REGSys® performs the automatic control of transformers with tap changers.
The system helps operations, engineering, and service teams reliably implement control tasks and monitor equipment.
Typical applications:
- Voltage regulation under fluctuating feed-in conditions or changing loads
- Load-dependent setpoint adjustment, parallel operation, and limit monitoring of various measured quantities
- Operation of transformers for special applications, such as phase-shifting transformers and variable shunt reactors (VSR), with different control requirements
- Smart additional functions such as transformer monitoring, recording functions, SCADA communication, and an integrated programming language
These devices are suitable, if:
- Voltage needs to be regulated automatically and transparently
- Simple or complex tasks involving the control of on-load tap changers need to be handled
- Different control tasks need to be implemented with a single device
- Operation, monitoring, control, and communication need to be combined within one system
What Is Important for Efficient Automatic Voltage Regulation?
Efficient automatic voltage regulation plays a crucial role in electrical power supply, especially when regulating transformers with on-load tap-changers. In general, voltage regulation is about keeping the output voltage of the transformer at a stable level (within the defined tolerance limits) by reacting to fluctuations in the input voltage or load changes. Precise and reliable regulation technology is essential for this purpose.
Our proven, multifunctional and flexible voltage regulators of the »REGSys®« family are designed for customer-specific automatic voltage regulation applications and simple operation. The devices continuously monitor the output voltage and adjust it accordingly to achieve and maintain the desired voltage. In addition, the devices of the »REGSys®« family can be easily interconnected to form a regulator network (e.g. parallel operation). The user will find the right solution for every task.
Automatic Voltage Regulation With REGSys® - Proven, Multifunctional, Flexible
Products
Application Areas
REGSys® - Voltage Regulation
A. Eberle GmbH & Co. KG
Measure. Regulate. Across All Grids.
A. Eberle GmbH & Co. KG, founded in 1980 and headquartered in Nuremberg, Germany, operates in the field of measurement and regulation technology for the energy sector as well as for medium-sized and large industrial companies. Our products and services ensure and enhance the availability of energy supply across all voltage levels and support the integration of renewable energy sources into power grids.
Comfortable Voltage Regulation
With the Intelligent Additional Functions of Our »REGSys®« Devices
The »REGSys®« voltage regulation system has been specifically developed for the regulation and continuous monitoring of transformers with tap changers in medium- and high-voltage grids.
Thanks to numerous freely configurable inputs and outputs, intuitive LED displays, and intelligent additional functions – recording, event logging, transducer functionality, statistical analysis, parallel operation with ParaGramer, and integrated transformer monitoring– REGSys® offers the highest level of user comfort.
Introduction Flyer »REGSys®«
Get to know the REGSys® voltage regulation system at a glance.
Which Standards Define Voltage and Power Quality?
At all voltage levels, there are norms and standards that precisely define and assess voltage and grid quality. In the field of automatic voltage regulation of transformers with tap changers in high and medium voltage, the following standards are particularly relevant:
IEC 60038 (DIN EN 60038)
This standard describes the standard voltage values for electrical power supply and traction current networks, consumer installations and devices.
EN 50160 (DIN EN 50160)
This standard describes the minimum quality of the mains supply, in particular the supply voltage, in terms of frequency, level, waveform and symmetry of the conductor voltages at the transfer point to the customer in public low- and medium-voltage networks.
IEC 61000-2-12
This standard describes the limit values and characteristics of voltage disturbances and signal distortions in electrical supply networks with a nominal voltage of up to 35 kV. It defines specific values and tolerances for parameters such as voltage deviations, harmonics, flicker and signal distortion in order to ensure a stable and reliable power supply.
Virtual Instruction Manual
Description of the Basic Approach for the
Commissioning of Our Voltage Regulator REG-D(A)
MORE Information
Where and When Do You Need Voltage Regulation Devices?
Voltage regulation devices are needed wherever a stable power supply is required, whether in industrial plants, transport, residential areas or the public energy sector. Voltage regulators are particularly indispensable in transformers with tap-changers, which are used for the distribution and transmission of electricity in power grids. They ensure a consistent voltage supply for consumers, which in turn increases the efficiency of the power grid and minimises outages.
In the energy supply sector, voltage regulation of transformers is a crucial step in ensuring a reliable and high-quality power supply. Voltage regulators such as our »REGSys®« voltage regulation system for transformers with on-load tap-changers play a central role for this purpose. Through their continuous monitoring and adjustment, they ensure that fluctuations in the power supply are minimised and the efficiency of the entire energy system is improved.
Design and Function of a Voltage Regulator
What Is the Function of Voltage Regulators?
A voltage regulator is a permanently installed measuring/monitoring and regulation device for switching on-load tap-changers on transformers. In order to realise the regulation, at least the current mains voltage is recorded and compared with the set target value. If the deviation between the actual and set value is greater than the permitted tolerance, regulation commands are sent to the on-load tap-changer of the transformer after an adjustable time delay. With our »REGSys®« voltage regulation system, voltage regulation can be supplemented by additional functions such as current influence (e.g. compensation of line impedances) or parallel operation. The measurement of the actual voltage and, if necessary, current values is usually carried out via instrument transformers. The correct function of the on-load tap-changer can be checked via the feedback of the tap position and the running lamp.
How Are Voltage Regulators Generally Constructed?
The voltage regulator is designed using digital technology. This means that, similar to a PC, the device is based on a processor on which the algorithms and processes required for the regulation process are executed. Either an analogue/digital or digital/analogue conversion or conditioning of the individual signals takes place at the interfaces between the device and the process. The most important signal for voltage regulation is the current measured voltage value. As the voltage regulator is generally used in the medium and high voltage range, the voltage measurement mainly takes place at a voltage transformer. The voltage output by the voltage transformer is transformed again at the measurement input of the regulator and then digitised in an A/D converter.
The voltage regulator has binary inputs to record the tap position, the running lamp and other binary signals. There, the voltage signals are converted into the on or off state by means of a circuit consisting of resistors and optocouplers, which can then be processed by the regulator programme. The tap changer is controlled by relays, which are controlled by the internal algorithm. In addition, the voltage regulator can record process values (e.g. tap position) via standard signals (e.g. -20 to 20 mA) or output them again.
What Makes the »REGSys®« Voltage Regulation System From A. Eberle so Special?
Our voltage regulation systems are valued by our customers around the world for their reliability and efficiency. With our »REGSys®« voltage regulation system, we can map the most complex applications precisely to customer requirements and are the global market leader in the field of voltage regulation on transformers with on-load tap-changers. Our devices are characterised by proven technology and precise regulation options and have been specially developed for use in transformers for energy applications in the high and medium voltage range.
REGSys®: Basics and Operating Principle
What is REGSys®?
REGSys® is an automatic voltage regulation system for transformers with on-load tap changers. REG-D® or REG-DA measures the controlled voltage and operates the transformer tap changer.
When is automatic transformer voltage regulation useful?
It is useful when grid voltage must remain reliably within the specified range despite changing loads, generation, or network configurations.
How do REG-D® and REG-DA regulate voltage?
The devices measure values such as voltage, current, and power factor, or receive them digitally. They calculate the control deviation and issue raise or lower commands to the on-load tap changer.
REGSys®: Regulation Principle, Transformers and Parallel Operation
Does REGSys® regulate the output voltage directly?
No. REGSys® is not an electronic linear or switching regulator. It controls the transformer on-load tap changer, which changes the turns ratio and therefore the voltage.
Which transformers can be controlled with REGSys®?
REGSys® is designed for tap-changing transformers. Depending on the configuration, it can also support parallel transformers, three-winding transformers, phase-shifting transformers, and transformer banks.
How does REGSys® support parallel transformer operation?
Multiple regulators can exchange data and coordinate tap positions, enabling reliable common control of transformers operating in parallel.
REGSys®: Monitoring, Condition Data and Communication
Which measurement and monitoring functions does REGSys® provide?
Depending on the configuration, functions include transducer operation, recording, tap-change statistics, ParaGramer, and transformer monitoring.
Which transformer condition data can be monitored?
Depending on the equipment, the system can monitor oil and hot-spot temperatures, tap-change operations, cooling stages, and calculated loss of transformer life.
Which communication protocols does REGSys® support?
Depending on the device configuration, available protocols include IEC 60870-5-101/103/104, IEC 61850, DNP 3.0, Modbus RTU, Profibus DP, and SPABUS. Refer to the current datasheet.
REGSys®: Digital Integration and Cybersecurity
Can REGSys® be integrated into digital substations?
Yes. Depending on the configuration, measurements and signals can be integrated via IEC 61850, IEC 61850-9-2 Sampled Values, GOOSE, or IEC 60870-5-104.
Which cybersecurity functions are available?
Depending on the configuration, current systems support role-based user management and RADIUS authentication. The exact feature set should be verified for the project.
REGSys®: Device Selection and Applications
What is the difference between REG-D® and REG-DA?
Both devices handle measurement, control, and regulation tasks for tap-changing transformers. Selection depends on the hardware design, interfaces, cybersecurity, monitoring, and project requirements.
Which criteria matter when selecting a REGSys® system?
Consider the transformer and tap-changer concept, measurement acquisition, parallel-operation requirements, communication protocols, cybersecurity, and required monitoring functions.
Where is REGSys® typically used?
Typical applications include substations, distribution grids, industrial networks, and other installations with automatically controlled tap-changing transformers.
News from the Productgroup
REGSys® - News
Blogpost
GRUNDIG AKADEMIE visits A. Eberle
7. August 2026
In 2026, the GRUNDIG AKADEMIE Nuremberg visited A. Eberle with a group of trainee technicians. During the visit, the participants gained an insight into our company, technical fields of work and potential[...]
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Blogpost
A. Eberle named one of the TOP 100 Innovators for 2026
22. July 2026
As part of the 2026 TOP 100 Awards, we had the honour of receiving a special accolade in Heidelberg last week – presented in person by Christian Wulff, former Federal President and mentor of the TOP[...]
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Webinar
»REGSys®« Webinar: New Requirements and Application Cases for Voltage Regulators in MV/HV-Grids
18. June 2026
Webinar recording from 2026-06-10: »REGSys®« New Requirements and Application Cases for Voltage Regulators in MV/HV-Grids[...]
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Blogpost
International Partner Week 2026 - Exchange, knowledge transfer and collaboration in Nuremberg
1. June 2026
We were delighted to welcome our international partners to Partner Week 2026. The chance to chat in person, seeing familiar faces and making new acquaintances made the week a special one for us.[...]
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General Knowledge
Transformer Monitoring
28. April 2026
Transformer monitoring helps detect critical operating conditions early, reduce outages and improve the safe operation of transformers in power grids and industrial systems.[...]
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Blogpost
A. Eberle and Bregal Unternehmerkapital enter into a growth partnership
14. April 2026
A. Eberle and Bregal enter into a growth partnership. The partnership with BU is intended to accelerate A. Eberle’s international expansion, innovation and technological advancement.[...]
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Webinar
»Cyber Security« Webinar: A Challenge for European Energy Companies
3. December 2025
Webinar recording from 2025-11-26: »Cyber Security« - A Challenge for European Energy Companies[...]
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Blogpost
A. Eberle at the Schwabach City Run 2025
24. November 2025
A. Eberle was represented by 37 participants at the 2025 Schwabach City Run, setting a new internal record for participation. Particularly noteworthy is Benjamin Rentsch's first place in the M 35 40 age[...]
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Blogpost
A. Eberle welcomes Amarillo as a new REGSys® partner in Mexico
20. October 2025
A. Eberle is expanding its international partner network and is pleased to welcome »Amarillo Naranja S.A. de C.V.« as a new »REGSys®«-partner in Mexico.[...]
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General Knowledge
Power in Multiphase Systems
7. August 2025
This technical report highlights the special features of power transmission in three-phase systems and offers valuable insights into the optimisation and analysis of modern power grids.[...]
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Blogpost
Visit From the Rudolf Diesel Technical School at A. Eberle
15. July 2025
We were happy to welcome you, Rudolf-Diesel-Fachschule! Yesterday, we had the pleasure of welcoming two classes of future electrical engineering technicians from the Rudolf-Diesel-Fachschule Nürnberg[...]
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Blogpost
TOP 100 Awards 2025: Innovation for the Energy Future
15. July 2025
💡 As part of the TOP 100 Awards 2025, we were honored to receive a special recognition last week in Mainz – personally presented by TV host and science journalist Ranga Yogeshwar.[...]
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Blogpost
University Excursion: Pentecost Excursion of the Friedrich-Alexander-University Erlangen-Nuremberg (FAU)
14. July 2025
As a company dedicated to innovation, education, and the energy transition, we are pleased to have once again supported the Whitsun excursion of Friedrich-Alexander University Erlangen-Nuremberg (FAU)[...]
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Blogpost
Further Growth at A. Eberle
14. July 2025
Welcome to the team! We welcome our new colleagues at A. Eberle.[...]
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General Knowledge
Voltage Stabilisation
7. July 2025
In this article, you will learn why voltage stabilisation in high, medium and low-voltage grids plays a central role in safe and efficient grid operation. You will learn the basics of ‘voltage stabilisation’[...]
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Training Video
»REGSys®« Training Video 8: Overview SCL-Config for IEC 61850
28. January 2025
In this video you will learn how you can export a CID file, how to adjust the IED name and working with the SCL-Config.[...]
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Training Video
»REGSys®« Training Video 7: How to Use the Winconfig Software
28. January 2025
In this video you will learn how to create a new parameter file, how to upload setting files or download setting files from the Scada card and what kind of parameters a setting file contains.[...]
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Training Video
»REGSys®« Training Video 6: Firmware Update via Winconfig
28. January 2025
In this video you will learn when it is reasonable to use the WinConfig for a firmware update and how to do a firmware update with the WinConfig.[...]
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Training Video
»REGSys®« Training Video 5: Firmware Update via RPL2
28. January 2025
In this video you will learn how to create a physical connection before the firmware update, how to use the RPL2 software and how to do a small test after the firmware update.[...]
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Training Video
»REGSys®« Training Video 4: Changing the Default Password
28. January 2025
In this video you will learn how to connect the SCADA card to your computer, start the software WinConfig and change the default password and define a new one.[...]
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