On-Load Tap-Changer Adapter for Resistance-Based Position Signals

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Solution Overview

Problem

Modern on-load tap-changer drives lack a display interface to record positions due to the replacement of old drives with servo drives, making it difficult to connect modern control devices to existing secondary devices that require resistance values for position representation.

Innovation Solution

An adapter device that uses resistors and switches to convert digital signals from modern control devices into resistance values, allowing connection to existing secondary devices without the need for additional resistors in the control device, and supports both types of secondary devices that do or do not require resistance values for position representation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If modern servo drives replace old drive systems, then the on-load tap-changer control becomes more efficient and compact, but the display interface and position recording capability are lost

Engineering Contradiction:
Improvedrive system complexityVSAvoidposition recording capability
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The adapter device serves as an intermediary between the modern control device and existing secondary devices. It receives digital position signals from the control device and converts them into resistance values that existing secondary devices can process, thereby bridging the compatibility gap without requiring replacement of either the control device or secondary devices

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention replaces the mechanical display interface (indicator gear and display) with an electrical signal conversion system. The adapter uses electronic components (resistors and switches) to convert digital signals into resistance values, eliminating the need for mechanical position indication while maintaining compatibility with existing systems

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If resistors are installed in the control device to represent each position, then position representation becomes possible, but the device complexity and cost increase significantly

Engineering Contradiction:
Improveposition representation capabilityVSAvoidcontrol device complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The adapter device segments the position representation function into separate components: the control device generates digital signals, the adapter converts these signals into resistance values using a limited set of resistors and switches, and the secondary device displays the position. This segmentation allows the control device to remain simple while achieving full position representation capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of installing resistors in the control device to represent each position directly, the invention inverts the approach by placing the resistors in the adapter device and using digital signals from the control device to switch them. This reversal transfers the complexity from the control device to the adapter, maintaining control device simplicity

Inventive Principle:
Principle #13The other way round (Inversion)

3Adaptability or versatility

If existing secondary devices are replaced to work with modern control devices, then compatibility is achieved, but the cost and operational disruption increase

Engineering Contradiction:
Improvesystem compatibilityVSAvoidimplementation cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The adapter device provides universal compatibility between modern control devices and existing secondary devices. It can work with various types of secondary devices (displays, voltage regulators, evaluation units) without requiring modifications to either the control device or the secondary device, making it a versatile solution for different system configurations

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The adapter device is installed in advance between the control device and secondary devices to establish compatibility before the system is put into operation. This preliminary action prevents the need for costly replacements or modifications of existing secondary devices, as the adapter pre-adapts the signal interface

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4248474B1Adapter device
Publication Date: 2025.10.01 REINHAUSEN GMBH
  • EP4248474B1 patent drawingFigure 1
  • EP4248474B1 patent drawingFigure 2
  • EP4248474B1 patent drawingFigure 3

AI summary

The invention relates to an adapter device (10) for transmitting positions of an on-load tap changer (1) from a control device (6) to a secondary device (50), comprising: an input (20) for receiving at least one position from the control device (6) of the on-load tap changer (1); - an output (30) to which the position of the on-load tap changer (1) is output; and - at least one resistor (22) and at least one switch (24) which are connected in parallel; wherein: - depending on the position of the on-load tap changer (1), the at least one switch (24) is actuated by the control device (6) and the at least one resistor (22) is switched on or switched off; and - the output position of the on-load tap changer (1) at the output (30) corresponds to the resistance value of the at least one resistor (22) which has been switched on or switched off.