FQ  Time Harmonic Magnetic (2D/3D)
 185  Analysis of Stray Loss in a Large Transformer
 Module:FQ,LS  20131217  Transformers are made to be used longterm, so it has become an important design policy to control running costs from losses. These losses include copper loss in the coil and iron loss in the core. In highcapacity transformers, however, there is also stray loss in the tank from flux leakage from the core. Stray loss is not only the total loss value, it also poses the risk of generating heat locally so there is a need to check loss distribution. Predicting these losses and the heat that they generate is a vital component of transformer design, but it is difficult to estimate them from desktop calculations, so evaluations and detailed analyses using the finite element method (FEM) are indispensable. This note obtains loss distribution for each component in drive condition and checks local overheating.

 183  Agitation Force Analysis of an Induction Furnace
 Module:FQ  20131217  The purpose of this Application Note is to help JMAG users understand the steps and settings used in a JMAG analysis. It is intended to help those who are working with a new analysis target better understand the analysis steps and the setting contents. The actual JMAG model described in this Application Note is available for download from the JMAG Application Catalog. This model will allow you to view the model, settings and results. You can also create a template from the model to use as a starting point when analyzing your own geometry. They can be downloaded using the same method as the analysis model data. Please refer to the JMAG manual for more information on templates.

 175  PWM Magnet Loss Analysis of an IPM Motor Using a Gap Flux Boundary
 Module:DP,FQ  20120608  It is becoming increasingly common for permanent magnet motors to use rare earth magnets in order to achieve higher output density because they have a high energy product. Neodymium rare earth magnets have a high electric conductivity because they contain a great deal of iron, so when a varying magnetic field is applied to them they produce joule loss from eddy currents. IPM structure adoption and field weakening controls have become prevalent in recent years in order to allow faster rotation. This has led to an increase in the frequencies and fluctuation ranges of the varying fields applied to magnets, resulting in a corresponding increase in joule losses. By dividing the magnet like one would a laminated core to control eddy currents, one can obtain a method of lowering the apparent electric conductivity while lowering the eddy currents. Armature reactions in the stator occur before the eddy currents produced in the magnet, so the eddy currents are determined by: The slot geometry of the stator core, the geometry of the rotor, the nonlinear magnetic properties of the core material, and the current waveform that flows through the coil. In order to examine these kinds of magnet eddy currents ahead of time, one has to be precise when accounting for things like these various geometries and material properties. This is why a magnetic field simulation using the finite element method (FEM), which can account for them, would be the most effective. This Application Note explains how to use the gap flux boundary condition to evaluate the eddy current loss in the magnet by changing the number of magnet divisions. This will make it possible to obtain effective results in a shorter period of time than with a normal transient response analysis.

 172  HighFrequency Induction Heating Analysis of a Test Piece (Rotational Induction Hardening)
 Module:FQ,HT  20131217  Machine parts like shafts and gears are made to be resistant to wear and tear. This is accomplished by giving them a certain degree of flexibility by maintaining their interior toughness while increasing the hardness of their surfaces. By using highfrequency induction heating, which is a type of surface hardening method, the part is heated rapidly on only its surface by a high frequency power source. This process also has many other benefits, such as providing a clean working environment because it uses electrical equipment, being very efficient, and providing uniform results for each product. This is why it is being aggressively implemented in the field. With induction hardening like the kind used on the work piece in this analysis, the main requirement is to heat a given surface uniformly and increase rigidity. The highfrequency's varying magnetic field produces eddy currents with an offset in the surface of the work piece, so handling the phenomena inside the work piece with a numerical analysis based on the finite element method (FEM) is the most effective means analyzing the process in detail. This Application Note explains how to create a numerical analysis model when obtaining the optimum coil geometry, current conditions (power supply frequency, current value), and rotation speed. It also shows how to evaluate whether the target temperature distribution is being achieved by analyzing the elevated temperature process.

 166  Line Start Simulation of an Induction Machine Using a Control Simulator and the JMAGRT
 Module:FQ,LS,RT  20130903  Collaborative design is difficult because the controls and motor are designed independently. However, it has become necessary to resolve challenges through highaccuracy simulations at the beginning of the development process in order meet demands for more advanced motors. An effective way of achieving this is for the simulations to be performed while collaborating on the motor design circuit/control designs. An induction motor's characteristics are influenced by leakage reactance and resistance, including resistance on the secondary side. The resistance on the secondary side is affected by the skin effect, so the finite element method (FEM) needs to be used to obtain the distribution of the secondary induced current. With JMAG, it is possible to use a magnetic field analysis to obtain the resistance and leakage reactance, and to create a model of an induction motor, as well. Incorporating this motor model, called a "JMAGRT model," to a circuit/control simulator makes it possible to use JMAGRT to run a linked simulation with it. This Application Note explains how to use the JMAGRT to create a JMAGRT model of an induction motor, import it to a circuit/control simulator, and run an induction motor line start simulation.

 158  Superimposed Direct Current Characteristic Analysis of a Reactor That Accounts for Minor Hysteresis Loops
 Module:FQ,ST  20131217  Highfrequency reactors used in equipment like DCDC converters have a highfrequency current accompanying the switching direct current. The reactor's performance requires a stable inductance in a wide direct current region that is superimposed by alternating current components. If there is only a direct current, the magnetic flux is generated against the external magnetic field, following the magnetic steel sheet's DC magnetization curve. However, when there is a current waveform whose highfrequency components are superimposed on the direct current component, the response displays a minor loop against the external magnetic field. The values of the inductance in the reactor can have significant differences depending on the method used to measure them. This can make it difficult to carry out a performance prediction during an actual state of operation. In order to handle the responsiveness of a magnetic field against a current waveform that is superimposed by a higher harmonic with a small amplitude for the direct current component, a magnetic field analysis that accounts for material modeling needs to be carried out. With a magnetic field analysis, it is possible to analyze the machine characteristics from the magnetic flux density distribution. This Application Note presents the use of the frozen permeability condition to obtain the superimposed direct current characteristic that includes minor hysteresis loops of a highfrequency reactor.

 157  Analysis of Eddy Currents in an IPM Motor Using the Gap Flux Boundary HOT!
 Module:DP,FQ  20140227  It is becoming increasingly common for permanent magnet motors to use rare earth magnets in order to achieve higher output density because they have a high energy product. Neodymium rare earth magnets have a high electric conductivity because they contain a great deal of iron, so when a varying magnetic field is applied to them they produce joule loss from eddy currents. IPM structure adoption and field weakening controls have become prevalent in recent years in order to allow faster rotation. This has led to an increase in the frequencies and fluctuation ranges of the varying fields applied to magnets, resulting in a corresponding increase in joule losses. By dividing the magnet like one would a laminated core to control eddy currents, one can obtain a method of raising the apparent electric conductivity while lowering the eddy currents. Armature reactions in the stator occur before the eddy currents produced in the magnet, so the eddy currents are determined by: The slot geometry of the stator core, the geometry of the rotor, the nonlinear magnetic properties of the core material, and the current waveform that flows through the coil. In order to examine these kinds of magnet eddy currents ahead of time, one has to be precise when accounting for things like these various geometries and material properties. This is why a magnetic field simulation using the finite element method (FEM), which can account for them, would be the most effective. This Application Note explains how to use the gap flux boundary condition to evaluate the eddy current loss in the magnet by changing the number of magnet divisions. This will make it possible to obtain effective results in a shorter period of time than with a normal transient response analysis.

 152  Electromagnetic Force Analysis of Shortcircuited Power Transformer Coils
 Module:FQ  20131217  A transformer is an electrical device that uses electromagnetic induction to convert the voltage level of alternating current power. Electromagnetic force is produced by the current and magnetic field in a transformer's coils while it is converting power. There is a risk that a large electromagnetic force can cause the coils to deform or rupture, particularly when something goes wrong and current flows in a short circuit. Electromagnetic force is produced by the current and magnetic field in a coil, but the coil is exposed to not only the magnetic field it produces by itself but also the magnetic field from other coils and leakage flux from the core. Because of this, it is important to evaluate in advance what kinds of forces are produced in what areas due to the arrangement of the coils and the positional relationship of the coils and core using magnetic field analysis. This analysis uses different coil positions to evaluate the Lorentz force density and electromagnetic force produced in the coils during a short circuit in order to confirm the effects that the primary and secondary coils have on each other.

 146  Analysis of Stray Loss in a Transformer
 Module:FQ,HT,LS  20130627  Transformers are made to be used longterm, so it has become an important design policy to control running costs from losses. These losses include copper loss in the coil and iron loss in the core. In highcapacity transformers, however, there is also stray loss in the tank from flux leakage from the core. From a safety standpoint, companies want to contain the heat produced from stray losses in the tank to well below the standards required for heat resistant design because they anticipate injuries from people touching the tank itself. Predicting these losses and the heat that they generate is a vital component of transformer design, but it is difficult to estimate them from desktop calculations, so evaluations and detailed analyses using the finite element method (FEM) are indispensible. This Application Note explains how to obtain losses in a transformer tank and use them to evaluate the temperature distribution in each part.

 139  Power Transmission Analysis Using Magnetic Resonance Phenomena HOT!
 Module:FQ  20140227  Recently, magnetic resonance is gaining attention as a new type of wireless transmission technology. Magnetic resonance differs from conventional types of electromagnetic induction transmission that are widely used today in that the axes of the transmission and receiving coils do not need to be aligned and in that it allows efficient transmission at a distance of several meters. A design for the coil geometry and circuit that is optimized for the frequency being used is necessary to make the transmitting and receiving sides resonate and thus transmit power. It is very difficult to use measurement to visualize how magnetic field is being generated, and is therefore transmitting power, in the space between the transmitting side and the receiving side. Reproducing the power transmission state using analysis can help with designing optimized coils. This Application Note presents how to confirm the power transmission efficiency and the magnetic flux density distribution.

 132  Loss Analysis of a Threephase Transformer
 Module:FQ,LS  20130617  Mid and largesized power transformers need to be able to operate over the long term, so they are always required to control running costs from losses. Iron loss is one of the main losses in a transformer, and it can lead to temperature increases and efficiency decreases because it consumes electric power as heat in a magnetic material. Using finite element analysis (FEA) to confirm the distribution of iron loss density makes it possible to study a transformer's local geometry during design. Further, evaluating the ratio and distribution of the iron and copper losses through FEA becomes advantageous when designing a transformer. This note presents how to obtain the iron and copper losses of a threephase transformer.

 127  Resistance Heating Analysis of Steel
 Module:FQ,HT  20131217  Deformation occurs when large metal parts such as shafts undergo machining, causing their material properties to worsen. Because of this, these material properties are restored by eliminating machining deformations using thermal processing, which returns the metal structure to its standard condition. It is necessary to heat the whole part to the same temperature in order to restore the metal's overall properties with thermal heating, and ohmic heating is often used for this purpose. It is helpful to measure the temperature distribution in advance with an investigation of heating conditions. Evaluation with analysis based on the finite element method (FEM) is necessary to find whether a product with a 3D geometry is heated uniformly by a given electrode configuration. This Application Note presents how to obtain the temperature distribution, temperature variations, and heat flux distribution in a body heated by ohmic heating.

 118  Thermal Analysis of a Busbar
 Module:FQ,HT  20130627  Current is supplied via busbars or wire bonding in power supply lines for power electronics devices such as inverters. Because inverters and similar devices operate with PWM carrier frequencies of several kHz, highfrequency current flows in their busbars. Influences from the skin effect cannot be ignored in this kind of highfrequency current, so increased resistance and loss become problems. A design that accounts for heat and temperature distributions at each frequency is vital because excess heat can cause a reduction in efficiency or even damage the device. Because a busbar's geometry is complicated, it is difficult to predict in advance where there will be unevenness in the current's flow while current is running, and whether this will cause heat generation. With magnetic field analysis using the Finite Element Method (FEM), it is possible to correctly obtain the unevenness in current distribution and the joule loss, and then predict the temperature distribution with these as causes of heat generation. This Application Note presents how to obtain the temperature distribution in a busbar or the like with changes in the power supply frequency.

 117  Iron Loss Analysis of a Transformer
 Module:FQ,LS  20130617  Mid and largesized power transformers need to be able to operate over the long term, so they are always required to control running costs from losses. Iron loss is one of the main losses in a transformer, and it can lead to temperature increases and efficiency decreases because it consumes electric power as heat in a magnetic material. Using finite element analysis (FEA) to confirm the distribution of iron loss density makes it possible to study a transformer's local geometry during design. Further, iron loss is divided into hysteresis loss caused by hysteresis in the core and joule loss caused by eddy currents, and analysis makes it possible to compare the relative contributions of each of these. This Application Note presents how to obtain the iron loss and the ratio of hysteresis loss and joule loss within that iron loss for a threephase transformer.

 113  Power Transmission Analysis of a Wireless Power Transfer System with Opposing Cores HOT!
 Module:FQ  20140227  A wireless power transfer system is a device which uses electromagnetic induction to provide electric power without physical contact. They can be used for various applications, such as supplying power to moving or rotating devices, or devices sealed inside enclosed spaces. Because the primary and secondary sides do not touch, the power transmission efficiency and leakage flux vary depending on their positions relative to each other. Therefore, it is important at the design stage to understand how properties change according to their placement. When evaluating the properties of a transformer whose primary and secondary sides are separated by a gap, it is helpful to use magnetic field analysis based on the finite element method (FEM), which allows precise modeling of the geometry of the parts and their relative positions, and makes it possible to visualize the leakage in the magnetic flux that is generated in the primary side and transmitted to the secondary side. This Application Note presents how to obtain the power transmission efficiency when the feeder wire's position is moved in both the horizontal and vertical directions from a reference position, and how to display the flow of magnetic flux.

 112  Starting Thrust Force Analysis of a Linear Induction Motor
 Module:FQ  20130426  Linear motors are widely used for carrier devices and machine tools because of their highspeed performance, high acceleration and deceleration, and accurate positioning. One type of linear motor, the linear induction motor, can be constructed at low cost because it can use a primary side with coils, and a secondary side made of a conductor that is not magnetized, such as aluminum or copper. There are some problems when building a linear inductance motor, such as complex eddy currents flowing in the secondary conductor sheet, and a large amount of leakage flux between the mover and stator. In order to improve linear inductance motor efficiency, therefore, it is important to gain an understanding of the paths of eddy currents and the leakage flux. Evaluation using the finite element method (FEM) is useful for this. This Application Note presents how to obtain the starting thrust force for a linear inductance motor.

 110  Loss Analysis of a Choke Coil
 Module:FQ,LS,TS  20120731  A choke coil is an electric component that is intended to filter highfrequency current. 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 current generated in the choke coil has offsets caused by the skin effect, proximity effect, and leakage flux near the gap, so it is distributed both inside of and between the wires. Iron loss generated in the core is also distributed by offsets in the core's magnetic flux density. It is helpful to get tips for the design quantitatively and visually studying these detailed distributions, and an effective way of doing this is a magnetic field analysis that uses the finite element method (FEM). This Application Note shows how to obtain the iron loss and copper loss in a choke coil.

 105  Leakage Inductance Analysis of a Transformer
 Module:FQ,TS  20120731  Inductance is an important physical quantity that determines a transformer's response characteristics against electric signals. Inductance is generally categorized into selfinductance and leakage inductance. Selfinductance is an indicator of to what extent the transformer can produce magnetic flux, and leakage inductance is an indicator of how much magnetic flux the transformer can send from the primary coil to the secondary coil without leaking. This is why selfinductance and leakage inductance are important items for transformer design requirements. The amount of inductance is dependent on the magnetic circuit, but the nonlinear characteristics of the magnetic properties make it so that the magnetic circuit changes when the operating point changes. The leakage inductance has all of the same properties, but it also has a flux path in nonmagnetic regions, making it easily affected by the arrangement and geometry of the winding in addition to the core. This is why a magnetic field analysis using the finite element method (FEM) is necessary when evaluating these types of inductance. This Application Note explains how to obtain selfinductance and leakage inductance for two types of secondary coiling in a transformer: uniform coiling and close coiling.

 100  Surface Heating Analysis of a Steel Plate
 Module:FQ,HT  20131028  Highfrequency induction heating is one heating method used when heat treating the surface of a steel plate. With induction heating, the heating depth can be adjusted because it is possible to localize heating by modifying the coil's geometry and electrical power. The coil geometry, heating conditions, etc. must be designed correctly in order to achieve heating as desired, but the cost and time needed for prototyping can be a problem. To make accurate predictions, it is necessary to account for the temperature dependency of the thermal conductivity, the electrical conductivity, and the detailed coil geometry in order to find the heat generation distribution. Electromagnetic field simulation using the finite element method (FEM) is needed for this type of prediction. This Application Note presents how to confirm the uniformity of the surface temperature distribution in the steel plate facing the coil and check for an eddy current loss density distribution that causes the temperature distribution to be uneven, when a mosquitocoilshaped coil is in position.

 97  Sound Pressure Analysis of a Transformer
 Module:DS,FQ  20130617  In recent years, the demand to reduce vibration and noise is growing while the requirements for higher efficiency and smaller and lighter transformers grow with environmental conservation trends. The primary cause of noise for transformers is the electromagnetic vibrations and the resonance phenomena at the eigenfrequency of the structure. A sound pressure analysis can be performed with a coupled magnetic field and structural analysis that uses the electromagnetic force as excitation force. This example presents the use of a coupled magnetic field and structural analysis to obtain the sound pressure distribution accounting for the electromagnetic force of the core when the transformer is operating on a power supply frequency of 6 kHz.

 86  Power Transmission Analysis of a Wireless Power Transfer System HOT!
 Module:FQ  20140227  A wireless power transfer system is a device which uses electromagnetic induction to provide electric power without physical contact. They can be used for various applications, such as moving or rotating devices, or devices sealed inside enclosed spaces. Because the primary and secondary sides do not touch, the power transmission efficiency and leakage flux vary depending on their positions relative to each other. Therefore, it is important at the design stage to understand how properties change according to their placement. When evaluating the properties of a transformer whose primary and secondary sides are separated by a gap, it is helpful to use magnetic field analysis based on the finite element method (FEM), which allows precise modeling of the geometry of the parts and their relative positions, and makes it possible to visualize the leakage in the magnetic flux that is generated in the primary side and transmitted to the secondary side. This Application Note presents how to obtain the power transmission efficiency when the feeder wire's position is moved in both the horizontal and vertical directions from a reference position, and how to display the flow of magnetic flux.

 85  HighFrequency Induction Heating Analysis of a Constant Velocity Joint
 Module:FQ,HT  20121114  Constant velocity joints are used in the connections at each end of a drive shaft in a vehicular drive system. The inside of the outer race of a constant velocity joint makes direct contact with steel balls or rollers on the inner race, so it needs to have increased hardness to improve its ability to resist wear and tear. On the other hand, its inside needs to retain its toughness in order to maintain its flexibility as a part. Highfrequency induction hardening is used as a heat treatment method that hardens only the surface of a product. With this method, using a highfrequency power supply makes it possible to heat the surface locally and rapidly. This process also has many other benefits, such as providing a clean working environment because it uses electrical equipment, being very efficient, and providing uniform results for each product. This is why it is being aggressively implemented in the field. It is difficult to predict the hardening of the inside of a constant velocity joint because its uneven geometry makes eddy currents and magnetic flux flow in a complex manner. With interior hardening like the kind used in this example, the heating coil design must follow spatial constraints. The eddy currents that are generated from a highfrequency varying magnetic field are offset on the surface of the part's interior, so the material properties change a great deal as the temperature rises. This is why it is necessary to predict the amount of heat generated in a numerical analysis based on the finite element method (FEM) in order to handle the detailed phenomena. This Application Note shows how to run an analysis of the elevated temperature process by using the geometry of a coil to evaluate whether or not the target temperature conditions are fulfilled.

 83  Magnetic Shielding Analysis of an Induction Furnace
 Module:FQ  20131217  An induction furnace is an apparatus that uses highfrequency induction heating to melt metal. Running current through the coil surrounding the crucible starts electromagnetic induction phenomena, which generate current in the metal in the crucible. This current produces joule losses in the metal, which are used to heat and melt it. Magnetic yokes are arranged around the coil. The yokes are used as strong components that prevent the Lorentz force generated by the coil from damaging and deforming it. The magnetic yokes also reduce the leakage flux that flows out of the appliance, preventing unintended heating in surrounding structures. Keeping the amount of material used in the magnetic yokes to a minimum makes it possible to reduce the cost of the apparatus. To understand the magnetic flux that spreads from the induction furnace, it is necessary to use the eddy current distribution and magnetic flux flow in the metal in the crucible, as well as the concentrations in magnetic flux caused by the positions of the yokes. This Application Note displays magnetic flux density distribution to evaluate the differences in magnetic flux with and without yokes.

 78  Loss Analysis of a Sheet Coil Transformer
 Module:FQ,LS  20131217  Power transformers need to be able to operate over the long term, so they are always required to control running costs from losses. Iron loss is one of the main losses in a transformer, and it can lead to temperature increases and efficiency decreases because it consumes electric power as heat in a magnetic material. Using a finite element analysis (FEA) to display the iron loss density distribution and obtain the iron loss values in a transformer makes it possible to study the local geometry and get design feedback at the design stage. This Application Note shows how to obtain the iron loss of a sheet coil transformer.

 77  Inductance Analysis of an RFID Tag
 Module:FQ  20131028  An RFID tag uses electromagnetic induction to communicate information by supplying electrical power to an IC chip from a reading device. In order to relay information in specific frequencies with a good degree of sensitivity, the RFID tag uses resonance between its internal coil antenna and capacitor. The coil antenna's inductance and the capacitor's resonance frequency need to be estimated for resonance to be produced accurately at the specified frequency. When the capacitor is external, the inductance of the coil antenna needs to be obtained accurately and the capacitor's capacity needs to be identified. Some RFID tags have magnetic sheets or metallic films on them. The sheet's magnetic properties and eddy currents generated in the film can affect the inductance. This Application Note performs a magnetic field analysis of an RFID tag that has a metallic film and a magnetic sheet with a resonance frequency of 13.56 MHz, and obtains the magnetic field distribution and the RFID tag's inductance.

 75  Iron Loss Analysis of a Reactor
 Module:FQ,LS  20131217  Reactors are installed on the input or output side of inverter circuits. Because they are required for longterm operation, the ability to control running costs from losses is an important challenge for their design. Iron loss is one of the major types of losses in a reactor. It consumes electric power as heat in a magnetic body, so it causes heat to increase and efficiency to decrease in the reactor. Using a finite element analysis (FEA) to confirm the distribution of iron loss density makes it possible to study a reactor's local geometry during its design, so it is useful in providing feedback about the design itself. This Application Note analyzes the iron loss of a reactor.

 70  Analysis of ImpedanceFrequency Characteristics of a Cable
 Module:FQ  20130426  Twisted pair cables are used in situations that require strict noise reduction like with signal lines and speaker cables because they are not affected by external noise and do not emit much noise of their own. The cable's performance relies on its electric properties, but these change depending on the state of the current that is flowing. For example, when the current frequency rises, the current is offset in the copper wires because of the skin effect and proximity effect. As a result, the apparent crosssectional area of the current flow is reduced, causing the alternating current resistance to increase and the inductance to change. An increase in the resistance leads to an increase in losses, and changes in inductance result in distortions in the signal. This is why these frequency characteristics need to be understood in advance. The above phenomena occur in the interior of the copper wires, so an evaluation using a magnetic field analysis based on the finite element method (FEM) is useful because they can be difficult to predict with manual calculations. This Application Note explains how to obtain the frequency characteristics of the resistance and inductance in twisted pair cables.

 63  Analysis of Torque Characteristics of a Cage Induction Motor
 Module:FQ  20130228  Induction motors have been widely used for a long time in general industries because they have a simple structure, and are affordable, robust and highly efficient. When an induction motor rotates at synchronous speed, no torque is produced. However, when proper slip is caused, the maximum torque can be obtained. Losses are generated in a cage induction motor when current flows through the cage, so the pros and cons of continuous rotation depending on the amount of the heat generated need to be studied. In an induction motor, the current induced by the auxiliary conductor exerts a large influence on its characteristics. It also causes strong magnetic saturation in the vicinity of the gap, in particular. This is why a magnetic field analysis based on the finite element method (FEM) is useful when investigating the motor's characteristics for a design study. This Application Note introduces a case example that obtains the SlipTorque curve, TorqueCurrent curve, CurrentVoltage curve at maximum torque, and the CurrentJoule Loss curve for the cage.

 53  Magnetic Shielding Analysis of a Shield Room
 Module:FQ  20130128  Shield rooms are meant to protect precision equipment from the influence of external magnetic fields, so they have to be an enclosed space that implements special processing in the walls that blocks magnetic flux. The effects of external magnetic fields inside the shield room depend on how they are generated, where the precision equipment is located, and the position of the shield room's opening and supply cable. A magnetic field analysis using the finite element method is necessary to perform an evaluation that deals with three dimensional and temporal variations to figure out how magnetic flux enters the shield room when several external magnetic fields have been applied. This Application Note explains how to handle the magnetic shielding phenomena used by the shield room when an external magnetic field is applied, and from there how to confirm the magnetic flux density distribution.

 52  Inductance Analysis of a Sheet Coil Transformer
 Module:FQ  20131028  Power transformer requires large currents, so their geometry tends to be large. This means that they are particularly hard parts to miniaturize when electrical product designs get smaller. The sheet coil transformer introduced in this Application Note achieves thinner dimensions by winding its coil in a thin sheet. Selfinductance and leakage inductance are critical items in a transformer's design requirements. The amount of inductance is dependent on the magnetic circuit, but the nonlinear characteristics of the magnetic properties make it so that the magnetic circuit changes when the operating point changes. The leakage inductance has all of the same properties, but it also has a flux path in nonmagnetic regions, making it easily affected by the geometry and coil arrangement in addition to the core. This is why a magnetic field analysis using the finite element method (FEM) is necessary when evaluating these types of inductance. This Application Note explains how to obtain the selfinductance and leakage inductance of a sheet coil transformer.

 51  HighFrequency Induction Heating Analysis of a Gear
 Module:FQ,HT  20130627  Gears are created in such a way that the surfaces of their teeth are hard in order to resist the wear and tear that occurs when they come into contact with the teeth of other gears. However, this has to be accomplished while maintaining the gear's overall toughness. By using highfrequency induction heating, which is a type of surface hardening method, the teeth are heated rapidly on only their surface by a high frequency power source. This process also has many other benefits, such as providing a clean working environment because it uses electrical equipment, being very efficient, and providing uniform results for each product. This is why it is being aggressively implemented in the field. On the other hand, there are several factors that need to be studied in order to heat the gear's surface uniformly, such as how to adjust the heating coil's geometry, arrangement, current frequency and size. The eddy currents generated by highfrequency varying magnetic fields are uneven in the tooth surface, so the material properties change a great deal as the temperature rises. In order to handle the detailed phenomena, it is necessary to calculate the heat generation amount in a numerical analysis based on the finite element method (FEM). This Application Note shows how to create a numerical analysis model when obtaining the optimum coil geometry and current conditions (power supply frequency and current value), analyze the elevated temperature process, and evaluate whether or not the model fulfills the target temperature distribution.

 50  HighFrequency Induction Heating Analysis of a Steel Wire (Translational Induction Hardening)
 Module:FQ,HT  20131217  Steel wires are made to be resistant to wear and tear. This is accomplished by giving them a certain degree of flexibility by maintaining their inner toughness while increasing the hardness of their surfaces. By using highfrequency induction heating, which is a type of surface hardening method, the steel wire is heated rapidly on only its surface by a high frequency power source. This process also has many other benefits, such as providing a clean working environment because it uses electrical equipment, being very efficient, and providing uniform results for each product. This is why it is being aggressively implemented in the field. On the other hand, when the heating target is a long steel wire, it is heated rapidly while passing through the heating coil. For this reason, there are several factors that need to be studied when assigning a heating amount to correspond to the speed at which the wire passes through the coil. Examples of these are: the arrangement of the heating coils so that it can fulfill the necessary heating amount, and how to adjust the current's frequency and size. This Application Note presents a simulation of the heating conditions of a sufficiently long steel wire that passes through a heating coil. The eddy currents produced from the high frequency's varying magnetic fields are uneven on the steel wire's surface, so its material properties change due to increases in temperature. This is why it is necessary to approximate the amount of heat generated in a numerical analysis based on the finite element method (FEM) in order to handle the detailed phenomena. This Application Note explains how to create a numerical analysis model when obtaining the optimum coil geometry, current conditions (power supply frequency, current value), and movement speed. It also shows how to evaluate whether the model fulfills the target heating speed by analyzing the elevated temperature process.

 49  HighFrequency Induction Heating Analysis of a Steel Sheet
 Module:FQ,HT  20120831  The rolling process of steel sheets changes the strength and properties of the product, so heat treatment is used. High frequency induction heating is a type of heat treatment that uses a high frequency power source to produce rapid heating, allowing the equipment on the production line to be smaller. It also has a multitude of benefits, such as being highly efficient and providing a clean working environment. When the object being heated is a long steel sheet, this process heats it quickly while sending it through a heating coil. For this reason, there are several factors that need to be studied when assigning a heating amount to correspond to the speed at which the sheet passes through the coil. Examples of these are: the arrangement of the heating coil so that it can fulfill the necessary heating amount, and how to adjust the current's frequency and size. This Application Note presents a simulation of the heating conditions of a sufficiently long steel sheet that passes through a heating coil. The eddy currents produced from the high frequency's varying magnetic fields are uneven on the steel sheet's surface, so its material properties change due to increases in temperature. This is why it is necessary to approximate the amount of heat generated in a numerical analysis based on the finite element method (FEM) in order to handle the detailed phenomena. This Application Note explains how to create a numerical analysis model when obtaining the optimum coil geometry, current conditions (power supply frequency, current value), and movement speed. It also shows how to evaluate whether the model fulfills the target heating speed by analyzing the elevated temperature process.

 48  HighFrequency Induction Heating Analysis of a Printer Roller
 Module:FQ,HT  20131217  A printer works by running a piece of paper with toner on it between a heated fuser roller and a pressure roller. The heated fuser roller then applies heat to fix the toner to the paper. The fuser roller needs to have uniform temperature distribution in order to handle various types of paper. It also requires the ability to heat up rapidly in order to shorten the standby time, allowing the person using the printer to print documents quickly. A magnetic field analysis using the finite element method (FEM) is useful in examining several aspects of the process, including: Differences in heating from the heating coil's geometry or placement, what kind of eddy currents are generated in the roller's thin surface and whether they provide uniform temperature, and how the magnetic flux flow spreads to the roller, air, and core. This Application Note confirms the nonuniformity in temperature distribution produced by an assumed coil geometry, as well as the temperature elevation in each part caused by rotation.

 47  HighFrequency Induction Heating Analysis of a Crankshaft
 Module:FQ,HT  20131217  Machine parts like shafts and gears are made to be resistant to wear and tear. This is accomplished by giving them a certain degree of flexibility by maintaining their interior toughness while increasing the hardness of their surfaces. By using highfrequency induction heating, which is a type of surface hardening method, the part is heated rapidly on only its surface by a high frequency power source. This process also has many other benefits, such as providing a clean working environment because it uses electrical equipment, being very efficient, and providing uniform results for each product. This is why it is being aggressively implemented in the field. With induction hardening like the kind used on the work piece in this analysis, the main requirement is to heat a given surface uniformly and increase rigidity. Eddy currents generated by the highfrequency varying magnetic field occur in the surface of the work piece. Examining these phenomena in detail requires handling the phenomena that occur in the work piece itself in a numerical analysis based on the finite element method (FEM). This Application Note shows an example of an evaluation performed by creating a numerical analysis model, analyzing the elevated temperature process, and seeing whether or not the desired temperature distribution is achieved. Use this analysis when obtaining the optimum coil geometry, current conditions (power supply frequency, current value), and rotation speed.

 45  HighFrequency Induction Heating Analysis of an IH Cooking Heater
 Module:FQ,HT  20131217  An IH cooking heater cooks food by heating a pot that acts as a conductive body. It heats this pot with an induction heating method that uses electromagnetic induction. Eddy currents flow in the iron pot when a high frequency current is applied to the coil. These eddy currents produce joule loss, which acts as a heat source to raise the temperature of the iron pot. When designing the heating coil, the main points to look out for are: What kind of magnetic circuit design will raise heating efficiency, and whether it is generating uniform heat in the iron pot. Another factor is controlling leakage flux to the circuit component in the board box that surrounds the apparatus. A magnetic field analysis simulation that uses the finite element method (FEM) is best for studying a three dimensional combination of the geometry, number, and alignment of the magnetic material that adjusts the magnetic circuit, and for quickly obtaining the electric circuit constant of the high frequency circuit that performs the heating. This Application Note shows how to obtain the magnetic flux density surrounding an IH cooking heater that uses high frequency induction heating and the temperature distribution of its iron pot.

 32  Analysis of a Transformer
 Module:FQ  20131217  A transformer is an electrical device that uses electromagnetic induction to convert the voltage level of alternating current power. In an ideal transformer the secondary voltage is constant regardless of the load, but in reality it tends to vary with the size of the load and the power factor. The size of a transformer's voltage variations is a vital output characteristic when considering constant voltage reception. It is also important to maintain a balanced state because an imbalance in the voltage and current in each phase can bring about a rise in the transformer's temperature or a fault in the device using the transformer. A transformer's output characteristics depend on the leakage flux from the iron core. Leakage flux passes through the air instead of the iron core, so it is hard to predict accurately during the design phase. It is possible to handle magnetic flux passing through the air in a magnetic field analysis, meaning that it is also possible to evaluate a transformer's output characteristics, including the effects of leakage flux. This Application Note presents the use of a magnetic field analysis to evaluate changes in the secondary voltage caused by load variations in a low frequency transformer.

 14  Inductance Analysis of a Busbar
 Module:FQ,Pi  20100831  Voltage surges can damage the components in electrical equipment such as an inverter. Busbar inductance can be a cause of surges. Therefore, it is important to reduce it to protect the electrical equipment. Using FEM allows for the calculation of inductance based on the magnetic field and current distribution obtained from the magnetic field analysis. This note presents a case study on the current distribution and the frequency versus inductance characteristic of the busbar.

 13  HighFrequency Induction Heating Analysis of a Shaft
 Module:FQ,HT  20120831  Shafts are used in parts like axles, which transfer power from the engine to rotate the tires, so the need to have sufficient strength to handle the torsion. They also need to have increased surface toughness to raise their degree of abrasion resistance in the areas that join with other parts, and they must maintain their interior toughness in order to obtain strength and fatigue resistance against torsion. By using highfrequency induction heating, which is a type of surface hardening method, the part is heated rapidly on only its surface by a high frequency power source. This process also has many other benefits, such as providing a clean working environment because it uses electrical equipment, being very efficient, and providing uniform results for each product. This is why it is being aggressively implemented in the field. Eddy currents generated by the highfrequency varying magnetic field occur in the surface of the shaft. The material properties also change due to the rising temperature. Examining detailed phenomena requires handling the phenomena that occur in the interior of the shaft in a numerical analysis based on the finite element method. This Application Note explains how to create a numerical analysis model and analyze the elevated temperature process in order to use the coil geometry and current conditions (power supply frequency, current value) to verify whether or not the target temperature distribution is obtained.

