12-06-2014, 02:32 PM
THEORITICAL & PRACTICAL ASPECTS OF TRANSFORMER
DEFINITION OF TRANSFORMER AS PER STDS
IEC 60076-1 A static piece of apparatus with two or more windings which, by electromagnetic induction, transforms a system
of alternating voltage and current into another system of voltage and current usually of different values and at the same frequency for the purpose of transmitting electrical power. IEEEC57.12.80-2002 A static device consisting of a winding, or two or more coupled windings with or without a magnetic core for introducing mutual coupling between electrical circuits.
WHY TRANSFORMER
To optimize cost of bulk transmission of power from generators to consumers
Reduction in transmission loss
To reduce or increase voltage in ac system
Enables safe supply voltage to consumers
Isolation of two systems for voltage regulation
Basic Components of a Transformer
current conductors – primary & secondary windings
magnetic flux conductor - laminated steel core and also
insulation cooling protection
supporting accessories
AUTO-TRANSFORMERS
Autotransformer is a one winding transformer in which a part of the winding is common to both HV & LV sides.
Used in electrical apparatus testing labs since the voltage can be smoothly and continuously varied.
Resonant transformer
When the primary coil is driven by a periodic source of alternating current, such as a square or sawtooth wave at the resonant frequency, each pulse of current helps to build up an oscillation in the secondary coil. Due to resonance, a very high voltage can develop across the secondary, until it is limited by some process such as electrical breakdown.
These devices are used to generate high alternating voltages, and the current available can be much larger than that from electrostatic machines such as the Van de Graaff generator.
DEFINITION OF TRANSFORMER AS PER STDS
IEC 60076-1 A static piece of apparatus with two or more windings which, by electromagnetic induction, transforms a system
of alternating voltage and current into another system of voltage and current usually of different values and at the same frequency for the purpose of transmitting electrical power. IEEEC57.12.80-2002 A static device consisting of a winding, or two or more coupled windings with or without a magnetic core for introducing mutual coupling between electrical circuits.
WHY TRANSFORMER
To optimize cost of bulk transmission of power from generators to consumers
Reduction in transmission loss
To reduce or increase voltage in ac system
Enables safe supply voltage to consumers
Isolation of two systems for voltage regulation
Basic Components of a Transformer
current conductors – primary & secondary windings
magnetic flux conductor - laminated steel core and also
insulation cooling protection
supporting accessories
AUTO-TRANSFORMERS
Autotransformer is a one winding transformer in which a part of the winding is common to both HV & LV sides.
Used in electrical apparatus testing labs since the voltage can be smoothly and continuously varied.
Resonant transformer
When the primary coil is driven by a periodic source of alternating current, such as a square or sawtooth wave at the resonant frequency, each pulse of current helps to build up an oscillation in the secondary coil. Due to resonance, a very high voltage can develop across the secondary, until it is limited by some process such as electrical breakdown.
These devices are used to generate high alternating voltages, and the current available can be much larger than that from electrostatic machines such as the Van de Graaff generator.