With the changing economic environment of recent years, the capability to ensure higher reliability of devices and systems and a rapid response to support miniaturization, lower prices, higher performance and greater functionality are sought. Responding to such requests in various product sectors, Fuji Electric is actively applying high-speed high-precision simulation technology, based on proprietary modeling techniques and methods for identifying physical properties, to product development and system analysis. Fuji Electric is also promoting the effective utilization of design data generated by a three-dimensional CAD system to realize higher quality by advancing and improving design and manufacturing processes and evaluation testing.

Fuji Electric develops and sells permanent magnet synchronous motors (PM motors) and drive control systems that enable medium and small electric motors to be made smaller, yet with higher efficiency and performance. A software platform for PM motor design has been built for use in the development process. Simulations are performed to assess the permanent magnet eddy-current loss, analyze the PM motor cogging torque, and to simulate the casting of a cast metal frame. By combining thermal predictive technology and technology for assessing the ability to withstand demagnetization, and linking such technology to design optimization and improved quality, Fuji Electric also provides motors suitable for customer applications.

Analysis of the performance of drive control devices is important from the standpoint of providing products that satisfy market needs and for adjusting control parameters to their optimal values. At Fuji Electric, analyses are performed by combining mechanical models generated from CAD data with control system simulations. For example, in the case of a table drive system operated by a servo motor, the mechanical portion is modeled using SimulationX, and then a combined analysis is performed by incorporating that mechanical model into a control model based on MATLAB/Simulink. The frequency characteristics and transient response were compared to those of an actual motor, and the simulation results were verified to be in close agreement with the actual motor characteristics.

With power electronics devices such as inverters and the like, electromagnetic interference (EMI) due to the switching of semiconductors is a problem. To solve this problem, Fuji Electric has developed the technologies to analyze the conductive noise using circuit simulator and to simulate the radiation noise based on electromagnetic fields. These technologies are being applied to the design of uninterruptible power supplies (UPS) and general-purpose inverters to contribute to the improvement of product quality and the reduction of the size of equipment that contain noise filters.

To improve the areal recording density of a magnetic Recording Media, it is necessary to resolve some conflicting requirements with regard to signal-to-noise ratio, writability, and thermal stability. Simulation technology was used to resolve these conflicts and obtain optimum design guidelines for the development of thermally-assisted magnetic recording media. Heat transfer simulation confirmed that the provision of a heat-sink layer between the substrate and recording layers significantly reduces the size of heat spots on a recording medium, and read/ write simulation clarified that minimization of the size of heat spots is an effective means to reduce thermal fluctuations immediately after recording.

In order to analyze the electrical characteristics of IGBT products, there is a need for highly accurate and versatile models of IPMs and IGBTs. The model of an IPM is configured from a model of a driver IC, the package, or the like. Using a package model, an LR equivalent circuit is obtained based on an analysis of the heat spreading characteristics of the package and an analysis of the electromagnetic field. That LR equivalent circuit is then used in an analysis of the electrical characteristics. The model of an igniter-use IGBT is configured from an equivalent circuit model that combines a MOSFET or and BJT with an auxiliary circuit that models transient characteristics. Use of these models enables electrical characteristics to be analyzed, and the results of such analysis show good agreement with measurement results and contribute to improving the design accuracy of IGBT products.

With the recent expanded application range of IGBT modules to include hybrid vehicles and the like, market demands for smallersize IGBT modules have increased, and packages are being required to provide higher heat dissipation performance than in the past. For this reason, during the package design stage, it is important that the module behavior during actual operation be understood sufficiently and that the package be optimized. During operation, the temperature distribution will change and the module shape will become deformed by the heat. This heat deformation causes the temperature distribution to change further. Based on thermal-structural coupled analysis of the relationship between the temperature distribution and heat deformation, package simulation technology, enabling the temperature of a device in its actual usage state to be estimated with greater accuracy than in the past, has been developed and is introduced in this paper.

Fuji Electric has improved the cooling performance of air-cooled turbine generators and boosted their output up to 300 MVA, which previously had been within the output range of hydrogen-cooled turbine generators. Cooling technology for turbine generators is essential for enhancing product reliability and performance, and in addition to conventional development based upon prototype testing, Fuji Electric also uses thermo-fluid flow analysis technology to improve the cooling performance. A large-scale analysis of the flow and temperature was performed for the entire generator, and measurements of the rotor coil temperature were in good agreement with the results of the analysis. The use of analysis technology makes it possible to estimate temperatures at locations in which measurements had been difficult to obtain and, by incorporating the results of such analyses into the design, enables the generator performance to be improved.

Thermal relays combined with electromagnetic contactors and used as electromagnetic switches are a type of safety device that utilize the fact that auxiliary contacts will change due to bimetal deformation occurring when heat generated by the conduction current exceeds a certain level. For an accurate deformation analysis of the bimetal, the temperature dependence of the electrical resistivity of the heater wire and the current distribution are important factors, and in consideration thereof, analysis that combined a current-heat transfer analysis and a heat deformation analysis was performed. We independently acquired values of such physical constants as thermal conductivity, electrical resistivity, coefficient of linear expansion of the bimetal, and the temperature dependency to realize a highly accurate analysis. Analysis results were incorporated into the thermal relay design to improve reliability.

The capability to perform highly accurate estimates of the temperature of products stored in a canned beverage vending machine is essential for achieving energy savings. We have newly developed a simulator that combines simulation of heat and ventilation circuit networks with thermal and fluid analysis software. Specifically, this simulator consists of a refrigeration cycle simulator, a storage compartment operation simulator, a storage compartment air flow simulator and a heat and ventilation circuit network simulator, and in comparison to actual measured values, we confirmed that product temperatures could be estimated with accuracy within 1K. Use of this simulator contributes to greater energy savings in automated vending machines and also increases customer satisfaction.

To prevent the occurrence of bill transport problems, regardless of the paper quality or existence of bends in the paper money handled by cash handling equipment such as the automatic change machines used at shops, supermarkets and the like, the transport, alignment and storage behavior of the paper money must be accurately estimated when designing such equipment. Therefore, Fuji Electric developed technology for predicting the behavior of paper money based on linear stress analysis, nonlinear structural analysis (impact deformation analysis) and mechanism analysis (motion analysis). Fuji also developed a platform capable of analyzing combined mechanism and control simulations, and has enabled visualization of the timing of paper money transport and mechanism operation to improve the quality of paper money transport.

To prevent products from becoming stuck inside canned beverage vending machines during vending operations, a vending mechanism compatible with diverse can shapes of canned beverage and materials must be provided. In order to design a serpentine-type vending rack on which products are stored and a vending mechanism for discharging products one at a time with a flapper, we performed analyses based on simulations. A simulation model was devised so as to be able to reproduce the surface deformation of the liquids inside cans and of the low-hardness PET bottles, and a design taking account of variations in the parts shapes and load conditions was implemented to improve reliability.

The plastic (resin) material used in most receiving/distribution and control equipment has excellent electrical insulation properties, is easy to work with, and performs a vital function. In order to improve the quality of plastic components, resin fl ow analysis is performed during the conceptual design stage to anticipate potential defects so that the analysis results can be incorporated into the product design and into the design of the mold for the plastic components. For low-voltage circuit breakers, we have optimized the shape of the top cover and the manufacturing method. The fi t between the cover and case of a power monitoring unit has been improved. For the winded part of an electromagnetic switch, the application of coupled analyses has enabled the mold to be made with thinner walls. Standardization of the analysis model has made the analyses more effective.

With the recent trends towards miniaturization and higher density, the soldered connections in electronic devices are required to provide longer-term reliability under severe environmental conditions. Meanwhile, with the trend toward eco-friendliness, the use of lead-free solder material is being advanced, but because that lead-free material has a different deformation mechanism than conventional lead solder, a new lifetime prediction technique was needed. To improve the reliability of lead-free solder connections in these electronic devices, Fuji Electric has derived an approximation equation for reproducing the distinctive plastic deformation mechanism of lead-free solder and has created evaluation technology for acquiring fatigue characteristics at the solidification structure level of soldered connections to establish highly accurate lifetime prediction technology for lead-free solder connections.

CAE/CAD/CAM/CAT system has been newly developed and used in the design, manufacture and assembly of the turbine blades and casing, formed from complex three-dimensional curved surfaces, in a thermal power steam turbine to maintain and improve product quality, which includes the quality of the design and manufacturing processes. In the blade manufacturing department, upstream design data is used in the NC processing, and the accuracy of blade measurements, which previously depended upon the experience of the operator, is improved by using a non-contact three-dimensional measurement apparatus which the operator experience is not required. Also, the optimization of the design and use of a 3D viewer help to improve the manufacturing and ease the assembly of the casing.

In wireless systems that use radio waves as their communications medium, the strength of the radio waves varies significantly within certain areas due to the installation of structures, people’s movements and the like, and therefore in order to construct wireless systems that are highly reliable, it is important that the wireless equipment installation and antenna technology consider how the radio waves are distributed. Fuji Electric is working to develop technology for efficiently and precisely analyzing the radio wave distributions and antenna characteristics. For antenna analysis technology, we are advancing the development of techniques optimized for the analysis objects, and are applying the results to actual devices. Also, for analyzing radio wave propagation characteristics, we use the ray trace method which enables highly accurate analyses for performing with a field strength error due to fading to be within several percent, so that wireless relay devices can be placed in their optimal locations when designing the layout of a wireless broadcast station.