Electricity in Transport Flashcards
How does a DC motor work?
A DC (directcurrent) motor is an electrical machine that converts electrical energy into mechanical energy.
It works on the principle of electromagnetism, wherea magnetic field is used by passing an electric current through a wire coil. This magnetic field interacts with a permanent magnet, creating a rotational force that drives the motor.
where is the electrical system in a car?
The electrical system in the battery which charged by the alternator and the battery runs out of energy if the lights are left on in the car.
where is the is the electrical system in a bus?
The electrical system in a bus is in three REES systems. Where one is in the front in the front part of the electrical bus (behind the driver cab) and the other two in the rear.
where is the is the electrical system in an electric Bicycle?
The electrical system is in the mechanical energy.
What is a common method used to control the speed of a DC motor?
by varying the supply voltage. Increasing the voltage increases the motor speed, while decreasing the voltage reduces it.
How is the **speed **of an AC motor typically controlled?
by** varying** the** frequency** of the supply current, using a device known as a Variable Frequency Drive (VFD). This method allows for precise and efficient speed control.
Brushless DC Motors (BLDC) are often used in electric vehicles (EVs) due to their efficiency and high power-to-weight ratio.
At what point does the electricity grid system supply transport systems such as trains?
Trains that take electrical power from the grid receive it at the consumption stage of the electric grid.
What makes BLDC motors a preferred choice for drones and electric aircraft?
BLDC motors are preferred for drones and electric aircraft because of their high efficiency, reliability, and excellent power-to-weight ratio, which are crucial attributes for flight applications.
How do electric boats and submarines benefit from using BLDC motors?
Electric boats and submarines benefit from using BLDC motors due to their efficiency and the ability to provide precise speed control, which is essential for accurate navigational purposes.
What is an alternative method to voltage control for adjusting the speed of a DC motor, and in what scenario is it more suitable?
An alternative method for adjusting the speed of a DC motor is field control, which involves adjusting the current in the field winding. This method is more suitable for applications requiring a wide range of speed control.
Can the supply voltage affect the speed of certain AC motors, and how does this method compare to frequency control?
Yes, varying the supply voltage can affect the speed of certain AC motors, but this method is not as efficient or precise as frequency control using a VFD.
At what point does the electric grid system supply transport systems such as trains
Trains that take electrical power from the grid receive it at the consumption stage of the electric grid.
What’s the difference between Induction AC Motor and a DC Motor?
Induction AC motors operate on alternating current (AC) without direct electrical connections to the rotor, using electromagnetic induction for motion.
DC motors use direct current (DC) and require physical contacts (brushes) to supply current to the rotor, offering precise speed control.
where is the is the electrical system in a boat?
The electrical system is in one or more batteries.
What is the electrical supply of a train?
it is a 25 kV AC at 60 Hz
What is a megaohmmeter?
A megaohmmeter, often referred to as an insulation tester, is a specialized type of ohmmeter designed to measure very high electrical resistance values, typically in the megaohm (MΩ) range and beyond.
In what specific situations or for which types of electrical equipment is a megaohmmeter most commonly used?
Megaohmmeters are commonly used to assess the condition of electrical insulation in electrical systems They are particularly useful for preventative maintenance and troubleshooting in systems where insulation integrity is critical, such as in motors, transformers, cables, and switchgear.
how is rectification accomplished?
through the use of diodes AC is Converted to DC if one diode is used then half wave rectification occurs and it is converted to DC
how is full wave rectification achieved?
full wave rectification is achieved by using four diodes. this will allow all of the sine wave to pass but it will not have all the waves on the positive side, so they will travel in the same direction.
