Are AC or DC motors more efficient?

Is there an engine in an electric car?

Battery electric vehicles, or BEVs, use electricity stored in a battery pack to power an electric motor and turn the wheels. When depleted, the batteries are recharged using grid electricity, either from a wall socket or a dedicated charging unit.

Actually, Tesla use synchronous electric motors, which uses both AC and DC. In a synchronous motor has a AC magnified stator coil (like a conventional induction motor), but it also has a DC magnified rotor (unlike a induction motor).

D.C wound field motors are constructed with brushes and a commutator, which add to the maintenance, limit the speed and usually reduce the life expectancy of brushed D.C. motors. A.C. induction motors do not use brushes; they are very rugged and have long life expectancies. The final basic difference is speed control.

Difference Between AC and DC Motors. Commonly ran by an AC variable frequency drive, an AC electric motor operates by applying alternating current (AC) power to the electric motor. An induction motor uses a magnetic field on the rotor of an induction motor that’s created by an induced current.

A long time ago cars used DC generators in their electrical systems, but today they use AC alternators almost exclusively. This may seem a bit strange to the casually informed observer because a generator can charge the battery directly, without need for rectifier diodes to convert AC to DC.

The primary advantage of the DC motor is that it can develop constant torque over a wide speed application. Power supply is an important consideration in the application of DC motors. The most common way to provide DC voltage to a motor from an AC line is through the use of an electronic drive.

A car battery is DC. However it is charged by an alternator, which is usually a three-phase AC generator. Of course the output of the alternator windings is immediately rectified to DC inside the alternator.

A brushless motor loses the brushes and the commutator. Because the copper windings are on the outside of the motor configuration, there is room to make them larger. Brushless motors also don’t have the friction and voltage drop that brushes create by dragging against the spinning commutator.

Many other combinations of voltage and utility frequency were formerly used, with frequencies between 25 Hz and 133 Hz and voltages from 100 V to 250 V. Direct current (DC) has been almost completely displaced by alternating current (AC) in public power systems, but DC was used especially in some city areas to the end

How does a DC Motor work? The DC motor is a machine that transforms electric energy into mechanical energy in form of rotation. Its movement is produced by the physical behavior of electromagnetism. DC motors have inductors inside, which produce the magnetic field used to generate movement.

Lets do the voltage first. 9 bricks X 3.6 volts X 11 moduals = 356.4 volts. But the Tesla specs say the battery is 375 volts. Backing into the nominal voltage needed to get 375 volts each battery has to have a nominal of 3.78 volts.

The article How Electric Motors Work explains how brushed motors work. In a typical DC motor, there are permanent magnets on the outside and a spinning armature on the inside. The permanent magnets are stationary, so they are called the stator. The armature rotates, so it is called the rotor.

A brushed DC motor is an internally commutated electric motor designed to be run from a direct current power source. Since the brushes wear down and require replacement, brushless DC motors using power electronic devices have displaced brushed motors from many applications.

It is possible to produce small appliance motors powered by either AC or DC. This is known as a universal motor. The AC line is directly connected to the stator of a repulsion motor with the commutator shorted by the brushes. Retractable shorted brushes may start a wound rotor induction motor.

An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding.

Brushless motors are typically 85-90% efficient whereas brushed DC motors are around 75-80% efficient. This difference in efficiency means that more of the total power used by the motor is being turned into rotational force and less is being lost as heat.

A brush is a device which conducts current between stationary wires and moving parts, most commonly in a rotating shaft. Typical applications include electric motors, alternators and electric generators.

Brushless DC motors are similar to AC synchronous motors. The major difference is that synchronous motors develop a sinusoidal back EMF, as compared to a rectangular, or trapezoidal, back EMF for brushless DC motors. Both have stator created rotating magnetic fields producing torque in a magnetic rotor.

In an AC motor, there’s a ring of electromagnets arranged around the outside (making up the stator), which are designed to produce a rotating magnetic field. Unlike in a DC motor, where you send power to the inner rotor, in an AC motor you send power to the outer coils that make up the stator.

Today, all the hybrids are powered by DC brushless drives, with no exceptions. The only notable uses of induction drives have been the General Motors EV-1; the AC Propulsion vehicles, including the tzero; and the Tesla Roadster. Both DC brushless and induction drives use motors having similar stators.