

SMA Solar Technology AG is the leading global specialist for photovoltaic system technology and offers innovative solutions for all photovoltaic applications with its more than 4,000 employees in 21 countries. SMA Solar Technology AG provides three-phase photovoltaic inverters for the low-voltage level for field and laboratory tests. In addition, the company's many years of experience in controller modeling will be incorporated.

MR Maschinenfabrik Reinhausen GmbH

MR Maschinenfabrik Reinhausen GmbH, based in Regensburg, is a high-voltage technology company and has established itself as the global market leader in this segment with its on-load tap-changers for power transformers. In addition to this core business, the company offers other innovative products and services to ensure a trouble-free power supply. As a further industrial partner, MR Maschinenfabrik Reinhausen GmbH makes an immense contribution with regard to the control methods used and thus helps to increase the informative value of the project.

The events in the "U-Quality" project are listed below in chronological order:

September 5th, 2019: Kick-off meeting at the TU Braunschweig

The kick-off meeting with the project partners took place on September 5th, 2019 at the Institute of High Voltage Technology and Electrical Power Systems at TU Braunschweig.

September 30th, 2019: Press release on the U-Quality research project

On September 30, 2019, a press release on the U-Quality research project was published on the TU Braunschweig blog. The article can be found here.

December 10th, 2019-December 11th, 2019: Implementation of the 1st working workshop in Aachen

On December 10th and 11th, 2020, the first workshop at working level took place between the project partners at the Institute for High Voltage Technology at RWTH Aachen University. Among other things, previous results and the next steps in the project were discussed.

December 16th, 2019 - January 21st, 2020: Implementation of field tests in Braunschweig

In the period from December 16th, 2019 to January 21st, 2020, measurements were carried out in a low-voltage grid in Braunschweig to record the actual state of the voltage quality. For this purpose, measuring devices were placed at the local grid station, at several distribution cabinets and in a household.

February 29th, 2020: Workshop in Munich to present a network impedance measuring device

In Munich, morEnergy GmbH and the Technical University of Munich will be presenting the ONIS grid impedance measuring device, which enables grid impedance measurements with a broad frequency spectrum.

1st quarter 2020: Implementation of field tests in Bavaria

In the first quarter of 2020, the Technical University of Munich carried out field tests in cooperation with Bayernwerk Netz GmbH. Among other things, the impedance was measured in a low-voltage grid.

May 14th-15th, 2020: Project meeting of the funded partners digitally "in Munich"

Discussion between the project partners about the results of the U-Quality project to date.

June 24th, 2020: Project meeting of all partners digitally "in Braunschweig"

The focus of this project meeting was on the statistical evaluation of current PQ problems.

3rd quarter 2020: Measurement of various components in the laboratories of TU Braunschweig and RWTH Aachen University

Including the measurement of various plug-in hybrids and battery electric vehicles.

September 24th, 2020: Project meeting of the university partners digitally "in Braunschweig"

Exchange of measurement results from the laboratory and field and advice on how to proceed in the simulations.

October 22nd, 2020: Project meeting of all partners digitally "in Braunschweig"

Coordination of pattern networks.

1st quarter 2021: Publications "Future electricity grids"

Two publications were submitted in the course of the online conference "Future electricity grids".

1st quarter 2021: Digital project meeting of all partners

Presentation of project results and discussion of the upcoming simulations and the controller prototype.

2nd quarter 2021: Development of power quality regulator

Concept and elaboration for the development of a power quality regulator.

3rd quarter 2021: Simulation environment of a power quality controller

Start of simulations in the simulation environment.

4th quarter 2021: Further development of the controller model in MATLAB/Simulink with different controller types. Creation of scenarios.

Further simulations in the simulation environment.

1st quarter 2022: Further development of the controller model in MATLAB/Simulink with different controller types. Creation of scenarios.

Further simulations in the simulation environment.

2nd quarter 2022: Further development of the controller model in MATLAB/Simulink. Creation of scenarios. Comprehensive publication of results of previous project work at the CIRED workshop in Porto

3rd quarter 2022: Final status of the controller model in MATLAB/Simulink.

The extensive controller model in MATLAB/Simulink with documentation can be found under the link: github.com/U-Quality-Regler/UPQC-Model here .

3rd quarter of 2022: Final workshop

Exchange of project findings, results of simulations and tests and discussion of recommendations for action.

4th quarter 2022: Preparation of the final report

1st quarter 2023: Submission of the final report and publication of the controller model in MATLAB/Simulink

The extensive controller model in MATLAB/Simulink with documentation can be found under the link: github.com/U-Quality-Regler/UPQC-Model here.

Biedermann, C.; Simon, S.; Vanselow, A.; Przibylla, J.; Golobart, M.; Di Modica, G.-L.; Garn, T.; Willenberg, D.; Witzmann, R.; Engel, B.: Spannungsqualität vor dem Hintergrund des Anstiegs an Photovoltaik, Elektrofahrzeugen, PV-Batteriespeichersystemen und Power-to-Heat, ENERGY FOR FUTURE - Wege zur Klimaneutralität, EnInnov2020 - 16. Symposium Energieinnovation, Graz, Graz/Austria: Verlag der Technischen Universität Graz, 12.-14. Februar 2020, S. 88-89. ISBN 978-3-85125-734-2

Biedermann, C.; Przibylla, J.; Di Modica, G.-L.; Engel, B.: Messung und Bewertung der Netzrückwirkungen von neuartigen elektrischen Erzeugern und Verbrauchern im Niederspannungsnetz, Online-Tagung Zukünftige Stromnetze, 27.-28. Januar und 3.-4. Februar, 2021

Vanselow, A.; Lehmann, D.; Krahl, S.: Analyse der Rückwirkungen veränderter Netzentgeltanreize auf die Spannungsqualität im Niederspannungsnetz, Online-Tagung Zukünftige Stromnetze, 27.-28. Januar und 3.-4. Februar, 2021

Di Modica, G.; Biedermann, C.; Garn, T.; Engel, B.: Influence of Electric Vehicles, PV Systems, Home Storage Systems and Heat Pumps on the Voltage Quality in the Low-Voltage Grid, ETG-Kongress 2021, 18.-19. Mai, 2021

Garn, T.; Biedermann, C.; Engel, B.: Parameters Of Rapid Voltage Changes And Their Effects On Power Quality, PESS 2021, Kassel, 25.-26. November 2021

Biedermann, C.; Di Modica, G.; Engel, B.: Measurement of the Voltage Quality and Load Profiles of Electric Vehicles, CIRED 2021, 20.-23. September, 2021

Simon, S.; Linnartz, P. P.; Willenberg, D.; Quester, M. A. Monti; A.: Experimental investigation of mirror frequency currents emitted by low voltage inverters under distorted grid voltage conditions, 2021 IEEE Madrid PowerTech: Conference Proceedings, 2021

Przibylla, J.; Lippich Golobart, M.; Di Modica, G.-L.; Biedermann, C.; Witzmann, R.: Determination of the positive- and zero-sequence components of line sections in low-voltage networks using impedance measurements, CIRED 2021, 20.-23. September, 2021

Vanselow, A.; Lehmann, D.; Krahl, S.; Moser, A.: Modelling the demand behaviour of active customers and the impact of price incentive-based control strategies, CIRED 2021, 20.-23. September, 2021

Garn, T.; Biedermann, C.; Engel, B.: Parameters of Rapid Voltage Changes and their Effects on Power Quality, PESS 2021, Kassel, 25.-26. November 2021

Simon, S.; Linnartz, P. P.; Willenberg, D.; Quester, M. A. Monti; A.: Experimental investigation of mirror frequency currents emitted by low voltage inverters under distorted grid voltage conditions, 2021 IEEE Madrid PowerTech : Conference Proceedings, 2021

Simon, S.; Winkens, A.; Monti, A.; Ulbig, A.: Extraction of Frequency-Dependent Impedances of Residential Loads in Low-Voltage Grids for Harmonic Stability Assessment, 22nd Power Systems Computation Conference, 2022

Garn, T.; Vanselow, A.; Biedermann, C.; Moser, A.; Engel, B.: Flicker Emission of Electric Vehicle Charging in Low Voltage Grids, CIRED workshop on E-mobility and power distribution systems, 2.-3. June 2022

Przibylla, J.; Lippich Golobart, M.; Witzmann, R.; Öztas, O.: Change in Standard Load Profile to Date and Further Changes due to Increasing Numbers of Electric Vehicles, CIRED workshop on E-mobility and power distribution systems, 2.-3. June 2022

Lippich Golobart, M.; Przibylla, J.; Witzmann, R.: Upgrading Low-Voltage Network Models for Power Quality Investigations with a Focus on Voltage Unbalance, CIRED workshop on E-mobility and power distribution systems, 2.-3. June 2022

Vanselow, A.; Garn, T.; Moser, A.; Engel, B.: “Analysing the Impact of Operating Strategies of Active Customers on Flicker and Voltage Unbalance”, Paper n° 10831, 27th International Conference on Electricity Distribution, Rome, 12-15 Juni 2023

Vanselow, A.; Kalisch, L; Krahl, S.; Moser, A.: “Simulation and comparison of the impact of different price tariffs on grid utiliatzion”, Paper n° 11155, 27th International Conference on Electricity Distribution, Rome, 12-15 Juni 2023

J. Przibylla, M. Lippich Golobart, S. Simon, C. Biedermann, D. Lehmann, R. Witzmann: „Performance Analysis of a 50 kVA Unified Power Quality Conditioner Model for Low Voltage Distribution Network Application”, Powertech23, Belgrad, Juni 2023

Final report

The final report of the "U-Quality" project can be downloaded here:

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