Current-Compensated Choke for Data Network Overvoltage Protection

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Solution Overview

Problem

Existing lightning and overvoltage protection devices for data networks, telephony, and electro-acoustic systems suffer from series inductance that causes power loss in continuous operation and inability to protect against common-mode interference without additional components, with known solutions like BLITZDUCTOR modules being inefficient.

Innovation Solution

The use of a current-compensated choke with a core, featuring a primary and secondary winding connected such that the load current flows in opposite directions, and a semiconductor switching device to divert surge currents during overvoltages, allowing the gas discharge arrester to be ignited effectively while minimizing power loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If series inductance is used for overvoltage protection, then protection against lightning and surge voltages is achieved, but power loss increases during continuous operation

Engineering Contradiction:
Improveovervoltage protectionVSAvoidpower loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies dynamic switching between two inductance configurations: during normal operation, the switch connects the load to the output terminal through a low-inductance path minimizing power loss; during overvoltage events, the switch reconfigures to connect through high-inductance paths for protection. This dynamic reconfiguration resolves the contradiction by adapting the inductance value to operational conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the effective inductance parameter based on operational state. The switchable circuit architecture allows the system to transition between low-inductance mode (for continuous operation with minimal power loss) and high-inductance mode (for overvoltage protection), thereby optimizing the inductance parameter according to real-time requirements.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If additional circuit components are used for common-mode interference protection, then protection capability is improved, but device complexity increases

Engineering Contradiction:
Improvecommon-mode interference protectionVSAvoidcircuit components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent achieves common-mode interference protection using the existing switchable inductance architecture without requiring separate dedicated components. The same switch and inductance elements that provide overvoltage protection also suppress common-mode interference by presenting high impedance to common-mode currents during protection mode, demonstrating multi-functionality that reduces overall device complexity.

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

3Reliability

If gas discharge arresters are used for overvoltage protection, then protection effectiveness is improved, but the arresters cannot be extinguished after overvoltage events

Engineering Contradiction:
Improveovervoltage protection effectivenessVSAvoidarrester operation continuity
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent employs switchable inductance that activates before or during overvoltage events to limit surge current magnitude and duration. By pre-configuring protection paths with appropriate inductance values, the system prevents gas discharge arresters from entering sustained arc states, enabling them to self-extinguish after transient events and maintain operational continuity.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution provides efficient protection against common-mode interference, reduces power loss in continuous operation, and allows for higher current carrying capabilities by quickly saturating the choke core to eliminate inductive coupling, ensuring reliable overvoltage protection with minimal power consumption.

Implementation Method 1

a current-compensated choke with a core (10, 11), having a primary winding (L1) and a secondary winding (L2), in which the load current flows in opposite directions through the windings, so that the magnetic fields cancel each other out

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

gas discharge arresters used must also be able to transmit the system-relevant signal parameters

Methodology Applied
Scientific EffectGas discharge: Townsend Discharge

Data Source

PatentEP3613114B1Lightning and overvoltage protection device for data networks, telephony services, electroacoustic installations or bus systems
Publication Date: 2021.05.05 DEHN SE CO KG
  • EP3613114B1 patent drawingFigure 1a~1b
  • EP3613114B1 patent drawingFigure 2a~2b

AI summary

The invention relates to a lightning and overvoltage protection device for data networks, telephony services, electroacoustic installations or bus systems having at least two grid-side input terminals and at least two output terminals, to which the load that is to be protected can be connected, furthermore having a gas-discharge surge arrester that connects the input terminals and an inductance located between the respective input and output terminal. According to the invention, the inductances are configured as current-compensated inductors having a core and a primary winding and a secondary winding, wherein the load current flows through the windings in different directions so that the respective magnetic fields cancel out. In the event of transient overvoltages, the arising surge current is bypassed by means of a switching device that then closes at one of the two windings, for example the secondary winding, in such a way that, owing to the winding through which current flows, for example the primary winding, the core reaches saturation and the coupling between the windings is released, with the result that no voltage is established across the load and the voltage applied to the winding through which current flows ignites the gas-discharge surge arrester.