 Open Access
 Total Downloads : 1733
 Authors : G. Sitaramaraju, B. Srinivas, C. Manoj Reddy, R. Sudha
 Paper ID : IJERTV2IS41002
 Volume & Issue : Volume 02, Issue 04 (April 2013)
 Published (First Online): 29042013
 ISSN (Online) : 22780181
 Publisher Name : IJERT
 License: This work is licensed under a Creative Commons Attribution 4.0 International License
Electical Characteristics of Metallized Polypropylene Film Capacitor with General Technical DataComparative Study
G. Sitaramaraju, B. Srinivas, C. Manoj Reddy, R. Sudha
School Of Electrical Engineering ,Vit University ,Vellore , India
ABSTRACT:On invention plastic films it became a revolution by replacing electrolyticcapacitor bymetalized plastic film capacitors. Metallized polypropylenefilm(MPPF) provide high insulation voltage
, this feature makes MPPF ideal for applications in high voltage engineering(HVE).The principal objective of the paper is to do about a brief study on Metalized Polypropylene film capacitors by comparativestudy with other metalized plastic films. By graphical study on effects of temperature and humidity across capacitive tolerance(c/c) and electrical characteristics of plastic films and proving how polypropylene films are ideal formaking capacitors by studying ESR and dissipation
factor by taking general technical data of metalized polypropylene films and values are tabulated . A final purpose of this paper is given to create a method of analysis that how the effect of climatic conditions doesnt make much impact on characteristics of MPPF. Therefore veryideal for precision applications.
Index words : metalized terepthalate(MKT ) ,metalized polypropylene(MKP) ,metalized polyethylene naphthalate (MKN),electrical series resistance(ESR).
INTRODUCTON
Polypropylene (PP) is a common polymeric material frequently used in diverse industrial applications because of its excellent mechanical properties. .

Light weight

low cost and

easy recyclability
Capacitor using it as a dielectric, particularly a biaxially oriented polypropylene film excellent in heat resistance and dielectric properties, less in insulation defects and excellent in the impregnation of an insulating oil into the clearances between film layers and swelling resistance when immersed in the insulatingoil, and a capacitor excellentin dielectric properties, corona resistance, longterm thermal durability and electric current resistance, using the film as dielectric.
Structure of polypropylene
Polypropylene film capacitorsare film capacitors with dielectric made of the thermoplastic, nonpolar, organic and partially crystalline polymer material
Polypropylene (PP), trade name Treofan, from the family of polyolefins. Polypropylene film is the mostuseddielectric film in industrial capacitors and also in power capacitor types. Predictable linear and low capacitance change with operating temperature.
APPLICATION
Suitable foruse in situations where failure of the capacitor could lead to danger of electric shock.Suitable for applications in Class1 frequency determining circuits and precision analog applications. Very narrow capacitances. Extremely low dissipation factor.Low moisture absorption, therefore suitable for "naked" designs with no coating. High insulation resistance. Usable in high power applications such as snubber or IGBT. Used also in AC power applications, such as in motors or power factor correction. Very low dielectric losses. Highfrequency and highpower applications such as induction heating. Widely used for safety/EMI suppression, including connection to power supply mains.
GENERAL TECHNICAL DATA

Dielectric: polypropylene film.

Plates:metal layer deposited by evaporation undervacuum.

Winding:Noninductive type.

Leads:Tinplated copper wire.

Plastic case: PBT material solven resistant &flame
retardant according to UL94V0.

Filling:Epoxy Resin with flame retardant according to UL94V0.

Marking: Company logo, capacitor type, capacitance, tolerance, capacitor class, rated voltage, approvals climatic category, passive flammability category, date code.

Operating temperature range: – 40 to +110 Climatic category: 40/110/56 IEC 600681

Related documents: IEC6038414, EN6038414 UL6038414, CSA6038414.
Damp heat steady state Test
Performance
condition
Dielectric strength:No dielectric
breakdown or flashover at 1500Vac/1
min.
Temperature: 40Â±2
Capacitance change:5%
Relative humidity: 93%Â±2%
Insulation resistance:50% of initial
Test duration: 56 days
limit
Endurance Test condition
Performance
Dielectric strength:No dielectric
breakdown or flashover at 1500Vac/1
Temperature: 110Â°CÂ±2C
min.
Test duration: 1000 h
Capacitance change: 10%
Voltage applied:
Insulation resistance: 50% of initial
1.7VR+1000Vac 0.1s/h
limit
Resistance to soldering heat Test
Performance
condition
Capacitance change: 2%
Solder bath temperature:
260Â°CÂ±5Â°C
Dipping time: 10sÂ±1s
Damp heat steady state Test
Performance
condition
Dielectric strength:No dielectric
breakdown or flashover at 1500Vac/1
min.
Temperature: 40Â±2
Capacitance change:5%
Relative humidity: 93%Â±2%
Insulation resistance:50% of initial
Test duration: 56 days
limit
Endurance Test condition
Performance
Dielectric strength:No dielectric
breakdown or flashover at 1500Vac/1
Temperature: 110Â°CÂ±2C
min.
Test duration: 1000 h
Capacitance change: 10%
Voltage applied:
Insulation resistance: 50% of initial
1.7VR+1000Vac 0.1s/h
limit
Resistance to soldering heat Test
Performance
condition
Capacitance change: 2%
Solder bath temperature:
260Â°CÂ±5Â°C
Dipping time: 10sÂ±1s
RELIBILITY TEST METHOD &PERFORMANCE:
ELECTRICAL CHARACTERISTICS TEST CONDITIONS

Capacitance range: 1000pF ~ 1.0F

Capacitance tolerances: (measured at 1KHZ )
.Â±10%(K); Â±20%(M)

Rated Voltage: 300Vac/1000Vdc;50/60Hz

Dissipation Factor: tg 104 at +25Â°CÂ±5Â°C
30 (20 D typical) at 1 kHZ
Insulation Resistance: Test conditions

Temperature: 25Â°C Â±5Â°C

Voltage charge: 100 Vdc

Charge time: 1 Min.
Performance

C 0.33uf : 1Ã—105 M (typical value . 5×10 5 M)

C > 0.33uF: 30000 s (typical value . 150000 s)

Test Voltage: at 25Â°C Â±5Â°C 2500VAC for . (Between terminal) 1 sec+ 5000Vdc for 1sec

www.
CHARACTERITICS OF PPF WHICH MADE T IDEAL WHEN COMPARED TO OTHER PLASTIC FILMS
Dielectric 
PP 
PET 
PEN 

Dielectric constant(r) 
2.2 
3.2 
3.0 

C drift with time(iz=c/c) 
% 
3 
3 
2 
C Temperature coefficient 
10^6 
250 
+600 
+200 
C humiditycoefficient c(50.95%) 
10^ 6/%r.h 
40..100 
500..700 
700..900 
Dissipation factor(1 kHz) 
0.0005 
0.0050 
0.0040 

Time constant 
s 
100000 
25000 
25000 
Dielectric absorption 
% 
.05 
0.2 
1.2 
ELECTICAL CHARACTERISTICS
EQUIVALENT CIRCUIT DIAGRAM
Any real capacitor can be modelled in following schematic:
Ls series inductance
Rs series resistance, due to contacts C capacitance
Rp parallel resistance,due to insulation resistance
Ls, C, Rsare the magnitudes that vary in frequency domain
Rpis the magnitude of insulation resistance measured in DC
CAPACITANCE
RATED CAPACITANCE/MEASURING CONDITIONS
Rated capacitance is the value of capacitor for which it is designed and indicated on it.
Capacitance is measured by standards IEC 600681
Measuring conditions 
Standard conditions 
Referee conditions 
Temperature 
1535Â°C 
(23Â±1)Â°C 
Relative humidity 
4575% 
(50Â±2)% 
Ambient atmospheric pressure 
86106kPa 
86106kPa 
Frequency 
1kHz 
1 kHz 
Voltage 
0.03*Vr(max. 5V) 
0.03*Vr(max. 5V) 
Prior to being measured capacitor should be maintained at standard temperature and humidity until entire capacitor maintain constant values.
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ijert.org
VARIATION OF CAPACITANCE WITH TEMPERATURE
Capacitance will undergo reversible changewithin a range of temperatures between the upperand lower category temperatures. The gradient of the capacitance/temperature curve is given bythe temperature coefficient c of the capacitance, which is defined as the average capacitance change, in relation to the capacitance measured at (20 Â±2)
Â°C, occurring within the temperaturerange T1 to T2. It is expressed in units of 106/K.
C1 Capacitance measured at temperature T1
C2 Capacitance measured at temperature T2
C3 Reference capacitance measured at (20 Â±2) Â°C The temperature coefficient is essentially determined by the properties of the dielectric, the capacitor construction and the manufacturing parameters. Polypropylene capacitors have negative temperature coefficients, polyester capacitors have positive temperature coefficients.
Dielectric 
PP 
PET 
PEN 

C temperature coefficient c 
106/K 
250 
+600 
+200 
Reversible changes of capacitance with temperature are usually expressed as C/Cshows typical temperature chara cteristics of different capacitor styles.
Relative capacitance change C/C vs. temperature T (typical values)
VARIATION OF CAPACITANCE WITH HUMIDITY
The capacitance of a plastic film capacitor will undergo a reversible change of value in relationto any change in the ambient humidity. Depending on thetype of capacitor design, both the dielectric and the effective air gap between the films will react to changes in the ambient humidity,which will thus affect the measured capacitance.The humidity coefficient c is defined as the relative capacitance change determined for a 1%change in humidity (at constant temperature).
C = 2*(C2 C1)/((C2+C2)*(F2F1))
C1 Capacitance at relative humidity F1 C2 Capacitance at relative humidity F2
The values of c given in table are valid for a
relative humidity range of 50% to 95%. At relative humidity below 30%, the humidity coefficient is rel atively low. Wide variations are to be expected
at relative humidity above 85%.
Figure shows typical capacitance/humidity character istics of different capacitor styles.
Relative capacitance change C/C vs. relative humid ity (typical values)
VARIATION OF CAPACITANCE WITH FREQUENCY
As figure shows, in polypropylene capacitors (PP
MKP, MFP), the capacitance remains virtually unaffected by fr equency up to 1 MHz. In polyester capacitors (PET
MKT) and especiallyin PEN capacitors (polyethylene naphthala te, MKN), the effect of frequency is more noticeable.
Dielectric 
PP 
PET 
PEN 

C humidity coefficient c 
10/%r.h 
40100 
500700 
700..900 
Relative capacitance change C/C vs. frequency f (typical exa mple)Additionally, in the vicinity of the natural resonant f
Since
requency of the capacitors, selfinductanceleads to an additio nal decrease of impedance.
2
V
V
ESR
=(ESR2/ESR2+(1/2f*C)2)*V2
VARIATION OF CAPACITANCE WITH TIME
and since for film capacitors tan = 2f C ESR<<0. 1
In addition to the changes described, the capacitance of a c apacitor is also subjected to irreversible changes known as dr
V
V
2
ESR
=ESR2*(2f*C)2*V2
ift iz = C/C . The values stated for capacitance drift (see tabl e below) are maximum values and refer to a twoyear period an d a temperature up to 40 Â°C. Here thereversible effects of tem perature changes (c and changes in relative humidity (c) are not takeninto consideration.
Drift is stabilized over time and thus provides the long
term stability of capacitance. However, itmay exceed the sp ecified values if a capacitor is subjected to frequent,large temperaturechanges in the vicinity of the upper category temper ature and relative humidity limits.
ESR AND DISSIPATION FACTOR
Under an AC voltage signal of specified frequency, the equivalent circuit diagram can be simplified to a series connection of the capacitance C, an equivalent series resista nce(ESR) and the series inductance LS.Simplified capacitor model for AC. Complex voltage calculation.For frequencies well below the natural resonant frequency (LS, VL ), due to the ESR the phaseshift between voltage and current is slightly less than90Â°. The difference between the phase angle and 90Â° is the defect angle , which is measured through the dissipation factor tan , i.e.the ratio of the equivalent series resistance ESR to the capacitive reactance
XC = 1/2f C.
It can easily be deduced that the dissipation factor is a lso the ratio of effective power (i.e. powerdissipation) to reactive power. Power dissipation can be express ed as a function of the voltageVESR across the equi valent series resistance ESR, or the current I through it:
Tan=ESRÂ·2fÂ·C
ESR
ESR
P=V2 /ESR =ESR*I2
the power can be expressed as P=2f*C*Tan*V2 or P=(2f*C)2*ESR*V2
Both ESR and tan are important because they dictate
the power dissipation of a capacitor andthus its self heating.
Variation of dissipation factor with temperature, h umidity and voltageThe dissipation factor of capacit ors with a polypropylene dielectric is largely unaffec te by temperature, whereas polyester capacitors sho w a characteristic dissipation factor minimum at app rox. 80 Â°C (at 1 kHz).
Dielectric 
PP 
PET 
PEN 
Capacitance drift ir (typical values) 
3% 
3% 
2% 
Dissipation factor tan vs. temperature T for f = 1 k Hz (typical values)
Variation of ESR with frequency
From the definition of tan , ESR can be expressed as:
ESR=tan/2f*C
Thus ESR comprises all the phenomena that can con tribute as resistivity, which have been described for t he dissipation factor . Figureshows a general frequenc y response for afilm capacitor:
At very low frequencies, leakage is prevalent (range no t represented).At low frequencies, ESR is dominated by the dielectric losses, decreasing roughly as f1.
At medium to high frequencies, losses in the conducto rs are dominant and ESR becomes relatively constant. At very high frequencies (>10 MHz) ESR increases by f due to the skin effect.
ESR vs. frequency for an MKT capacitor
ESR variations with temperature and humidity follow t hose of dissipation factor
Insulation resistance
Measuring conditions
The insulation resistance Rins of a capacitor is a meas ure of its resistivity in DC. Under a stationary DC volt age, a leakage current flows through the dielectric and over the capacitor surfaces.Rins is measured by deter mining the ratio of the applied DC voltage to the res ulting leakage current flowing through the capacitor, once the initial charging current has ceased (typical ly after aperiod of 1 min 5 s).The measuring voltage depends on the rated voltage. It is specified in IEC 60 3841.
The specified measuring temperature is 20 Â°C. At othe r temperatures, a correction shall be madeto the measu red value to obtain the equivalent value for 20 Â°C by multiplying the measured resultby the appropriate corr ection factor.
Measuring temperature in Â°C 
Correction factor(average values) according to the sectional specification 

MKT,MFT 
MKN 
MKP,MFP 

15 
0.79 
0.79 
0.75 
20 
1.00 
1.00 
1.00 
23 
1.15 
1.15 
1.25 
27 
1.38 
1.38 
1.50 
30 
1.59 
1.59 
1.75 
35 
2.00 
2.00 
2.00 
In case of doubt a referee measurement at 20 Â°C and (50
Â±2)% relative humidity is decisive.
In the data sheets for the individual types, the insulation resistance Rins is given as a minimum as
delivered value and as a limit value attained after the "da mp heat, steadystate" test.
For capacitors with capacitance ratings >0.33 ÂµF the in sulation is given in terms of a time constant.
= Rins CR (in s)
Factors affecting insulation resistance
As could already be deduced from the correction factor t able, the insulation resistance is affected by temperature , Figure shows the typical behavior of individual types
Rated voltage VR of capacitor 
Measuring voltage 
10VVR<100V 
(10Â±1)V 
100VVR<500V 
(100Â±15)V 
500VVR 
(500Â±50)V 
Insulation as selfdischarge time constant (= Rins Â· CR) in s ( M Â· ÂµF) vs. temperature T(typical valu es)
Insulation resistance is also affected significantly b y humidity (as humidity increases, insulation resistance decreases).
Selfinductance
The selfinductance or series inductance LS of a film ca pacitor is due to the magnetic field createdby the curre ntin the film metallization and the connections. It is t hus determined by the windingstructure, thegeometric design and the length and thickness of the contact path
s. As far as possible, all capacitors described in this dat a book are constructed with lowinductance bifilar elect rodecurrent paths or extendedfoil contacts,and thus fe ature very low inductance. A general rule fordeducin g LS states that the maximum value is 1 nH per mm of lead length and capacitor length.LS can also be calc ulated from the resonant frequency.
Impedance, resonant frequency
The impedance Z represents the component's oppositio n to current flow and is both resistive andreactive in n ature. It is thus of particular importance in AC and ripp le current filtering.From the capacitor model in figure , Z is defined as the magnitude of the vectorial sum of ESRand the total reactance (inductive reactance minus capacitive reactance):
Z=(ESR2+(2fÂ·Ls1/2fÂ·C)2)1/2
Typical impedance characteristics of film capacitors
At low frequencies, the capacitive reactance XC = 1/2f C pr evails, whereas at very high frequencies the inductive reactan ce XL = 2f LS is dominant. When capacitive reactance eq uals inductive reactance, natural resonance occurs. At this po int the reactances cancel each other out andimpedance equals ESR. The natural resonant frequency therefore given by:
fres=1/2*C*Ls
The frequency range of natural resonance (also termed sel
fresonance) as a function of capacitance can be read off th e following diagram
Resonant frequency fresversus capacitance C(typical values)
RESULT
The temperature and frequency dependenciesof electrical parameters for polypropylene film capacitors are very low, the PP capacitors have a linear, negative temperature coefficient of capacitance of Â±2,5 % within their temperature range. Therefore, polypropylene film capacitors are suitable for applications in first class frequencydetermining circuits, filters, oscillator circuits, audio circuits, and
timers. They are also useful for compensation of inductive coils in precision filter applications, and for highfrequency applications.
In addition, PP film capacitors have the lowest dielectric absorption capacity, it makes them suitable for applications such as VCO timing capacitors, sampleandhold and audio circuits.They are available for these precisionapplicationsin very narrow capacitance tolerances.
The dissipation factor of PP film capacitors is smaller than that of other film capacitors. Due to the low and very stable dissipation factor over a wide temperature and frequency range, even at very high frequencies, and their high dielectric strength of 650 V/Âµm, PP film capacitors can be used in metalized and in film/foil versions as capacitors for pulse applications, such as CRTscan deflection circuits, or as socalled "snubber" capacitors, or in IGBT applications. In addition, polypropylene film capacitors are used in AC power applications, such as motor run capacitors or PFC capacitors.
Conclusion
During a few decades, polypropylene allfilm power capacitors impregnated with fluids madefrom biodegradable and nontoxic vegetable oils are of interestamong researchers worldwide. There are four electrical properties of model capacitors which are taken into considerations; capacitance, withstand voltage.
ACKNOWLEDGMENT
We arethankful to Authoritiesat VITUniversity
for their continuous encouragement in using facilities and field work studies.
REFERENCES

Ralph M. keriggan , "Metalized polypropylene film capacitors for low duty cycle in NWL capacitor Division,204 carolina drive ,snow hill.

Film Capacitors
Metallized Polypropylene Film Capacitors (MKP) Series/Type: B32674 … B32678
Date: December 2012
Â© EPCOS AG 2012 [3]M.H.elhusseini, P.venet, G.rojat and C.joubert,Thermal optimization of metalized polypropylene film capacitors, IEEE ind. Applica. Conference,vol.5, pp. 30633068,2000.

M.H.elhusseini, M.H. CNRS, Claude Bernard, Villeurbarne, F.venet, G.rojat and C.joubert , Thermal simulation for geometric optimization of metallized polypropylene film capacitors, IEEE Trans.ind. Applica.,vol.38,pp.713718, May/Jun 2002.

Gustavo Malagoni Buiatti, Juan A. MartÃnRamos AcÃ¡cio, M. R. Amaral ,Piotr Dworakowski and Antonio J. Marques Cardoso, Condition Monitoring of Metallized Polypropylene Film Capacitors in Railway Power Trains, IEEE Trans. Instru. and
measurement, Vol. 58 , Issue: 10 ,pp.37963805, Oct. 2009.

M.H.elhusseini, M.H. CNRS, Villeurbarne, F.venet, G.rojat , ALMajid,M.Fatallah, Improving pulse handling capability of metalized polypropylene films capacitors , Industry Applica. Conference, ThirtySixth IAS Annual Meeting. Conference Record IEEE,vol.4,pp.24812486, Sept. 30 2001Oct. 4 2001.

Metallized polypropylene film capacitor MKP –
Switching – High current www.icel.it/pdf/16_PHC.pdf
G.sita rama raju pursuing BTECH(EEE) in VIT university,vellore.
B.srinivas pursuing BTECH(EEE) in VIT university,vellore.
C.manoj reddy pursuing BTECH(EEE) in VIT university,vellore.
R.Sudha:Assistant Professor(Senior) (SELECT) at VIT University, Vellore