Core Manufacturers Research Articles

The Private Virtual Network Operator Model for Field Area Network

Uninterrupted grid edge connectivity is essential for distribution utilities driving towards a future where efficient, secure, and reliable field area network (FAN) operation is not just preferable but required. Communications and network connectivity have been rapidly evolving over the last several years and will continue to do so—including in the areas of spectrum options, carrier solutions, device manufacturers, core manufacturers, and network management options. Utilities have a greater choice of options to deploy, while needing to remain prudent in their investments. One of the options gaining traction in the United States is the private virtual network operator (PVNO) model.

A neural network approach for prediction of tyre rolling noise during indoor tests

Nowadays, noise has become one of the main concerns of environmental pollution, especially in the automotive and transport industry. Tyre noise has a core influence and manufacturers, pushed by regulations, invest several resources in experimental tests and numerical simulations to improve their products performances. In this context, predictive models represent useful tools to support the virtual prototyping. In this paper a statistical modelling approach for the prediction of sound intensity measurements in indoor condition is proposed. Particular attention is paid to the selection of the parameters related to tyre/road noise and to their processing. At first, sound intensity levels are measured for a set of tyres rolling on drum at different speeds. Then, noise-related tyre features are measured and processed. Eventually, an artificial neural network is used to define the statical model relating these features with the measured sound intensities. Promising results support the proposed approach.

Analysis of Enterprise Data-Driven Innovation Diffusion Supervision System Based on the Perspective of Green Supply Chain

To promote the market substitution of digital innovation technology and green products and alleviate the pressure of energy and environment, a three-party evolutionary game model of innovation diffusion based on core manufacturers, affiliated enterprises and the government is established in the article to explore the adjustment of the three-party game strategy of core manufacturers and affiliated enterprises under government supervision, and then analyze the optimal stability conditions that are conducive to the innovation diffusion of digital innovation technology. It is found that the core manufacturers would choose the diffusion strategy of digital innovation technology, which would take the initiative to adopt the diffused digital innovation technology due to cost considerations, without easily choosing independent research and development (hereafter R&D strategy); the reward and punishment mechanism made by the government for core manufacturers' digital innovation technology diffusion could effectively promote technology diffusion in the market.

Measurement and Calculation Techniques of Complex Permeability Applied to Mn-Zn Ferrites Based on Iterative Approximation Curve Fitting and Modified Equivalent Inductor Model

In many cases, power inductors are responsible for most of the power loss, volume, and cost if applied to high-frequency power electronics applications. It is desirable to optimize their design by the proper calculation of winding and core loss. It allows faster and cheaper commercial product release, which is the key to being successful in a highly competitive market. This is only possible if existing calculation techniques and technical data given by, e.g., core manufacturers, are verified and correct; otherwise, the inductor optimization process is less precise and requires several iterations to achieve good convergence. This paper addresses existing and proposes improved measurement and calculation techniques with regard to complex permeability, one of the key quantities that define inductor behavior in the frequency domain. This is done through impedance measurement and improved definition of the equivalent inductor model. Moreover, the proposed calculation techniques fulfill the need for the simple, accurate analytical methods required in commercial designs.

Selecting the Best Magnetic Core Geometry

Selecting the best core geometry for a given application can be challenging given all the options available. For high-frequency applications using ferrite and other low loss materials, many different shapes are available from core manufacturers. For power electronics applications, frequencies are not constrained to power line frequencies leading to more complex core designs. Proximity effects, nonlinear core excitation, and sensitivity to frequency are just some effects to consider for good designs. Whether designs are intended for 50 Hz or 100 kHz, the basic design equations are the same.

Research on the Cooperation Strategy of Core Manufacturers Leading Low-carbon Supply Chain

Research on the Cooperation Strategy of Core Manufacturers Leading Low-carbon Supply Chain

A collaboration mechanism for service-oriented manufacturing processes with uncertain duration: a perspective of efficiency

ABSTRACT The Industrial Internet is widely leveraged to connect diverse manufacturing resources, thus manufacturing allies can be dynamically organized to meet market opportunities. Manufacturing resources at various levels are virtualized in the form of manufacturing services and the core manufacturers can organize their manufacturing processes by choosing appropriate services to complete certain manufacturing tasks. When multiple services are orchestrated together, a collaboration mechanism is crucially important for the performance of the service-oriented manufacturing processes. However, many uncertain factors punctuate services from performing in a sound rhythm. In this paper, the authors analyze the factors that have impacts on the service to complete a certain task, establish a framework of the mechanism for service collaboration, propose an efficiency measurement method for the collaborative service processes, and construct a service collaboration model considering service duration, task relation and set probability. A Monte Carlo simulation improved Particle Swarm Optimization algorithm is developed to solve the model. An experimental study has been made with a car manufacturing process to verify the mechanism and the results show that the overall performance will be improved when services collaborate with this mechanism.

Core loss calculation for power electronics converter excitation from a sinusoidal excited core loss data

The authors propose a core loss calculation method for power electronics converter excitation from sinusoidal excited core loss data. This method is based on Brockmeyer’s theory and adapts to calculate core loss under DC-bias excitation conditions. Furthermore, the number of core loss test conditions are reduced as this method only requires the addition of DC-bias characteristics to the sinusoidal excitation core loss data provided by the core manufacturers. To validate the proposed method, the core losses under sinusoidal and square voltage excitations are first measured by a BH analyzer with a DC-bias excitation unit. Then, the measured values under a square voltage excitation and the calculated values from a sinusoidal excited core loss data are compared.

A Practical Approach for Core Loss Estimation of a High-Current Gapped Inductor in PWM Converters With a User-Friendly Loss Map

Core loss estimation of filter inductors is increasingly important for modeling and optimizing high-frequency, high-efficiency, and high-density pulsewidth modulation (PWM) power electronic converters. However, data provided by inductor core manufacturers are insufficient for core loss estimation in PWM converters, particularly in the case of customized gapped inductors. This paper presents a whole process of characterizing and estimating the core loss of a customized high-current gapped inductor for PWM converters. To excite the inductor for the B–H loop measurement, a test circuit formed by a half-bridge structure is proposed, which has the ability to compensate the asymmetric rectangular voltage on the inductor caused by the device voltage drops. To overcome the other challenges raised by a high excitation current, a refined discontinuous test procedure, triple pulse test, is proposed to reduce the requirements of the high-current test setup (thermal stress, current–time stress for current probes, capacity of dc sources, etc.). For practical purposes, a user-friendly loss map approach is proposed involving only time-domain and electrical variables to replace magnetic variables to enable the straightforward loss mapping process and core loss calculations. Presented experimental results show consistency between the estimated inductor loss and measured values. Overall, the proposed testing approach can be easily implemented on the user's side to develop a loss map of a given inductor. The established core loss map enables the users to accurately and rapidly estimate the core loss of a tested inductor for given PWM waveforms.

Experimental Determination of Specific Power Losses and Magnetostriction Strain of Grain-Oriented Electrical Steel Coils

This paper presents a new method for measuring the specific losses and magnetostriction of grain-oriented electrical steel coils of up to 6000 kg. Since large power transformer (LPT) core manufacturers are mainly supplied with entire steel coils, a fast incoming goods inspection is desirable. The proposed method identifies the specific losses of the entire steel coil. In addition, we measured the magnetostriction of the coiled material, which in turn enabled us to classify the main property for LPT no-load noise. Furthermore, we show the structure and setup of the developed coil measurement system. We provide an explanation of the measurement technique and identify its requirements. Exemplary results of specific power losses and magnetostriction of steel coils are provided, and the reproducibility of the results is shown.

Experimental Investigation of DC-Bias Related Core Losses in a Boost Inductor

Soft magnetic components in electronic systems are often subjected to dc bias-flux conditions. These dc bias conditions result in distorted hysteresis loops, increased core losses, and have been shown to be independent of core material. The physical origin of these increased losses is not well understood and there is no simple model that can predict these losses without extensive measurements. Absence of a widely accepted model coupled with the complete lack of dc loss attributes on core manufacturers' data sheets result in a requirement to empirically determine loss values for specific design applications. These deficiencies have motivated our efforts to investigate dc bias dependent loss phenomenon in a Fe-based Metglas core inductor operating in a dc-dc boost converter. Since dc flux levels in the core are proportional to the controllable converter load currents, this topology is ideal to study dc-related losses. Inductor core B - H hysteresis loop characterization was accomplished as a function of switching frequency, input voltage, and load current operating conditions and parameters. In this paper, the core loss results were presented as a function of the dc bias conditions, and the results showed that the core losses increased with the pre-magnetized (B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">de</sub> ) fields. As a result of our observations, we have proposed a modification to the conventional Steinmetz loss equation to include the effects of dc pre-magnetization flux in the core.

Constructing the Collaborative Supply Logistics Operation Mode in Assembly System under JIT Environment

In the JIT assembly system, if any supplier does not deliver the raw materials or components on time, or in the right quantity, the core manufacturers will not assemble on the schedule, which will bring great loss to the whole supply chain and greatly reduce the competitiveness and collaboration of the entire supply chain. Based on a survey on supply chain collaboration and operation model, supply logistics in JIT environment are analyzed from both the inside and outside system with the research goal of coordinating the upstream supply logistics. In order to help manufacturers implement the JIT production, the VMI-Hub operation mode is proposed from the aspect of inside system, and from outside system, cross-docking dispatch operation mode is considered to coordinate the supply logistics in assembly system.

Neural network-based software tool for predicting magnetic performance of strip-wound magnetic cores at medium to high frequency

Although magnetic wound cores have simple geometries, their magnetic properties vary in a complex manner depending on many factors such as core geometry, dimensions and interlaminar air flux between adjacent wound layers. These can set up internal stress which seriously affects internal flux distribution and hence permeability and losses. For core manufacturers to satisfy customer requirements, a need arises for a reliable tool for more accurate prediction of magnetic performance of strip wound cores. The magnetic performance of a range of strip wound cores has been measured over a wide frequency range (50 Hz-100 kHz). Using this information a neural network-based software package coined 'MagnetWolf', has been developed for predicting core performance. Input parameters include core geometry, core dimension, core material and strip width. A subneural network approach employed reduces the amount of representative data required for network training. This provides rapid network development and enhances accuracy. A JAVA graphical user interface makes it possible for the tool to be accessible via the internet. A comparison of predicted and measured results shows this to be a reliable tool with potential industrial applications.

Numerical modelling and simulation of hysteresis effects in magnetic cores using transmission-line modelling and the Preisach theory

The transmission line modelling method and the Preisach theory are employed to model and simulate the hysteresis effects of magnetic cores. This combined approach provides a useful method, which allows fast and accurate prediction of magnetic core losses, and simple software implementation of the dynamic discrete model. The model can be developed easily, using data provided by core manufacturers and simple measurements. This paper describes, in a tutorial style, the numerical aspects and software implementation of the modelling and simulation of hysteresis for a magnetic core. Step-by-step procedures of the modelling and simulation are included, and demonstrated in a computer simulation. Both simulated and measured results are presented.