This technical article briefly describes seven very important tests you should perform during commissioning of a dry-type transformer. Usually, tests are performed in the factory where transformers are produced.
This document describes a thesis presented by Durlav Mudbhari to Lehigh University for a Master of Science degree in mechanical engineering. The thesis involved designing and developing an experimental setup to measure unsteady forces and power of functionally graded, chordwise flexible wings. A flapping wing system was created with rigid and flexible regions to model functionally graded materials. Experiments were conducted in a wind tunnel and vacuum chamber to measure thrust production, lift/drag forces, and power consumption of wings with varying flexibility. The goal was to better understand how non-homogeneous flexibility impacts wing performance. Potential applications include more efficient autonomous underwater vehicles and ship propulsion through flexible hydrofoils.
This document provides tips and tricks for measuring the control loop stability of switch-mode power supplies (SMPS) using an oscilloscope. It discusses selecting the right injection point, using an injection transformer for galvanic isolation and injecting a small AC signal. It also covers amplitude profiling of the injected signal, probe selection, measuring stability over various operating conditions like input voltage and load, simulating the converter design, and effects of the input filter on loop stability. The goal is to help users verify loop stability with confidence without requiring an expensive network analyzer.
Pressure Distribution on an Airfoil
The team conducted the experiment to determine the effects of pressure distribution on lift and pitching moment and the behavior of stall for laminar and turbulent boundary layers in the USNA Closed-Circuit Wing Tunnel (CCWT) with an NACA 65-012 airfoil at a Reynolds number of 1,000,000. The airfoil was tested in a clean configuration at angles of attack of 0, 5, 8, 10, and 12 degrees. Tape added to the leading edge tripped the boundary layer, and pressure distributions were taken at 8, 10, and 12 degrees angle of attack. Experimental results showed a suction peak at less than 1% of chord, providing a beneficial test article for contrast between smooth and laminar boundary layer behavior at the stall condition. The maximum lift coefficient for the clean airfoil was 0.9 at 10 degrees angle of attack, and tripped airfoil reached a maximum lift coefficient of 1.03 at 12 degrees angle of attack, a 14% increase. These data were 10% lower than the empirical airfoil data found in Theory of Wing Sections from Abbott and von Doenhoff. Pitching moment coefficient about the quarter chord remained near zero below stall as expected for a symmetrical airfoil, but rapidly became negative after stall for experimental and empirical data. The airfoil exhibited a leading edge stall for both laminar and turbulent boundary layers.
This document is a master's thesis that examines using terahertz spectroscopy to monitor water vapor and carbon monoxide in an industrial gasifier. It describes setting up a terahertz spectrometer with a gas cell, source, and detector to take measurements between 300-500 GHz. Laboratory experiments were conducted to measure water vapor at different humidity levels and temperatures. Field tests were performed to detect water vapor and potentially carbon monoxide in the raw gas from a gasifier. The results showed promise for online monitoring of gases in the harsh environment of a gasifier with a response time of a few minutes.
This thesis contains research work by Alejandro Alonso on the ATLAS experiment at the LHC. The first part focuses on calibrating the Transition Radiation Tracker (TRT) to improve charged particle reconstruction. A calibration technique is developed using cosmic ray and collision data and applied to all ATLAS data. The second part presents three analyses: a study of multiparticle correlations in early ATLAS data, and searches for same-sign top quarks and supersymmetry in collision data, finding results consistent with the Standard Model.
This report summarizes experimental studies of premixed flame structure and propagation in compressible turbulent flows. Major accomplishments include: 1) Development of subsonic and supersonic experimental facilities to generate premixed flows with controllable turbulence over a range of Mach numbers. 2) Characterization of the turbulent flows using diagnostics such as hot-wire anemometry, PIV and OH-PLIF. 3) Analysis of laser-ignited flame kernel growth in the turbulent premixed flows, showing good agreement with low speed studies but deviation with increasing Mach number. The results provide new insight into premixed combustion in highly turbulent compressible conditions.
This thesis examines shallow gas anomalies in the North Sea using AVO analysis and seismic inversion. The author creates a wedge model to estimate the thickness of a thin gas sand detected at 520ms that shows high amplitudes on seismic data. AVO cross-plotting shows the anomaly deviates from the background trend into quadrant III, indicating a Class III gas effect. Tuning curves from the wedge model suggest the anomaly is affected by both gas saturation and tuning effects. Seismic inversion enhances interpretation by showing anomalous low impedance associated with the high amplitude anomaly.
MSc Thesis - Luis Felipe Paulinyi - Separation Prediction Using State of the ...Luis Felipe Paulinyi
This thesis examines flow separation prediction using state-of-the-art turbulence models. Computational fluid dynamics simulations were conducted on the T106 turbine cascade blade geometry using OpenFOAM. Different turbulence models, including explicit algebraic stress models, were assessed and compared to classical models like Spalart-Almaras at Reynolds numbers of 60,000 and 150,000. At the lower Reynolds number, the φ-α-EASM model showed better agreement with experiments and DNS for attached flow regions, but failed to predict separation. Laminar simulations provided better separation prediction due to the low Reynolds number.
This document describes a thesis presented by Durlav Mudbhari to Lehigh University for a Master of Science degree in mechanical engineering. The thesis involved designing and developing an experimental setup to measure unsteady forces and power of functionally graded, chordwise flexible wings. A flapping wing system was created with rigid and flexible regions to model functionally graded materials. Experiments were conducted in a wind tunnel and vacuum chamber to measure thrust production, lift/drag forces, and power consumption of wings with varying flexibility. The goal was to better understand how non-homogeneous flexibility impacts wing performance. Potential applications include more efficient autonomous underwater vehicles and ship propulsion through flexible hydrofoils.
This document provides tips and tricks for measuring the control loop stability of switch-mode power supplies (SMPS) using an oscilloscope. It discusses selecting the right injection point, using an injection transformer for galvanic isolation and injecting a small AC signal. It also covers amplitude profiling of the injected signal, probe selection, measuring stability over various operating conditions like input voltage and load, simulating the converter design, and effects of the input filter on loop stability. The goal is to help users verify loop stability with confidence without requiring an expensive network analyzer.
Pressure Distribution on an Airfoil
The team conducted the experiment to determine the effects of pressure distribution on lift and pitching moment and the behavior of stall for laminar and turbulent boundary layers in the USNA Closed-Circuit Wing Tunnel (CCWT) with an NACA 65-012 airfoil at a Reynolds number of 1,000,000. The airfoil was tested in a clean configuration at angles of attack of 0, 5, 8, 10, and 12 degrees. Tape added to the leading edge tripped the boundary layer, and pressure distributions were taken at 8, 10, and 12 degrees angle of attack. Experimental results showed a suction peak at less than 1% of chord, providing a beneficial test article for contrast between smooth and laminar boundary layer behavior at the stall condition. The maximum lift coefficient for the clean airfoil was 0.9 at 10 degrees angle of attack, and tripped airfoil reached a maximum lift coefficient of 1.03 at 12 degrees angle of attack, a 14% increase. These data were 10% lower than the empirical airfoil data found in Theory of Wing Sections from Abbott and von Doenhoff. Pitching moment coefficient about the quarter chord remained near zero below stall as expected for a symmetrical airfoil, but rapidly became negative after stall for experimental and empirical data. The airfoil exhibited a leading edge stall for both laminar and turbulent boundary layers.
This document is a master's thesis that examines using terahertz spectroscopy to monitor water vapor and carbon monoxide in an industrial gasifier. It describes setting up a terahertz spectrometer with a gas cell, source, and detector to take measurements between 300-500 GHz. Laboratory experiments were conducted to measure water vapor at different humidity levels and temperatures. Field tests were performed to detect water vapor and potentially carbon monoxide in the raw gas from a gasifier. The results showed promise for online monitoring of gases in the harsh environment of a gasifier with a response time of a few minutes.
This thesis contains research work by Alejandro Alonso on the ATLAS experiment at the LHC. The first part focuses on calibrating the Transition Radiation Tracker (TRT) to improve charged particle reconstruction. A calibration technique is developed using cosmic ray and collision data and applied to all ATLAS data. The second part presents three analyses: a study of multiparticle correlations in early ATLAS data, and searches for same-sign top quarks and supersymmetry in collision data, finding results consistent with the Standard Model.
This report summarizes experimental studies of premixed flame structure and propagation in compressible turbulent flows. Major accomplishments include: 1) Development of subsonic and supersonic experimental facilities to generate premixed flows with controllable turbulence over a range of Mach numbers. 2) Characterization of the turbulent flows using diagnostics such as hot-wire anemometry, PIV and OH-PLIF. 3) Analysis of laser-ignited flame kernel growth in the turbulent premixed flows, showing good agreement with low speed studies but deviation with increasing Mach number. The results provide new insight into premixed combustion in highly turbulent compressible conditions.
This thesis examines shallow gas anomalies in the North Sea using AVO analysis and seismic inversion. The author creates a wedge model to estimate the thickness of a thin gas sand detected at 520ms that shows high amplitudes on seismic data. AVO cross-plotting shows the anomaly deviates from the background trend into quadrant III, indicating a Class III gas effect. Tuning curves from the wedge model suggest the anomaly is affected by both gas saturation and tuning effects. Seismic inversion enhances interpretation by showing anomalous low impedance associated with the high amplitude anomaly.
MSc Thesis - Luis Felipe Paulinyi - Separation Prediction Using State of the ...Luis Felipe Paulinyi
This thesis examines flow separation prediction using state-of-the-art turbulence models. Computational fluid dynamics simulations were conducted on the T106 turbine cascade blade geometry using OpenFOAM. Different turbulence models, including explicit algebraic stress models, were assessed and compared to classical models like Spalart-Almaras at Reynolds numbers of 60,000 and 150,000. At the lower Reynolds number, the φ-α-EASM model showed better agreement with experiments and DNS for attached flow regions, but failed to predict separation. Laminar simulations provided better separation prediction due to the low Reynolds number.
Audio Equalization Using LMS Adaptive FilteringBob Minnich
This document describes research into using an adaptive filter with the LMS algorithm for audio equalization. It introduces audio equalization and the problem of frequency response variations between the source and listener. The proposed solution is to use an adaptive filter to adjust for these variations. It then provides details on adaptive filtering and the LMS algorithm. Finally, it describes MATLAB simulations conducted to test the approach, including using white noise as an input signal, simulating signal distortions, and accounting for room delay using cross-correlation.
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This document discusses the design of MEMS resonator systems with integrated readout circuitry. It first describes methods for extracting the threshold voltage of MOSFETs. It then covers the design of a differential amplifier, including determining its transconductance, voltage transfer characteristics, input common mode range, slew rate and frequency response. Next, it examines modeling an electromechanical nanocantilever sensor for mass detection. It provides equations for calculating small mass changes and the snap-in voltage of the cantilever-driver system. Finally, it presents the design process and SPICE simulation of a two-stage operational amplifier.
The document is a master's thesis that describes the development of an integrated underwater acoustic localization and communication modem. A line array transducer was designed and built using piezoelectric elements to enable beamforming capabilities. Algorithms for localization using time difference of arrival and time of arrival were implemented. Digital phase shift keying modulation was used for communication. The modem was tested in a pool environment and showed the ability to localize, communicate, and mitigate echoes through beamforming, although echoes still impacted performance.
This document is the thesis abstract for a master's degree in engineering robotics. It summarizes the development of an integrated underwater acoustic localization and communication modem. A line array transducer was designed and built using piezoelectric elements to enable beamforming for directed transmission and reception. Localization was implemented using time difference of arrival and time of arrival measurements to estimate bearing and range. Digital phase shift keying modulation was used for communication. The modem was tested in a pool, where echo was found to significantly impact performance in some cases. The work included hardware, algorithms for localization and communication, and testing of the integrated system.
This thesis documents the development of non-intrusive optical diagnostic methods using planar laser Rayleigh scattering (PLRS) and OH-based planar laser-induced fluorescence (PLIF) to study ethylene flame dynamics in a laboratory-scale scramjet model. PLRS is used to visualize turbulent structures without combustion, while PLIF images OH radicals to visualize flame structures during transient combustion. Multiple measurement planes are utilized to reconstruct 3D flow physics. Experimental setup details are provided for the scramjet wind tunnel, laser systems, timing circuits and condensed operating manual. Results show PLRS visualizing flow features, PLIF tracking flame structures at different equivalence ratios, and chemiluminescence identifying reaction zones.
Droplet Behaviour and Thermal Separation in Ranque-Hilsch Vortex TubesRaoul Liew
This chapter provides background information on gas separation technologies such as cyclone separators and rotational particle separators. It then introduces the Ranque-Hilsch vortex tube (RHVT) as a device that can produce both hot and cold gas streams from a single inlet stream, as well as potentially separate gas mixtures. The motivation for studying droplet behaviour and thermal separation in the RHVT is presented, with the goal of better understanding its separation capabilities. An overview of the thesis is given which includes theoretical analysis of droplet behaviour, experimental methods and equipment, experimental studies of flow and droplets, energy separation modelling, and a preliminary study of the RHVT as a separator.
Cfd fundamental study of flow past a circular cylinder with convective heat t...Sammy Jamar
This CFD project simulates flow past a heated circular cylinder confined between parallel plates using ANSYS Fluent. It studies the effects of Reynolds number on flow patterns, boundary layer separation angle, heat transfer via conduction and convection, and drag coefficient. Results are validated against experimental data and show increasing convection and better agreement with experiments at higher Reynolds numbers from 0.038 to 10,000. The relationship between Reynolds and Nusselt numbers is determined, indicating their proportional variation and the transition from conduction-dominant to convection-dominant heat transfer with increasing flow velocity.
This thesis analyzes the effect of N2 vibrational energy on flow characteristics in high-speed flight using computational fluid dynamics (CFD). The author validates relaxation models for N2 vibrational energy transfer and compares results with and without including vibrational energy effects. A key finding is that including N2 vibrational energy shows different thermal energy redistribution over a blunt body, with significant impacts on pressure and temperature profiles.
This document discusses dynamic range in spectrum analyzers. It defines dynamic range as the ratio of the largest to smallest signals that can be measured simultaneously. Dynamic range is important because it determines if low-level signals will be visible when large signals are present. The document describes different interpretations of dynamic range, including measurement range, display range, and the effects of mixer compression, internal distortion, and noise. It provides guidance on optimizing measurements by considering factors like preamplifier use, attenuator settings, filters, and noise floor.
The document discusses using electromagnetically induced transparency (EIT) to increase the sensitivity of gravitational wave interferometers. It explores EIT properties through modeling and simulation to determine parameters that theoretically allow high transmission and narrow linewidths suitable for filtering squeezed light. Experimentally, the largest contrast observed was 3.9% with a linewidth of 657 Hz, while the narrowest linewidth was 202 Hz with 0.84% contrast. Both simulation and experimental results are presented and compared.
This document is an internship report describing the development of a fiber-based terahertz time domain spectroscopy system for on-chip analysis using graphene and InGaAs photoconductive switches. The report includes:
1) A description of the experimental setup including fiber optic arms and an original electro-optic probe for detection.
2) Characterization of InGaAs photoswitches including electrical measurements and THz pulse detection.
3) Preliminary investigations of monolayer graphene photoswitches including growth, fabrication, and initial electrical measurements in preparation for THz pump-probe spectroscopy.
The fiber-based approach aims to provide a more robust system compared to free-space tabletop setups
This document is Francesco Volpe's 2003 PhD thesis from Ernst Moritz Arndt University in Greifswald, Germany. The thesis presents a novel diagnostic technique for measuring electron temperature profiles in the W7-AS stellarator plasma above the electron cyclotron emission cutoff density. The technique uses electron Bernstein waves, which are confined within the upper hybrid layers and converted to ordinary mode waves that propagate out of the plasma. An antenna and transmission line were designed and optimized using ray tracing calculations to maximize the conversion efficiency. Experimental results demonstrated measurements of electron temperature profiles, edge localized modes, confinement transitions, and radiative collapses using this diagnostic up to densities of 3.8×1020 m-3. The technique was also
This document summarizes a master's thesis that studied irradiation-induced swelling in two ODS steels. Samples of a 15CRA-3 alloy and a PM2000 alloy were irradiated with helium ions from room temperature to 800°C to a dose of 0.84 dpa with 4000 appm helium/dpa. Surface displacements were measured using white light interferometry. Low swelling was found in both alloys, with the PM2000 showing slightly higher swelling of around 0.8%/dpa at 600°C compared to 0.3%/dpa for 15CRA-3 over the full temperature range. The higher swelling resistance of 15CRA-3 is attributed to its finer
This document describes a dissertation on using nuclear magnetic resonance (NMR) in pulsed high magnetic fields up to 62 Tesla. The author developed an NMR spectrometer that was implemented at the Hochfeld-Magnetlabor Dresden facility. Precise measurements of the time-dependent pulsed magnetic fields were performed using NMR. Advanced NMR experiments were also conducted, including measurements of chemical shift, Knight shift, spin-spin and spin-lattice relaxation rates. Long-time behavior of coupled spin systems was also investigated and described in terms of chaotic dynamics. This work demonstrated applications of NMR in pulsed high magnetic fields to study electronic properties of materials.
screen for expl prop in high pressure vessel_Whitmore Knorr_2007Sara Kotnik
This document summarizes the results of a round-robin test comparing measurements from different laboratories using closed pressure vessel tests (CPVT) to evaluate the explosive properties of organic compounds. The key findings were:
1) There were considerable differences between laboratories in maximum pressure, rate of pressure rise, and event temperature measurements.
2) While numerical criteria proposed in previous studies showed inconsistencies, a strong correlation was observed between each laboratory's results.
3) The authors propose that criteria based on the results of reference materials in each individual laboratory may provide better discrimination than numerical criteria alone. This could allow different testing equipment to be used while leveraging accumulated data.
This thesis proposes a technique called live range splitting to reduce spill code generated during register allocation. It identifies low register pressure regions within live ranges where spill code is not needed. The algorithm computes these regions using Reif and Tarjan's algorithm for symbolic covers. It then finds load and store candidates within the low pressure regions to limit spill code insertion. Experimental results show the approach reduces static spills by up to 25% and dynamic loads by up to 20%, with an average execution time decrease of 2.3% and small increase in register allocation time.
Transformer vector group_test_conditionsSARAVANAN A
The document provides test conditions for various transformer vector groups including YNyn0, YNyn6, Dd0, Dd6, YNd1, YNd11, Dyn11, and Dyn1. For each vector group, 3 measurement conditions are listed that involve measuring voltages between different transformer terminals when voltage is applied to the HV side. The conditions are designed such that satisfying all 3 confirms the vector group by establishing the phase shift between the primary and secondary windings.
Simple Surge Arrester (SA) Testing for Switchyard EquipmentSARAVANAN A
The pre-commissioning test report summarizes surge arrestor testing at a substation. It documents insulation resistance measurements between stacks and earth that met minimum requirements. It also records the surge counter serial number, make, and reading to check operation. Signatures and dates from four people witnessing the tests are provided to verify successful completion.
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This chapter provides background information on gas separation technologies such as cyclone separators and rotational particle separators. It then introduces the Ranque-Hilsch vortex tube (RHVT) as a device that can produce both hot and cold gas streams from a single inlet stream, as well as potentially separate gas mixtures. The motivation for studying droplet behaviour and thermal separation in the RHVT is presented, with the goal of better understanding its separation capabilities. An overview of the thesis is given which includes theoretical analysis of droplet behaviour, experimental methods and equipment, experimental studies of flow and droplets, energy separation modelling, and a preliminary study of the RHVT as a separator.
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2. Page 2 of 43
1. SCOPE 5
2. STANDARDS 6
3. LIGHTNING IMPULSE TEST 7
4. SOUND LEVEL MEASUREMENT 8
4.1. STANDARD 8
4.2. AIM 8
4.3. THEORETICAL PRINCIPAL 9
4.4. MEASUREMENT 10
4.4.1. Measurement chamber............................................................................................................... 10
4.4.2. Tapping position for measurement............................................................................................. 10
4.4.3. Equivalent circuit diagram for a transformer in no-load ............................................................ 10
4.4.4. Test setup.................................................................................................................................... 11
4.4.7. Commonly used measuring devices for measurement ............................................................... 12
4.4.8. Recorded values for the measurement ....................................................................................... 12
4.5. CALCULATIONS TO DETERMINE SOUND LEVEL VALUES 13
4.6. TEST CRITERIA / MAXIMUM VALUES 13
5. MEASUREMENT OF EXCITATION 14
5.1. STANDARD 14
5.2. AIM 14
5.3. MEASUREMENT 14
5.3.1. Tapping position for measurement............................................................................................. 15
5.3.2. Equivalent circuit diagram for a transformer in no-load ............................................................ 15
5.3.3. Test setup.................................................................................................................................... 15
5.3.4. Commonly used measuring devices for measurement ............................................................... 16
5.3.5. Recorded values for the measurement ....................................................................................... 16
5.4. TEST CRITERIA / MAXIMUM VALUES 16
6. DETERMINATION OF THE CAPACITY OF THE WINDINGS AGAINST EARTH AND BETWEEN THE WINDINGS
AS WELL AS LOSS FACTORS (TAN Δ) 17
6.1. STANDARD 17
6.2. AIM 17
6.3. MEASUREMENT 17
6.3.1. Preparing the transformer for the measurement ....................................................................... 18
6.3.2. Test voltage................................................................................................................................. 18
6.3.3. Test frequency............................................................................................................................. 18
6.3.4. Climate conditions....................................................................................................................... 18
6.3.5. Test circuits ................................................................................................................................. 19
6.3.6. Commonly used measuring devices for measurement ............................................................... 20
6.3.7. Recorded values for the measurement ....................................................................................... 20
6.4. TEST CRITERIA / MAXIMUM VALUES 20
7. INSULATION RESISTANCE 21
7.1. STANDARD 21
7.2. AIM 21
7.3. MEASUREMENT 21
7.3.1. Test voltage................................................................................................................................. 21
3. Page 3 of 43
7.3.2. Test setup.................................................................................................................................... 21
7.3.1. Commonly used measuring devices for measurement ............................................................... 22
7.3.2. Recorded values for the measurement ....................................................................................... 22
7.4. TEST CRITERIA / MAXIMUM VALUES 22
8. SWEEP FREQUENCY RESPONSE ANALYSIS (SFRA) 23
8.1. STANDARD 23
8.2. AIM 23
8.3. MEASUREMENT 24
8.3.1. Testing voltage and frequency.................................................................................................... 24
8.3.2. Test setup.................................................................................................................................... 24
8.3.7. Commonly used measuring devices for measurement ............................................................... 26
8.3.8. Recorded values for the measurement ....................................................................................... 26
8.4. TEST CRITERIA / MAXIMUM VALUES 26
9. MEASUREMENT OF ZERO SEQUENCE IMPEDANCE 27
9.1. STANDARD 27
9.2. AIM 27
9.3. MEASUREMENT 27
9.3.1. Testing current and frequency .................................................................................................... 27
9.3.2. Test setup.................................................................................................................................... 27
9.3.3. Commonly used measuring devices for measurement ............................................................... 28
9.3.4. Recorded values for the measurement ....................................................................................... 28
9.4. TEST CRITERIA / MAXIMUM VALUES 28
10. MEASUREMENT OF HARMONICS OF THE NO-LOAD CURRENT IN % OF FUNDAMENTAL COMPONENTS
29
10.1. STANDARD 29
10.2. AIM 29
10.3. MEASUREMENT 29
10.3.1. Tapping position for measurement............................................................................................. 29
10.3.1. Equivalent circuit diagram for a transformer in no-load ............................................................ 29
10.3.2. Test setup.................................................................................................................................... 30
10.3.3. Commonly used measuring devices for measurement ............................................................... 30
10.3.4. Recorded values for the measurement ....................................................................................... 30
10.4. TEST CRITERIA / MAXIMUM VALUES 30
11. MEASUREMENT OF PARTIAL DISCHARGE WITH EARTH 31
11.1. STANDARD 31
11.2. AIM 31
11.3. MEASUREMENT 31
11.3.1. Differences to the routine partical discarge measurement ........................................................ 31
11.3.2. Commonly used measuring devices for measurement ............................................................... 31
11.3.3. Recorded values for the measurement ....................................................................................... 31
11.4. TEST CRITERIA / MAXIMUM VALUES 31
12. APPENDIX 32
12.1. EXAMPLE TEST CERTIFICATE SOUND LEVEL MEASUREMENT 32
12.2. EXAMPLE TEST CERTIFICATE MEASUREMENT OF EXCITATION 33
4. Page 4 of 43
12.3. EXAMPLE TEST CERTIFICATE DETERMINATION OF THE CAPACITY OF THE WINDINGS AGAINST EARTH AND BETWEEN THE
WINDINGS AS WELL AS LOSS FACTORS (TAN Δ) 35
12.4. EXAMPLE TEST CERTIFICATE INSULATION RESISTANCE 36
12.5. EXAMPLE TEST CERTIFICATE SFRA 37
12.6. EXAMPLE TEST CERTIFICATE ZERO SEQUENCE IMPEDANCE 38
12.7. EXAMPLE TEST CERTIFICATE MEASUREMENT OF HARMONICS OF THE NO-LOAD CURRENT IN % OF FUNDAMENTAL
COMPONENTS 39
12.8. EXAMPLE TEST CERTIFICATE MEASUREMENT OF PARTIAL DISCHARGE WITH EARTH 40
12.9. EXAMPLE CALIBRATION LIST 41
12.10. TEST LAB LAYOUT 42
12.11. LIST OF PICTURES, FORMULAS, TABLES AND SOURCES 43
5. Page 5 of 43
Issued by:
Starkstrom-Gerätebau GmbH
Test lab cast resin transformers
Christopher Kammermeier GTTP
Document No.: 02.04.80-11.006 Rev H on 03.03.2020
1. Scope
This is a general test description for cast-resin and dry-type transformers.
Special costumer standards or values are not included.
If not indicated, the description is for a two-winding transformer.
Auxiliary parts of the transformer are also not included, except as indicated e.g. temperature sensors.
The scope of this chapter describes “special” tests, this means the standard does not require these tests.
They are carried out only upon customer request (if applicable).
6. Page 6 of 43
2. Standards
Part 11: Dry-type transformers
IEC 60076-11:2018
Replacement for
DIN EN 60726
(VDE 0532-726):2003-10
with reference to:
IEC 60076-1:2011 Power transformers - General
IEC 60076-3:2013 Insulation levels, dielectric tests and external clearances in air
IEC 60076-10:2016 Determination of sound levels
IEC 60076-16:2011 Transformers for wind turbine application
IEC 60076-18:2012 Measurement of frequency response
IEC 60060-1:2010 High voltage test techniques – General definitions and test requirements
7. Page 7 of 43
3. Lightning impulse test
The lightning impulse voltage test with chopped waves or neutral impulse test is described in the “Test
description for dry-type-transformers for type tests”.
8. Page 8 of 43
4. Sound level measurement
4.1. Standard
IEC 60076-11:2018 clause 14.4.2 // part 10
4.2. Aim
Determination of the guaranteed sound level values e.g.:
➢ LP(A) sound pressure level (A-weighted)
LP = ten times the logarithm to the base 10 of the ratio of the square of the r.m.s. sound pressure to the square
of the reference sound pressure (𝑝0 = 20 ∗ 10−6
𝑃𝑎).
𝐿𝑝 = 10 ∗ log
𝑝2
𝑝02
formula 1: calculation of Lp
➢ LW(A) sound power level (A-weighted)
LW = ten times the logarithm to the base 10 of the ratio of a given r.m.s. sound power to the reference sound
power (𝑤0 = 1 ∗ 10−12
𝑊).
𝐿𝑤 = 10 ∗ log
𝑊
𝑊0
formula 2: calculation of Lw
9. Page 9 of 43
4.3. Theoretical principal
Basically, a measurement at no-load and load is possible.
Due to the sizes of our transformers, the noise level measurement in loaded operation is not performed as it
has no significant influence.
Usually we perform this measurement as:
Measurement of A-weighted sound level by sound pressure method at no load
(based on IEC 60076-10:2016)
This means:
➢ We only measure a sound pressure
➢ A sound power will be calculated using the measured sound pressure
➢ We measure in an A-weighted sound spectrum (see picture below)
➢ We only measure in no-load (excitation) condition
➢ It´s based on standard because we do not use correction factors for the recorded values (the
measurement result would be lower).
picture 1: sound level meter response characteristics for the A, B, and C weighting
10. Page 10 of 43
4.4. Measurement
The measurement of the sound level is made using the same test setup as for the no-load measurement
(chapter for routine tests, clause (6)). It is carried out with the rated voltage UR and the rated frequency fR. The
measurement voltage is applied as close to UR as possible.
The transformer will always be measured at IP00 AN, if applicable also in AF and with the FAN´s alone.
Sound level measurement in an enclosure (e.g. IP21) is a special test and must be ordered separately.
4.4.1.Measurement chamber
The measurement is carried out in a soundproofed chamber (-31 dB(A)).
4.4.2.Tapping position for measurement
It is only necessary to reach the rated turn voltage.
Therefore, the tapping position does not matter. Usually it is the principal tapping position.
4.4.3.Equivalent circuit diagram for a transformer in no-load
picture 2: transformer in no-load
11. Page 11 of 43
4.4.4.Test setup
4.4.5.for supplying
S: electricity supply
T2: transformer to be tested P1: wattmeter
T3: current transformer P2: amperemeter (IRMS)
T4: voltage transformer P3: voltmeter (URMS)
4.4.6.for measuring
Surrounding the transformer, there are 12 microphones at a distance of one meter from the transformer and
located at the middle height of the coils.
picture 3: test setup for measurement of sound level
picture 4: microphones surrounding the transformer
12. Page 12 of 43
4.4.7.Commonly used measuring devices for measurement
measuring
devices
manufacturer type range / accuracy frequency class
Precision
Power
Analyzer
ZIMMER LMG 500 U rms 1000 V / I rms 32 A
U pk 3200 V / I pk 120 A
DC - 10
MHz
0,01-0,03
LV-current-
transf.
H&B Ti 48 2,5-500 A/5 A 50/60 Hz 0,1
HV-voltage-
transf.
epro NVRD 40 2-40 kV/100 V 50/60 Hz 0,02
HV-current-
transf.
epro NCO 60 1-600 A/5 A 50/60 Hz 0,01
12
microphones
G.R.A.S 1/2" freefild
microphone 46AE
CCP-preamplifier
26CA
3,15 Hz - 20 kHz -> ± 2,0 dB
5 Hz - 10 kHz -> ± 1,0 dB
n.a. n.a.
12
datalogging
modules
Heim Systems
GmbH
DATaRec 4 Bandwidth max. 20 kHz
<0.2°
±0.1 % or ±1 mV
n.a. n.a.
table 1: Commonly used measuring devices
4.4.8.Recorded values for the measurement
For each of the 12 microphones the A-weighted sound pressure level LP(A) and a sound spectrum from 0-2kHz is
given (see picture below).
If AF and FAN sound is applicable than we will note the A-weighted sound pressure level LP(A) for this also.
picture 5: sound pressure level sepctrum
13. Page 13 of 43
4.5. Calculations to determine sound level values
The first step is that the average A-weighted sound pressure level LP(A) will be calculated.
𝐿𝑃(𝐴)[𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑢𝑛𝑐𝑜𝑟𝑟𝑒𝑐𝑡𝑒𝑑] = 10 log [
1
𝑁
∑ 100,1𝐿𝑃(𝐴) 𝑖
𝑁
𝑖=1
]
formula 3: calculation of the average A-weighted sound pressure level LP(A)
N = number of microphones
𝐿𝑃(𝐴) 𝑖 = A-weighted sound pressure level LP(A) of microphone no. i
If the measured distance or the guaranteed distance is not 1m, then the A-weighted sound pressure level shall
be LP(A) corrected according the formula from IEC 60076-10:2016.
𝐿𝑃(𝐴)𝑎𝑡 𝑟𝑎𝑡𝑒𝑑 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝐿𝑃(𝐴)𝑎𝑡 𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 − 10 log
𝑆𝑎𝑡 𝑟𝑎𝑡𝑒𝑑 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒
𝑆𝑎𝑡 𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒
formula 4: correction for distance
S = measurement surface
Finally, the calculation of the sound power level LW(A)
𝐿𝑊(𝐴) = 𝐿𝑃(𝐴) + 10 log
𝑆
𝑆0
formula 5: calculation of the sound power level LW(A)
S = measurement surface
S0 = is equal to the reference area (1 m²)
4.6. Test criteria / Maximum values
The guarantee sound level values must be held.
14. Page 14 of 43
5. Measurement of excitation
5.1. Standard
None
5.2. Aim
Determination of the point of core saturation
5.3. Measurement
The measurement of the excitation is made using the same test setup as for the no-load measurement (chapter
for routine tests, clause 6). It is carried out with rated frequency fR and multiple voltages (see below).
percent of rated voltage
(if applicable, due to high core saturation)
table 2: usual voltages for excitation curve
10%
20%
30%
40%
50%
60%
70%
75%
80%
83%
85%
88%
90%
93%
95%
98%
100%
103%
105%
108%
110%
113%
115%
118%
120%
123%
125%
130%
15. Page 15 of 43
5.3.1.Tapping position for measurement
It is only necessary to reach the rated turn voltage.
Therefore, the tapping position does not matter. Usually it is the principal tapping position.
5.3.2.Equivalent circuit diagram for a transformer in no-load
5.3.3.Test setup
S: electricity supply
T2: transformer to be tested P1: wattmeter
T3: current transformer P2: amperemeter (IRMS)
T4: voltage transformer P3: voltmeter (URMS)
picture 6: transformer in no-load
picture 7: test setup for measurement of excitation
16. Page 16 of 43
5.3.4.Commonly used measuring devices for measurement
measuring devices manufacturer type range / accuracy frequency class
Precision Power
Analyzer
ZIMMER LMG 500 U rms 1000 V / I rms 32 A
U pk 3200 V / I pk 120 A
DC - 10 MHz 0,01-0,03
LV-current-transf. H&B Ti 48 2,5-500 A/5 A 50/60 Hz 0,1
HV-voltage-transf. epro NVRD 40 2-40 kV/100 V 50/60 Hz 0,02
HV-current-transf. epro NCO 60 1-600 A/5 A 50/60 Hz 0,01
table 3: Commonly used measuring devices
5.3.5.Recorded values for the measurement
Voltage [V], amperage [A] and losses [W] for all phases (in R.M.S.) are recorded.
The Magnetic flux density [T] is indicated based on the individual test voltages.
5.4. Test criteria / Maximum values
none
17. Page 17 of 43
6. Determination of the capacity of the windings against earth and between
the windings as well as loss factors (tan δ)
6.1. Standard
IEC 60076-1:2011 clause 11.1.2.2 a
6.2. Aim
The purpose of the measurement is to determine the value of the capacity of the windings against earth and
between the windings as well as loss factors (tan δ).
This value can be compared with the measured value after x years or between the factory and installation site.
A difference between the values can occur e.g.: due to changing of the coil position, humidity on the
transformers or aging of the insolating material.
Note: Any change in the climatic conditions will change the measured readings.
6.3. Measurement
The determination of capacity windings-to-earth and between windings shall be made according to IEC 60076-
1:2011 (chapter 11.1.2.2 a) as a routine test for transformers with a Um > 72.5 kV.
For transformers with Um <72.5 kV, the test will only be done at the explicit request of the customer.
The measurement of dissipation factor (tan δ) of the insulation system capacitance is described as special test
according IEC 60076-1:2011 (chapter 11.1.4 c & d).
In the current IEC standard, there is nothing mentioned about this measurement except for its existence. In the
last version of the standard (IEC 60076-1:2000), the following comment was made (see picture below).
picture 8: excerpt from the standard
18. Page 18 of 43
6.3.1.Preparing the transformer for the measurement
➢ For the measurement, all windings have to be shorted.
➢ The mean earth terminal of the transformer has to be connected with the earth of the measurement
device (e.g. frame of CPC 100 + CP TD1).
➢ For three-winding transformers with two LV windings, the two LV terminals should be connected
together. The connection setup shall be used from a two-winding transformer.
➢ If at all possible, the measurement shall be made in the enclosure.
6.3.2.Test voltage
The test voltage should not exceed 80% of the value of the separate-source AC withstand voltage test for the
connected winding.
6.3.3.Test frequency
The test frequency should be the rated transformer frequency.
6.3.4.Climate conditions
The climate conditions shall be noted as accurately as possible
➢ Temperature in °C
➢ Humidity in %
➢ Air-pressure in hPa
19. Page 19 of 43
6.3.5.Test circuits
6.3.5.1. For two-winding transformers
no.: circ.: High voltage connection red lead (A) blue lead (B)
C3 GSTg-A HV (OS) LV (US) n.c.
C2 UST-A HV (OS) LV (US) n.c.
C1 GSTg-A LV (US) HV (OS) n.c.
table 4: circuits for two-winding transformers
For transformers with a shield winding between HV and LV an extra measurement must be made, this is
necessary because the measurement between the windings isn´t possible. The circuit designated C2 will
determine the value of the HV to the shield. The extra circuit C2 is for the value LV to shield.
no.: circ.: High voltage connection red lead (A) blue lead (B)
C2 extra UST-A LV (US) HV (OS) n.c.
table 5: additional circuits for two-winding transformers
picture 9: test setup for capacity measurement at two-winding transformers
20. Page 20 of 43
6.3.5.2. For three-winding transformers
6.3.6.Commonly used measuring devices for measurement
measuring devices manufacturer type range / accuracy frequency class
universal measuring
instrument
Omicron CPC 100
CP TD1
CP SB1
0-400 Hz n.a.
table 7: Commonly used measuring devices
6.3.7.Recorded values for the measurement
The following measured values should be noted:
Circuit
Voltage in kV
Currentsin mA
Losses in W (not necessary)
Tan delta in % (at reference from 10 kV or at testing voltage)
Capacity Cx in pF (at reference from 10 kV or at testing voltage)
6.4. Test criteria / Maximum values
none
no.: circ.: High voltage connection red lead (A) blue lead (B)
C3 UST-A HV (OS) MV (MS) LV (US)
C4 GSTg-A+B HV (OS) MV (MS) LV (US)
C2 UST-B MV (MS) HV (OS) LV (US)
C5 GSTg-A+B MV (MS) HV (OS) LV (US)
C1 GSTg-A+B LV (US) HV (OS) MV (MS)
C6 UST-A LV (US) HV (OS) MV (MS)
table 6: circuits for three-winding transformers
picture 10: test setup for capacity measurement at three-winding transformers
21. Page 21 of 43
7. Insulation resistance
7.1. Standard
None for transformers
7.2. Aim
The purpose of the measurement is to determine the value of the DC resistance of the windings against earth
and between the windings.
This value can be compared with the measured value after x years or between the factory and installation site.
A difference between the values can occur e.g.: due to changing of the coil position, humidity on the
transformers or aging of the insolating material.
Note: Any change in the climatic conditions will change the measured readings.
7.3. Measurement
The largest insulation factor in regard to dry type transformers is the air itself.
During the measurement of the insulation resistance as well as the capacitance measurement, ambient
conditions (ambient temperature, air pressure and Relative Humidity) have a huge significance.
Consideration should be taken that no condensation has formed on/in the transformer.
7.3.1.Test voltage
For windings, the test voltage should be 2,5 kV DC, for insulated core bolts 500 V DC.
7.3.2.Test setup
For this test, the windings shall be tested against earth as well as winding system against winding system
(within the three-phase connection).
e.g. HV to LV // HV to ground // LV to ground
Also, the core bolts will be tested (if applicable). e.g. bolts to ground
picture 11: test setup for insulation resistance
22. Page 22 of 43
7.3.1.Commonly used measuring devices for measurement
measuring devices manufacturer type range / accuracy frequency class
Ins. resist. - meter GOSSEN Metriso 5000 0-4GΩ DC 1,5
table 8: Commonly used measuring devices
7.3.2.Recorded values for the measurement
The following measured values should be noted:
Connection
Voltage in kV DC
Resistance in MΩ or GΩ
7.4. Test criteria / Maximum values
In the standard for dry transformers this test is not required, listed or provided with minimum values.
The minimum insulation resistance can be determined by a rule of thumb. This was valid until 1985 (per volt a
1kOhm).
When tested at the factory, we expect as a minimum value (Un [V] / 1000 + 1) MΩ.
e.g. HV with 15 kV and LV with 690 V
HV = 15 kV corresponds 16 MΩ
LV = 690 V corresponds 1,69 MΩ
Bolts = 0 V corresponds 1 MΩ
23. Page 23 of 43
8. Sweep Frequency Response Analysis (SFRA)
8.1. Standard
IEC 60076-16:2011 Appendix A.4
8.2. Aim
The purpose of the measurement is to be a non-intrusive tool for verifying the geometric integrity of the
transformer.
This graph can be compared with the original graph after x years or between the factory and installation site.
A difference between the values can occur e.g.: due to changing of the coil position, humidity or a turn-to-turn
short on the transformer.
This measurement has more relevance when measuring oil-type transformers, as a dry type transformer can be
physically measured when referencing possible shifting of coils due to transport issues and when assessing a
possible transformer failure such as a winding failure or other damage to the windings themselves, the failure
is generally either possible to diagnose visually or by basic testing procedures.
24. Page 24 of 43
8.3. Measurement
When performing this measurement, it is crucial that the variables are controlled as much as possible as any
deviation from the original measurement will create a deviation on the new performed results. Variables
include, but are not limited to, temperature, humidity, air pressure, the location of the test contacts and the
tightness of the testing contacts. Especially at higher frequencies, the type of grounding is significant for the
results.
8.3.1.Testing voltage and frequency
The testing output voltage is 2.83 Volts and uses a varying frequency, starting at 10 Hz and measures until 20
MHz (possible).
8.3.2.Test setup
8.3.3.Excerpt from the standard IEC 60076-16
With the 3 LV phases short circuited, 3 different ways of HV injection should be considered:
➢ HV phases B and C connected together and LV neutral connected to the ground of transformer. This
case shall be used when the LV neutral is earthed during operation and gives the value of phase A.
➢ HV phases B and C connected together and connected to ground and LV neutral connected to the
ground of transformer. This case is valid to see the difference in case of high voltage system ground
fault and gives the value of phase A.
➢ HV phases B and C connected together and LV neutral not connected. This case shall be used when
the LV neutral is not earthed during operation, Figure A.4 shows this kind of measurement
configuration and gives the value of phase A.
For measurement of the other phases, rotation of the same sequences should be applied.
The following connection diagrams show the above explained case 1
picture 12: HV Injection test figure
25. Page 25 of 43
8.3.4.Measurement between phase 1 and phase 2
picture 13: Measurement between phase 1 and phase 2
Red & Yellow cable: 1U
Blue cable: 1V (1V and 1W are shorted)
LV: 2U, 2V, 2W are shorted (2N is grounded)
Key
1U, 1V, 1W High voltage terminals
2U, 2V, 2W Low voltage terminals
2N is neutral terminal
8.3.5.Measurement between phase 2 and phase 3
picture 14: Measurement between phase 2 and phase 3
Red & Yellow cable: 1V
Blue cable: 1W (1W and 1U are shorted)
LV: 2U, 2V, 2W are shorted (2N is grounded)
Key
1U, 1V, 1W High voltage terminals
2U, 2V, 2W Low voltage terminals
2N is neutral terminal
26. Page 26 of 43
8.3.6.Measurement between phase 3 and phase 1
picture 15: Measurement between phase 3 and phase 1
Red & Yellow cable: 1W
Blue cable: 1U (1U and 1V are shorted)
LV: 2U, 2V, 2W are shorted (2N is grounded)
Key
1U, 1V, 1W High voltage terminals
2U, 2V, 2W Low voltage terminals
2N is neutral terminal
8.3.7.Commonly used measuring devices for measurement
measuring devices manufacturer type range / accuracy frequency class
SFRA Analyzer Omicron FRAnalyzer 20Hz-20MHz AC --
Table 9: Commonly used measuring devices
8.3.8.Recorded values for the measurement
A spectrum from 20Hz-20MHz will be given in the test sheet for Magnitude and Phaseangle. Additional if the
customer wishes, we can supply a “tfra”-file from Omicron with all raw measument data.
8.4. Test criteria / Maximum values
none
27. Page 27 of 43
9. Measurement of zero sequence impedance
9.1. Standard
IEC 60076-1:2011 clause 11.6
9.2. Aim
The purpose of the measurement is to give the impedance based upon the transformer for informative
purposes when designing earth-fault protection and earth-fault current calculations.
9.3. Measurement
The measurement is possible on star or zigzag connected windings. The measurement is carried out by
supplying a current at rated frequency between the three parallel connected phase systems and the neutral
terminal.
9.3.1.Testing current and frequency
The appropriate current shall either be 30% of the nominal current or the maximal available current available
through testing facilities. According to the IEC, the current on the neutral and the duration of application
should be limited to avoid excessive temperatures of metallic constructive parts. The test shall always be
carried out at nominal frequency in nominal tapping position.
9.3.2.Test setup
picture 16: test setup for zero sequence impedance
28. Page 28 of 43
9.3.3.Commonly used measuring devices for measurement
measuring devices manufacturer type range / accuracy frequency class
Precision Power
Analyzer
ZIMMER LMG 500 U rms 1000 V / I rms 32 A
U pk 3200 V / I pk 120 A
DC - 10 MHz 0,01-0,03
LV-current-transf. H&B Ti 48 2,5-500 A/5 A 50/60 Hz 0,1
HV-voltage-transf. epro NVRD 40 2-40 kV/100 V 50/60 Hz 0,02
HV-current-transf. epro NCO 60 1-600 A/5 A 50/60 Hz 0,01
Table 10: Commonly used measuring devices
9.3.4.Recorded values for the measurement
The voltage, current and losses per phase are measured and documented.
9.4. Test criteria / Maximum values
none
29. Page 29 of 43
10. Measurement of harmonics of the no-load current in % of fundamental
components
10.1. Standard
IEC 60076-1:2000 clause 10.6
10.2. Aim
The purpose of the measurement is to give the harmonics of the no-load current in the three phases.
10.3. Measurement
The measurement of the excitation is made using the same test setup as for the no-load measurement (chapter
for routine tests, clause 6). It is carried out with the rated voltage UR and the rated frequency fR.
10.3.1. Tapping position for measurement
It is only necessary to reach the rated turn voltage.
Therefore, the tapping position does not matter. Usually it is the principal tapping position.
10.3.1. Equivalent circuit diagram for a transformer in no-load
picture 17 transformer in no-load
30. Page 30 of 43
10.3.2. Test setup
S: electricity supply
T2: transformer to be tested P1: wattmeter
T3: current transformer P2: amperemeter (IRMS)
T4: voltage transformer P3: voltmeter (URMS)
10.3.3. Commonly used measuring devices for measurement
measuring devices manufacturer type range / accuracy frequency class
Precision Power
Analyzer
ZIMMER LMG 500 U rms 1000 V / I rms 32 A
U pk 3200 V / I pk 120 A
DC - 10 MHz 0,01-0,03
LV-current-transf. H&B Ti 48 2,5-500 A/5 A 50/60 Hz 0,1
HV-voltage-transf. epro NVRD 40 2-40 kV/100 V 50/60 Hz 0,02
HV-current-transf. epro NCO 60 1-600 A/5 A 50/60 Hz 0,01
Table 11: Commonly used measuring devices
10.3.4. Recorded values for the measurement
The harmonics of the no-load current in the three phases are measured and the magnitude of the harmonics is
expressed as a percentage of the fundamental component.
10.4. Test criteria / Maximum values
none
picture 18: test setup for measurement of harmonics of the
no-load current in % of fundamental components
31. Page 31 of 43
11.Measurement of partial discharge with earth
11.1. Standard
IEC 60076-11:2018 clause 14.4.1
11.2. Aim
Partial discharge measurement of single-phase line-to-earth fault condition.
This special test is for transformers connected to systems which are isolated or earthed
through a high value impedance and which can continue to be operated under a single phase
line-to-earth fault condition.
11.3. Measurement
For detailed information on the partical discarge measurement and the measurement environment, please see
(chapter for routine tests, clause 10).
11.3.1. Differences to the routine partical discarge measurement
A phase-to-phase voltage of 1,3 Ur shall be induced for 30 s, with one line terminal earthed, followed without
interruption by a phase-to-phase voltage of Ur for 3 min during which the partial discharge shall be measured.
This test shall be repeated with another line terminal earthed.
picture 19: measurement of partial discharge with earth
All other criteria refer to routine partical discarge measurement.
11.3.2. Commonly used measuring devices for measurement
measuring devices manufacturer type range / accuracy frequency class
PD-measurement
system
Omicron MCU502
4xMPD600
3xMPP600
500 fC - 3nC 0 - 32 MHz 0,01-0,03
Table 12: Commonly used measuring devices
11.3.3. Recorded values for the measurement
The background level and the maximum PD values within the 180 sec. for all phases in [pC], are then recorded
in the test protocol.
11.4. Test criteria / Maximum values
The partial discharge level is allowed a maximum of 10pC with correction factor.
32. Page 32 of 43
12.Appendix
12.1. Example test certificate Sound level measurement
33. Page 33 of 43
12.2. Example test certificate measurement of excitation
35. Page 35 of 43
12.3. Example test certificate determination of the capacity of the windings against
earth and between the windings as well as loss factors (tan δ)
36. Page 36 of 43
12.4. Example test certificate Insulation resistance
37. Page 37 of 43
12.5. Example test certificate SFRA
Note: Omicron FRAnalyzer software (freeware) is required to open the raw data file.
38. Page 38 of 43
12.6. Example test certificate zero sequence impedance
39. Page 39 of 43
12.7. Example test certificate Measurement of harmonics of the no-load current in % of
fundamental components
40. Page 40 of 43
12.8. Example test certificate Measurement of partial discharge with earth
42. Page 42 of 43
12.10. Test lab layout
picture 20: test lab layout
picture 21: routine and heat rise bays
picture 22: PD and sound chamber
43. Page 43 of 43
12.11. List of pictures, formulas, tables and sources
LIST OF PICTURES:
PICTURE 1: SOUND LEVEL METER RESPONSE CHARACTERISTICS FOR THE A, B, AND C WEIGHTING 9
PICTURE 2: TRANSFORMER IN NO-LOAD 10
PICTURE 3: TEST SETUP FOR MEASUREMENT OF SOUND LEVEL 11
PICTURE 4: MICROPHONES SURROUNDING THE TRANSFORMER 11
PICTURE 5: SOUND PRESSURE LEVEL SEPCTRUM 12
PICTURE 6: TRANSFORMER IN NO-LOAD 15
PICTURE 7: TEST SETUP FOR MEASUREMENT OF EXCITATION 15
PICTURE 8: EXCERPT FROM THE STANDARD 17
PICTURE 9: TEST SETUP FOR CAPACITY MEASUREMENT AT TWO-WINDING TRANSFORMERS 19
PICTURE 10: TEST SETUP FOR CAPACITY MEASUREMENT AT THREE-WINDING TRANSFORMERS 20
PICTURE 11: TEST SETUP FOR INSULATION RESISTANCE 21
PICTURE 12: HV INJECTION TEST FIGURE 24
PICTURE 13: MEASUREMENT BETWEEN PHASE 1 AND PHASE 2 25
PICTURE 14: MEASUREMENT BETWEEN PHASE 2 AND PHASE 3 25
PICTURE 15: MEASUREMENT BETWEEN PHASE 3 AND PHASE 1 26
PICTURE 16: TEST SETUP FOR ZERO SEQUENCE IMPEDANCE 27
PICTURE 17 TRANSFORMER IN NO-LOAD 29
PICTURE 18: TEST SETUP FOR MEASUREMENT OF HARMONICS OF THE NO-LOAD CURRENT IN % OF FUNDAMENTAL COMPONENTS 30
PICTURE 19: MEASUREMENT OF PARTIAL DISCHARGE WITH EARTH 31
PICTURE 22: TEST LAB LAYOUT 42
PICTURE 23: ROUTINE AND HEAT RISE BAYS 42
PICTURE 24: PD AND SOUND CHAMBER 42
LIST OF FORMULAS:
FORMULA 1: CALCULATION OF LP 8
FORMULA 2: CALCULATION OF LW 8
FORMULA 3: CALCULATION OF THE AVERAGE A-WEIGHTED SOUND PRESSURE LEVEL LP(A) 13
FORMULA 4: CORRECTION FOR DISTANCE 13
FORMULA 5: CALCULATION OF THE SOUND POWER LEVEL LW(A) 13
LIST OF TABLES:
TABLE 1: COMMONLY USED MEASURING DEVICES 12
TABLE 2: USUAL VOLTAGES FOR EXCITATION CURVE 14
TABLE 3: COMMONLY USED MEASURING DEVICES 16
TABLE 4: CIRCUITS FOR TWO-WINDING TRANSFORMERS 19
TABLE 5: ADDITIONAL CIRCUITS FOR TWO-WINDING TRANSFORMERS 19
TABLE 6: CIRCUITS FOR THREE-WINDING TRANSFORMERS 20
TABLE 7: COMMONLY USED MEASURING DEVICES 20
TABLE 8: COMMONLY USED MEASURING DEVICES 22
TABLE 9: COMMONLY USED MEASURING DEVICES 26
TABLE 10: COMMONLY USED MEASURING DEVICES 28
TABLE 11: COMMONLY USED MEASURING DEVICES 30
TABLE 12: COMMONLY USED MEASURING DEVICES 31
list of sources:
➢ D.J. Kraaij - Die Prüfung von Leistungstransformatoren
➢ Wikipedia
➢ IEC