scholarly journals Reliability and Characteristic Analysis Considering the Circuit Structure and Operation Risk of Forward Converters

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 3006
Author(s):  
Yun-Gi Kwak ◽  
Dae-Ho Heo ◽  
Feel-Soon Kang
Keyword(s):  
Failure Rate ◽  
High Reliability ◽  
Environmental Conservation ◽  
Economic Feasibility ◽  
Analysis Method ◽  
Operating Characteristics ◽  
Characteristic Analysis ◽  
Forward Converter ◽  
Forward Converters ◽  
Operation Risk

The forward converter is divided into two circuit topologies depending on the method of resetting the energy stored in the magnetizing inductance of the transformer: a single-ended structure using a reset circuit and a double-ended structure called a two-switch forward converter and, accordingly, a difference occurs in the operational mode. Generally, forward converters are designed with low power of less than 500 W and are sold at low prices, so it is common to replace them in case of failure. However, in terms of environmental conservation through resource saving, it is desirable to design with as high reliability as possible. In this paper, reliability is analyzed for the two representative circuit topologies of forward converters. The conventional PCA (part count failure analysis) method determines the failure rate only by the number of circuit components constituting the converter and the correlation between the components, but the FTA (fault-tree analysis) method can additionally consider the operation risk of the converter according to the circuit configuration and operation. Therefore, it is possible to analyze the failure rate according to the operating characteristics of the two converters from the difference in the failure rate obtained by the two methods. In addition, the two converters were manufactured as a 300 W prototype, respectively, and the volume, weight, and power loss were compared, and the economic feasibility was analyzed based on the cost model.

scholarly journals Engineering Mathematical Analysis Method for Productivity Rate in Linear Arrangement Serial Structure Automated Flow Assembly Line

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Tan Chan Sin ◽  
Ryspek Usubamatov ◽  
M. A. Fairuz ◽  
Mohd Fidzwan B. Md. Amin Hamzas ◽  
Low Kin Wai
Keyword(s):  
Mathematical Model ◽  
Failure Rate ◽  
Mathematical Analysis ◽  
Assembly Line ◽  
Flow Line ◽  
Analysis Method ◽  
Machining Time ◽  
Linear Arrangement ◽  
Final Assembly ◽  
Productivity Rate

Productivity rate (Q) or production rate is one of the important indicator criteria for industrial engineer to improve the system and finish good output in production or assembly line. Mathematical and statistical analysis method is required to be applied for productivity rate in industry visual overviews of the failure factors and further improvement within the production line especially for automated flow line since it is complicated. Mathematical model of productivity rate in linear arrangement serial structure automated flow line with different failure rate and bottleneck machining time parameters becomes the basic model for this productivity analysis. This paper presents the engineering mathematical analysis method which is applied in an automotive company which possesses automated flow assembly line in final assembly line to produce motorcycle in Malaysia. DCAS engineering and mathematical analysis method that consists of four stages known as data collection, calculation and comparison, analysis, and sustainable improvement is used to analyze productivity in automated flow assembly line based on particular mathematical model. Variety of failure rate that causes loss of productivity and bottleneck machining time is shown specifically in mathematic figure and presents the sustainable solution for productivity improvement for this final assembly automated flow line.

Conjoint Analysis of Focusing Field Characteristics of Radially Polarized Beams Based on LabVIEW and MATLAB

2014 ◽  
Vol 651-653 ◽  
pp. 2414-2417
Author(s):  
Xiao Qing Zhang ◽  
Yu Dong Jia ◽  
Fu Rong Du
Keyword(s):  
Conjoint Analysis ◽  
Radial Component ◽  
Axial Component ◽  
Analysis Method ◽  
Characteristic Analysis ◽  
Polarized Beams ◽  
Matlab Program ◽  
Late Application ◽  
Beam Transmission ◽  
Radially Polarized

For the aim of analyzing focusing field characteristics of radially polarized beams, a conjoint analyzing method is presented based on LabVIEW and MATLAB. The main program is programmed in the LabVIEW environment, connecting with MATLAB program through ActiveX control. Experimental results show that the strength of the radial component in the center is zero and the strength of the axial component in the center is the largest. The conjoint analysis method realized characteristic analysis of focusing field for radially polarized beams, laying the groundwork for beam transmission of the late application.

scholarly journals Short-term Load Forecasting Model Considering Meteorological Factors

2019 ◽  
Vol 118 ◽  
pp. 02050
Author(s):  
Xi Yunhua ◽  
Zhu Haojun ◽  
Dong Nan
Keyword(s):  
Decision Tree ◽  
Meteorological Factors ◽  
Load Forecasting ◽  
Forecasting Model ◽  
Analysis Method ◽  
Decision Tree Algorithm ◽  
Characteristic Analysis ◽  
Short Term ◽  
Tree Algorithm ◽  
Short Term Load Forecasting

Because of the limitation of basic data and processing methods, the traditional load characteristic analysis method can not achieve user-level refined prediction. This paper builds a user-level short-term load forecasting model based on algorithms such as decision trees and neural networks in big data technology. Firstly, based on the grey relational analysis method, the influence of meteorological factors on load characteristics is quantitatively analyzed. The key factors are selected as input vectors of decision tree algorithm. This paper builds a category label for each daily load curve after clustering the user’s historical load data. The decision tree algorithm is used to establish classification rules and classify the days to be predicted. Finally, Elman neural network is used to predict the short-term load of a user, and the validity of the model is verified.

In-plane dynamic response of a hydraulic pipe subjected to random vibration

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wei Qu ◽  
Huailiang Zhang ◽  
Wei Li ◽  
Ling Peng ◽  
Wenqian Sun
Keyword(s):  
Random Vibration ◽  
Tunnel Boring Machine ◽  
Transmission Efficiency ◽  
Hydraulic Systems ◽  
Analysis Method ◽  
The Finite Element Method ◽  
Characteristic Analysis ◽  
Content Type ◽  
Tunnel Boring ◽  
Selection Of

Purpose To improve the transmission efficiency and reduce the damage to pipes in the hydraulic systems of tunnel boring machine subjected to random vibration, this paper aims to propose a novel dynamic characteristic analysis method that considers random vibration. Design/methodology/approach A fluid-structure interaction motion equation of the pipe is established by using Hamilton’s principle. The finite element method and discrete analysis method of random vibration are used to construct a model of the dynamic behavior of the pipe. Findings The influences of fluid parameters and external excitation parameters on the dynamic characteristics of pipes are analyzed. The experimental results are found to be in good agreement with the simulation results, which demonstrates that the proposed analytical method can provide a theoretical reference for the design and selection of hydraulic pipes subjected to random vibration. Originality/value The proposed method can be regarded as a future calculation method for pipes subjected to random vibration, and the transmission efficiency of the pipe can be improved.

scholarly journals Study of the Effect of Intake Layout on the Wavefront in a Beam Expanding System of a Telescope

2020 ◽  
Vol 10 (10) ◽  
pp. 3643
Author(s):  
Qingpeng Zhang ◽  
Yi Tan ◽  
Ge Ren ◽  
Tao Tang
Keyword(s):  
High Reliability ◽  
Wavefront Aberration ◽  
Flow State ◽  
Analysis Method ◽  
Smooth Flow ◽  
Main Disadvantage ◽  
The Matrix ◽  
Calculation Results ◽  
Ray Tracing Simulation ◽  
Small Holes

The main disadvantage of windowless beam expansion systems is that they cannot achieve a good sealing effect. Turbulence and impurities in the environment can easily affect the imaging and primary mirror. Thus, in this study, a matrix of small holes was introduced for inflation to form a stable and smooth flow inside the system to avoid these disadvantages. In order to study the layout of the matrix, the flow state of the model was analysed, and the Lorentz–Lorenz formula and Barron gradient operator were used for ray tracing. Simulation results show that when the matrix of small holes is arranged in 16 rows with 360 holes in each row, inflation has a lesser effect on the wavefront aberration of the system. Moreover, the root mean square (RMS) of wavefront aberration was only 0.077 μm, which was superior to the other layouts considered. Experimental results show that the RMS was 0.08 μm in this state, which is consistent with the analysis. This indicates that this analysis method can meet actual work needs. The calculation methods and calculation results have high reliability and, thus, can be also used in similar situations.

scholarly journals Forward Converter Current Fed Equalizer for Lithium Based Batteries in Ultralight Electrical Vehicles

Electronics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 408 ◽  
Author(s):  
Ali Farzan Moghaddam ◽  
Alex Van den Bossche
Keyword(s):  
Electromagnetic Interference ◽  
Buck Converter ◽  
Battery Pack ◽  
Forward Converter ◽  
Electrical Vehicles ◽  
Battery Packs ◽  
Electrical Vehicle ◽  
In Series ◽  
Forward Converters ◽  
Zero Voltage

In this paper, the concept of a forward balancing technique fed by a buck converter for lithium-based batteries in Electrical Vehicle (EV) applications is investigated. The proposed active topology equalizes eight cells in a series in a battery pack, by using a forward converter for each battery pack and the whole battery packs, using a buck converter. The battery bank consists of four battery packs, which are in series. Therefore, the proposed system will equalize 32 cells in series. In this paper, the proposed circuit employs a single transistor used in a Zero Voltage Switch (ZVS) for the forward converter. In practice, this means a capacitor in parallel with the switch at the same time a demagnetizing of the transformer is obtained. The circuit realizes a low Electromagnetic Interference (EMI) and reduces ringing. To overcome the problem of many pins on a coil former, the transformer secondary windings are made by using hairpin winding, on a ring core. It permits, e.g., having eight secondaries and uniform output voltages. Each secondary winding is made by two hairpin turns using two zero-Ohm resistors in series. The proposed topology has less components and circuitry, and it can equalize multiple battery packs by using a single buck converter and several forward converters for each battery pack. Experimental and simulation results are performed to verify the viability of the proposed topology.

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