 Transformer / Reactor
| 158 - Superimposed Direct Current Characteristic Analysis of a Reactor
Accounting for the Minor Hysteresis Loop |
Module:ST,FQ |
2011-01-17 |
A high-frequency reactor, used in equipment such as DC-DC converters, has
a high-frequency current accompanying the switching direct current. The
performance of a reactor is evaluated by a stable inductance in a wide
direct current region superimposed with alternating current components.
The initial magnetization curve is typically used for the magnetization
properties of electromagnetic steel sheet in the magnetic field analysis,
but the operating points are on the miner loops of the hysteresis curve
when a high-frequency alternating current component is superimposed on
the direct current component. (Fig. 1) Differences in the superimposed
direct current characteristics become apparent when the minor loops differ
significantly from the initial magnetization curve. In this case, the inductance
needs to be obtained by taking into account the minor loop.
This example presents the use of a magnetic field analysis to obtain the
superimposed direct current characteristics of a high-frequency reactor
accounting for the minor hysteresis loop by using the frozen permeability
condition. |
| 152 - Electromagnetic Force Analysis of Short-circuited Power Transformer
Windings |
Module:FQ |
2011-07-12 |
Electromagnetic force is produced by the current on the windings of the
transformer. The windings can be deformed or damaged by the powerful electromagnetic
force produced when there is a short-circuit current flowing. Therefore,
confirming where the various forces are acting on the windings using analyses
is vital.
This note presents the use of a magnetic field analysis to obtain the Lorentz
force density and electromagnetic force produced in the windings when short-circuited
by changing the position of the windings to display the effects of the
primary and secondary windings. |
| 151 - Evaluation Analysis of Insulation for a Power Transformer |
Module:EL |
2011-07-12 |
Insulation technology such as the winding structure, insulation material,
and the insulated structure are vital to supporting further miniaturization
and larger capacities of power transformers. Evaluating the insulation
using electric field analyses is necessary because the insulation strength
of transforms depends on the intensity of the electric field. The design
does not only need to include the steady state of the insulated structure,
but also the overvoltage including the power surges and short circuits.
This example presents the use of an electric field analysis to obtain the
electric field intensity distribution when the maximum electric potential
is applied between windings. |
146 - Stray Loss Analysis of a Transformer
|
Module:FQ,HT,LS |
2011-07-12 |
In recent years, the demands to increase the capacity of high-voltage transformers
while miniaturizing and reducing the cost are getting stricter. Countermeasures
for overheating in areas of the tank caused by leakage flux are important,
especially for transformers with a large voltage capacity.
This note presents the use of loss and thermal analyses to obtain the losses
of the transformer and tank, and then obtain the temperature distribution
of each part based on the losses. |
| 143 - Inductance Analysis of an Air Core Coil |
Module:ST |
2011-01-17 |
| Air core coils that have a smaller inductance than a coil with a core are
used in high-frequency filters and oscillators.The inductance needs to
be investigated thoroughly because any change to the dimensions can affect
the inductance.This example presents the use of a magnetic field analysis
to compare the analyzed inductance of an air core coil with the inductance
that is theorized. |
| 133 - Thermal Analysis of a Three-phase Transformer |
Module:HT |
2011-02-28 |
| Recently, the growing demand for energy conservation and highly efficient
transformers is raising the importance of reducing losses.The iron loss
of the core and the copper loss of the winding cause a raise in temperature
and reduction in the efficiency of a transformer because the energy is
released as heat.Evaluating the heat generated by the iron and copper losses
through simulation becomes advantageous when designing a transformer.This
example presents the use of a thermal analysis to obtain the temperature
distribution of the heat generated by the iron losses and copper losses
of the three-phase transformer. |
| 132 - Loss Analysis of a Three-phase Transformer |
Module:FQ,LS |
2011-01-17 |
| Recently, the growing demand for energy conservation and highly efficient
transformers is raising the importance of reducing losses. The iron losses
of the core and the copper losses of the coil cause a raise in temperature
and reduction in the efficiency of a transformer because the energy is
released as heat. Evaluating the ratio and distribution of the iron and
copper losses through simulation becomes advantageous when designing a
transformer.This note presents the use of a magnetic field analysis to
obtain the iron and copper losses of a three-phase transformer. |
| 123 - Thermal Analysis of a Choke Coil |
Module:HT,TS |
2011-03-31 |
| A choke coil is an electronic component use to prevent currents that exceed
the predetermined frequency. The heat generated by the iron losses of the
core and the copper losses of the coil inside the choke coil need to be
evaluated because of problems that can occur in the choke coil. The loss
distribution obtained with a magnetic field analysis can be used as the
heat source for a thermal analysis in JMAG-Designer. This example presents
the use of a thermal and magnetic field analysis to obtain the temperature
distribution using the iron losses and copper losses in the choke coil
as the heat source. |
| 117 - Iron Loss Analysis of a Transformer |
Module:FQ,LS |
2011-01-17 |
| Recently, the growing demand for energy conservation and highly efficient
transformers is raising the importance of reducing the amount of loss.
Iron loss, which is one of the major losses for transformers, consumes
electric power as heat inside magnetic materials, causing the efficiency
of the transformer to decrease, and the temperature to rise.Evaluating
the percentage and distribution of the iron losses through simulation becomes
advantageous when designing a transformer. This example presents the use
of a magnetic field analysis to obtain the iron loss of a transformer. |
| 110 - Loss Analysis of a Choke Coil |
Module:FQ,TS,LS |
2011-02-28 |
| A choke coil is an electronic component use to prevent currents that exceed
the predetermined frequency. Measures to evaluate the heat source as well
as the core iron losses that occur within the choke coil and the copper
losses of the coil that decrease efficiency need to be used for this analysis.
The iron loss of the core can be obtained from the copper loss and iron
loss of the coil obtained with a mangetic field analysis in JMAG-Designer.
The example presents the use of a copper and iron loss analysis to obtain
the copper and iron losses of a choke coil. |
| 105 - Leakage Inductance of a Transformer |
Module:FQ,TS |
2012-01-25 |
Estimating the size of the inductance for a transformer is vital during
the design process. It is advantageous to measure the leakage inductance
using a simulation as it is difficult to calculate by hand.
This example presents the use of a magnetic field analysis to obtain the
self-inductance and leakage inductance of a transformer when the arrangement
of the secondary coil is modified. |
| 101 - AL-Value Current Characteristic Analysis of a Choke Coil |
Module:ST |
2011-01-17 |
The AL-value indicating the inductance for the number of turns of a coil
is one of the vital parameters when designing a transformer or choke coil.
Analyzing the current characteristics for the AL-value using a simulation
is advantageous because the AL-value is often set by the design specifications
and the AL-value varies with the input current.
This example presents the use of a magnetic field analysis to obtain the
AL-value current characteristics of a choke coil. |
| 99 - Superimposed Direct Current Characteristic Analysis of a High Current
Reactor |
Module:TR |
2011-01-17 |
| High current reactors with a high-frequency have a superimposed current
composed of a high-frequency ripple and direct current.The performance
of a reactor is evaluated by a stable inductance in a wide direct current
region.The gap that is designed to prevent magnetic saturation from the
core largely affects the inductance. The gap is a vital parameter of the
reactor's design.This example analyzes the superimposed direct current
characteristics of a high current reactor with a high frequency. |
| 97 - Sound Pressure Analysis of a Transformer |
Module:FQ,DS |
2011-07-12 |
| In recent years, the demand to reduce the vibration and noise while improving
the efficiency of transformers is increasing with the demand for environmental
conservation, such as energy conservation. A sound pressure analysis using
the electromagnetic force obtained with a magnetic field analysis as excitation
force can be used to evaluate the resonance phenomena of transformers caused
by the electromagnetic force and the eigenfrequencies. This note presents
the use of a coupled magnetic field and sound pressure analysis to obtain
the electromagnetic force produced in the core and the sound pressure distribution
caused by the resonance of the eigenfrequency in the transformer. |
| 81 - AL-value Analysis of a Choke Coil |
Module:ST |
2011-02-28 |
The AL-value is one of the vital parameters when designing choke coils.
Analyzing the air gap versus the AL-value using simulations is advantageous
because the AL-value is often set by the design specifications and it varies
with the width of the air gap.
This example presents the use of a magnetic field analysis to obtain characteristics
of the air gap versus the AL-value for a choke coil. |
| 78 - Loss Analysis of a Sheet Coil Transformer |
Module:FQ,LS |
2011-01-17 |
| Recently, the growing demand for energy conservation and highly efficient
transformers is raising the importance of reducing the amount of loss.
Iron loss, which is one of the major losses for transformers, consumes
electric power as heat inside magnetic materials, causing the efficiency
of the transformer to decrease, and the temperature to rise. Evaluating
the ratio and distribution of the iron losses through simulation becomes
advantageous when designing a transformer.This note presents the use of
a magnetic field analysis to obtain the iron losses of a transformer. |
| 75 - Iron Loss Analysis of a Reactor |
Module:FQ,LS |
2011-01-17 |
| Recently, the growing demand for energy conservation and highly efficient
reactors is raising the importance of reducing the losses from reactors.Iron
loss, which is one of the major losses for reactors, is produced when energy
is released as heat, causing the efficiency to decrease, and the temperature
of the reactor to rise.Evaluating the percentage and distribution of iron
loss through simulation becomes advantageous when designing a reactor.The
example analyzes the iron loss of a reactor. |
| 61 - Current Distribution Analysis of a Choke Coil |
Module:DP,TS |
2011-02-28 |
A choke coil is an electronic component use to prevent high-frequency currents
that exceed the predetermined frequency.
The cooper losses of the coil produced within the choke coil not only decrease
the efficiency, but also generate heat.
In addition to the skin effect and proximity effect, an imbalanced current
caused by flux leakage around the gap increases the copper losses.
This example presents the use of a magnetic field analysis to obtain the
current distribution and copper losses of a choke coil. |
| 60 - Superimposed Direct Current Characteristic Analysis of a Reactor |
Module:TR |
2011-01-17 |
| A high-frequency reactor, used in equipment such as DC-DC converters, has
a high-frequency current accompanying the switching direct current.The
performance of a reactor is evaluated by a stable inductance in a wide
direct current region.The gap that is designed to prevent magnetic saturation
from the core largely affects the inductance. The gap is a vital parameter
of the reactor. |
| 52 - Inductance Analysis of a Sheet Coil Transformer |
Module:FQ |
2011-01-17 |
| The geometry of transformers used for power supply circuits, etc., gets
larger as the current flowing through the transformer gets larger. A sheet
coil transformer is a transformer that is made flat by winding the coil
with thin sheets of metal. One vital element required in the design of
transformers is the inductance. The product development stage can be streamlined
by obtaining the inductance in advance through a simulation. This note
presents the use of a magnetic field analysis to obtain the inductance
of a coil sheet transformer. |
| 32 - Analysis of a Transformer |
Module:FQ |
2011-01-17 |
A transformer is an electrical device that converts the voltage level of
alternating-current power using electromagnetic induction.
Although the secondary voltage is required to be constant regardless of
the load, it varies with amount of the load and the power factor. To ensure
the access to constant voltage, the size of the voltage variation is one
of the important output characteristics of the transformer.
Maintaining the balanced state is also the critical issue, since the imbalanced
voltage and current of each phase may cause the trouble to the device as
well as the temperature rise.
This note presents the use of magnetic field analysis to evaluate the changes
in the secondary voltage caused by the load variation of a low frequency
transformer. |
| 4 - Sound Pressure Analysis of a Reactor UP! | Module:DS,TR | 2012-04-10 | Reactors are used in a variety of electric power systems. For instance, they fill the role of making the current pulsation between an inverter and a motor more smooth. On the other hand, the sound that originates from a resonance phenomenon between an electromagnetic force and an eigenfrequency can become a problem.
The reactor in this analysis has a gap in the magnetic circuit to prevent magnetic saturation. Due to the magnetic fields that occur with high frequency currents, electromagnetic force generates near the gap, and this electromagnetic excitation force in turn causes noise. Vibration and sound grow larger when the electromagnetic excitation force and the transformer's eigenmode resonate. In order to evaluate this phenomenon with good accuracy, it is necessary to find the electromagnetic force distribution and eigenmode in the high frequencies that become particular problems by using the finite element method (FEM).
This Application Note shows an example of an evaluation of a reactor's sound pressure when a part of a spacer has been removed.
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