RL Transformer Damping Network for DC Bus Resonance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electrical systems with direct current (DC) voltage buses experience resonance and unwanted oscillations due to the combination of capacitors and inductances, which can lead to damage from excessive voltage fluctuations.

Innovation Solution

An electrical damping device is designed to reduce resonance by incorporating resistive-inductive (RL) networks and transformers, which are strategically coupled between the positive and negative terminals of the DC ports to dampen potential resonances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If capacitors are added to the DC voltage bus to reduce AC ripple, then the ripple reduction effect is improved, but resonance and unwanted oscillations occur due to the combination of capacitors and inductances

Engineering Contradiction:
ImproveAC ripple reductionVSAvoidresonance and oscillations
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

A damping network comprising resistive-inductive (RL) circuits is introduced as an intermediary element between the capacitors and the DC voltage bus. This damping network acts as a mediator that dissipates resonant energy through controlled resistance while maintaining the capacitor's ripple filtering capability, thereby eliminating harmful oscillations without sacrificing AC ripple reduction performance

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If inductances are present in the transmission line, then power transmission is enabled, but resonance frequency oscillations are generated when combined with capacitors

Engineering Contradiction:
Improvepower transmissionVSAvoidresonance oscillations
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The inherent inductances of the transmission line, which originally cause harmful resonance when combined with capacitors, are utilized as part of the damping network design. The RL circuits are configured to work with the existing line inductances, converting the harmful resonant effect into a controlled damping mechanism that dissipates energy beneficially while maintaining power transmission capability

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If resonance oscillations occur on the DC voltage bus, then voltage fluctuations exceed design limits, but adding damping components increases device complexity

Engineering Contradiction:
Improvevoltage stabilityVSAvoiddamping device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The damping network is designed with multi-functionality to minimize added complexity. The same RL circuits serve both as damping elements for resonance suppression and as part of the overall power distribution architecture. The network can be integrated into existing bus structures without requiring completely separate damping components, thereby achieving voltage stability while limiting increases in device complexity

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

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

The electrical damping device effectively attenuates resonance and oscillations, preventing damage from voltage fluctuations and ensuring stable operation of the DC voltage bus.

Implementation Method 1

the electrical damping device comprises a positive path that comprises a first resistive-inductive (RL) network in parallel with a second RL network

Methodology Applied
Scientific EffectJoule Heating: Joule Heating

Implementation Method 2

A first transformer is defined by a first inductance of first RL network and a third inductance of the third RL network, wherein the first transformer comprises windings arranged for mutual coupling between the positive path and the negative path

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP4560864A1Electrical damping device for a DC voltage bus
Publication Date: 2025.05.28 DEERE & CO
  • EP4560864A1 patent drawingFigure 1A
  • EP4560864A1 patent drawingFigure 1B
  • EP4560864A1 patent drawingFigure 2

AI summary

An electrical damping device comprises a positive path that comprises a first resistive-inductive (RL) network in parallel with a second RL network, wherein the positive path is coupled between the positive terminals of the DC ports. A negative path comprises a third RL network in parallel with a fourth RL network, wherein the negative path is coupled between the negative terminals of the DC ports. A first transformer is defined by a first inductance of first RL network and a third inductance of the third RL network, wherein the first transformer comprises windings arranged for mutual coupling between the positive path and the negative path. A second transformer is defined by a second inductance of the second RL network and a fourth inductance of the fourth RL network, wherein the second transformer comprises windings arranged for mutual coupling between the positive path and the negative path.