3D Printed Ceramic Winding Assembly for High-Temperature Electrical Machines

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Solution Overview

Problem

Conventional electrical machine windings face temperature limitations due to insulation degradation and partial discharge issues, particularly at high temperatures and with high-frequency PWM applications, leading to reduced lifespan and potential short circuits.

Innovation Solution

A 3D printing method is used to create a winding assembly with a ceramic insulating body and controlled spatial separation between turns, filled with an electrically conducting material, which mitigates partial discharge and enhances heat transfer, allowing for higher temperature operation without cooling systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If polymer-coated wire insulation is used, then flexibility and ease of manufacture are improved, but temperature capability is limited to 220 degrees Celsius maximum

Engineering Contradiction:
Improveease of manufactureVSAvoidtemperature capability
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent applies composite materials by combining ceramic insulation with copper wire to create a winding assembly that achieves both high temperature capability (up to 1000°C) and functional performance. The ceramic material provides thermal stability and insulation properties that polymer coatings cannot achieve, while the copper provides electrical conductivity.

Inventive Principle:
Principle #40Composite materials

2Temperature

If ceramic insulated wires are used, then temperature capability is improved to above 220 degrees Celsius, but flexibility and reliability deteriorate due to cracking and thermal shock

Engineering Contradiction:
Improvetemperature capabilityVSAvoidreliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent applies local quality by providing ceramic insulation specifically where thermal stability is needed (around the copper wire) while accepting that the ceramic itself has brittleness issues. The overall assembly design accounts for ceramic properties by controlling thermal gradients and avoiding rapid heating/cooling cycles that would cause cracking.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the thermal parameter capability by using ceramic insulation with maximum operating temperature of 1000°C compared to polymer insulation limited to 220°C. This parameter change enables high-temperature operation while the patent manages the reliability concerns through controlled thermal management in the manufacturing and operating conditions.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If PWM switching is used to control electrical machines, then power control flexibility is improved, but partial discharge and insulation degradation occur due to voltage overshoot

Engineering Contradiction:
Improvepower control flexibilityVSAvoidinsulation reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by using ceramic insulation that inherently withstands high voltage stress and partial discharge conditions before they occur. The ceramic material's high dielectric strength and thermal stability provide a buffer against the damaging effects of PWM-induced voltage overshoot and repeated electrical stress, preventing insulation degradation before it starts.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Temperature

If active or passive cooling systems are added to maintain wire temperature below 220 degrees Celsius, then temperature control is improved, but device complexity and weight increase

Engineering Contradiction:
Improvetemperature controlVSAvoiddevice complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent applies taking out by removing the need for complex active or passive cooling systems entirely. By extracting the temperature limitation constraint through the use of ceramic insulation capable of withstanding 1000°C, the design eliminates entire subsystems (cooling fans, heat sinks, thermal management electronics) that would otherwise be required to maintain polymer-insulated wires below 220°C.

Inventive Principle:
Principle #2Taking out (Extraction)

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 solution effectively reduces the probability of partial discharge and extends the operational temperature range of electrical machines, enabling high-temperature and high-voltage applications without the need for cooling systems, thus improving the power density and reliability of electrical machines.

Implementation Method 1

forming, by three-dimensional, 3D, printing, an electrically insulating body comprising a channel defining the winding path

Methodology Applied
Scientific Effect3D Printing: 3D Printing

Implementation Method 2

heating the electrically insulating body to a temperature above the melting point of an electrically conducting material; flowing the electrically conducting material through the inlet to the outlet

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

the impedance of the cables leading to the electric motor and the winding itself can be considered as a RLC (resistance, inductance and capacitance) circuit... the overshoots affects the electrical insulation between adjacent turns of the winding

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3836360B1Electrical machine winding assembly
Publication Date: 2023.07.19 ROLLS ROYCE PLC
  • EP3836360B1 patent drawingFigure 1
  • EP3836360B1 patent drawingFigure 2
  • EP3836360B1 patent drawingFigure 3~4

AI summary

A winding assembly (200) for an electrical machine, the winding assembly comprising a monolithic electrically insulating body (202) having a first channel (204) defining a first winding path, the first channel being filled with an electrically conducting material (214), wherein an average spatial separation between first and second turns of the first winding path is larger than an average spatial separation between the second and subsequent turns of the first winding path.