What is an Isolation transformer and how is it useful in power system

What is a Transformer

Transformers is used in power system which is capable to step up the power generated at low voltages to extra high voltages for transmission over long distances and then it could be transformed at low voltages In order to utilize it at load centers. It can transform power from one circuit to another by stepping up or down the primary voltage without any change in frequency.

Current in the primary winding will create a varying magnetic flux in the core of the transformer and thus it will create a varying magnetic field in the secondary windings and this is done by mutual inductance

What is an Isolation transformer

An isolation transformer can be used to transfer electrical power from an alternating current source to a device and the device will be isolated from the power source. It can provide galvanic isolation to the electrical system

Any transformer which is used to transfer signals or power is isolating because the primary or secondary is not connected by conductors instead of that it is done by induction. The transformers which have its main function to isolate circuits can be called as isolation transformers

In isolation transformer, the primary voltage value will be equal to the secondary voltage and the two windings will have the same number of turns to compensate for losses

Advantages of isolation transformer

  • It can be used to protect people against the dangers of electric shocks
  • It can block the transmission of DC signal from one circuit to the other and allows AC signals to pass
  • It can block interference caused by ground loops
  • Isolation transformers with an electrostatic shield can be used for the power supplies of sensitive equipment

How to do double isolation

Double isolation can be done by putting a metallic safety shield between the primary and the secondary windings and then connecting it to the ground. So if the isolation breaks the electricity will flow to the ground and thus provides electrical safety the shield

Another method of double isolation is by using reinforced insulation and this type of insulation is made up of multiple layers, so if one layer breaks the next layer will provide the required safety

Applications of an isolation transformer

  • It can be used as a power supply for sensitive equipment like medical and laboratory equipment
  • It can be used to isolate the machine or equipment from the rest of the electrical installation to avoid loss of power in case of a first installation fault
  • Isolation transformer can be used to create a star point in grids that do not have such a point
  • Appliances induce a high level of interference back to their power supply if the equipment needs to be protected from this noise isolation transformer can be used for their supply
  • Equipment can be protected from power disturbances like voltage transients, spikes, from DC leakage…
  • It can provide an isolated neutral ground reference to sensitive equipment
  • High noise attenuation level even in high-frequency applications
  • Reduced coupling capacitance
  • Suitable for higher harmonic area installation
  • Longer life of the transformer because of less heat dissipation

It can be used as a medical transformer

  • To isolate the patient and operator from electric shock
  • protects the equipment from faulty components or power surges
  • It provides a safer patient environment by reducing the potential hazards and by ensuring that under single fault condition there is still the continuity of supply