What is active power Reactive power Apparent power?

Active power is also called average power. The instantaneous power of alternating current is not a constant value, the average value of power in a cycle is called active power, which refers to the power consumed in the resistive part of the circuit, and for the motor, it refers to its output, which is represented by the letter P in kilowatts (kW).

Reactive power: In a circuit with an inductor (or capacitor), the inductor (or capacitor) stores the energy of the power supply into a magnetic field (or electric field) in half a cycle, and returns the stored magnetic field (or electric field) energy to the power supply in the other half a cycle. They just exchange energy with the power source and don't really consume energy.

We call the amplitude value of the energy exchanged with the power supply reactive power, which is represented by the letter Q and is measured in kvar.

Apparent power: In a circuit with resistance and reactance, the product of voltage and current is called apparent power, which is represented by the letter s or symbol.

PS stands for kilovolt-amperes (kVA).

Hope it helps!

First of all, kva, kw and kvar are not power, they are only units of power, which are the units of apparent power (denoted by s), active power (denoted by p) and reactive power (denoted by q) respectively.

Remember whether it is active or reactive, not useful or useless!!

Apparent power: s=ui

Active power: p=uicos

Reactive power: q=uisin

The cosine of the phase difference ( ) between voltage and current is called the power factor and is denoted by the symbol cos.

According to the formula, we can see that the relationship between them is: s = p + q

We can draw three kinds of power success triangles, the two right-angled sides represent the active power and reactive power respectively, and the hypotenuse side represents the apparent power.

<> In AC circuits, there are two kinds of power supplied to the load by the power supply: one is active power and the other is reactive power. Active power is the electrical power required to maintain the normal operation of electrical equipment, that is, the electrical power that converts electrical energy into other forms of energy (such as mechanical energy, light energy, and thermal energy).

Reactive power is more abstract, it is the electrical power used to exchange the electric field and the magnetic field in the circuit, and is used to establish and maintain the magnetic field in the electrical equipment. It does not work externally, but is transformed into other forms of energy. Any electrical equipment with an electromagnetic coil needs to consume reactive power to establish a magnetic field.

Reactive power is by no means useless power, it is very useful. The motor needs to establish and maintain a rotating magnetic field to rotate the rotor, thereby driving the mechanical movement, and the rotor magnetic field of the motor is established by obtaining reactive power from the power supply. 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 and the transformer will not be transformable.

There was a handsome guy who moved with a cart and hung everything in front, and the handsome guy pushed while pressing the handlebars, tired and sweating; A beautiful woman came over, sitting on the side of the cart closer to the handlebars, haha, it was a lot lighter. The handsome guy pushed it easily and comfortably. The force of the handsome guy pressing the handlebar is reactive current, the thrust that overcomes the friction force and moves forward is the active current, and the push of things to the destination is active.

Beauty is reactive compensation. Without reactive power compensation, the power supply system can also work, but it is tired and consumes a lot of energy; With beautiful women, men and women match, work is not tired, efficient, and happy. Things are in the front, and the beauty is in the back, which is accommodating and reactive; Things are in the back, and beauties are in the front, which is sensual and useless.

The relationship between apparent power, active power, and reactive power is: apparent power root number (square of active power, square of reactive power), active power, apparent power, power factor.

The relationship between apparent power (s), active power (p) and reactive power (q) can be represented by a power triangle, as shown in the figure below. It is a right-angled triangle with two right-angled sides respectively q and p, and the hypotenuse is the angle between the two right-angled sides and p is the power factor angle, which reflects the phase difference (angle) between voltage and current in this AC circuit.

S = (kva) full power (apparent power), p = (kw) active power, q = (kva) reactive power, cos = p s It can be seen that the power factor cos can be defined as the ratio of the active power consumed by the load to its apparent power, which characterizes the proportion of the active power consumed by the load in the apparent power.

The electricity bill paid by everyone in daily life converts electrical energy into other forms of energy, and the actual power consumed by electrical appliances is active power (active electricity); Unit: kW (kilowatts). For example, if there is a capacitive coil in a household refrigerator, the capacitor coil will always be in a state of charging and discharging when working, and does not really consume electricity, and the power of this part is called reactive power; In addition to providing active power to electrical equipment, transformers (power supplies) also need to provide reactive power, and the total power of the two is apparent power, in kva (kilovolt ampere).

The relationship is:Apparent powerUnder the root number (the square of the active powerReactive powerof the square), active power apparent powerPower factor

There are delayed front work power, reactive power, and apparent power, and there is a right triangle between them.

The relationship between the three of them, see the attached diagram, is this right triangle. As for the difference, that's how they are defined.

Active power: It is the power that has done work externally. It is used to describe the working capacity of the device.

Reactive power: It is the power required by the electrical equipment, to maintain the normal operation of the equipment, not to do external work, and to exist between the power grid and the equipment. It's a bit awkward to say this, it's hard to understand, let's talk about the essence of reactive power from another angle. Yard slammed.

Take the motor as an example: when the motor is running, there needs to be a rotating magnetic field, Zhiyuan needs energy to establish this magnetic field, after the magnetic field is established, it will be maintained to maintain the stable work of the motor, this energy will not leave the motor, but it is real energy, this energy, is what we call reactive power.

Real power: It is the product of real current and voltage. It is used to measure the capacity of the grid (or the ability to supply electricity).

The apparent quantitative relationship between the power S, the active power P, and the reactive power Q is exactly equivalent to the trilateral relationship of a right-angled triangle, S is equivalent to the hypotenuse, and P and Q are equivalent to two right-angled sides, which is called the power triangle.

The conversion formula is as follows:

s²＝q²＋p²

cos = p s The power factor cos can be defined as the ratio of the active power consumed by the load to its apparent power, which characterizes the proportion of the active power consumed by the load in the apparent power.

In a three-phase load, these three types of power always exist at the same time at any time, and the electricity generated by the engine must include these three powers

Apparent power s=

Active power p = power to do work and generate heat)

Reactive power q = the power to build up the magnetic field to transport energy).

Power factor cos = p s (active power, apparent power).

sin = q s (reactive power apparent power).

1.Apparent power: In AC circuits, due to inductive or capacitive energy storage devices, there is a phase difference between voltage and current, which is commonly known as voltage.

It does not arrive at the same time as the current; Therefore, on the surface, how big the voltage and how big the current is, in fact, it does not do so much work, and there is the energy conversion between the power supply and the energy storage equipment; So it's called apparent power.

Apparent power is under the root (square of active power and square of reactive power).

s^2=p^2+q^2

2.Active power: It is the electrical power required to maintain the normal operation of electrical equipment, that is, the electrical power that converts electrical energy into other forms of energy (mechanical energy, light energy, thermal energy).

Active power, apparent power, power factor.

p has active s in cos

3.Reactive power: It is the electrical power used to exchange the electric field with the magnetic field in the circuit and to establish and maintain the magnetic field in the electrical equipment. It does not work externally, but is transformed into other forms of energy.

What is the relationship between active power, reactive power, and apparent power:

q Reactive power = s depending on sin

Find the sin according to the cos

q＝s× sinφ

Definition of apparent power: in a circuit with resistance and reactance, the product of voltage and current is the apparent power, apparent power = active power + reactive power, as for what products can measure the apparent power, it is recommended to use the comprehensive fuel meter of the 3000 series of Hongrun company, which can be switched to display the above three powers.

Apparent powerActive powerReactive powerThe relationship is:

Apparently under the root number (square of active power and square of reactive power), active power Apparent power is the power factor.

Active power, reactive power, apparent power, and the relationship between them is a right triangle.

Effect of reactive power:

Reactive power is more abstract, it is used to exchange the electric field in the circuit with the magnetic field, and is used to build and lift the lead in the electrical equipment to maintain the magnetic field.

It does not do work directly with the external call, but converts it into other forms of energy. For example, fluorescent lamp, it is through the ballast to make the lamp light, in addition to the power that the lamp needs to consume, the ballast also needs a certain consumption, and the ballast is reactive power.