What Is Power Factor?

Power factor refers to the ratio of the active power to the apparent power of an AC circuit. Consumer electrical equipment under a certain voltage and power, the higher the value, the better the benefit, the more fully the power generation equipment can be used. Commonly expressed as cos ^[1] .

The size of the Power Factor and

The root cause of the low power factor is electrical

Common non-linear loads on power systems include rectifiers (used in power supplies), or equipment like fluorescent lamps, electric welders or arc furnace arc discharges. Because the current of these systems is interrupted by the switching of components, the current will contain harmonic components, and its frequency is an integer multiple of the power system. Distortion Power Factor can be used to measure the impact of harmonic distortion of current on its average power.

The sine wave voltage and non-sine wave current of the computer power supply have a distortion power factor of 0.75.

In the grid

Due to the presence of inductive, capacitive, or non-linear loads, the system has reactive power, which results in active power not equal to apparent power. The relationship between the three is as follows:

S ^ 2 = P ^ 2 + Q ^ 2

; S is the apparent power, P is the active power, and Q is the reactive power. The units of the three are VA (or kVA), W (or kW), and var (or kvar).

To put it simply, in the above formula, if the value of kvar is zero, kVA will be equal to kW, then 1kVA of electricity from the power supply bureau is equal to the user's consumption of 1kW. At this time, the cost efficiency is the highest, so the power factor Is a coefficient that the power supply bureau is very concerned about. If the user does not reach the ideal power factor, it is relatively consuming the resources of the power supply bureau, so this is why the power factor is a regulatory limitation. For domestic purposes, the power factor requirement must be between

Common appliance power factor

Some people have tested the power consumption and power factor of various household appliances, and the results are as follows:

No. Name Equipment Capacity (W) Power Factor Reactive Power (var) Apparent Power (VA)

1 Lighting 200 0.90 96.86 222.22

2 Air conditioner 3000 0.80 2250.00 3750.00

3 Refrigerator 150 0.60 200.00 250.00

4 Microwave oven 1000 0.90 484.32 1111.11

5 Electric water heater 2000 1.00 0.00 2000.00

6 Rice cooker 1000 1.00 0.00 1000.00

7 Computer 300 0.80 225.00 375.00

Measuring the power factor of a computer

8 Printer 250 0.80 187.50 312.50

9 TV 200 0.80 150.00 250.00

10 Washing machine 200 0.60 266.67 333.33

11 Range hood 50 0. 80 37.50 62.50

12 Audio 300 0.60 400.00 500.00

13 Water dispenser 600 1.00 0.00 600.00

Power factor of water dispenser

14 Sanitary equipment 1000 1.00 0.00 1000.00

15 Health equipment 600 0.80 450.00 750.00

16 VCR 200 0.90 96.86 222.22

17 DVD \ VCD 100 0.90 48.43 111.11

These figures are, of course, for reference only.

Description

1. The power factor of all electric heating appliances is equal to 1, because they are all resistive loads.

2. All household appliances with motors (most white appliances) are inductive loads.

3. All household appliances (TV sets, stereos) with transformers are also inductive loads.

4. A refrigerator that works continuously for 24 hours is an inductive load that consumes a lot of power and has a low power factor.

5. Because the lighting fixtures are mainly incandescent lamps, the power factor will approach 1. ^[2]