IEC 62836:2024 provides an efficient and reliable procedure to test the internal electric field in the insulating materials used for high-voltage applications, by using the pressure wave propagation (PWP) method. It is suitable for a planar and coaxial geometry sample with homogeneous insulating materials of thickness larger or equal to 0,5 mm and an electric field higher than 1 kV\/mm, but it is also dependent on the thickness of the sample and the pressure wave generator. This first edition cancels and replaces IEC TS 62836 published in 2020. This edition includes the following significant technical changes with respect to IEC TS 62836: a) addition of Clause 12 for the measurement of space charge distribution in a planar sample; b) addition of Clause 13 for coaxial geometry samples; c) addition of Annex D with measurement examples for coaxial geometry samples; d) addition of a Bibliography; e) measurement examples for a planar sample have been moved from Clause 12 in IEC TS 62836 to Annex C.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 4<\/td>\n | European foreword Endorsement notice <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 1 Scope 2 Normative references 3 Terms, definitions and abbreviated terms 3.1 Terms and definitions 3.2 Abbreviated terms <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4 Principle of the method <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | Figures Figure 1 \u2013 Principle of the PWP method <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 5 Samples 6 Electrode materials 7 Pressure pulse wave generation <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 8 Set-up of the measurement Figure 2 \u2013 Measurement set-up for the PWP method Figure 3 \u2013 Sample of circuit to protect the amplifier from damage by a small discharge on the sample <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 9 Calibrating the electric field 10 Measurement procedure <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 11 Data processing for experimental measurement <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 13 Impact of coaxial geometry 13.1 Measuring set-up of pressure wave propagation method for the coaxial geometry sample <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 13.2 Physical model in coaxial geometry Figure 4 \u2013 Diagram of the pressure wave propagationmethod set-up for a coaxial sample Figure 5 \u2013 Diagram of wave propagation of PWP for a coaxial geometry sample <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 13.3 Measuring conditions <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 13.4 Calibration of electric field for a coaxial sample 13.4.1 Summary 13.4.2 Linearity verification 13.4.3 Validity verification of the ratio between two current peaks Figure 6 \u2013 Diagram of the propagation of pressure wave on the section of a cylinder <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 13.4.4 Method for retrieving internal electric field from the measured current signal <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | Figure 7 \u2013 Flowchart for the computation of the electric fieldin a coaxial sample from PWP measured currents <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | Annex A (informative)Preconditional method of the original signal forthe PWP method on a planar sample A.1 Simple integration limitation Figure A.1 \u2013 Comparison between practical and ideal pressure pulses <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | A.2 Analysis of the resiliency effect and correction procedure Figure A.2 \u2013 Original signal of the sample free of charge under moderate voltage <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | A.3 Example of the correction procedure on a PE sample Figure A.3 \u2013 Comparison between original and corrected reference signals with a sample free of charge under moderate voltage <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | A.4 Estimation of the correction coefficients Figure A.4 \u2013 Electric field in a sample under voltage with spacecharge calculated from original and corrected signals <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | Figure A.5 \u2013 Geometrical characteristics of the referencesignal for the correction coefficient estimation Figure A.6 \u2013 Reference signal corrected with coefficients graphically obtained and adjusted <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | A.5 MATLAB\u00ae code Figure A.7 \u2013 Electric field in a sample under voltage with space charge calculated with graphically obtained coefficient and adjusted coefficient Table A.1 \u2013 Variants of symbols used in the text <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Annex B (informative)Linearity verification of the measuring system B.1 Linearity verification B.2 Sample conditions B.3 Linearity verification procedure B.4 Example of linearity verification <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Figure B.1 \u2013 Voltage signals obtained from the oscilloscopeby the amplifier with different amplifications Figure B.2 \u2013 Current signals induced by the sample, consideringthe input impedance and the amplification of the amplifier <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Figure B.3 \u2013 Relationship between the measured current peakof the first electrode and applied voltage <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Annex C (informative)Measurement examples for planar plaque samples C.1 Samples C.2 Pressure pulse generation C.3 Calibration of sample and signal Figure C.1 \u2013 Measured current signal under \u22125,8 kV <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | C.4 Testing sample and experimental results C.4.1 Measurement results Figure C.2 \u2013 First measured current signal (< 1 min) Figure C.3 \u2013 Measured current signal after 1,5 h under \u221246,4 kV <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | C.4.2 Internal electric field distribution in the testing sample Figure C.4 \u2013 Measured current signal without applied voltage after 1,5 h under \u221246,4 kV Figure C.5 \u2013 Internal electric field distribution under \u22125,8 kV <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | Figure C.6 \u2013 Internal electric field distributionunder \u221246,4 kV, at the initial state Figure C.7 \u2013 Internal electric field distribution after 1,5 h under \u221246,4 kV <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | C.4.3 Distribution of space charge density in the testing sample Figure C.8 \u2013 Internal electric field distribution withoutapplied voltage after 1,5 h under \u221246,4 kV <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Figure C.9 \u2013 Space charge distribution after 1,5 h under \u201346,4 kV Figure C.10 \u2013 Space charge distribution without applied voltageafter 1,5 h under \u221246,4 kV <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | Annex D (informative)Measurement examples for coaxial geometry samples D.1 Example of linearity verification of coaxial geometry D.1.1 Sample conditions D.1.2 Linearity verification procedure D.1.3 Example of linearity verification <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | D.2 Verification of the current peak area ratio between the outer and inner electrodes D.2.1 Verification principle Figure D.1 \u2013 Measured currents from the LDPE coaxial sampleunder different applied voltages in a few minutes Figure D.2 \u2013 Relationships between the peak amplitude of the measuredcurrent at outer and inner electrodes and applied voltage <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | D.2.2 Example of verification of the current peak area ratio D.3 Testing sample and experimental results D.3.1 Raw results of measurements Figure D.3 \u2013 First measured current signal (< 1 min) for the coaxial sample Table D.2 \u2013 Analysis of ratio between theoretical and measured peak area for measured current signal <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | Figure D.4 \u2013 Measured current signals for the coaxial sample at beginning and after 2 h under \u221290,0 kV Figure D.5 \u2013 Measured current signals for the coaxial sample after 2 h under \u221290,0 kV, and without applied voltage after 2 h under high voltage <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | D.3.2 Electric field distribution in the coaxial sample Figure D.6 \u2013 Internal electric field distribution under \u201322,5 kV for the coaxial sample <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | Figure D.7 \u2013 Internal electric field distribution under \u201390,0 kVfor the coaxial sample, at the initial state Figure D.8 \u2013 Internal electric field distribution after 2 h under \u201390,0 kV <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | D.3.3 Space charge distribution in the coaxial sample Figure D.9 \u2013 Internal electric field distribution withoutapplied voltage after 2 h under \u221290,0 kV <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | Figure D.10 \u2013 Space charge distribution with and withoutapplied voltage after 2 h under \u221290,0 kV <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Measurement of internal electric field in insulating materials. Pressure wave propagation method<\/b><\/p>\n |