Automatic Power Factor Corrector
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This document describes an automatic power factor corrector system. It begins with an introduction to power factor, different types of power factor correction including static capacitors and synchronous condensers. It then discusses the importance of power factor correction including reduced utility charges and system losses. The document outlines the principles, sections, advantages of an automatic power factor correction system. It shows results for inductive and resistive loads before and after correction. It concludes that automatic power factor correction provides an efficient way to improve power factor through static capacitors.
Automatic Power Factor Corrector
- 1. NAME:- NITESH ARUN KAMBLI TITLE:- AUTOMATIC POWER FACTOR CORRECTOR.
- 2. CONTENTS Power Factor: An Introduction Types of PF Correction • Static Capacitor • Synchronous Condense • PhaseAdvancer Importance of power factor Disadvantages of low power factor Principle Section ofAPFC Advantages Result Conclusion
- 3. Introduction It is also defined as the cosine of the angle between the voltage and current phases. Power Factor (cos Ø) = Active Power (kW) / Apparent Power (kVA). The closer cos Ø is to unity, the less reactive power is drawn from the supply.
- 4. TYPES OF PFC There are Three types of power factor correction as follow. • Static Capacitor • Synchronous Condense • PhaseAdvancer The type of loads which doesn’t change Which is always constant there we used Static Capacitor. The load which is changed i.e. dynamic in nature there we used synchronous condenser or phase advancer.
- 5. IMPORTANT OF POWER FACTOR Lower Utility Charges • Reducing Peak KW billing demand • Eliminating the power factor penalty Increased System Capacity and Reduced System Losses in our Electrical System • By adding capacitors (KVAR generators) to the system, the power factor is improved and the KW capacity of the system is increased.
- 6. DISADVANTAGES OF LOW PF Higher current is required by the equipment, due to which the economic cost of the equipment is increased. Large Line Losses (Copper Losses) • We know that Line Losses is directly proportional to the squire of Current “I2” Power Loss = I2xR i.e., the larger the current, the greater the line losses. Large kVArating and Size of Electrical Equipment • As we know that almost all Electrical Machinery rated in kVA • Therefore, The Lower the Power factor, the larger the kVA rating of Machines also, the larger the kVArating of Machines. • The larger the Size of Machines and The Larger the size of Machines, The Larger the Cost of machines. Greater Conductor Size and Cost • In case of low power factor, current will be increased, thus, to transmit this high current, we need the larger size of conductor.
- 7. PRINCIPLE Automatic Power Factor detection and correction operates on the principal of constantly monitoring the power factor of the system and to initiate the required correction in case the power factor is less than the set value of power factor. The current and voltage signals are sampled by employing instrument transformers connected in the circuit. The sampled analog signals are converted to suitable digital signals by the zero crossing detectors. The ZCD signals are then added in order to obtain pulses which represent the time difference between the zero crossing of the current and voltage signals. The time period obtained is used to calculate the power factor of the circuit. Now if the calculated power factor is less than the minimum power factor limit set at about 0.96-0.98, then the microcontroller switches on the require number of capacitors until the power factor is greater than or equal to the set value.
- 8. ADVANTAGE It’s an automatic system adjusting itself to control the power factor above a desired value by a bank of capacitors switched by means of contractors Contractors are controlled by a regulator that measures PF in the network Depending upon the load PF the controller will adjust the PF by switching the necessary no of capacitors from the bank
- 9. SECTION OFAPFC Power supply:- Basically this section provide supply to all circuit of our system which perform different operation. Sensing Section:- This section sense current and voltage across the load and then using this signal consider particular power factor and signal send to control circuit. Controlling Section:- This section sense pf and switch capacitor across load and improve pf accordingly.
- 10. ADVANTAGES They have low losses. They require little maintenance as there are no rotating parts. They can be easily installed as they are light and require no foundation. They can work under ordinary atmospheric conditions.
- 12. AFTER PFC:-
- 14. CONCLUSION • The Automatic Power Factor Detection and Correction provides an efficient technique to improve the power factor of a power system by an economical way. Static capacitors are invariably used for power factor improvement in factories or distribution line. • However, this system makes use of capacitors only when power factor is low otherwise they are cut off from line. Thus, it not only improves the power factor but also increases the life time of static capacitors. • The power factor of any distribution line can also be improved easily by low cost small rating capacitor. This system with static capacitor can improve the power factor of any distribution line from load side. • As, if this static capacitor will apply in the high voltage transmission line then its rating will be unexpectedly large which will be uneconomical & inefficient. So a variable speed synchronous condenser can be used in any high voltage transmission line to improve power factor & the speed of synchronous condenser can be controlled by microcontroller.
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