Title:- APFC USING ARDUINO

CONTENTSPower Factor: An Introduction

Types of PF Correction • Static Capacitor

• Synchronous Condense

• Phase Advancer

Importance of power factor

Disadvantages of low power factor

Principle

Section of APFC

Advantages

Result

Conclusion

Power factor: An

introduction

It is also defined as the cosine of theangle between the voltage and currentphases.

Power Factor (cos Ø) = Active Power(kW) / Apparent Power (kVA).

The closer cos Ø is to unity, the lessreactive power is drawn from thesupply.

Types of PFC

There are Three types of power factor correction

as follow.

• Static Capacitor

• Synchronous Condense

• Phase Advancer

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.

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.

DISADVANTAGES OF LOW PF

Higher current is required by the equipment, due to which the economic cost of theequipment 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 kVA rating 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 Machinesalso, the larger the kVA rating of Machines.

• The larger the Size of Machines and The Larger the size of Machines, TheLarger the Cost of machines.

Greater Conductor Size and Cost

• In case of low power factor, current will be increased, thus, to transmit thishigh current, we need the larger size of conductor.

PRINCIPLE

Automatic Power Factor detection and correction operates on theprincipal of constantly monitoring the power factor of the system and toinitiate the required correction in case the power factor is less than the setvalue of power factor.

The current and voltage signals are sampled by employing instrumenttransformers connected in the circuit.

The sampled analog signals are converted to suitable digital signals by thezero crossing detectors.

The ZCD signals are then added in order to obtain pulses which representthe time difference between the zero crossing of the current and voltagesignals.

The time period obtained is used to calculate the power factor of thecircuit.

Now if the calculated power factor is less than the minimum power factorlimit set at about 0.96-0.98, then the microcontroller switches on therequire number of capacitors until the power factor is greater than or equalto the set value.

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

SECTION OF APFCPower 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.

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

INDUCTIVE LOAD:-

Before PFC:-

RESULT

After PFC:-

Resistive Load:-

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.