How much capacitance should be used for 18kw to increase the power factor of 10

The most feasible method; The selection of 90% of the no-load current of the equipment power can basically meet the requirements.

18*Capacitance. In order to improve the service life of the capacitor, the rated capacitor can be selected, but the output decreases under the operation of about 10kvar, then the phase-shifting power capacitor with the rated power rating of 10kvar can be selected for parallel random compensation.

The key is what is the power factor of the equipment when it is running, and the power factor before the compensation is: cos 1, (the general power supply department assesses the power factor of industrial users as cos =, and the power factor after compensation is: cos 2.)

The formula is qc = p * (tan 1 - tan 2), where qc – indicates the capacity to be compensated.

p - indicates the user's rated power (i.e., 18kw in the above question).

Q = 3 IU Q is the no-load reactive power of the motor (kvar), i is the no-load current of the motor (a), u is the rated voltage of the motor (v) qc calculation compensation capacity qc = (

...Khan: There's a formula, I forgot it, you look it up on the Internet, you can find it when you apply it, and any electrician book has it.

Such a large capacitor must not be discharged by direct short circuit, not to mention the loud sound, it will definitely burn the terminal of the capacitor, and the internal leads may also be burned. According to the 42000 F 450V capacitor, the energy of sufficient electricity is, according to the 10 second discharge time, at least use a resistance of more than 450W, it is recommended to use two 200W 220V bulbs in series as the discharge resistor, not only the cost is much cheaper than the resistor, but also from the light emitting situation of the bulb to judge the discharge state of the capacitor.

The 20W superscript of the resistor is the rated power of the resistor, 200 J means that the rated resistance of the resistor is 200, and J is the error level of the resistance value.

The 200 J means that the resistance is 200 ohms, and the J means that it is a metal film resistor.

The time constant for capacitor charging and discharging is.

t=rc means that the greater the resistance in series, the longer the discharge time. The smaller the resistance in series, the shorter the discharge time. If you discharge directly with a wire, it is equivalent to a short circuit. The resistance is very small, the time is extremely short, the current is very large, and of course it will blow up.

You have to discharge with a resistance of 200 ohms, which is the discharge time.

t=200*10000uf=2000000us=2s, which is unsafe, and the current is still very large.

It should be greater than the time constant by more than 5 times. That is, it is necessary to discharge with a resistance of more than 1000 ohms for more than 10 seconds.

Summary. Pro, the power factor refers to the ratio of the useful work to the apparent work in the circuit, <> in general, when the power factor is lower, it <>

It is necessary to invest capacitors to compensate for reactive power, improve the power factor<> the existence of reactive power will lead to an <>increase in the energy consumption of the power grid

At the same time, it also has an impact on the operational stability of electrical equipment<> therefore, for electrical equipment and large-scale industrial production equipment that need to be operated for a long time, the power factor <> required to be above <>

In order to ensure the operation efficiency and safety <> of the equipment

For some small devices that operate for a short period of time, <>

When the power factor is lower, it <>

It may not be necessary to invest in capacitors to compensate for the <>

It needs to be judged and dealt with on a case-by-case basis<>

How much less power factor is to put in capacitors.

Pro, the power factor refers to the ratio of the useful work to the apparent work in the circuit, <> in general, when the power factor is lower, it <>

It is necessary to invest capacitors to compensate for the reactive power and improve the power factor<> the existence of reactive power will lead to the increase of energy consumption of the power grid in Heting<> and also have an impact on the operational stability of electrical equipment<> therefore, for the electrical equipment and large-scale industrial production equipment that need to operate for a long time, the power factor <> required to be above <>

In order to ensure the operation efficiency and safety <> of the equipment

For some small devices that operate for a short period of time, <>

When the power factor is lower, it <>

It may not be necessary to cast a tape pat into the capacitor to compensate for the <>

It needs to be judged and dealt with on a case-by-case basis<>

Under what circumstances can high-voltage capacitance compensation be put into operation?

Pro, high-voltage capacitor is an important component in the compensation circuit, which is <> used to improve the power factor of the circuit and <>

Reducing the good spine reactive power in the grid and improving the power quality <> high-voltage capacitance compensation usually needs to be put into operation only in the following cases:<>1There is a large number of well-known inductive loads in the circuit, <>

Such as motors, transformers and other equipment, <>

When these devices transmit electrical energy, they will produce more reactive power<> resulting in a decrease in the power factor of the circuit<>

It is necessary to invest in a high-voltage capacitor compensator to improve the power factor<>2There are long transmission lines in the power grid, <>

These lines create an inductive impedance <>

Causes the power factor of the circuit to drop and <>

It is also necessary to invest in high-voltage capacitance compensators to improve the power factor<>3There is a large nonlinear load in the power grid, <>

Such as electronic devices, chargers, etc., <>

These devices will generate large harmonic currents on the grid<>

Harbin <> that leads to a decline in the power quality of the power grid

At this time, it is also necessary to invest in high-voltage capacitance compensators to improve the power quality and penetration<> but the operation of high-voltage capacitance compensators needs to be judged and determined according to the specific situation<> improper use will lead to circuit failure or equipment damage<>

The <> that should be operated under the guidance of a professional

When the total power factor of the electricity consumption unit is lower, the shunt capacitor should be put in.

Power Factor Adjustment Electricity Tariffs and Standards:

For industrial enterprises, the level of power factor will affect the electricity bill paid by the enterprise. According to the "Measures for Adjusting Power Factor Electricity Charges", when the power factor is lower than the corresponding standard, the enterprise needs to pay an additional power adjustment fee (equivalent to a fine) to the Electricity Bureau; When the power factor is higher than the corresponding standard, the enterprise can get a certain percentage of electricity fee reduction (equivalent to an incentive).

Attention to power capacitor compensation:

To install the reactive power compensation of the electric power capacitor, it is necessary to pay attention to the selection of compensation capacity. If the compensation capacity is low, the reactive power compensation effect cannot be achieved, and the economic efficiency of the enterprise will not be greatly improved; If the compensation capacity is too high, there may be problems such as no filial piety and overcompensation, which may lead to a series of failures. Therefore, when using power capacitors for compensation, it is necessary to select the appropriate compensation capacity.

With the continuous development of industry, the concept of reactive power compensation is deeply rooted in the hearts of the people, and more and more enterprises have begun to use power capacitors for reactive power compensation. <