How is electromagnetism applied in maglev trains?

Electromagnetism is used in maglev trains to levitate and propel the train without physical contact with the tracks.

Maglev, short for magnetic levitation, trains use powerful electromagnets to lift the train above the tracks, eliminating friction and allowing for smoother and faster travel. The system relies on two main sets of electromagnets: levitation magnets and propulsion magnets. Levitation magnets are placed along the sides or bottom of the train and interact with magnets on the track to create a repulsive force that lifts the train. This process is known as electromagnetic suspension (EMS) or electrodynamic suspension (EDS), depending on the specific technology used.

In EMS systems, electromagnets on the train are constantly adjusted to maintain a stable levitation height, typically a few centimetres above the track. Sensors monitor the gap between the train and the track, and a control system adjusts the current in the electromagnets to keep the train levitated. In EDS systems, superconducting magnets are used, which can create stronger magnetic fields and allow for higher levitation heights, but they require cooling to very low temperatures.

For propulsion, maglev trains use a linear motor system. Instead of a traditional rotating motor, a linear motor creates a travelling magnetic field along the track. This field interacts with magnets on the train, generating a force that pushes the train forward. By changing the direction of the magnetic field, the train can be accelerated, decelerated, or even brought to a stop.

Maglev trains are highly efficient and can reach speeds of over 500 km/h, making them an attractive option for high-speed transportation. The lack of friction also means less wear and tear on the train and track, reducing maintenance costs and increasing the lifespan of the system.