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When the curent Is in the secundary for the highervalues Ip in the primary coil are not equal proportional than for the lower curent. Is/Ip for lower values is for exemple 100 Is/Ip for higher values are for exemple 70
The reason is the magnetique flux saturation in the closed iron core.
Roger
What else can I help you with?
What causes saturation in a welding transformer?
what causes saturation in welding machine
How is transformer saturation avoided in class B push pull amplifier operation?
In class B amplifier no DC biasing required, thus lack of of DC current in inpunt and load, saturation of core avoided
Why transformers take high input current at start?
Inrush current is a result of core saturation. The magnetic flux in the core of a transformer is 90 degrees out of phase with the voltage. Ideally the transformer switching device will be closed at a peak voltage, and the transformer core will have no residual flux from the last close. If this occurs, the flux in the core in the first cycle will be no larger than it normally would be. If the switching device closes at a zero voltage, or there is some residual flux, the transformer's core will be driven into partial saturation within the first cycle, unless it has been oversized to prevent saturation. Decreasing the applied voltage at energization will keep this from occuring. One method is to use pre-insertion resistors which cause a voltage drop to the transformer that is significant enough to prevent saturation within the first few cycles, and then they are removed. Another method is to de-engerize the transformer core, and close at voltage peaks only (controlled closing).
What factor cause spill current on external fault in case of transformer differential protection?
Spill current during an external fault in transformer differential protection is primarily caused by the unequal impedance in the transformer windings and the connected power system. When an external fault occurs, the fault current flowing through the transformer can create a differential current between the primary and secondary windings due to their differing voltage drops and phase shifts. Additionally, the presence of harmonics and the effects of CT (current transformer) saturation can further contribute to this spill current, complicating the differential relay's ability to distinguish between internal and external faults.
How is current controlled in welding transformer?
in welding machine, the transformer used is basically a current transforrmer. so by changing the tap of secondary side of transformer, we can increase or decrease the current in the transformer.
What type of current must be used with a transformer?
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.
What causes saturation in a welding transformer?
what causes saturation in welding machine
What has the author David John Corns written?
David John Corns has written: 'Current transformer saturation and the effect on protective devices'
What is mean core saturation?
Core saturation occurs in electrical transformers when the magnetic flux in the core reaches its maximum limit, resulting in a decrease in efficiency and potential overheating. It can be caused by excessive current or voltage in the transformer, leading to distortion in the output waveform and potential damage to the transformer.
How is transformer saturation avoided in class B push pull amplifier operation?
In class B amplifier no DC biasing required, thus lack of of DC current in inpunt and load, saturation of core avoided
What will happen if transformer are connected to dc supply?
It will get core saturation
Why transformers take high input current at start?
Inrush current is a result of core saturation. The magnetic flux in the core of a transformer is 90 degrees out of phase with the voltage. Ideally the transformer switching device will be closed at a peak voltage, and the transformer core will have no residual flux from the last close. If this occurs, the flux in the core in the first cycle will be no larger than it normally would be. If the switching device closes at a zero voltage, or there is some residual flux, the transformer's core will be driven into partial saturation within the first cycle, unless it has been oversized to prevent saturation. Decreasing the applied voltage at energization will keep this from occuring. One method is to use pre-insertion resistors which cause a voltage drop to the transformer that is significant enough to prevent saturation within the first few cycles, and then they are removed. Another method is to de-engerize the transformer core, and close at voltage peaks only (controlled closing).
What factor cause spill current on external fault in case of transformer differential protection?
Spill current during an external fault in transformer differential protection is primarily caused by the unequal impedance in the transformer windings and the connected power system. When an external fault occurs, the fault current flowing through the transformer can create a differential current between the primary and secondary windings due to their differing voltage drops and phase shifts. Additionally, the presence of harmonics and the effects of CT (current transformer) saturation can further contribute to this spill current, complicating the differential relay's ability to distinguish between internal and external faults.
Why the transformers input current is non sinusoidal?
The input current of a transformer is non-sinusoidal primarily due to the presence of non-linear loads connected to the transformer, which introduce harmonics into the system. Additionally, the transformer itself can exhibit non-linear characteristics, especially when operating near saturation or under varying loads. These factors result in a distorted current waveform that deviates from a pure sinusoidal shape, leading to increased losses and potential overheating in the transformer and connected equipment.
What is the affect of core saturation upon turns ratio of a transformer?
Electrical Engineering
What is a c200 current transformer?
This is a class of current transformers, and is a fairly low class. This has to do with what kind of burden can be placed on the secondary. A general rule is a C200 current transformer can supply ~200 volts at full ratio to its' secondary. If the burden (the CT resistance + cable resistance + relay or instrument resistance) times the maximum expected current is higher than 200 volts, the CT is likely to saturate. During multiple fault events, a CT may keep some magnetizing current causing CT saturation to be higher on a reclose event. Typically CT's are sized and their ratios are chosen to minimize saturation when feasible.
How is current controlled in welding transformer?
in welding machine, the transformer used is basically a current transforrmer. so by changing the tap of secondary side of transformer, we can increase or decrease the current in the transformer.
