DEKI CAPACITOR SOLUTIONS - PDF document

DEKI CAPACITOR SOLUTIONSByVishnu –
DEKI CAPACITOR SOLUTIONSByVishnu –Engineer R&DA capacitoris a passive electronic component. It forms the basic building block of an electronic circuit. Without capacitor electronic circuits cannot be designedIt is a device for storing electric charge.consisting of

a pair of conductorsseparated by a d
a pair of conductorsseparated by a dielectric.for blocking direct currentwhile allowing alternating currentto passC = Q/V Farads2CAPACITOR…DEKI ELECTRONICS LTD3CAPACITOR…DEKI ELECTRONICS LTDCONSTRUCTIONSYMBOLTheory of OperationWhen the supply is

given to the conducting plates.Th
given to the conducting plates.The dielectric between the conducting plates will polarize and arrange themselves in a regular fashion.An electron flow occurs from negatively charged plate to the positively charged plate due to polarizationThus current flow from

positively charged plate to the negativ
positively charged plate to the negative plateThe energy stored in the capacitor is given by E=CV2/24DEKI ELECTRONICS LTDParametersA capacitor has four important parameters. Rated Capacitance Rated VoltageInsulation ResistanceIt is the measure of r

esistivity in dc. Under a stationary dc
esistivity in dc. Under a stationary dc voltage, a leakage current flows through the dielectric and over the capacitance surfaces.Rins =V (applied voltage)/I (Leakage current)Loss Factor or dissipation Factor(Tanδ)5DEKI ELECTRONICS LTD6With a perfect dielectric ca

pacitor, current will lead the applied v
pacitor, current will lead the applied voltage by 90º. When dealing with less than perfect dielectric materials, current in a capacitor will lead the applied voltage by less than 90°. This can be visualized in the current-voltage phase relation of a dielectric visualized inThe

loss angle is usually expressed as the
loss angle is usually expressed as the tangent of delta, or just tan delta(dissipation factor)Dissipation Factor…DEKI ELECTRONICS LTD7The ESR is the resistive part of the equivalent series circuit and is temperature and frequency dependent. The ESR can be calculated from the

dissipation factor (tan δ) as follows
dissipation factor (tan δ) as follows:ESR = tan δ / ϖCThe power dissipated by a capacitor is a function of the voltage across or the current (I) through the equivalent series resistance ESR.P = w ×C ×tan δ ×U2P = 2 ×π ×f ×C ×tan δ ×U2where f = frequenc

y, tan δ = maximum value specified, U
y, tan δ = maximum value specified, U =rated voltageESR & Power dissipation…DEKI ELECTRONICS LTDTypes of capacitorsDepending upon the dielectric used, there are several types of capacitorsCeramic CapacitorsPaper capacitorsGlass capacitorsElectrolytic capac

itorsFilm capacitorsPolyester
itorsFilm capacitorsPolyester film dielectricPolypropylene film dielectricPolyethylene Naphthalate dielectricPolyphenylene sulphide dielectric9INDUCTIVE (MYLAR)NON-INDUCTIVE1 ) PP (POLYPROPYLENE)2) PET (POLYESTER)3) PEP (POLYPROPYLENE + POLYESTER)4)

PES5) PSH1 )MPP2) MPET3) PP-NI,PE
PES5) PSH1 )MPP2) MPET3) PP-NI,PET-NI4) PP-MPPDEKI ELECTRONICS LTDDEKI Film CAPACITORS…10INDUCTIVE (MYLAR)High Dv/dt High IRGood Current carrying capability.Better capacitance stabilityDEKI ELECTRONICS LTD11NON-INDUCTIVEFor voltage 250 VAC

For voltage 500 VACFor voltage 750 V
For voltage 500 VACFor voltage 750 VACDEKI ELECTRONICS LTDSmaller size.High ReliabilitySelf Healing12Self Healing…For capacitors made with metalized film, self-healing or "clearing" removes a fault or short circuit in the dielectric film by vaporizin

g the metallization near the defect
g the metallization near the defectThe vaporized metal oxidizes over time, aiding in the isolation of a fault area. The self-healing feature of the metallized capacitor offers a distinct advantage over the non-metallized unit. DEKI ELECTRONICS LTDIf the maximum op

erating temperature105oC -PP
erating temperature105oC -PP film120oC -PET film150oC -PEN film�150oC -PPS film (upto to 170oC)For PP film, •Tanδ<0.0008 at 1 kHz,•Tanδ<0.001 at 10 kHz,•Tanδ<0.003 at 100 kHz.In cost, PP�SPEN�PP&

#x0000;PET film13Selection of filmsDE
#x0000;PET film13Selection of filmsDEKI ELECTRONICS LTDFor PET film,•Tanδ0.008 at 1 kHz,•Tanδ0.015 at 10 kHz,•Tanδ0.030 at 100 kHz.Properties of Films14For PET film:For PP film:Dielectric constant Vs TemperatureDEKI ELECTRONICS LTDC = εoεrA/D15Pro

perties of FilmsFor PP film:For PET fi
perties of FilmsFor PP film:For PET film:Tanδ Vs TemperatureDEKI ELECTRONICS LTDESR = tan δ / 2fC16Properties of FilmsInsulation resistance Vs TemperatureFor PET film:For PP film:DEKI ELECTRONICS LTD17Comparison of filmsDEKI ELECTRONICS LTDDC ApplicationVr &#x

0000; DC voltage of the signalIR shoul
0000; DC voltage of the signalIR should be very highAC Applicationtanδ is very importantself-heating Pulse Applicationhigh current/voltage pulses at short durationsself-heating 18DEKI ELECTRONICS LTDSelection by applicationWHY POLYPROPYLENE CAPACITOR FOR SWITC

HING Polypropylenecapacitoriside
HING Polypropylenecapacitorisidealchoiceforhighfrequencyapplicationsbecauseofitslowlossfactor.Forstriking,thecapacitorshouldhavehighdv/dtratingandlowlossfactor.LowlossfactorispreferredbecauseP=2..f.C.tanδ.VRMS2--------(1)

∆T=P.RTHC--------(2)ïƒ
∆T=P.RTHC--------(2)P=powerdissipationincapacitor.∆T=TemperatureRiseRTH=ThermalresistanceofthecapacitorFromaboveeq.wecantellpowerdissipationisdirectlyproportionaltothefrequency,lossfactorandVRMS.Heatgeneratedin

thecapacitorisproportionaltothepow
thecapacitorisproportionaltothepowerdissipation.Buttemperatureriseisnotallowedmorethan10Catitscategorytemperature.Forpolypropylenecapacitorslossfactorislowathighfrequency.sothetemperatureriseconsiderablelessthanothercapacitor.1920DEKI ELE

CTRONICS LTDCFL…21RFI SUPPRESSION-
CTRONICS LTDCFL…21RFI SUPPRESSION-(C1)Cap Value : 68nf to 220nfX2-Series –275 VACMPET –( 400 –630 Vdc)START UP-(C2)Cap Value :10nf to 100nf(63 –100Vdc) PET Film foil inductive typeMPET For �C 0.082 MfdCFL…( RFI Suppression a

nd Startup)DEKI ELECTRONICS LTD22CFLâ
nd Startup)DEKI ELECTRONICS LTD22CFL…( Snubber & Blocking)SNUBBER-(C3)0.68nf to 0.0033μf(630-1000Vdc)PP Film foil inductive PEP film foil inductive BLOCKING-(C4)Recommended Capacitor is PET ( Film/Foil) .MPET ( Box &Dip) Cap Value : 0.022 –

0.068μfRated Voltage : 250 –400Vd
0.068μfRated Voltage : 250 –400VdcDEKI ELECTRONICS LTD23STRIKING-( C5)cap 0.0022μF to 0.0068 μf.PP inductive typePET inductive type PEP film foil inductiveDPSHMPP-MPPCFL…( Striking)DEKI ELECTRONICS LTD24H.F Ballast…Capacitance value(R

FI Filter) : 0.0047 Mfd to 2.2 Mfd
FI Filter) : 0.0047 Mfd to 2.2 Mfd (for C1-X2 Class (275VAC/305Vac)0.001Mfd to 0.1 Mfd (for C2,C3-250 ~275VAC)For smoothening the wave form after PFC correction Deki has MPET as well as MPP series .Range starts from 10 nf to 10 Mfd . Voltage range is from 420

VDC to 630 VDC. DEKI ELECTRONICS LTDR
VDC to 630 VDC. DEKI ELECTRONICS LTDRFI FilterP.F.C25H.F Ballast…(Striking)Deki Range …AC & Pulse capacitor seriesa) MPP/MPP AC-seriesb) PP/MPP seriesc) MMPP seriesDEKI ELECTRONICS LTD26Selection of capacitor for strikingFollowing condition should be satisfied wh

en selecting capacitor for striking app
en selecting capacitor for striking application.VP Should be less than D.C Rated voltage.VP-P should be less than 2x1.414x VRMS.dv/dt rating should be fulfilledPeak current should be less than C(dv/dt)Temperature rise should be less than 10˚C at its cate

gory temperature.DEKI ELECTRONICS LTD
gory temperature.DEKI ELECTRONICS LTDCapacitors for Energy metersA capacitive power supply is the best solution for a low-cost energy meter. It works on the principle of reducing the line voltage (Voltage dropper) by having a series capacitor between phase and neutral. Cu

rrent flowing through this capacitor is
rrent flowing through this capacitor is inversely proportional to the impedance of the capacitor as given by the formula:Impedance (Z) = 1/(2πfC)f is the line frequency andC is the capacitance of the series impedance capacitor.DEKI ELECTRONICS LTDCapacitanceFunctionT

ypeVoltage RangeCapacitance rangeC1N
ypeVoltage RangeCapacitance rangeC1Noise filterMPP-X2275Vac/305Vac0.01 to 1μFC2Ripple filterElectrolytic--C3 (Series impedance capacitor)Voltage DropperMPP-AC, MPP-X2, MPET-AC-High capacitance stability275Vac/305Vac, 325Vac, 440Vac0.1 to 1μFDEKI E