Research on Maximizing Power Transfer Efficiency of Wireless In‐Wheel Motor by Primary and Load‐Side Voltage Control

The authors have developed a wireless power transfer (WPT) system for an in‐wheel motor (IWM). It is called a wireless in‐wheel motor (W‐IWM). This paper presents a method that enhances the WPT efficiency in this system. Some methods that maximize the power transfer efficiency by power converter control have been proposed in the past WPT research. In this research, a dc‐dc converter is inserted on the receiver side to vary the load state. However, the space on the receiver side is very small for the W‐IWM; therefore, it is preferable to make the secondary circuit small. Therefore, a full bridge converter is used instead of a dc‐dc converter in the W‐IWM. In this paper, the authors propose a theoretical formula for the transfer efficiency of the IW‐IWM. From an analysis of this formula, there is a combination of a primary voltage and load voltage that maximize the efficiency. The feasibility is validated by an experiment using a motor bench set.     

An Investigation of Size‐Reduction Effects in High Power Density Boost Converters with a Magnetic Coupling

The dc–dc converter using integrated magnetic components that may achieve high power density has gained attention in environmentally friendly cars such as electric vehicles and hybrid electric vehicles. This paper focused on interleaved boost converters using close‐coupled inductors (CCIs) and loose‐coupled inductors (LCIs) that are the integrated magnetic components. Following, detailed electromagnetically analysis for these circuit types were conducted in order to calculate volume of inductors and capacitors that are occupied the large part of space in the converters. The total volume of inductors and capacitors in these circuits were demonstrated clearly through comparison with conventional circuits such as an interleaved boost converter and a single‐phase boost converter. As a result, it became clear that interleaved boost converter using LCIs was effective for miniaturization of total volume. Furthermore, duty ratio of the minimum volume of CCI method is different from the duty ratio of the minimum volume of LCI method.     

A new stochastic neural network model and its application to grouping parts and tools in flexible manufacturing systems

Recently, some stochastic neural network models have been presented for the purpose of overcoming the defect that the deterministic neural network models do not have the ability to escape from a local optimal solution. However, the specification of the values of various parameters and weights in these stochastic neural network models is more complicated than that in the deterministic neural network models. In this paper, a new stochastic neural network model is proposed in order to reduce the complication of specifying the values of parameters and weights. For a practical purpose, the proposed model is applied to the problem of grouping parts and tools in flexible manufacturing systems (FMSs).     

Analyses of Various MHD Phenomena in EPM Application to Steelmaking Processes by Finite Volume Method

Applied technologies of magnetohydrodynamics(MHD)have been widely used in steelmaking based on their characteristics of clean and remote control of liquid metal.Generally,phenomena are quite complex and coupled among hydrodynamics,electromagnetism and thermodynamics,so numerical simulations play important roles in various applications of MHD for equipments design and control parameters decision.In the simulation,it is preferable to use one package calculation rather than coupled analyses such as the one between finite element method(FEM)and finite difference method(FDM)with the data conversion caused by different schemes.For the resolution,a three-dimensional finite volume approach for MHD is established based on scalar and vector potential and magnetic induction equation treated as transport equations.In this paper,results of the analyses of various MHD phenomena in EPM application to steelmaking process are described with some examples such as plasma heating and electromagnetic flow control tools.     

A design method for a self-tuning regulator for a distributed-parameter system

A design method for a self-tuning regulator for a distributed-parameter system is presented. This system is assumed to have some actuators fixed in the spatial domain. The power of each actuator is estimated by a least-squares algorithm. Some numerical examples are given.     

Relaxation optimizing operations in extended probabilistic space

The classical probabilistic relaxation method has been widely used to solve optimization problems in various fields, including image processing and pattern recognition. The authors have also been developing handwritten character recognition system using the probabilistic relaxation method. However, we realize that there exist cases in which a probability theoretic model is inadequate, especially where there exists incompleteness in available information by noise such as patchy segments and ink spots. In that case, we must introduce ad hoc rules for one-to-two correspondence and no correspondence in the probabilistic algorithm. As the Dempster-Shafer (DS) theory is a kind of natural extension of the probabilistic theory by reducing additivity on probability measure and it can cope with incomplete data. This paper proposes a relaxation matching method based on the Dempster-Shafer theory. Then the update process in probabilistic relaxation method is derived as a special case of Dempster's combination rule in DS theory.     

Improvement of Data Readout Disturbance Effect in 1T2C-Type Ferroelectric Memory

The data disturbance effect in readout operation was investigated in a 1T2C-type FeRAM cell array. Based on the analysis, a method for reducing the data disturbance effect is proposed and verified by SPICE simulation as well as experimental results. Current on/off ratio of about two orders of magnitude which is sufficient to distinguish stored binary data was maintained even under the maximum disturbance condition.     

Study on Sludge Formation during the Oxidation Process of Turbine Oils

Against the backdrop of increased needs for longer operating life of turbine oils, there is a tendency to use amine-type antioxidants for steam turbine oils as well as gas turbine oils. Amine-type antioxidants are known to form sludge during the oxidation process, and the sludge formation from turbine oils involves the high risk for a power plant of bearing temperature rise caused by sludge deposition onto the bearing surface. But currently, there is no global specification to evaluate the sludge formation from turbine oils that have high rotating bomb oxidation test (RBOT) life. In this study, we examined 18 kinds of commercially produced turbine oils and two kinds of originally prepared oils with amine additives on sludge formation under 120°C dry turbine oil oxidation stability test (TOST) accelerated degradation test. Consequently, we found a criterion to check the quality of sludge resistance of turbine oils based on the relationship between the RBOT residual ratio and weight of filter residues(1μ m pore filter).     

NaBH_4的水性还原法制备纳米铜颗粒(英文)

在碱性溶液中用NaBH4还原Cu2+制备纳米铜颗粒,研究NaBH4浓度和滴加速率对Cu纳米颗粒制备的影响。反应的最佳条件是:0.2mol/LCu2+,溶液pH12,温度313K,1%明胶作为分散剂,将0.4mol/LNaBH4溶液以50mL/min的速率加入CuSO4溶液中。氨水是最佳的络合剂。采用一系列实验研究不同时间点的反应进程。