non linear B-H characteristics
A transformer used to step up or down the value of voltage.
No. A megger's output voltage is not high enough to test the insulation of a high-voltage transformer if, by 'high-voltage transformer ', you mean a distribution transformer or power transformer. Instead, a high-voltage test set or 'pressure tester' (e.g. a 'HiPot' tester) must be used, as these produce far higher voltages.
The core is responsible for the hysteresis losses in a transformer. These are the losses associated with the ease, or otherwise, by which the core is able to become magnetised in one direction, demagnetise and, then, remagnetise in the opposite direction. These days, the type of material used (variations on silicon steel) are about as efficient as possible.
The difference between current transformer and potential transformer is that the secondary of a current transformer can not be open circuited while under service whereas that of the potential transformer an be open circuited without any damage to the transformer.
the auto transformer is the one winding transformer. it ismaily used in practical purpose.
Because aluminium is, in simple terms, 'non-magnetic' and will not support the formation of magnetic flux. 'Soft' ferrousmetals with low reluctance* (i.e. metals such as iron or silicon steel) must be used.[*'reluctance' is equivalent to 'resistance' in an electric circuit]
A pure hydrocarbon/fluorocarbon plastic contains no ferromagnetic material, so it will not be influenced by a magnet. If a plastic is loaded with ferromagnetic material (such as iron particles), then it will be influenced by an electromagnet. Ceramic materials loaded with ferromagentic materials, known as ferrites, are widely used in electrical and electronic equipment.
ferromagnetic
DC current cannot be used in a transformer only AC will work. A transformer needs the continual build and collapse of the magnetic field to keep the iron core from reaching saturation. Only alternating current will transfer power through a transformer.
The magnetic field in an electromagnet is actually produced by the coil of wires with a current running through it. However certain materials, termed 'ferromagnetic' materials concentrate the magnetic flux when a rod of the material is placed within the coil (termed the 'magnetic core'). The most common of materials used for this have been iron based.
There is a laminated iron core for the magnetic field and then a lot of enamelled copper wire. Step-up transformers use the same materials.
A transformer steps the voltage of an electrical power supply up or down. The transformer must be correctly designed for the voltage and current levels that it is intended for. Only ac can be used with a transformer, which is designed to work at a particular frequency.
If you are referring to 'power transformers' used in transmission systems, then the requirements are far too complicated to be answered in this forum. If, on the other hand, you are referring to a 'power transformer' in the sense of a small transformer used to reduce your mains or supply voltage at home, then the volt ampere rating of the transformer must equal or exceed the load requirement. The primary and secondary voltages must match the primary supply voltage and the voltage requirement for the load. Any requirements for earthing (grounding) must be observed.
ferromagnetic material
A transformer used to step up or down the value of voltage.
In general, the lower the frequency of operation, the more weight must be added to the core laminations to avoid magnetic field saturation. This increases the size and weight of the transformer as the frequency decreases.
No. A megger's output voltage is not high enough to test the insulation of a high-voltage transformer if, by 'high-voltage transformer ', you mean a distribution transformer or power transformer. Instead, a high-voltage test set or 'pressure tester' (e.g. a 'HiPot' tester) must be used, as these produce far higher voltages.