prepared by Jamilah Abbas Building Services Eng.JKA PSA

1. POWER FACTOR CORRECTION

2. DEFINITION the angle of this “power triangle” graphically indicates the ratio between the amount of consumed power and the amount of returned power. It also happens to be the same angle as that of the circuit's impedance in polar form. When expressed as a fraction, this ratio between true power and apparent power is called the power factor for this circuit. Because true power and apparent power form the adjacent and hypotenuse sides of a right triangle, respectively, the power factor ratio is also equal to the cosine of that phase angle. Using values from the last example circuit: It should be noted that power factor, like all ratio measurements, is a unitless quantity

3. FORMULA

4. DISADVANTAGES LOW POWER FACTOR Cost for the electricity supply is high because voltage must be increased in order to obtain equalpower as electricity that is produced witha high power factor. This will cause the need to replace equipment such as generators, transformers and others.

5. 2. If the voltage cannotbe increased, the current should be increased to obtain equalpower of a high power factor. This will cause more spending in the conversion of cable size and current rating.

6. 3. With the increase voltage drop and copper losses, the efficiency decreases

7. Why Improve Your Power Factor? Some of the benefits of improving your power factor are: Your utility bill will be smaller. Low power factor requires an increase in the electric utility’s transmission and distribution capacity in order to handle the reactive power component caused by inductive loads. Utilities usually charge large customers with power factors less than about 0.95 an additional fee. You can avoid this additional fee by increasing your power factor. Your internal electrical system’s capacity will increase. Uncorrected power factor will cause increased losses in your electrical distribution system and limit capacity for expansion. Voltage drop at the point of use will be reduced (i.e. improved). Voltages below equipment rating will cause reduced efficiency, increased current, and reduced starting torque in motors. Under-voltage reduces the load motors can carry without overheating or stalling. Under voltagealso reduces output from lighting and resistance heating equipment.

8. EQUIPMENTS TO IMPROVE THE POWER FACTOR CAPASITOR SYNCHRONOUS MOTOR FORWARD PHASE