JMAG Newsletter January, 2014JMAG-VTB is Now Easier to Use


We simultaneously released JMAG-Designer Ver. 13 and JMAG-VTB Ver. 3.0 in December 2013. We improved the method of using JMAG-VTB Ver 3.0 and added a navigation function. Even analysis beginners can easily obtain analysis results using JMAG-VTB. JMAG-Designer license-holders can use it immediately, so why not give it a try? This article will describe JMAG-VTB features and latest updates to the software.

What is JMAG-VTB?

JMAG-VTB is a tool that can solve the problems of those who've thought about analysis but don't know how to analyze, those who are so busy with other work they don't have the time to spend on analysis or those confused by the idea that analysis results will differ depending on the size of the mesh used.
JMAG-VTB can run analyses with inputting just an analysis model and design parameters, so for those starting out on analyses it's a solution tool that is also easy to use. Scenarios prepared for each application enable immediate analyses (Fig. 1). Scenarios are defined in an analysis flow decided for each application and analysis objective. For example, if a power transformer designer is evaluating stray loss, they can choose a stray loss scenario. Or if an insulation breakdown evaluation is required, select the insulation evaluation scenario.
Settings are also simple All a user need do is enter the design parameters they normally use and it's possible to run an analysis. Selecting analysis conditions and the like is simple, even if you don't know about settings or operational procedures in JMAG-Designer. And even though JMAG-VTB has automated procedures, that doesn't mean that it's merely an automatic tool. JSOL-provided scenarios in JMAG-VTB include analysis know-how JSOL has accumulated, so users can obtain appropriate results without having any analysis expertise.
Let's have a look here at the types of analysis know-how included in the scenarios.

Fig. 1 Objective-oriented Scenario
Fig. 1 Objective-oriented Scenario

This shows an example using a power transformer. Please refer to the list at the end of the article for supported.

An appropriate mesh size is decided automatically

JMAG-VTB will automatically decide the appropriate mesh for each scenario. I'll describe an example following selection of a scenario for a stray loss analysis in a power transformer. Leakage flux from the coils in a power transformer raise the fear of generating eddy current loss in the tank encasement. To accurately obtain this eddy current loss, you need to generate a mesh that will express the eddy current distribution bias toward the tank surface. Skin depth δ, which dampens the current density from the surface to 1/e, can be calculated according to Formula (1).

Formula 1

We can understand from Formula(1) that the skin depth differs depending on the analysis conditions and changing these conditions requires examination or changing for each user. And know-how is needed to decide on what is actually the right mesh thickness needed to express the eddy current. With the skin depth obtained from Formula(1) it is not possible to accurately express the eddy current distribution and that we need to thicken divisions that have already been separated. JSOL-provided scenarios not only include Formula(1), they also incorporate know-how accumulated up until now and this enables automatic generation of the right mesh.

Evaluation Methods Supporting Analysis Objectives

JMAG-VTB summarizes analysis results that should be evaluated for each scenario and outputs these on a dashboard. For example, if analyzing high-frequency induction hardening in a gear, to check whether hardening is progressing as supposed, it will confirm whether the hardening temperature has attained the maximum achieving temperature. Naturally, using JMAG-Designer will show the maximum achieving temperature distribution, but using JMAG-VTB enables obtaining the appropriate analysis results without having to know how to operate JMAG-Designer. This high-frequency induction hardening scenario displays bicolored contours setting the hardening temperature as a threshold (Fig.2).

Fig. 2 Diagram showing Bicolored Contours Setting the Hardening Temperature as a Threshold
Fig. 2 Diagram showing Bicolored Contours Setting the Hardening Temperature as a Threshold

Description of JMAG-VTB Ver 3.0, the Latest Version

JMAG-VTB Ver 3.0 has been made with the goal of being easy to use and we have added a navigation function to use JMAG-VTB. Here, we'll describe the software and its new functions.

The guide function will navigate us

This function displays the guide explaining how to operate what a user is going to operate at a timing when a user actually is operating items like input settings. The guide function displays contents related to what the user is showing, enabling worry free settings.
So that JMAG-VTB can support arbitrary models, you need to be able to make settings in JMAG-VTB regarding information of the input model. A user may know from among the part names about which part is the coil, but they may not know which coil is the U-phase if there are three phases to choose from. So, it is necessary to import a model into JMAG-Designer and set which one is U-phase coil. When booting up JMAG-Designer, the guide will display simultaneously and this will enable easy settings (Fig. 3).

Fig. 3 Guide Function
Fig. 3 Guide Function

Also Supports Arbitrary Part Numbers

JMAG-VTB Ver3.0 also supports models with a number of parts that differs to the number of parts specified when creating the scenario. Here we'll give an example using a description of a scenario for a single-phase induction motor. The scenario includes the shaft as one of the parts. An imported model can also be supported even if it does not include parts like the shaft, or there are fewer parts in the model than the scenario. And when importing a model with a large number of parts and a frame around the stator exterior, it can be supported by adding in the settings an increased number of parts. (Fig. 4)

Fig. 4 Example Using Increase/Decrease of Part Numbers (Single-phase Induction Motor)
Fig. 4 Example Using Increase/Decrease of Part Numbers
(Single-phase Induction Motor)

Arbitrary coil numbers can also be supported

The number of coils, which comprise the coil part, also supports arbitrary numbers. We assume that it's common to change number of coil turns or winding pattern in response to changes being made in the analysis model geometry. FEM coil conditions and the FEM conductor conditions are specified at that time, o changing the number of turns or winding pattern may also require creating or adding new setting conditions. JMAG-VTB automatically sets the appropriate conditions in response to an arbitrary number of coils. For example, when running an induction heating analysis of something like an induction furnace, the FEM conductor condition needs to be used to allow for current distribution in the heating coil. Consequently, FEM conductor condition settings must be made for each individual coil, and a change in the number of coils means an increase or decrease in the number of conditions applying to them. Using JMAG-VTB, the FEM conductor conditions and FEM conductor components on circuits will be created automatically in conjunction with the number of coils being used (Fig. 5.) In such cases, the user need only input the number of coils and the coil placement intervals.

Fig. 5 Circuit Components Created in an Induction Furnace (Left: 8 coils, Right: 4 coils)
Fig. 5 Circuit Components Created in an Induction Furnace
(Left: 8 coils, Right: 4 coils)

Select the design parameters from the connection pattern

Even if you have decided on the application you would like to analyze, I guess you'd probably still like to look at making many more exchanges to the circuits that you will use. With JMAG-VTB, circuits to be used are already registered as a parameter, so it's simple to confirm results obtained after changing the circuit.
For example, in a scenario of stray loss analysis in a power transformer, you can choose from four patterns of connection (Fig. 6). Users need only to select from the parameters the connection pattern that they would like to use in the analysis and they can easily confirm the effect that changing the connection would have.

Fig. 6 Selecting a Circuit from the Design Parameters
Fig. 6 Selecting a Circuit from the Design Parameters

Design parameters are easier to understand

Design parameters are selected when running an analysis and from JMAG-VTB Ver 3.0, now there is a pop-up explanation given for each design parameter (Fig. 7). This makes it much easier to understand the meaning behind each design parameter and you can enter the design parameters without having to ponder over what they actually do.

Fig. 7 Description of Design Parameters
Fig. 7 Description of Design Parameters

Improved JSOL-provided Scenarios

JSOL has until now provided over 100 different scenarios, but with the latest version it has made improved versions of the scenarios it provides. Among the main applications improved with this version are for device, single-phase induction motors and non-contact power supplies using power transformers, inductors and induction heating phenomena. These scenarios can be used in their existing formats or given additional improvements by users to enable them to be used in even wider areas.

How to Use JMAG-VTB

If you have a license for JMAG-Designer's Prepost and Solver, you can use JMAG-VTB immediately without any additional cost or license. JMAG-VTB is included with the JMAG-Designer installer, so install both at the same time.

There are functions we couldn't give a description of within the bounds of this article.
We had a hands-on seminar for JMAG-VTB for the Users Conference and gave participants a chance to actually operate the latest version. We hope using JMAG-VTB will be useful for your work.

(Tetsuya Hattori)

List of Applications JMAG-VTB Supports

  • IPM Motors
  • SPM Motors
  • Three Phase Induction Motors
  • Single-Phase Induction Motors
  • Switched Reluctance Motors
  • Brush Motors
  • Synchronous Reluctance Motors
  • Stepping Motors
  • DC Generators
  • Linear Motors
  • Linear Solenoids
  • Electromagnetic Relays
  • Electromagnetic Breaks
  • Power Transformers
  • Inductors (Reactors)
  • Switching Transformers
  • Sensors
  • Contact-less Power Transfer
  • High Frequency Hardening
  • IH Cooking Equipment
  • Electromagnetic Forming
  • Induction Furnace
  • Resistance Heating
  • Printer
  • Circuit Breakers
  • RFID
  • Magnetic heads
  • Shield Rooms
  • Capacitors
  • Cables

 1. Implementing JMAG   - Panasonic Corporation   Taking household appliance technologies and presenting them to industry partners -
 2. Product Report   - Introducing JMAG-Designer Ver.13 -
 3. Product Report   - JMAG-VTB is Now Easier to Use -
 4. Solutions   - Motor Design Course   - Issue 2 Moving Forward with Motor Concept Design -
 5. Solutions   - Starting With Vibration Noise Analyses Vol. 1 (Motor Edition 1) -
 6. Paper Introduction   - Issue 6 Lesson on Advanced Iron Loss Analysis -
 7. Fully Mastering JMAG   - Common Questions for JMAG -
 8. Fully Mastering JMAG   - Issue 11 Electric Field Analysis from A to Z -
 9. JMAG University Partner Introduction   - Shanghai University -
 10. JMAG Product Partner Introduction   - Dassault Systèmes Simulia -
 11. Event Information

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