This document discusses testing of transformers. It provides an overview of transformers and their functions in transmission and distribution of electrical energy. It then describes various routine, type, and special tests performed on transformers, including winding resistance measurement, voltage ratio measurement, no-load loss measurement, load loss measurement, insulation resistance measurement, and dielectric tests. It also discusses short-circuit testing procedures and criteria. Temperature rise testing and its limits are also summarized.
Tan delta is the insulation power factor & is equal to the ratio of power dissipated in the insulation in watts to the product of effective voltage & current in volt ampere when tested under sinusoidal voltage.
Testing and Condition Monitoring of Substation EquipmentsSumeet Ratnawat
Testing and condition monitoring of substation equipments,Transformer specifications,Monitoring of Transformer,On-load Tap changer,Overhauling,Tan delta and capacitance,Thermal imaging,Sweep frequency response analysis,Oil analysis of Switchgear elements containing oil,tests on insulating oil,Breaker monitoring,Condition monitoring of CT,Condition monitoring of CVT,Surge Arresters,Condition monitoring of relays.
Tan delta is the insulation power factor & is equal to the ratio of power dissipated in the insulation in watts to the product of effective voltage & current in volt ampere when tested under sinusoidal voltage.
Testing and Condition Monitoring of Substation EquipmentsSumeet Ratnawat
Testing and condition monitoring of substation equipments,Transformer specifications,Monitoring of Transformer,On-load Tap changer,Overhauling,Tan delta and capacitance,Thermal imaging,Sweep frequency response analysis,Oil analysis of Switchgear elements containing oil,tests on insulating oil,Breaker monitoring,Condition monitoring of CT,Condition monitoring of CVT,Surge Arresters,Condition monitoring of relays.
Test done on Power transformers.
Insulation Resistance test, Winding Resistance test, Ratio Measurements, Magnetic balance test, Tan delta test, DIssolved gas analysis for transformer, Sweep frequency response analysis.
This is the presentation I gave during my seventh semester of Electrical Engineering course at NIT Durgapur. It is here for you guys. Make life easier. Cheers! For more information mail me: sdey.enteract@gmail.com
The following topics are covered: components of power distribution systems, fuses, padmounted transformers, pole mounted transformers, vault installed transformers, transformer stations protection, transformer connections, thermometers, pressure relief devices, restricted ground faults, differential protection current transformers connections, overexcitation, inrush current, percentage differential relays, gas relays, characteristics of CTs.
This PPT explains about the circuit breaker, and its types. Then about the need and purpose of the circuit breaker. And finally the testing and types of testing of circuit breakers.
Design factors; Limitations; Modern trends; Electrical
Engineering Materials; Space factor; Choice of Specific
Electric and Magnetic loadings; Thermal Considerations;
Heat flow; Temperature rise; Insulating Materials; Properties;
Rating of Machines; Various Standard Specifications ;
Transformer vector group_test_conditionsSARAVANAN A
Test Conditions for various vector groups commonly under use are listed along with pictorial representation. Assuming the reader has sufficient exposure to transformer winding connections.
Transformer Vector Group Test conditions
YNd1, YNd11, Dyn11, YNyn0and more
Introduction to feedback (block diagram and types of feedback) , Analysis at middle, low and high frequency of multi-stage amplifier with RC coupling and direct coupling, cascade amplifiers-Darlington Pair.
Test done on Power transformers.
Insulation Resistance test, Winding Resistance test, Ratio Measurements, Magnetic balance test, Tan delta test, DIssolved gas analysis for transformer, Sweep frequency response analysis.
This is the presentation I gave during my seventh semester of Electrical Engineering course at NIT Durgapur. It is here for you guys. Make life easier. Cheers! For more information mail me: sdey.enteract@gmail.com
The following topics are covered: components of power distribution systems, fuses, padmounted transformers, pole mounted transformers, vault installed transformers, transformer stations protection, transformer connections, thermometers, pressure relief devices, restricted ground faults, differential protection current transformers connections, overexcitation, inrush current, percentage differential relays, gas relays, characteristics of CTs.
This PPT explains about the circuit breaker, and its types. Then about the need and purpose of the circuit breaker. And finally the testing and types of testing of circuit breakers.
Design factors; Limitations; Modern trends; Electrical
Engineering Materials; Space factor; Choice of Specific
Electric and Magnetic loadings; Thermal Considerations;
Heat flow; Temperature rise; Insulating Materials; Properties;
Rating of Machines; Various Standard Specifications ;
Transformer vector group_test_conditionsSARAVANAN A
Test Conditions for various vector groups commonly under use are listed along with pictorial representation. Assuming the reader has sufficient exposure to transformer winding connections.
Transformer Vector Group Test conditions
YNd1, YNd11, Dyn11, YNyn0and more
Introduction to feedback (block diagram and types of feedback) , Analysis at middle, low and high frequency of multi-stage amplifier with RC coupling and direct coupling, cascade amplifiers-Darlington Pair.
Module 2 ee369 KTU syllabus-high voltage ac generation,resonant circuitsAsha Anu Kurian
Generation of high AC voltages-Testing transformer – single unit testing transformer, cascaded transformer – equivalent circuit of cascaded transformer – generation of high frequency AC voltages- series resonance circuit – resonant transformer – voltage regulation.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
4. Overview
A MODERN TRANSFORMER IS A
COMPLEX ELECTROMAGNETIC
APPARATUS
TRANSFORMERS SERVE FOR
TRANSMISSION AND DISTRIBUTION
OF ELECTRICAL ENERGY
TRANSFORMERS (DISTRIBUTION)
ARE THE LAST MAJOR LINK
BETWEEN UTILITY & CONSUMER
5. Introduction
TRANSFORMERS ARE STATIC
ALTERNATING CURRENT MACHINES
PRINCIPLE IS BASED ON MUTUAL
INDUCTION BETWEEN WINDINGS
THROUGH A COMMON CORE
OIL-IMMERSED AND DRY TYPES
POWER AND DISTRIBUTION TYPES
SPECIAL TYPES
7. Measurement of winding resistance
Measurement of voltage ratio
Polarity test
Measurement of no-load loss & no-load current
Measurement of load-loss & short-circuit impedance
Measurement of insulation resistance
Dielectric tests
Routine tests
8. Measurement of winding resistance
Measurement of voltage ratio
Polarity test
Measurement of no-load loss & no-load current
Measurement of load-loss & short-circuit impedance
Measurement of insulation resistance
Dielectric tests
Temperature-rise test
Type tests
9. Dielectric test
Short-circuit test
Measurement of zero-sequence
impedance of three phase transformers
Measurement of acoustic noise level
Measurement of harmonics of the no-load
current
Measurement of power taken by the fans
& oil pumps
Special tests
10. Dielectric test
Short-circuit test
Measurement of zero-sequence
impedance of three phase transformers
Measurement of acoustic noise level
Measurement of harmonics of the no-load
current
Measurement of power taken by the fans
& oil pumps
Special tests
11. • Separate source voltage withstand test
• Induced over voltage withstand test
• Impulse voltage withstand test
Dielectric test
12. Terminals of windings under test connected to HV terminal of the
source . All other windings, core, frame and tank are earthed.
Duration of test is 60 secs.
Highest system voltage(kV) Power frequency voltage(kV)
1.1 3
3.6 10
7.2 20
12 28
24 50
36 70
52 95
72.5 140
Separate source voltage withstand test
13. This test is useful in determining
layer insulation and inter turn
insulation of windings.
HV is kept open & twice the rated
voltage at twice the rated frequency
is applied to the LV for a duration of
60 secs.
Induced over voltage withstand test
14. Testing facilities
• Impulse generator
• Discharge circuit
• Recording system
• Voltage divider for measurement
Standard Impulse wave
Impulse withstand test
15. Wave shape
Standard wave shape of impulse voltage is
1.2/50µsec.
t1 is the rise time = 1.2µsecs.
t2 is the tail time = 50 µ secs.
Tolerance on t1 is ±30% & ±20% on t2.
Impulse generator
Impulse wave is generated by discharge of
capacitors charged in parallel into a wave shaping
circuit.
19. Oscilograms contd.
Fig 7.3.3 Connection diagram
Generator capacitance 0.0625 uF
Series resistance 160 ohms
Tail resistance 1040 ohms
Voltage divider 1200 pF in parallel with 100 ohms
Impulse applications : (Negative Polarity)
Oscillogram No. 7.3.15. Reduced full wave 43 kV (Peak)
7.3.16. 100% full wave - 75 kV (Peak)
7.3.17. 100% full wave 75 kV (peak)
Comparison of oscillograms 15 & 16 indicates that the second voltage wave
oscillogram has collapsed and the corresponding point of the neutral current
there are high frequency oscillations. This indicates an arc over across major
portion of the transformer winding as a result of failure of the transformer
insulation.
21. MINOR INSULATION -conductor turns,
layers
●
enamel, paper
●
oil ducts, paper cylinders
MAJOR INSULATION- winding, core
●
press board cylinders, oil ducts
BUSHINGS - porcelain , condenser
22. Power & distribution transformers must be constructed to
withstand mechanical stresses caused by external faults.
These stresses are produced due to electromagnetic forces
as a result of very high current in the windings during
short-circuits.
Short-circuit test
23. Prior to the short-circuit, transformer
is subjected to routine tests.
Asymmetrical current
The peak current that transformer is
required to withstand = Isc(peak)=K Isc
Dynamic ability to withstand short-circuit
Value of K :
x/r 1 1.5 2 3 4 5 6 8 10 >14
K 1.51 1.64 1.76 1.95 2.09 2.19 2.27 2.38 2.46 2.55
24. Short-circuit may be
a) Preset or
b) Post set
Duration of each test
being 0.5 sec. ( > 5 MVA 0.25 sec)
For 1φ Transformers
No. of tests = Three
one test with tap at highest voltage ratio, one test in principal taping &
one test in
lowest voltage ratio
Short-circuit testing procedure
25. 3φ Transformers
No. of tests = Nine
Three tests with tap at highest voltage ratio, three
tests in principal taping & three tests in lowest voltage
ratio
Tolerances on
Asymmetrical current = ±5 %
Symmetrical current = ±10 %
Test duration = ±10 %
26. Oscillogram of dynamic short-circuit test on
3Phase 11/0.433kV 500kVA Distribution
transformer
27. All the routine tests shall be repeated
Dielectric test shall be at 75%
Transformer shall be untanked
Reactance measured after s.c. test shall not
differ by more than 2% for circular coils & 7.5%
for non-circular coils.
Analysis of the results
SC Test contd.
28. This is to ascertain that transformer & its cooling arrangements
are effectively designed so that temp. rise of winding & cooling
medium does not exceed the permissible limits.
Temp. rise limits for Dry type transformers
Class of insulation Temp. rise °C
A 50
E 65
B 70
F 90
H 115
C 140
Temperature rise test
29. Temp. rise limits for oil immersed transformers
Part Temp. rise °C
External cooling medium
Air Water
Winding 55 60
(temp.rise by resistance method)
Top oil 50 55
(temp.rise by thermometer method)
30. a) Direct loading
b) Back-to-Back method
c) Short-circuit method
Loading methods
Duration of test
Top oil temperature-rise does not vary more than
10
C/hour during 4 consecutive hourly readings