IEEH

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Designing of Endwinding Corona Protection by help of Simulation

Milan, 09.10.2012 Moyan Wei

Excerpt from the Proceedings of the 2012 COMSOL Conference in Milan

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Milan, 10/23/2012 Slide 2

Outline

1 Introduction and Motivation 2 Simulative approach with COMSOL

3 Conclusion

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 3

1 Introduction and Motivation Field of application – HV Rotating Machines

Milan, 10/23/2012

Endwinding Corona Protection (ECP)

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 4 Milan, 10/23/2012

no ECP

U

x

Conductor

GND CORE

Insulation

This potential jump could lead to discharge, which are harmful to the insulation

with ECP

ECP Control of potential distribution is realized by applying ECP layer onto the coil surface

Problem: ECP causes extra loss and heating

Potential jump at the end of GND

1 Introduction and Motivation Potential Control

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 5 Milan, 10/23/2012

GND ECP

GND ECP

To be clear: • Value of the field strength • Temperature of the Object

Thermal runaway

Study the details of electrical and thermal behavior of ECP

FEM modeling: Electric Current Heat Transfer

1 Introduction and Motivation Overheating of the ECP

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 6 Milan, 10/23/2012

Cu ISO

Heat Transfer: ECP as heat source; initial and ambient temperature: 25°C; convective and radiative cooling.

Electric Current: AC (50Hz Û=31kV), GND

2 Simulative Approach 2D Axisymmetric

ECP

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 7 Milan, 10/23/2012

The inner impedance of the probe has influenced the measure-ment!

2 Simulative Approach Potential Distribution Û=31 kV

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 8 Milan, 10/23/2012

2 Simulative Approach Temperature Distribution 2D Û=31 kV

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 9 Milan, 10/23/2012

Cu strips serve as measuring electrodes, but have different emissivity

2 Simulative Approach Temperature Distribution 2D Û=31 kV

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 10

2 Simulative Approach 3D Modeling

Milan, 10/23/2012

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 11

2 Simulative Approach Temperature Distribution: 3D Û=31 kV

Milan, 10/23/2012

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Slide 12

2 Simulative Approach Temperature Distribution: 3D Û=31 kV

Milan, 10/23/2012

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

• Simulation tools for 2D and 3D were developed • Pre-calculation: Potential distribution • Pre-calculation: Heating effect • Experimental verification • Successfully applied in ECP design

Slide 13 Milan, 10/23/2012

3 Conclusion

Faculty of Electrical and Computer Engineering Institute of Electrical Power Systems and High Voltage Engineering

Thank you for your attention

Slide 14 Milan, 10/23/2012