Current Transformers Photos








Small 600-V-class window-type CT mounted over a bushing on a 15-kV recloser.






Large 600-V-class window-type CT (slipover)






8.7-kV-class window-type CT with rectangular opening. (Photos courtesy of Kuhlman Electric Corp.)






15-kV wound-type CT cast in epoxy resin. (Photo courtesy of Kuhlman Electric Corp.)






15-kV-class window-type CTs with porcelain sleeve mounted on substation structure.






600-V-class window-type CTs mounted over a 15-kV bus inside a metal enclosure.






High-voltage wound-type CT in combination steel tank, oil, and porcelain construction. (Photo courtesy of Kuhlman Electric Corp.)
 
See More Current Transformers Photos 
Ge Current Transformer
Current Transformer Failed Open Circuited
115kv-Power-Metering-Current Transformer
110 kV Current Transformer
132 KV Current Transformer
Current Transformer Window Medium Voltage
400 KV Current Transformer
 
 Current Transformers Types:
Bushing Type:
 
A bushing current transformer (CT) consists of secondary windings on an annular magnetic core. The core encircles the high-voltage (HV) bushings used on circuit breakers, power transformers, generators, and switchgear. The secondary turns of a bushing CT should be distributed to minimize leakage reactance. Physically, this is accomplished by distributing each section of the tapped secondary winding completely around the circumference of the core. In North American practice, CTs are tapped as per the IEEE and CSA standards [S1, S7], and are referred to as multiratio bushing current transformers, whereas international practice usually provides a 50% secondary tap only.
Bar Type
 
A bar-type CT is of similar construction as a bushing type. These current transformers have a single concentrically placed primary conductor, sometimes permanently built into the CT and provided with the necessary primary insulation. 

Window Type
 
The window-type CT, which is used at medium- and low-voltage equipment, has a magnetic core with a center opening through which a power conductor passes to form the primary turns. The secondary is wound on the core, and in some styles the center assembly is encased in molded insulating material. The core may be annular in shape with a uniformly distributed secondary winding (similar to bushing CT), or rectangular in shape with the secondary winding either distributed or wound on only two legs.


Wound Type

A wound-type CT has a primary winding of one or more turns and a secondary winding on a common core, similar to power transformers. These are commonly used in medium-voltage (MV) and low-voltage (LV) starters. 

Post Type
 
High-voltage CTs for external use need physical height to provide the required phaseto- ground insulation while providing the same insulation level between the primary and secondary windings. Depending on the supplier, these may consist of a single bar or multiple pass, primarily through a series of bar-type cores. In international practice, reconnectable primary tap arrangements are used to series- or parallel-connect two primary (or group of primary) passes through the CT cores; these are also used to provide a half tap ratio without reducing the knee point of the CT.

Auxiliary CT

Auxiliary CTs are sometimes used in the secondary circuits of other types of current transformers to change either, or both, the ratio and the phase angle of the secondary current. Such CTs are used in some electromagnetic designs of transformer differential protections to correct for differences in primary CT ratios to balance the scheme and avoid the need for multiratio CTs on transformer bushings. They can also provide the Wye-Delta connections required, allowing the main CT to be always connected in Wye and not connected to meet the Delta CT connection requirements of the protection of Wye-Delta transformers.

Linear Couplers (Air-Core Mutual Reactors)
 
A linear coupler consists of a toroidal secondary winding on a nonmagnetic annular core. Like the bushing CT, it is designed for mounting on a bushing, with the power conductor forming a single primary turn. The absence of iron eliminates core saturation problems. A linear relationship exists between primary current and secondary voltage.

Optical or Digital CT

Fully digital current and potential transformers have been under development since the early 1970s but only reached commercial service in the late 1990s. These CTs usually convert the current signal into a digital code that can be transmitted via fiber-optic links to the measuring device. Most designs used proprietary protocols to transmit this data, and hence development suffered from not having a universal standard to match the 1 A/5 A interface for the electromagnetic devices.

The instrument optical current transformers (OCT) will bring a new level of accuracy to current instrument transformers. They operate on the principle that the magnetic field created as current flows through a conductor influences the polarization of light on a path encircling that conductor.

The sensor is based on an optic system that has a trusted reputation for accuracy and reliability in industrial applications. The sensor can be column mounted on an advanced polymeric insulating column, or bus mounted with a suspension insulator to bring the optical fiber to ground.

Previous
Next Post »
My photo

Hi, I`m Sostenes, Electrical Technician and PLC`S Programmer.
Everyday I`m exploring the world of Electrical to find better solution for Automation. I believe everyday can become a Electrician with the right learning materials.
My goal with BLOG is to help you learn Electrical.
Related Posts Plugin for WordPress, Blogger...

Label

KITAIFA NEWS KIMATAIFA MICHEZO BURUDANI SIASA TECHNICAL ARTICLES f HAPA KAZI TU. LEKULE TV EDITORIALS ARTICLES DC DIGITAL ROBOTICS SEMICONDUCTORS MAKALA GENERATOR GALLERY AC EXPERIMENTS MANUFACTURING-ENGINEERING MAGAZETI REFERENCE IOT FUNDAMENTAL OF ELECTRICITY ELECTRONICS ELECTRICAL ENGINEER MEASUREMENT VIDEO ZANZIBAR YETU TRANSDUCER & SENSOR MITINDO ARDUINO RENEWABLE ENERGY AUTOMOBILE SYNCHRONOUS GENERATOR ELECTRICAL DISTRIBUTION CABLES DIGITAL ELECTRONICS AUTOMOTIVE PROTECTION SOLAR TEARDOWN DIODE AND CIRCUITS BASIC ELECTRICAL ELECTRONICS MOTOR SWITCHES CIRCUIT BREAKERS MICROCONTROLLER CIRCUITS THEORY PANEL BUILDING ELECTRONICS DEVICES MIRACLES SWITCHGEAR ANALOG MOBILE DEVICES CAMERA TECHNOLOGY GENERATION WEARABLES BATTERIES COMMUNICATION FREE CIRCUITS INDUSTRIAL AUTOMATION SPECIAL MACHINES ELECTRICAL SAFETY ENERGY EFFIDIENCY-BUILDING DRONE NUCLEAR ENERGY CONTROL SYSTEM FILTER`S SMATRPHONE BIOGAS POWER TANZIA BELT CONVEYOR MATERIAL HANDLING RELAY ELECTRICAL INSTRUMENTS PLC`S TRANSFORMER AC CIRCUITS CIRCUIT SCHEMATIC SYMBOLS DDISCRETE SEMICONDUCTOR CIRCUITS WIND POWER C.B DEVICES DC CIRCUITS DIODES AND RECTIFIERS FUSE SPECIAL TRANSFORMER THERMAL POWER PLANT cartoon CELL CHEMISTRY EARTHING SYSTEM ELECTRIC LAMP ENERGY SOURCE FUNDAMENTAL OF ELECTRICITY 2 BIPOLAR JUNCTION TRANSISTOR 555 TIMER CIRCUITS AUTOCAD C PROGRAMMING HYDRO POWER LOGIC GATES OPERATIONAL AMPLIFIER`S SOLID-STATE DEVICE THEORRY DEFECE & MILITARY FLUORESCENT LAMP HOME AUTOMATION INDUSTRIAL ROBOTICS ANDROID COMPUTER ELECTRICAL DRIVES GROUNDING SYSTEM BLUETOOTH CALCULUS REFERENCE DC METERING CIRCUITS DC NETWORK ANALYSIS ELECTRICAL SAFETY TIPS ELECTRICIAN SCHOOL ELECTRON TUBES FUNDAMENTAL OF ELECTRICITY 1 INDUCTION MACHINES INSULATIONS ALGEBRA REFERENCE HMI[Human Interface Machines] INDUCTION MOTOR KARNAUGH MAPPING USEUL EQUIATIONS AND CONVERSION FACTOR ANALOG INTEGRATED CIRCUITS BASIC CONCEPTS AND TEST EQUIPMENTS DIGITAL COMMUNICATION DIGITAL-ANALOG CONVERSION ELECTRICAL SOFTWARE GAS TURBINE ILLUMINATION OHM`S LAW POWER ELECTRONICS THYRISTOR USB AUDIO BOOLEAN ALGEBRA DIGITAL INTEGRATED CIRCUITS FUNDAMENTAL OF ELECTRICITY 3 PHYSICS OF CONDUCTORS AND INSULATORS SPECIAL MOTOR STEAM POWER PLANTS TESTING TRANSMISION LINE C-BISCUIT CAPACITORS COMBINATION LOGIC FUNCTION COMPLEX NUMBERS ELECTRICAL LAWS HMI[HUMANI INTERFACE MACHINES INVERTER LADDER DIAGRAM MULTIVIBRATORS RC AND L/R TIME CONSTANTS SCADA SERIES AND PARALLEL CIRCUITS USING THE SPICE CIRCUIT SIMULATION PROGRAM AMPLIFIERS AND ACTIVE DEVICES BASIC CONCEPTS OF ELECTRICITY CONDUCTOR AND INSULATORS TABLES CONDUITS FITTING AND SUPPORTS CONTROL MOTION ELECTRICAL INSTRUMENTATION SIGNALS ELECTRICAL TOOLS INDUCTORS LiDAR MAGNETISM AND ELECTROMAGNETISM PLYPHASE AC CIRCUITS RECLOSER SAFE LIVING WITH GAS AND LPG SAFETY CLOTHING STEPPER MOTOR SYNCHRONOUS MOTOR AC METRING CIRCUITS APPS & SOFTWARE BASIC AC THEORY BECOME AN ELECTRICIAN BINARY ARITHMETIC BUSHING DIGITAL STORAGE MEMROY ELECTRICIAN JOBS HEAT ENGINES HOME THEATER INPECTIONS LIGHT SABER MOSFET NUMERATION SYSTEM POWER FACTORS REACTANCE AND IMPEDANCE INDUCTIVE RESONANCE SCIENTIFIC NOTATION AND METRIC PREFIXES SULFURIC ACID TROUBLESHOOTING TROUBLESHOOTING-THEORY & PRACTICE 12C BUS APPLE BATTERIES AND POWER SYSTEMS ELECTROMECHANICAL RELAYS ENERGY EFFICIENCY-LIGHT INDUSTRIAL SAFETY EQUIPMENTS MEGGER MXED-FREQUENCY AC SIGNALS PRINCIPLE OF DIGITAL COMPUTING QUESTIONS REACTANCE AND IMPEDANCE-CAPATIVE RECTIFIER AND CONVERTERS SEQUENTIAL CIRCUITS SERRIES-PARALLEL COMBINATION CIRCUITS SHIFT REGISTERS BUILDING SERVICES COMPRESSOR CRANES DC MOTOR DRIVES DIVIDER CIRCUIT AND KIRCHHOFF`S LAW ELECTRICAL DISTRIBUTION EQUIPMENTS 1 ELECTRICAL DISTRIBUTION EQUIPMENTS B ELECTRICAL TOOL KIT ELECTRICIAN JOB DESCRIPTION LAPTOP THERMOCOUPLE TRIGONOMENTRY REFERENCE UART WIRELESS BIOMASS CONTACTOR ELECTRIC ILLUMINATION ELECTRICAL SAFETY TRAINING FILTER DESIGN HARDWARE INDUSTRIAL DRIVES JUNCTION FIELD-EFFECT TRANSISTORS NASA NUCLEAR POWER SCIENCE VALVE WWE oscilloscope 3D TECHNOLOGIES COLOR CODES ELECTRIC TRACTION FEATURED FLEXIBLE ELECTRONICS FLUKE GEARMOTORS INTRODUCTION LASSER MATERIAL PID PUMP SEAL ELECTRICIAN CAREER ELECTRICITY SUPPLY AND DISTRIBUTION MUSIC NEUTRAL PERIODIC TABLES OF THE ELEMENTS POLYPHASE AC CIRCUITS PROJECTS REATORS SATELLITE STAR DELTA VIBRATION WATERPROOF