OILTAP® V Motor-Drive Unit Overview

Questions and Answers

What is the primary function of the motor-drive unit in the on-load tap-changer system?

To physically change the oil in the transformer

To adjust the transmission ratio based on operating requirements (correct)

To receive control impulses from various transformers

To initiate a voltage regulation process

Which component directly supports the on-load tap-changer on the transformer?

Cylindrical pressure-proof oil compartment

On-load tap-changer head (correct)

Vertical drive shaft

RS protective relay

In the context of the described system, what is the role of the insulating fluid?

To enhance the efficiency of the motor-drive unit

To prevent electrical surges during operation

To lubricate the bevel gear system

To separate the transformer oil from the tap-changer (correct)

What mechanism is utilized by the on-load tap-changer to change the transmission ratio?

A mechanical diverter switch Signup and view all the answers

Which part is responsible for transmitting control impulses to the motor-drive unit?

Voltage regulator Signup and view all the answers

What is the primary function of the DW 2000 pressure monitoring device?

To protect the on-load tap-changer from excessive pressure Signup and view all the answers

What combination does the on-load tap-changer uniquely provide?

Diverter switch and tap selector Signup and view all the answers

How does the pressure monitoring device detect a pressure increase?

Using a corrugated tube linked with a spring mechanism Signup and view all the answers

What occurs when the pressure monitoring device is tripped?

The circuit breaker is triggered and the transformer is de-energized Signup and view all the answers

How is the on-load tap-changer and motor-drive unit shipped?

In the adjustment position Signup and view all the answers

What does the cylindrical pressure-proof oil compartment do in the system?

Separates insulating fluid from transformer oil Signup and view all the answers

How is the tripping pressure of the pressure monitoring device established?

It is preset at the factory and cannot be changed Signup and view all the answers

What is needed to reset the pressure monitoring device after it has tripped?

Manual intervention to return the switch to initial position Signup and view all the answers

In what way does the pressure monitoring device respond to pressure changes compared to the protective relay?

It responds faster to large pressure increases Signup and view all the answers

What kind of pressures does the DW 2000 monitor?

Both static and dynamic pressures Signup and view all the answers

Where is the pressure monitoring device installed in relation to the on-load tap-changer?

On the outside of the on-load tap-changer Signup and view all the answers

What is the maximum temperature allowed during the vacuum-drying process of the on-load tap-changer?

125 °C Signup and view all the answers

What is the required duration for pre-drying the on-load tap-changer in circulating air?

20 hours Signup and view all the answers

What should be the residual pressure of the on-load tap-changer after the drying process?

10-3 bar Signup and view all the answers

Which step must be performed to avoid damage when securing the on-load tap-changer head cover?

Cleaning sealing surfaces Signup and view all the answers

What temperature increase rate is recommended when heating up the on-load tap-changer?

10 °C/h Signup and view all the answers

What must be ensured regarding the o-ring during the mounting of the head cover?

It must remain undamaged Signup and view all the answers

How should the on-load tap-changer head cover be aligned before securing it?

With red triangular markings aligned Signup and view all the answers

What is the implication of having a missing or damaged o-ring?

It leads to insulating fluid escaping Signup and view all the answers

What is the primary function of the rupture disk mentioned in the content?

To relieve pressure in the oil compartment Signup and view all the answers

Which standard does the rupture disk comply with?

IEC 60214-1 Signup and view all the answers

What is the response mechanism of the MPreC® pressure relief device?

It responds to a defined overpressure Signup and view all the answers

What does the temperature monitoring system track?

Temperature of the insulating fluid in the oil compartment Signup and view all the answers

In what locations are the pressure relief devices located?

In the on-load tap-changer head cover Signup and view all the answers

How does the MPreC® pressure relief device differ from the rupture disk?

It is supplied only upon request Signup and view all the answers

Which component does NOT provide a signaling function?

Rupture disk Signup and view all the answers

Which component is responsible for monitoring the pressure in the system?

MPreC® pressure relief device Signup and view all the answers

What is the maximum allowable speed for drilling when working with the on-load tap-changer?

250 rpm Signup and view all the answers

What action should be taken if an incomplete tap-change operation occurs?

Continue cranking to complete the tap-change operation Signup and view all the answers

In a multiple-column application, what is required for connecting on-load tap-changer heads?

A shared drive using horizontal drive shaft parts Signup and view all the answers

How many revolutions should be cranked after operating the diverter switch to complete the tap-change operation?

2.5 revolutions Signup and view all the answers

What should be done after completing the transformer ratio test?

Switch the on-load tap-changer to adjustment position Signup and view all the answers

What tool can be used for actuating the change-over selector if higher torque is required?

A hand wheel or crank Signup and view all the answers

What should not be exceeded when reaching the end positions while operating the on-load tap-changer?

The limit indicated in the connection diagram Signup and view all the answers

What is the purpose of opening the kerosene drain plug in the oil compartment?

To dry the on-load tap-changer with kerosene Signup and view all the answers

The on-load tap-changer head features 6 pipe connections.

False Signup and view all the answers

Pipe connection Q is intended for connecting the oil filter unit.

True Signup and view all the answers

The functions of the R and Q pipe connections can be interchanged.

True Signup and view all the answers

All pipe bends can be swiveled without loosening the pressure ring.

False Signup and view all the answers

A rupture disk is located outside of the oil compartment.

False Signup and view all the answers

The OILTAP® V on-load tap-changer is designed for a limited number of maximum operating positions.

True Signup and view all the answers

Pipe connection Q has an open connection for the oil filter unit.

False Signup and view all the answers

The upper gear unit is a part of the on-load tap-changer assembly.

True Signup and view all the answers

The on-load tap-changer can switch 3 times the rated through-current $I_r$ at its rated step voltage $U_{ir}$.

False Signup and view all the answers

Only qualified personnel should perform necessary work on the product.

True Signup and view all the answers

The product is designed to operate under direct current conditions with a frequency of 50/60 Hz.

False Signup and view all the answers

The serial numbers of on-load tap-changer accessories must match if supplied as a set in one order.

True Signup and view all the answers

Operating the product contrary to the provided technical file is permissible if conditions allow.

False Signup and view all the answers

The nameplate of the product includes the standard valid for the product and the year of issue.

True Signup and view all the answers

Special tools not included in the scope of delivery may be used for the intended purpose of the equipment.

False Signup and view all the answers

An on-load tap-changer must be operated in accordance with the specified delivery conditions and technical data.

True Signup and view all the answers

The DW 2000 pressure monitoring device operates without any mechanical components.

False Signup and view all the answers

The pressure monitoring device is designed to trip under conditions of low-energy interference.

False Signup and view all the answers

After triggering, the sensor on the snap-action switch must be reset manually to its initial position.

True Signup and view all the answers

The tripping pressure of the pressure monitoring device can be adjusted after installation.

False Signup and view all the answers

The pressure monitoring device is installed inside the oil compartment of the on-load tap-changer.

False Signup and view all the answers

The pressure monitoring device reacts more slowly to pressure increases than the protective relay.

False Signup and view all the answers

A corrugated tube in the pressure monitoring device functions similarly to a barometer.

True Signup and view all the answers

Once tripped, the transformer is immediately re-energized without any manual intervention.

False Signup and view all the answers

The maximum permissible axial offset for the drive shaft is 4°.

False Signup and view all the answers

An intermediate bearing is required when the maximum value of 2472 mm is exceeded.

True Signup and view all the answers

The standard version of the drive shaft includes a cardan joint and an insulator.

False Signup and view all the answers

The middle of the hand crank and the middle of the bevel gear measures 536 mm.

True Signup and view all the answers

The protective cover is a critical component of the drive shaft assembly.

False Signup and view all the answers

A hose clip is used to secure the coupling bracket in the drive shaft system.

False Signup and view all the answers

Crates should be stacked above a height of 1.5 m to ensure stability during transport.

False Signup and view all the answers

The outer marking on the packaging indicates if the on-load tap-changer has been packed upright.

True Signup and view all the answers

Desiccant is added after the plastic foil is bonded around the packaged goods.

False Signup and view all the answers

Sealed packaging surrounds the packaged goods with plastic foil on all sides to enhance protection.

True Signup and view all the answers

It is permissible to stack up to three equally sized crates on top of each other.

False Signup and view all the answers

Adherence to packaging markings is optional for the shipment of non-hazardous goods.

False Signup and view all the answers

The packaging is designed to prevent the parts from touching the loading surface during transportation.

True Signup and view all the answers

Incorrectly stacked crates can lead to damage to the packaged goods during transportation.

True Signup and view all the answers

What is the first step in checking the protective relay before commissioning the transformer?

Ensure that the flap valve is in the OPERATION position Signup and view all the answers

During the testing of the pressure monitoring device, why is it important to ground the transformer on both the high-voltage and low-voltage sides?

To ensure the safety of personnel during testing Signup and view all the answers

Which condition must be satisfied during the pressure monitoring device test to ensure safety?

The transformer needs to remain de-energized Signup and view all the answers

What action should be taken after activating the sensor on the snap-action switch during the passive protection test?

Leave the transformer's danger zone Signup and view all the answers

What is the primary purpose of pressing the OFF test button during the protective relay check?

To confirm the protective relay is functioning Signup and view all the answers

Which operation must be performed to ensure the circuit breaker cannot be closed during the pressure monitoring device check?

Ground the transformer on both sides Signup and view all the answers

What indicates that the sensor on the snap-action switch is in the OFF position?

The sensor requires activation for testing Signup and view all the answers

When testing the transformer, how should the circuit breaker be handled after deactivating the fire extinguishing device?

It must remain open until all tests are complete Signup and view all the answers

What is the consequence of activating the tap-change supervisory device?

The motor-drive unit can no longer be electrically actuated. Signup and view all the answers

What should be checked if the fill level of the insulating fluid has fallen below the minimum?

For leaks in the pipe system and the condition of the insulating fluid. Signup and view all the answers

Which action should be taken after the tripping of the motor protective switch in the motor-drive unit?

Refer to the fault elimination chapter in the operating instructions. Signup and view all the answers

What is strictly prohibited when the transformer is switched on?

Manual operation of the motor-drive unit with the hand crank. Signup and view all the answers

Under what condition must the on-load tap-changer and transformer be checked?

After any tripping event to determine the cause. Signup and view all the answers

What could activation of a rupture disk in the on-load tap-changer head indicate?

Potential pressure malfunction requiring immediate attention. Signup and view all the answers

When addressing a signaling contact that indicates insufficient insulating fluid, what must be prioritized?

Verification of the tap-changer's oil conservator quality. Signup and view all the answers

What is the initial action to be taken when motor-drive unit tripping occurs?

Refer to specific manufacturer fault elimination instructions. Signup and view all the answers

What can result from improper use of insulating fluids in the on-load tap-changer?

Damage to the on-load tap-changer Signup and view all the answers

What is a crucial safety measure when operating the on-load tap-changer?

Ensuring the pressure relief device is fitted if applicable Signup and view all the answers

Which of the following actions is essential to avoid an explosion when using the on-load tap-changer?

Preventing operations outside of permitted conditions Signup and view all the answers

What should be checked before operating the on-load tap-changer?

Whether a pressure relief device is attached if required Signup and view all the answers

What is a significant risk when the on-load tap-changer is overloaded?

Potential for explosion and serious injuries Signup and view all the answers

Which measure can be taken to mitigate the risk of static charge during commissioning?

Using grounded hoses and approved equipment Signup and view all the answers

What must be ensured regarding the on-load tap-changer's operational conditions?

It should adhere to the manufacturer’s specified limits. Signup and view all the answers

What could potentially happen if the on-load tap-changer head cover lacks a pressure relief device?

Possible damage to the on-load tap-changer Signup and view all the answers

Which information is NOT required to be reported to Maschinenfabrik Reinhausen after a protective relay trip?

Temperature of the transformer at tripping Signup and view all the answers

What action should be taken if the pressure monitoring device has been tripped?

Contact Maschinenfabrik Reinhausen for inspection Signup and view all the answers

What should be verified before recommissioning a transformer after an incident?

Both the protective relay and transformer are tested Signup and view all the answers

Why is it important to ensure the on-load tap-changer and transformer are sufficiently tested?

To prevent equipment operation during a fault condition Signup and view all the answers

When referencing the tripping of protective relay, which of the following is NOT a question to ask?

Was the transformer inspected last year? Signup and view all the answers

What potential consequence is indicated for insufficient testing of on-load tap-changer and transformer?

Risk of death or severe injury Signup and view all the answers

After identifying and fixing the cause of a protective relay trip, what is the first step in re-commissioning the transformer?

Check the protective relay Signup and view all the answers

What factor should NOT be ignored when performing the steps after a pressure monitoring device trip?

Performing unnecessary repairs immediately Signup and view all the answers

What potential consequence can result from using spare parts that are not approved by Maschinenfabrik Reinhausen GmbH?

Physical injury and product malfunctions Signup and view all the answers

Which characteristic defines an electrically skilled person in relation to safety and operational standards?

Identifies and avoids potential dangers independently Signup and view all the answers

How should an electrically trained person approach their assigned tasks according to the qualifications expected?

They require initial and continuous instruction from an electrically skilled person Signup and view all the answers

What is an essential requirement for the personnel responsible for assembly, commissioning, and maintenance of the system?

Sufficient qualification and technical training Signup and view all the answers

What role does the electrically skilled person fulfill in terms of compliance with laws and regulations?

Must comply with necessary statutory regulations for accident prevention Signup and view all the answers

What must be confirmed about the electrically skilled person's qualifications when performing electrical work?

They possess knowledge of applicable standards and regulations Signup and view all the answers

Which scenario correctly depicts the guidelines for using spare parts as established by Maschinenfabrik Reinhausen GmbH?

Consulting with Maschinenfabrik Reinhausen GmbH before modifications Signup and view all the answers

What indicates an electrically skilled person's ability to perform tasks related to electrical systems?

Technical qualification and proficiency in identifying dangers Signup and view all the answers

Pictograms provide a warning of dangerous electrical voltage.

True Signup and view all the answers

Multi-step instructions consist of only a single process step.

False Signup and view all the answers

Important information is presented to complicate understanding of procedures.

False Signup and view all the answers

The aim of action is a common component in both single-step and multi-step instructions.

True Signup and view all the answers

A pictogram warning of a danger of crushing is unnecessary in safety instructions.

False Signup and view all the answers

Tables are used to organize information regarding pictograms and instructions.

True Signup and view all the answers

The result of action is only optional in multi-step instructions.

False Signup and view all the answers

Only single-step instructions can include requirements related to the task.

False Signup and view all the answers

The maximum axial offset permissible for the drive shaft without a cardan joint is 3°.

False Signup and view all the answers

An intermediate bearing is required when the length exceeds 2472 mm.

True Signup and view all the answers

The standard version of the drive shaft includes a cardan joint.

False Signup and view all the answers

The middle of the hand crank is located 536 mm from the middle of the bevel gear in the drive shaft configuration.

True Signup and view all the answers

The coupling bracket is one of the components of the drive shaft.

True Signup and view all the answers

The square tube is not a part of the drive shaft assembly.

False Signup and view all the answers

An incompletely bled suction pipe does not affect the insulation capability of the on-load tap changer to ground.

False Signup and view all the answers

The motor-drive unit can operate without the insulating fluid in the oil compartment.

False Signup and view all the answers

Only circuits not stated in the technical data for position transmitter equipment may be connected to the position transmitter module.

False Signup and view all the answers

The vent screw must be opened and closed without bleeding the suction pipe.

False Signup and view all the answers

The selector/de-energized tap changer can operate when it's only partially filled with insulating fluid.

False Signup and view all the answers

Damage can occur to the on-load tap-changer if incorrect circuits are used for the position transmitter.

True Signup and view all the answers

Sealing the vent screw with the screw cap is a final step after ensuring the suction pipe is bled.

True Signup and view all the answers

The on-load tap-changer is designed for infinite maximum operating positions.

False Signup and view all the answers

It is safe to re-commission the transformer without contacting Maschinenfabrik Reinhausen after a protective relay has tripped.

False Signup and view all the answers

The pressure monitoring device can be tripped without any risk of injury if proper testing is not conducted.

False Signup and view all the answers

The transformer can be put back into operation immediately if the reason for the protective relay tripping is unknown.

False Signup and view all the answers

Overvoltages may be registered at the instant of tripping the transformer.

True Signup and view all the answers

The load of the transformer does not need to be reported to Maschinenfabrik Reinhausen when tripping occurs.

False Signup and view all the answers

It is recommended to check the protective relay before commissioning the transformer post-trip.

True Signup and view all the answers

Switching operations in the network can affect the operation of the transformer and should be reported at the time of tripping.

True Signup and view all the answers

Only the protective relay is responsible for the trip condition; no other devices need to be checked.

False Signup and view all the answers

An OF 100 oil filter unit with paper filter insert is recommended for on-load tap-changers that operate less than 15,000 tap-change operations per year.

False Signup and view all the answers

In tropical climates, the OF 100 oil filter unit must be used with a combined filter insert if the highest operating voltage is above 55 kV.

True Signup and view all the answers

The oil compartment of the on-load tap-changer poses no risk of explosion if handled correctly.

False Signup and view all the answers

When designing on-load tap-changers, ensuring the inclusion of an OF 100 oil filter unit is optional regardless of the climate conditions.

False Signup and view all the answers

The recommendation for an OF 100 oil filter unit extends the maintenance intervals for on-load tap-changers.

True Signup and view all the answers

Explosive gases in oil conservators can only develop during the operation of the on-load tap-changer.

False Signup and view all the answers

The use of the OF 100 oil filter unit is not recommended for on-load tap-changers operating in dry climates.

True Signup and view all the answers

In operations above the dew point, dielectric properties of insulating fluid in on-load tap-changers are not affected.

False Signup and view all the answers

Study Notes

Product Description

Motor-drive unit alters the on-load tap-changer's position based on control impulses, optimizing the transformer’s transmission ratio.
On-load tap-changer combines diverter switch and tap selector functions within a tubular design.
Insulating fluid is separated from transformer oil via a cylindrical pressure-proof compartment.
Unit comes shipped in an adjustment position, secure to the transformer via a dedicated head.

Pressure Monitoring Device

DW 2000 device protects against excessive pressure, enhancing transformer safety.
Installed externally, it reacts to static and dynamic pressures in the oil compartment.
Utilizes a corrugated tube with a spring for sensing, linking to a snap-action switch that triggers the circuit breaker if pressure exceeds set levels.
Requires manual reset post-tripping; low-energy interference does not cause false tripping.

Safety Devices

Rupture disk acts as a pressure relief mechanism adhering to IEC 60214-1, positioned on the tap-changer head cover.
Option for MPreC® pressure relief device that also meets IEC standards, available upon request.

Temperature Monitoring

System monitors insulating fluid temperature in the oil compartment, allowing temperature checks via a compatible tool.
Inspection window assists in verifying operating position—excessive overshooting is to be avoided.

Maintenance and Operation

For multiple-column setups, horizontal drive shafts must connect the on-load tap-changer heads.
Specific procedures for movement include cranking the drive shaft post-operation for complete tap-change.
Transformer ratio tests must be conducted in all positions, followed by necessary drying and sealing processes.

Mounting Procedure

Heating protocol includes gradual temperature increase to maximum 110 °C.
Pre-drying should occur at upward of 110 °C for 20 hours, followed by vacuum drying at 105-125 °C for at least 50 hours.
Securing head cover requires careful handling of o-ring and sealing surfaces to prevent insulating fluid leakage.
Proper alignment of markings on head and cover is essential during installation.

Intended Use

Products must be used only with the specified transformer or motor-drive unit listed in the order.
Serial numbers of on-load tap-changer and associated accessories must match when supplied as a set.
Valid standards and issue year can be found on the product's nameplate.
Products should be operated according to the technical file, agreed delivery conditions, and technical data.
Only qualified personnel should perform necessary work on the equipment.
Utilize only equipment and special tools included in the delivery and as specified in technical documents.

Operating Conditions

The on-load tap-changer is designed for sinusoidal 50/60 Hz alternating current.
It can switch 2 times the rated through-current (Ir) at the rated step voltage (Uir).
Key components of the on-load tap-changer are detailed in installation drawings included in the appendix.

Product Description

Reference maximum operating positions for the on-load tap-changer in technical data.
The on-load tap-changer head contains 4 pipe connections for various functions, some fitted with pipe bends at the factory.

Pipe Connections

Pipe connection Q is designated for connecting the oil filter unit, closed with a blank cover.
Functions of pipe connections R and Q can be interchanged.

Pressure Monitoring Device

The DW 2000 device protects the on-load tap-changer from excessive pressure.
It is triggered by static and dynamic pressures in the oil compartment.
Utilizes a corrugated tube and spring mechanism to activate a sensor that de-energizes the transformer when pressure increases.
The device requires manual reset post-tripping and is unaffected by low-energy interference.

Drive Shaft Configuration

Drive shaft without cardan joint or insulator has specific configuration details, including allowable axial offsets.
An intermediate bearing is necessary when shaft lengths exceed specified limits.

Packaging, Transport, and Storage

Incorrect stacking of crates can damage contents, emphasizing the need for following outer packaging instructions.
Crates should not be stacked above 1.5 m; up to 2 equally sized crates can be stacked.
Packaging is designed to comply with transportation laws and includes sturdy crates with protective features against humidity.
Markings provide instructions for safe transport and proper storage adherence.

Spare Parts and Modifications

Consult Maschinenfabrik Reinhausen GmbH before modifying any product.
Non-approved spare parts may cause physical injury, product damage, and malfunctions.
Always use officially approved spare parts for safety and reliability.

Personnel Qualifications

Personnel responsible for assembly, commissioning, operation, maintenance, and inspection must be adequately qualified.
An electrically skilled person possesses technical qualifications, knowledge of standards, and the ability to identify and avoid potential hazards.
Electrically trained persons require guidance from an electrically skilled person regarding their tasks and hazards.

Safety Measures and Procedures

Prevent static charge build-up near transformers during commissioning to mitigate explosion risks.
Use conductive and grounded equipment approved for flammable liquids.
Overloading the on-load tap-changer poses explosion hazards and significant risks of injury and property damage.

Commissioning the Transformer

Only approved insulating fluids should be used in the on-load tap-changer’s oil compartment to prevent damage.
A pressure relief device must be installed if the tap-changer head cover has a flange for it.

Protective Relay and Pressure Monitoring Device Checks

Before commissioning, ensure the protective relay is functioning correctly.
Perform active and passive protection tests by grounding the transformer and checking various states of the circuit breaker and sensor positions.
For pressure monitoring, verify that the transformer is de-energized, and ensure all connections remain intact during testing.

Fault Response and Re-Commissioning

Upon tripping of the pressure monitoring device, immediate consultation with Maschinenfabrik Reinhausen is required to assess potential damages.
Detailed records must be kept regarding the tripping circumstances and any related protective device responses.
Re-commissioning can occur only after verifying the protective relay's functionality and addressing the causes of the trip.

General Warnings

Inadequately tested equipment poses extreme risks of severe injury or death.
Always confirm the integrity of the on-load tap-changer and transformer before resuming operations.

Warning Notices and Pictograms

Pictograms indicate specific dangers: danger points, dangerous electrical voltage, combustible substances, risk of tipping, and crushing hazards.
Information systems in technical files aim to simplify understanding of procedures.

Instruction Systems

Single-step instructions outline aim, optional requirements, one step, and optional results.
Multi-step instructions structure includes aim, optional requirements, sequential steps, and optional results for each step.

Drive Shaft Specifications

Standard version of drive shaft lacks cardan joint and insulator.
Key component dimensions include: middle of hand crank to middle of bevel gear at 536 mm.
Maximum axial offset is 2°; an intermediate bearing is required if exceeded.

Oil Filter Unit Recommendations

For on-load tap-changers with >15,000 operations/year, use OF 100 oil filter unit to extend maintenance intervals.
In humid tropical/subtropical climates, a combined filter insert is needed to maintain dielectric properties under high humidity and low temperatures.

Commissioning Precautions

Danger of explosion is noted related to explosive gases in oil compartments; all ignition sources must be eliminated.
Incomplete bleeding of suction pipes impairs insulation capability; bleeding is essential to ensure operational integrity.

Maintenance and Operational Notices

Ensure on-load tap-changer is fully immersed in insulating fluid to avoid damage; complete filling is critical.
Incorrect connections of position transmitter equipment can damage both the tap-changer and motor-drive unit; use specified circuits only.

Re-commissioning Process

After resolving issues with the protective relay, conduct checks and ensure the transformer can be safely commissioned again.

Fault Elimination Safety Warnings

Tripping of the pressure monitoring device poses serious safety risks; always consult Maschinenfabrik Reinhausen before reusing equipment to confirm safety.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the functionalities of the OILTAP® V motor-drive unit, designed to change the operating position of on-load tap-changers. This unit plays a crucial role in adapting the transformer's transmission ratio according to controlling impulses like those received from a voltage regulator. Gain insights into its engineering and operation principles.