Power factor improvement

article shows how power factor is related to the energy conservation

1. NEED OF POWER FACTOR IMPROVEMENT CONTENTS… WHAT IS POWER FACTOR NEED OF IMPROVEMENT OF POWER FACTOR RELATION BETWEEN PF IMPROVEMENT & ENERGY SAVING HOW TO IMPROVE POWER FACTOR IMPACT OF PF ON THE SYSTEM LOCATION OF SHUNT CAPACITOR FOR PF IMPROVEMENT DIFFRENCE IN WORKING OF SHUNT CAPACITOR AND SYNCHRONOUS CONDENSER

2. WHAT IS POWER FACTOR Power Factor may be defined by three definitions and formals as follow. 1).   The Cosine of angle between Current and Voltage is called Power Factor. Cos θ = P / V I  2). The ratio between resistance and Impedance is Called Power Factor. Cosθ = R/Z 3).   The ratio between Actual Power and  Apparent Power is called power factor. Cosθ = kW / kVA

3.  Low lagging power factor conditions can be caused by various combinations of the following inductive devices: Induction motors Inductive loads of fluorescent ballasts Rectifiers providing a DC power supply Arc welders Solenoids Induction heaters Lifting magnets Transformers. NEED OF IMPROVEMENT OF POWER FACTOR

4. ARC WELDER TRANSFORMER INDUCTION MOTOR SOLENOIDS MAGNET LIFTERS

5. RELATION OF PF IMPROVEMENT AND ENERGY CONSERVATION

6. HOW TO IMPROVE POWER FACTOR Why there is need to improve power factor? Why the power factor is important ? Exactly what is power factor correction? How the power factor will helps in the energy conservation?

7. IMPROVEMENT IN POWER FACTOR Static capacitor The power factor can be improved by connecting a capacitor in parallel with the inductive load. As we know that capacitor draws a leading current which can neutralize the lagging power factor produced by the inductive loads. For three phase loads, the capacitors can be connected in star or delta.

8. Synchronous condenser Synchronous motors take the leading current when they are over excited and therefore they behave like capacitors. So an overexcited synchronous motors running at no load is called synchronous condenser. When such machines are connected in parallel with the supply, it takes the leading current which partially neutralizes or tend to minimize the low power factor. Hence the power factor is improved.

9. Single phase diagram with a synchronous condenser connected to grid

10. Phase advancers Phase advancer is also a power factor improvement device. As we know that the low power factor is due to induction motor’s stator, because it draws very high current which lags behind the supply voltage by 90 . Phase advancer in real is an external ac excitation for the motor which relieves the stator winding of exciting current and the power factor can be improved.

11. IMPACT OF POWER FACTOR ON THE SYSTEM 1.) Large Line Losses (Copper Losses) 2.) Greater Conductor Size and Cost 3.) Poor Voltage Regulation and Large Voltage Drop 4.) Low Efficiency 5.)  Penalty from Electric Power Supply Company on Low Power factor

12. A Capacitor Bank has to go through different abnormal system conditions, during its life span. To with stand these abnormalities at optimum manufacturing cost, the capacitor banks are rated with following allowable parameters. A capacitor bank should continue its service with in the following limits. 110 % of normal system peak voltage. 120 % of normal system rms voltage. 135 % of rated KVAR. 180 % of normal rated rms current. Specification of capacitor bank

13. Theoretically it is always desired to commission a capacitor bank nearer to reactive load. This makes transmission of reactive KVARS is removed from a greater part of the network. Moreover if capacitor and load are connected simultaneously, during disconnection of load, Capacitor is also disconnected from rest of the circuit. Hence, there is no question of over compensation. But connecting capacitor with each individual load is not practical in the economical point of view. As the size of loads extremely differs for different consumers. So various size of capacitors are not always readily available. Hence proper compensation can not be possible at each loading point. Again each load is not connected with system for 24 × 7 hours. So the capacitor connected to the load also can not be fully utilized. Hence, capacitor, is not installed at small load but for medium and large loads, capacitor bank can be installed at consumer own premises. On viewing of these difficulties, instead of connecting Capacitor to each load, large capacitor bank is installed at main distribution sub-station or secondary grid sub-station. Location of Capacitor Bank

14. CONNECTION DIAGRAM FOR CAPACITOR BANK IN POWER SYSTEM

15. ENERGY CONSERVATION AND POWER FACTOR Improve power factor by installing capacitors to reduced KVA demand charges and also reduce line losses. Improvement of power factor from 0.85 – 0.96 will give reduction of 11.5 % peak KVA. And 21.6 % reduction in peak losses This corresponds to 14.5 % reduction in average losses for a load factor of 0.8

16. BENEFITS OF POWER FACTOR CORRECTION for energy conservation REDUCED DEMAND CHARGES INCREASED LOAD CARRYING CAPABILITIES IN EXISTING CIRCUITS IMPROVED VOLTAGE REDUCED POWER SYSTEM LOSSES REDUCED CARBON FOOTPRINT

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