Why is a transformer used to connect a generator in a power station?

The three-phase power leaves the generator and enters a transmission substation at the power plant. This substation uses large transformers to convert the generator’s voltage (which is at the thousands of volts level) up to extremely high voltages for long-distance transmission on the transmission grid.

Why ships use alternators instead of DC generator as their primary source of electrical power?

AC was adopted for power transmission in the early days of electricity supply because it had two major advantages over direct current (DC): its voltage could be stepped up or down according to need using transformers, and it could be interrupted more easily than DC.

What is the difference between AC generator and DC generator?

AC generator is a mechanical device that converts mechanical energy into AC electrical power. DC generator is a mechanical device that converts mechanical energy into DC electrical power. In an AC generator, the electrical current reverses direction periodically.

Why exciter is used in generator?

The main purpose of exciter in a generator(alternator) is to provide stationary rotating magnetic field. Which is used to induce the e.m.f in the armature coil. So, DC power is given to exciter and the exciter is nothing but a coil, and the exciter creates a magnetic field.

Why are transformers used?

Transformers are employed for widely varying purposes; e.g., to reduce the voltage of conventional power circuits to operate low-voltage devices, such as doorbells and toy electric trains, and to raise the voltage from electric generators so that electric power can be transmitted over long distances.

What is the purpose of transformer?

Transformers are most commonly used for increasing low AC voltages at high current (a step-up transformer) or decreasing high AC voltages at low current (a step-down transformer) in electric power applications, and for coupling the stages of signal-processing circuits.

Why do ship’s generators have different output voltage?

As the ship size increases, there is a need to install more powerful engines and other machineries. This increase in size of machineries and other equipment demands more electrical power and thus it is required to use higher voltages on board a ship.

Why is AC distribution preferred over DC distribution onboard a ship?

In ships,AC System is preferred over DC System because of the following reasons : Smaller, lighter compact and compact machine size , for a kilowatts. High power and high voltage AC generator can be easily manufactured. Voltage can be raised or lowered by Transformer.

How does a DC generator work?

The working principle of the DC generator is based on Faraday’s laws of electromagnetic induction. When a conductor is located in an unstable magnetic field, an electromotive force gets induced within the conductor. The induced e.m.f magnitude can be measured from the equation of the electromotive force of a generator.

How voltage is generated in a DC generator?

A direct-current (DC) generator is a rotating machine that supplies an electrical output with unidirectional voltage and current. Voltage is induced in coils by the rate of change of the magnetic field through the coils as the machine rotates.

What happens when a transformer is connected to a DC supply?

If the primary of a transformer is connected to the DC supply, the primary will draw a steady current and hence produce a constant flux. Consequently, no back EMF will be produced.

Why is a transformer used only with an AC source?

The most simple answer is, DC produces a constant flux and it heats the transformer winding and may burn the winding which is heart of transformer. Hence a transformer is never given a DC supply. Originally Answered: Why is a transformer used only with an AC source and not with a DC source?

What is the working of transformer?

At a different voltage level, transformers can change the electrical energy of a given voltage. It consists of two coils named as Primary coil and a Secondary coil which is wound on a soft iron core. The soft iron core is laminated to minimize eddy currents.

What happens when di/dt = 0 in a transformer?

At this stage, current (i) will increase to the dangerous level and stop changing. When there is no change in current (i), the induced voltage in the primary will be zero as di/dt = 0 which leads to short circuit the transformer winding with the appalled DC source.