Electrical power / torque

In summary, as we load down a generator, which requires more current to flow out of it, the generator needs to apply more torque to supply the power. This is due to the opposing magnetic fields created by the induced current, which is described by Lenz's law. The increased torque is needed to overcome this resistance and continue supplying power.
  • #1
Evil Bunny
241
0
Lets say we have a fixed voltage output on a generator... As we load it down (require more current to flow out of it), the generator needs to apply more torque to supply the power.

Why? What is resisting the rotor from turning?
 
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  • #3
in this case(the motor is loaded), will the mechanical power converted by the motor be smaller though the intensity of current has increased??

since P(mechanical)=E'*I where E' is the back emf, E' decreases when the motor is loaded?
 
  • #4
Curl said:
there's the answer.

That's actually not an answer. It's a reading assignment...

Here's my guess. We induce a current onto a wire with a magnetic field. As current is flowing through that wire, it creates it's own magnetic field that is opposite in polarity to the magnetic field that is being induced onto it... These fields oppose each other which requires more torque from the prime mover to overcome it..?
 
  • #5
bump... Is this correct?

Is the induced current creating a magnetic field that is opposite in polarity that makes it resist the current that was originally induced... Which makes them oppose each other, like the prime mover is now trying to overcome the opposing magnetic fields as if you were trying to force two north poles of magnets together?

Is this right?
 
  • #6
Yes.

Do a search on Lenz's law and it basically says the same thing.
 

What is electrical power and how is it measured?

Electrical power is the rate at which electrical energy is transferred or converted into another form of energy. It is measured in watts (W), which is equal to one joule per second. The power of an electrical circuit can be calculated by multiplying the voltage (V) by the current (I), or by using the formula P=VI.

What is torque and how is it related to electrical power?

Torque is a measure of the twisting force exerted on an object. In the context of electrical power, torque is the force that causes a rotating object, such as a motor, to rotate. The higher the torque, the greater the rotational force and the more power is required to maintain the rotation.

What factors affect the power and torque of an electrical system?

The power and torque of an electrical system can be influenced by several factors, including the voltage and current levels, the type and size of the electrical components, and the efficiency of the system. The design and configuration of the system can also impact its power and torque capabilities.

How does power and torque relate to the efficiency of an electrical system?

The efficiency of an electrical system refers to the amount of input power that is converted into useful output power. A more efficient system will require less power to produce the same amount of torque. Therefore, a higher efficiency system will have a higher power-to-torque ratio and will be able to achieve the same amount of work with less energy.

What are some common applications of electrical power and torque?

Electrical power and torque are used in a wide range of applications, including transportation (electric cars and trains), manufacturing (industrial motors), household appliances (washing machines, refrigerators), and renewable energy systems (wind turbines, solar panels). Power and torque are also important in robotics and other mechanical systems that require precise control and movement.

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