EPCOS Product Profile 2013
Power Factor Correction
Power Quality Solutions
www.epcos.com
Contents
Power Quality Solutions
Preview
PFC capacitor series overview
PQS key components overview
Important notes
PFC capacitors
¼
PhaseCap Premium (230 … 800 V, 5.0 … 33 kvar)
¼
PhaseCap Compact (230 … 1000 V, 5.0 … 33 kvar)
¼
PhaseCap HD (400 … 525 V, 40 … 60 kvar)
¼
PhiCap (230 … 525 V, 0.5 … 30 kvar)
¼
MKV capacitors (400 … 800 V, 4.2 … 30 kvar)
PF controllers and measuring devices
¼
BR604, BR6000, BR7000, BR7000-T, BR7000-I series and BR7000-SOFT
¼
Multi Measuring Interfaces
¼
Grid analysis tool MC7000-3
Switching devices
¼
Capacitor contactors
¼
Thryristor modules for dynamic PFC TSM series
Reactors
¼
Reactors – Antiresonance harmonic filter
¼
Discharge reactor
Fundamentals of Power Factor Correction
¼
Components for Power Factor Correction
¼
Standard values: Selection tables for cables, cable cross sections and fuses
¼
Calculation table for reactive power demand (Qc)
¼
Individual PFC for motors
¼
Individual PFC for transformers
¼
Detuned PFC in general
¼
Detuned PFC: Important facts and instructions
¼
Component selection tables for detuned PFC
¼
Dynamic PFC: Important facts and instructions
¼
Component selection tables for dynamic PFC
¼
PFC basic formulas
Cautions
Addresses
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© EPCOS AG 2013
Preview
General
The increasing demand of electrical
power and the awareness of the
necessity of energy saving is very up
to date these days. Also the aware-
ness of power quality is increasing,
and power factor correction (PFC) and
harmonic filtering will be implemented
on a growing scale. Enhancing power
quality – improvement of power factor
– saves costs and ensures a fast
return on investment. In power distrib-
ution, in low- and medium-voltage
networks, PFC focuses on the power
flow (cos
ϕ)
and the optimization of
voltage stability by generating reactive
power – to improve voltage quality and
reliability at distribution level.
How reactive power is generated
Every electric load that works with
magnetic fields (motors, chokes,
transformers, inductive heating, arc
welding, generators) produces a vary-
ing degree of electrical lag, which is
called inductance. This lag of inductive
loads maintains the current sense (e.g.
positive) for a time even though the
negative-going voltage tries to reverse
it. This phase shift between current
and voltage is maintained, current and
voltage having opposite signs. During
this time, negative power or energy
is produced and fed back into the
network. When current and voltage
have the same sign again, the same
amount of energy is again needed to
build up the magnetic fields in induc-
tive loads. This magnetic reversal
energy is called reactive power.
In AC networks (50/60 Hz) such a
process is repeated 50 or 60 times a
second. So an obvious solution is to
briefly store the magnetic reversal
energy in capacitors and relieve the
network (supply line) of this reactive
energy. For this reason, automatic
reactive power compensation systems
(detuned/conventional) are installed for
larger loads like industrial machinery.
Such systems consist of a group of
capacitor units that can be cut in and
cut out and which are driven and
switched by a power factor controller.
Apparent power S =
√P²
+ Q²
Active power P = S * cos
ϕ
Reactive power Q = S * sin
ϕ
With power factor correction the apparent power
S can be decreased by reducing the reactive
power Q.
Reactive Power [kvar]
Q
2
= S
2
— P
2
Q
2
Q
1
P
Q
C
ϕ
1
ϕ
2
S
2
S
1
Apparent Power [kVA]
S
2
= P
2
+ Q
2
Active Power [kW]
P
2
= S
2
— Q
2
© EPCOS AG 2013
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Preview
Power factor
Low power factor (cos
ϕ)
Low cos
ϕ
results in
¼
higher energy consumption and
costs,
¼
less power distributed via the
network,
¼
power loss in the network,
¼
higher transformer losses,
¼
increased voltage drop in power
distribution networks.
Power factor improvement
Power factor improvement can be
achieved by
¼
compensation of reactive power
with capacitors,
¼
active compensation – using
semiconductors,
¼
overexcited synchronous machine
(motor/generator).
Types of PFC
(detuned or conventional)
¼
individual or fixed compensation
(each reactive power producer is
individually compensated),
¼
group compensation (reactive power
producers connected as a group
and compensated as a whole),
¼
central or automatic compensation
(by a PFC system at a central point),
¼
mixed compensation.
Uninterruptible Power
Supply
(optional)
C
EMC filter
Power Factor Correction (PFC)
and Harmonic Filtering
DC link
(Aluminum electrolytic
or film capacitors)
Frequency converter
Tuned
harmonic
filters
Overvoltage
protection
Linear load
with fixed
PFC
Overvoltage
protection
Dynamic
PFC
systems
Overvoltage
protection
Passive
harmonic
filters
Overvoltage
protection
Active
harmonic
filters
Overvoltage
protection
M
3~
Output filter
C
Charging
resistor
EMC filter
250/350/
550 Hz
M
3~
(detuned
PFC
systems)
4
© EPCOS AG 2013
Preview
U
I
I
U
Linear loads:
voltage was followed
by current.
Non linear load produce
non sinusoidal currents when
connected to sinusoidal voltage.
PQS strategy
Along with the emerging demand for
power quality and a growing aware-
ness of the need for environmental
protection, the complexity in the ener-
gy market is increasing: users and
decision-makers are consequently
finding it increasingly difficult to locate
the best product on the market and to
make objective decisions. It is in most
cases not fruitful to compare catalogs
and data sheets, as many of their
parameters are identical in line with
the relevant standards. Thus operating
times are specified on the basis of
tests under laboratory conditions that
may differ significantly from the reality
in the field. In addition, load structures
have changed from being mainly linear
in the past to non-linear today. All this
produces a clear trend: the market
is calling increasingly for customized
solutions rather than off-the-shelf
products. This is where Power Quality
Solutions come into the picture. It of-
fers all key components for an effec-
tive PFC system from a single source,
together with:
¼
Application know-how
¼
Technical skills
¼
Extensive experience in the field of
power quality improvement
¼
A worldwide network of partners
¼
Continuous development
¼
Sharing of information
These are the cornerstones on which
Power Quality Solutions are built. On
the basis of this strategy, EPCOS is
not only the leading manufacturer of
power capacitors for PFC applications
but also a PQS supplier with a century
of field experience, reputation and
reliability.
© EPCOS AG 2013
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