Which type of motor is used in Metro?

Which type of motor is used in Metro?

RING INDUCTION MOTOR
THREE PHASE SLIP RING INDUCTION MOTOR has been used in DELHI METRO. Dc series motor is ideal for traction but the maintenance cost of which is very high also needs the conversion and smoothening of AC voltages.IM has less maintenance,high starting torque, cheap etc.

Do electric trains run on AC or DC?

Railways and electrical utilities use AC for the same reason: to use transformers, which require AC, to produce higher voltages. The higher the voltage, the lower the current for the same power, which reduces line loss, thus allowing higher power to be delivered.

Which type of current is used in Metro?

Although about 97% of Metros in the world run on DC mode, policymakers have given preference to AC mode for Metros in the country including Delhi and Mumbai. “Requirement of substations at every 10 km to 15 km is shown as a major reason for rejection to DC.

How does an AC traction motor work?

Traction motors are powered by electricity and generate the power to rotate the wheels of the train. The turning force produced by traction motors is transmitted to the wheels via the driving gear unit and axle. Traction motors are typically mounted in the trucks where the wheels are housed.

Why is AC preferred to DC system for powering to electric traction?

DC train consumes less energy compared to AC unit for operating same service conditions. The equipment in DC traction system is less costly, lighter and more efficient than AC traction system. It causes no electrical interference with nearby communication lines.

Are diesel electric trains AC or DC?

In a diesel–electric locomotive, the diesel engine drives either an electrical DC generator (generally, less than 3,000 horsepower (2,200 kW) net for traction), or an electrical AC alternator-rectifier (generally 3,000 horsepower (2,200 kW) net or more for traction), the output of which provides power to the traction …

Why is AC current preferred over DC?

Hence, the voltage through transmission lines is very high, which reduces the current, which in turn minimizes the energy lost through transmission. This is why alternating current is preferred over direct current for transmitting electricity, as it is much cheaper to change the voltage of an alternating current.

Is Delhi Metro DC or AC?

decided to adopt 25 KV AC Traction. This metro has been constructed on a private basis by DLF (now taken over by IL&FS). Given the short length and lower PHPDT of the Metro, the operator has adopted 750 V DC.

How does a metro train run?

On subway trains, the third rail is the source of the electrical delivery system. The same power is delivered to light-rail lines such as the Blue, Gold, Green and Expo lines via an overhead catenary system. No petroleum gas for the trains. Like petroleum gasoline and compressed natural gas, Metro buys it.

Can an AC motor run on DC supply?

(1) AC motor cannot run on DC Supply because of most of AC motor like Single-Phase Induction Motors, Three Phase Induction Motors, Synchronous Motors need alternating flux, not static flux. As we know that only AC can produce alternating flux.

Can a DC shunt motor run on AC supply?

For the change the rotation of the DC Shunt Motor we must interchange the terminals of anyone either armature terminal or field terminal. So you can say that a DC Shunt motor can run on AC Supply. As the motor is DC so the field and armature winding made for DC supply.

Why does a DC motor have more resistance than AC motor?

As the motor is DC so the field and armature winding made for DC supply. The winding which is made for DC always has more resistance than the winding which is made for AC. So when we give AC supply self-inductance will be produced in the winding which opposes the current which further decreases the production of flux.

How does a universal motor work with AC power?

For proper operation with AC supply, a universal motor incorporates a compensation winding, in series with the armature and field winding. When the motor runs on AC voltage, the alternating flux causes a reactance voltage, which limits the current to a much lower level than would be produced with DC voltage.