What Is Reactive Power and Its Use?
by Starlight Generator dieselgeneratortechReactive power is
relatively abstract, it is used to exchange electric and magnetic fields in the
circuit, and is used to establish and maintain the electrical power of the
magnetic field in electrical equipment. It does not work externally, but
instead transforms it into other forms of energy. For electrical equipment with
electromagnetic coils, reactive power must be consumed to establish a magnetic
field. Because it does not work outside, it is called "reactive." The
sign of reactive power is represented by Q, and the unit is either Var or kVar.
Reactive power is by no
means useless power, and it is very useful. The motor needs to establish and
maintain a rotating magnetic field to rotate the rotor, thereby driving the
mechanical motion. The rotor magnetic field of the motor is established by taking
reactive power from the power source. The transformer also needs reactive power
to generate a magnetic field in the primary coil of the transformer and induce
a voltage in the secondary coil. Therefore, without reactive power, the motor
will not rotate, the transformer will not be transformed, and the AC contactor
will not pull.
Under normal
circumstances, the powered device not only needs to obtain active power from
the power supply, but also needs to obtain reactive power from the power
supply. If the reactive power in the power grid is in short supply, the power
equipment does not have enough reactive power to establish a normal
electromagnetic field. Then, the power equipment cannot be operated under the
rated condition, and the terminal voltage of the power equipment is lowered.
Thereby affecting the normal operation of the electrical equipment. Reactive
power has certain adverse effects on supply and use of electricity, mainly in:
1. Reduce the output of
the generator's active power.
2. Reduce the power
supply capacity of transmission and transformation equipment.
3. This causes an
increase in line voltage loss and an increase in power loss.
4. This results in low
power factor operation and voltage drop, resulting in insufficient electrical
equipment capacity.
The reactive power
supplied from the generator and the high-voltage transmission line can not meet
the needs of the load, so some reactive power compensation devices should be
set in the power grid to supplement the reactive power to ensure the user's
need for reactive power. Electrical equipment can operate at rated voltage.
This is the reason why the grid needs to install reactive power compensation
devices.
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Created on Oct 14th 2019 03:38. Viewed 239 times.