POWER FACTOR CORRECTION OF MACHINE LABORATORY AND CNC MACHINE BY USING IPFC CONTROLLER Submitted by:- DEEPAK KUMAR BAGHAR PRAVAT KUMAR PATRA DEVIPRASAD SINGHDEO SARTHAK PATI ASHIS PANDA ANUP MANGARAJ 110301EER101 110301EER076 110301EER014 110301EER036 110301EER044 110301EER109 GUIDED BY Shri Surya Narayan Sahu
INTRODUCTION Power factor is the ratio of true power or watts to apparent power or volt amps. They are identical only when current and voltage are in phase then the power factor is1.0. The cosine of angle between voltage and current in ac circuit is known as power factor. In ac circuit there is generally a phase difference φ between voltage and current. The term cosφ is called the power factor of circuit VI cosφ represent the active power in Watt or KW VIsin φ represent the reactive power in VAR or KVAR VI represents apparent power in VA or KVA Power factor cosφ= (active power / apparent power)=(kw/kva)
The lagging reactive power is responsible for the low power factor. It is clear from the power triangle that smaller the reactive power component higher is the power factor of the circuit. KVAR=KVA sniφ=(kw/ cosφ)* sinφ KVAR=KW tanφ
INSTANTANEOUS POWER As in DC circuits, the instantaneous electric power in an AC circuit is given byp=vi where V and I are the instantaneous voltage and current. Instantaneous voltageand current. Since V = Vm sinωt & I = Im sin (ωt - φ)
Then the instantaneous power at any time t can be expressed as Pinstanteneous = Vm Im sinωt sin (ωt-φ) After using trigonometric identity:sin (t-φ) = sinωt cosφ- cosωt sinφ The power becomes: instantaneous = Vm Im sin 2ωt cosφ - Vm Im sinωt sinφ cos ωt
NEEDS OF POWER FACTOR CONTROLLER Power factor correction (PFC) is a technique of counteracting the undesirable effects of electric loads that create a power factor that is less than one. Power factor correction may be applied either by an electrical power transmission utility to improve the stability and efficiency of the transmission network or correction may be installed by individual electrical customers to reduce the costs charged to them by their electricity supplier.
TYPES OF POWER FACTOR CONTROLLER Passive PFC This is a simple way of correcting the nonlinearity of a load by using capacitor banks. Active PFC An active power factor corrector (active PFC) is a power electronic system that controls the amount of power drawn by a load in order to obtain a Power factor as close as possible to unity.
CAPACITIVE POWER FACTOR CORRECTION (CPFC) Capacitive Power Factor correction is applied to circuits, which include induction motors as a means of reducing the inductive component of the current and thereby reduce the losses in the supply. There should be no effect on the operation of the motor itself. An induction motor draws current from the supply, which is made up of resistive components and inductive components.
DIFFERENT TYPES OF CAPACITIVE POWER FACTOR CORRECTION Bulk correction Static correction Inverter Solid-state soft starter Bulk correction
Static correction Inverter Static Power factor correction must not be used when a variable speed drive or inverter controls the motor. The connection of capacitors to the output of an inverter can cause serious damage to the inverter and the capacitors due to the high frequency switched voltage on the output of the inverters.
Solid state soft starter.
HARDWARE AND ITS CONFIGURATION The design aims to monitor phase angle continuously and in the event of phase angle deviation, a correction action is initialized to compensate for this difference by continuous changing variable capacitors value via switching process. IPFC(Intellegent Power Factor Controller)
BENEFITS Three Phase Sensing - Accurate measurement of PF Fault Detection (Over Compensation, Under Compensation, Over Voltage, Over Current, Under Voltage, over harmonics voltage and current) Automatic or Manual Control (manual control with power backup option) Intelligent operation
CAPACITOR BANK A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store energy electro statically in an electric field.
CONTROLE SCHEME Circuit Diagram
Over voltage For all these above there is a threshold set through RS-232communication.When ever it crosses above that threshold particular alarm status will display on LCD. Under voltage For all these above there is a threshold set through RS-232communication.When ever it crosses above that threshold particular alarm status will display on LCD.
Over Compensation When all capacitor bank steps (max) gets OFF and IPFC still don t achieve required Target PF this alarm will display. Under Compensation When all capacitor bank steps(max) gets ON and IPFC still don t achieve required Target Power factor this alarm will display. Under Current Condition until current is restored above 50mA and all capacitor steps get disconnected.
PRACTICAL ANALYSIS
After Correction Of Machine Laboratory
PRACTICAL CORRECTION OF POWER FACTOR FOR CNC LABORATORY Before Correction
After Correction of CNC laboratory