Superconducting DC Cable Layout for Medium-Voltage Power Transfer

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing power transmission systems face challenges in providing efficient, cost-effective, and clear power transmission, especially for high current DC loads and integrating energy storage systems, due to the large difference in characteristic voltages and the need for multiple conversion steps.

Innovation Solution

The use of superconducting DC cables and units for medium voltage (100 kV or less) power transmission, integrating energy storage systems, and reducing intermediate conversion steps, with a cryogenic cooling unit for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional AC power transmission is used, then the system can operate at high voltage, but transmission losses increase and efficiency decreases

Engineering Contradiction:
Improvetransmission lossVSAvoidtransmission efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent changes the fundamental parameters of power transmission by using DC instead of AC, operating at medium voltage (100 kV or less) instead of high voltage, and utilizing superconducting cables to achieve zero resistance. This parameter transformation enables lossless transmission while maintaining system productivity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs superconducting materials with zero electrical resistance to create transmission cables that eliminate resistive losses. This composite material approach combines superconducting properties with cryogenic cooling systems to achieve efficient power transmission without energy loss.

Inventive Principle:
Principle #40Composite materials

2Adaptability or versatility

If multiple conversion steps are used to integrate energy storage systems, then voltage matching is achieved, but system complexity and cost increase

Engineering Contradiction:
Improveintegration capabilityVSAvoidnumber of conversion steps
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the intermediate conversion steps (rectifiers, inverters, transformers) that normally complicate the integration of energy storage systems. By using superconducting DC cables operating at medium voltage, the system directly connects power sources, storage systems, and loads without requiring multiple voltage conversion stages.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The superconducting DC unit serves multiple functions simultaneously: it transmits power, integrates energy storage systems, and provides voltage matching capability, replacing what would traditionally require separate conversion devices. This multi-functionality reduces overall system complexity while maintaining adaptability.

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

3Loss of energy

If superconducting DC cables are used for medium voltage transmission, then transmission efficiency improves and losses reduce, but cooling infrastructure is required

Engineering Contradiction:
Improvetransmission lossVSAvoidcooling infrastructure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent merges the cooling infrastructure with the transmission cable system itself, integrating the cryogenic cooling unit directly with the superconducting DC cables. This combination creates a unified system where the cooling requirement becomes part of the transmission solution rather than a separate complexity burden.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables efficient, cost-saving power transmission with reduced losses and converter volume, allowing integration of high power DC loads and energy storage systems, particularly in densely built areas, and reducing engineering costs.

Implementation Method 1

a superconducting DC cable (4) that electrically connects the power source (1) and the power load (2) for DC high power transmission

Methodology Applied
Scientific EffectSuperconductivity: Superconductivity

Implementation Method 2

a cryogenic cooling unit (7) that is coupled to the superconducting DC unit (2) for cooling

Methodology Applied
Scientific EffectCryogenic cooling: Cryogenics

Data Source

PatentEP4607735A1Electrical power transmission system
Publication Date: 2025.08.27 HITACHI ENERGY LTD
  • EP4607735A1 patent drawingFigure 1
  • EP4607735A1 patent drawingFigure 2
  • EP4607735A1 patent drawingFigure 3

AI summary

An electrical power transmission system (100) comprises a power source (1) for supplying power, a power load (3) that requires electrical power for operation, and a superconducting DC unit (2) that comprises one or more superconducting DC cables (4) and that electrically connects the power source (1) and the power load (3) for DC high power transmission such that the system (100) is operatable at a medium voltage in a range of 100 kV or less.