General Information

General Information
Vishay ESTA
High Voltage Power Capacitors
SCOPE
Single phase capacitor units from 1kV up to maximum 24kV,
50 or 60Hz, 20kVAr up to maximum 1000kVAr
for indoor or outdoor use.
- with dead casing, open terminal IP00 (2 bushings)
- with dead casing, type of enclosure IP55 (2 bushings)
- with live casing, open terminal IP00 (1 bushing)
Three phase capacitor units from 1kV up to maximum 12kV,
50 or 60Hz, 20kVAr up to max. 800kVAr with pressure
monitoring device.
- with dead casing (3 bushings), open terminal IP00
(indoor use only)
- with dead casing (3 bushings), protected terminals, type of
enclosure IP55 (indoor or outdoor)
STANDARDS
- VDE 0560/4 “Bestimmungen für Leistungs-Kondensatoren”
- IEC 60871-1 Power Capacitors
- IEC 143 ‘Series capacitors for power systems
- AS 2897 Shunt Capacitors for connection to Power
frequency systems
- ANSI IEEE Std 18 Shunt power capacitors
- NEMA CP-1 Shunt Capacitors
- CSA C22.2 No.190 ‘Capacitors for power factor correction
- BS 1650 Specification for Capacitors for connection to
power frequency systems
Capacitors in accordance with other standards, available
upon request.
QUALITY MANAGEMENT SYSTEM
ISO 9001, BS 5750
QUALIFICATIONS
- EDF (HN 54-S-05)
- CSA Std. C22.2 No 190-M1985
SAFETY REGULATIONS
When installing the equipment, relevant ICE or VDE
recommendations shall be observed, in particular VDE 0101
and 0111, as well as VDE 0560 Part 4 Section C.
Quality management system: ISO 9001, BS 5750
Qualifications: EDF (HN 54-S-05), CSA
FIELDS OF APPLICATION
POWER FACTOR CORRECTION
The active power produced by the active current can alone
be turned into an effective use for the consumer; while the
reactive power produced by the reactive current does not
yield usable power, and consequently, is not registered
on the active performance meter. The reactive power has,
however, a negative effect on generators, transformers, and
conductor lines, while causing voltage drops and financial
losses due to additional electric heating.
www.vishay.com
2
The reactive power required for the creation of the magnetic
fields around motors, transformers, and conductor lines
continuously oscillates between the current generators and
the consumers. A more cost effective way to provide this
reactive power is to produce it by placing capacitors close
to the consumers of reactive power (motors, transformers),
thus relieving the line between generator and consumer
of the transport of the reactive current portion. This way,
several more current consumers can be connected to an
existing supply system without having to extend or amplify
that system if the capacitors are suitably positioned.
Individual Power Factor Correction
The power factor correction capacitor is connected directly to
the terminals of the consumer and will be switched together
with it. The advantages of this method are: Relief of the
conductor lines and switches, no capacitor switches or
discharge resistors are needed, and the installation is simple
and cheap. The individual compensation is the best solution
for large consumers (e.g. motors), particularly if they are
in continuous operation.
Individual Power Factor Correction of 3-Phase Motors
The motor and the capacitor are connected in parallel.
They are both switched in and out by means of one and
the same switchgear and also monitored by a common
protective device. A discharge device is not required, because
discharging takes place through the motor windings.
The switchgear must be rated to be capable of withstanding
the inrush current of the capacitor and the connection lines
must be capable of withstanding the full load current of the
motor. The capacitor, in this case, has to be installed in close
proximity to the motor.
Individual Power Factor Correction of Power Transformers
The direct connection of the capacitor to a power transformer,
which is jointly switched in and out, is feasible and permissible
both at the H.V. side and the L.V. side.
In cases where harmonics exist in the line, the line should
be checked to determine whether the capacitors and the
power transformer are connected in series and create a
resonance.
Care should be taken not to overcompensate the power
transformer during low load operation in order to avoid an
unacceptable rise in voltage.
Individual Power Factor Correction of Welding Machines
The output of capacitors for welding transformers and
resistance welding machines only needs to be in the range of
30% to 50% of the nominal transformer capacity. For welding
rectifiers, a capacitor output of about 10% of the nominal
capacity of the transformer/rectifier is sufficient.
Group Power Factor Correction
The power factor correction capacitor is connected to the
secondary distribution system which feeds a number of
individual motors, operating either continuously or at intervals.
The motors and the capacitors are each switched in and
out separately and are monitored by separate protective
devices. The capacitors can be switched in or out individually
or in groups.
Document Number: 13107
Revision 27-May-02
General Information
High Voltage Power Capacitors
In large installations where many individual electrical
appliances of various size (motors etc.) operate at different
times and for different periods, the power factor correction
capacitors are centrally connected to the main buss bar. The
capacitors can be switched either manually or, by means of
power factor control relays, automatically.
Curve 1
Losses as a function of operating time
Losses=f(t)
W/kvar
Central Power Factor Correction
Vishay ESTA
0.2
0.15
0.1
Advantage
Automatic control and optimal matching of the capacitor
output to the specific requirements for reactive power insures
that the specified cos phi is maintained in the most cost
effective way.
0.05
0
0
3
6
Disadvantage
The conductor lines between the buss bar and electrical
appliances are not relieved of the reactive current.
D General Data
9
12
operating time in months
Losses variation of a representative capacitor unit
Curve 2
Losses as a function of dielectric temperature
Dielectric
An all film dielectric is used and consists of polypropylene
in the form of biaxially oriented film, hazy on both side,
and in 2 or 3 layers with a laser cut aluminium foil for the
electrodes.
W/kvar
Losses=f(T)
0.2
0.15
0.1
Impregnating Agent
0.05
The capacitors are impregnated with a NON-PCB based
fluid.
0
–20
Dielectric Losses and Total Losses
The dielectric losses, depending on capacitor design, shall
be added to the losses caused by:
- discharge resistors
- internal connections
- internal fuses
Total losses will reach values from 0.07 to approx.
0.15W/kVAr.
20
40
60
80
100
Temperature (˚C)
Curve 3
Capacitance as a function dielectric temperature
Capacitance=f(T)
Cn/C20°C [%]
Dielectric losses in new state are approx. 0.1W/kVar and
reduce after 500 operating hours to a stable state of approx.
0.02 to 0.05W/kVar (see curve 1 and curve 2).
0
104
102
100
98
Testing
Capacitors are tested in accordance with IEC-Standard
60871-1
Other standards upon request.
Document Number: 13107
Revision 27-May-02
96
–20
0
20
40
60
80
100
www.vishay.com
3
General Information
Vishay ESTA
High Voltage Power Capacitors
Temperature Range
Capacitors are classified in temperature categories, with each category being specified by a number followed by a letter.
AMBIENT AIR TEMPERATURE (°C)
SYMBOL
MAXIMUM
HIGHEST MEAN OVER ANY PERIOD OF
24 HOURS
1 YEAR
A
40
30
20
B
45
35
25
C
50
40
30
D
55
45
35
The number represents the lowest ambient air temperature at which the capacitor may operate.
The letters represent upper limits of temperature variation ranges, having maximum values specified in above table.
Overloads
a) Maximum permissible voltage (continuous)
Capacitor units shall be suitable for operation at voltage levels according to the following table.
The amplitudes of the over voltages that may be tolerated without significant deterioration of the capacitor depend on the
duration, the total number and the capacitor temperature.
TYPE
Power
frequency
VOLTAGE FACTOR
(t.m.s)
MAXIMUM
DURATION
OBSERVATION
1.0UN
continuous
Highest average value during any period of
capacitor energization. For energization periods
less than 24h, exceptions apply in accordance with
the value below
1.1UN
12h in every 24h
System voltage regulation and fluctuations
1.15UN
30 min in every 24h
System voltage regulation and fluctuations
1.2UN
5 min
Voltage rise at light load
1.3UN
1 min
b) Maximum permissible current
Capacitor units shall be suitable for continuous operation at an r.m.s. current of 1.30 times the current that occurs at rated
sinusoidal voltage and rated frequency, excluding transients.
Discharging
Following may be used as discharge device:
- discharge resistors
- discharge coils
- discharge transformers
- windings of motors or transformers
Each capacitor unit shall be provided with means for discharging to 75V or less.
Corrosion Protection
Case material:
Pre-treatment:
First coating:
Top coating:
Coating thickness:
www.vishay.com
4
stainless steel (ref.: 4512)
-pickling with acid
-washing with water
-alkalinous degreasing
-washing with water
-washing with distilled water
two-component agent on polyacryl basis, (Percotex LA-Universal green)
Dedelan, two component agent on acryl-polyurethan basis (color RAL 7033)
total 50-60µm
Document Number: 13107
Revision 27-May-02
General Information
High Voltage Power Capacitors
Vishay ESTA
Protection Devices for Power Capacitors
Detailed information is provided in IEC 60871-3 “Protection
of shunt capacitors and shunt capacitor banks.”
a) Internal Fuses
Detailed information is provided in IEC 60871-4 “Internal
fuses.”
Internal fuses are designed to isolate faulty elements in order
to allow further operation of the capacitor unit and the bank
in which the capacitor is connected.
Complete protection is obtained when using internal fuses
together with an unbalance protection device.
b) Pressure Monitoring Device
The pressure inside the capacitor casing is monitored by
means of an over pressure sensor. In the event that the
setting (critical value) is exceeded, a change-over contact
initiates disconnection of the capacitor. Such an early
disconnection from the source of supply after an internal
breakdown can stop gas evolution in the capacitor casing,
avoiding the bursting of it.
Complete protection is obtained when using the pressure
monitoring device together with H.R.C. fuses.
Technical Data
Casing:
Electrical connection:
Contacts:
Insulation test voltage:
Setting range:
Standard setting:
Pressure limit:
Accessory:
Temperature range:
Dimension:
Fitting:
Mounting position:
Testing:
Important !
Bakelite, resistant up to 100°C
AMP-plug type lugs 6.35mm
1 change-over contact 15 A/220V ohmic load
1500V
0.2 - 0.9 bar
0.6 - 0.8 bar
6.0 bar
rubber protective cap
- 25° up to + 70°C
see dimension
R 1/4" and mechanical protection
dependant on design of capacitor
functional test and leakage test
If the pressure monitoring device has operated, the capacitor must not be placed back into service,
but returned together with the device to our factory for examination.
EXAMPLES OF MOUNTING:
35
80
120
2
1
4
Pg9
35
=
=
85
75
2
4
1
55
65
=
Document Number: 13107
Revision 27-May-02
=
www.vishay.com
5