• Title/Summary/Keyword: SRM analysis

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Analysis of Switched Reluctance Motors using Parameters obtained by Finite Element Method (유한요소법으로 계산한 파라메타를 이용한 스위치드 릴럭턴스 모타의 해석)

  • Lee, Joon-Ho;Lee, Sang-Ho;Lee, Ki-Sik
    • Proceedings of the KIEE Conference
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    • 1997.07a
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    • pp.47-50
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    • 1997
  • The FEM(Finite Element Method) can be used to analysis SRM(Switched Reluctance Motor) as it can account for the salient pole geometry of the stator and rotor and the nonlinear properties of the magnetic materials. However, FEM requirers a lot of computer memory and computing time because, the kind of SRM drivers is verity and the switching strategies are various for one SRM driver. In this paper we proposed the method of analysis of a SRM which results are similar to FEM and has very short computing time. The Inductance and torque for each phase current at each rotor position are calculated by using two-dimensional nonlinear FEM analysis. Using the look-up table of inductance and torque and the voltage equations of SRM we obtained the phase current and torque. To verify proposed algorithm, 3 phase 6/4 SRM is analysed and found a good agreement with FEM results. And computing time is about 1/1600 of the FEM analysis.

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Association of Serum and Salivary Tumor Necrosis Factor-α with Histological Grading in Oral Cancer and its Role in Differentiating Premalignant and Malignant Oral Disease

  • Krishnan, Rajkumar;Thayalan, Dinesh Kumar;Padmanaban, Rajashree;Ramadas, Ramya;Annasamy, Ramesh Kumar;Anandan, Nirmala
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7141-7148
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    • 2014
  • Background: Oral squamous cell carcinoma (OSCC) is an important malignancy throughout the world; early detection is an important criterion for achieving high cure rate. Out of the many reported markers for OSCC, this study validated the efficacy of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in differentially diagnosing premalignant oral lesions and OSCC. Also, the study aimed to correlate the levels of salivary and serum TNF-${\alpha}$ with clinicopathologic factors. Materials and Methods: A prospective experimental laboratory study was designed. Serum and salivary samples from 100 subjects in each group of healthy control, premalignant disease (PMD) and OSCC were collected for the study following appropriate exclusion and inclusion criteria. Serum and salivary level of TNF-${\alpha}$ was analysed by enzyme linked immunosorbent assay. The data obtained were subjected to appropriate statistical analysis. Results: Increased level of both serum and salivary TNF-${\alpha}$ was observed in OSCC subjects compared to healthy control and PMD group. Receiver operator characteristic curve analysis and area under curve values showed high specificity and sensitivity for salivary TNF-${\alpha}$ in differentiating OSCC from PMD and healthy controls. There was significant increase in TNF-${\alpha}$ level in moderately and poorly differentiated lesion compared to well differentiated lesion and in stage IV of clinical stage. A positive correlation was observed only with histological grading of OSCC and TNF-${\alpha}$. Conclusions: Salivary TNF-${\alpha}$ is proved to be superior for detecting OSCC. Increase in TNF-${\alpha}$ with histological grading and clinical staging suggests a role in prognosis.

Sensitivity-based reliability analysis of earth slopes using finite element method

  • Ji, Jian;Liao, Hong-Jian
    • Geomechanics and Engineering
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    • v.6 no.6
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    • pp.545-560
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    • 2014
  • For slope stability analysis, an alternative to the classical limit equilibrium method (LEM) of slices is the shear strength reduction method (SRM), which can be integrated into finite element analysis or finite difference analysis. Recently, probabilistic analysis of earth slopes has been very attractive because it is capable to take the soil uncertainty into account. However, the SRM is less commonly extended to probabilistic framework compared to a variety of probabilistic LEM analysis of earth slopes. To overcome some limitations that hinder the development of probabilistic SRM stability analysis, a new procedure based on recursive algorithm FORM with sensitivity analysis in the space of original variables is proposed. It can be used to deal with correlated non-normal variables subjected to implicit limit state surface. Using the proposed approach, a probabilistic finite element analysis of the stability of an existing earth dam is carried out in this paper.

Modelling Study on Sustainable Resources Management System Using Material Flow Analysis(MFA) in Korea (물질흐름분석을 이용한 국내 지속가능한 자원관리 시스템 모형 연구)

  • Kim, Yu-Jeong;Kim, Seong-Yong;Heo, Eun-Nyeong
    • Economic and Environmental Geology
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    • v.41 no.2
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    • pp.253-265
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    • 2008
  • Sustainable resource management(SRM) is regarded as the core strategy to achieve Dematerialisation and Decoupling of economic growth from the use of natural resources and environmental degradation. This paper presents status SRM policy and research in worldwide, and analyzes decoupling of economic activity from energy consumption of domestic manufacturing, using decoupling factor. Also This paper suggests methodologies and strategies of SRM in Korea. SRM is established through various analysis and survey as following; forecasting of resource demand, material flow analysis and value chain analysis, resource market structure analysis. Through these analysis, we can obtain hot-spot and solution of environmental burden, recycling market management, recycling technology and best-optimal supply rate of primary and secondary resource. In Korea, resource management system must be linked with national and regional material flow analysis, and it is necessary to make SRM-law of national dimension for effective run of sustainable resource management system.

A Study on the SRM Torque Computation According to Different Stator Pole Shapes (스위치드 릴럭턴스 전동기의 스테이터 형상에 따른 토크량 계산에 관한 연구)

  • Jo, Hee;Lee, Jong-Woo;Kim, Kyeong-Hwa
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.693-696
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    • 2011
  • The SRM (Switched Reluctance Motor) is composed of silicon steel plates where the rotor structure is simple and laminated without coil winding or permanent magnet, making it mechanically robust and its maintenance and repair excellent. Applying SRM as traction motor for railway vehicle is given consideration because of its ruggedness capability in severe loading condition and its compact structure. Optimal design of SRM is needed to reduce torque ripple to apply SRM for railway traction drive because SRM has high torque ripple. In this paper, switched reluctance motor with three different stator pole shapes is taken for magnetic analysis using 3d finite element method to apply SRM as traction drive for railway vehicle. It is observed that the model 3 added Tooth Tang Depth and Slot Round to stator shape gives the improved inductance and torque characteristic.

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Analysis of Neural Network Approaches for Nonlinear Modeling of Switched Reluctance Motor Drive

  • Saravanan, P;Balaji, M;Balaji, Nagaraj K;Arumugam, R
    • Journal of Electrical Engineering and Technology
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    • v.12 no.4
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    • pp.1548-1555
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    • 2017
  • This paper attempts to employ and investigate neural based approaches as interpolation tools for modeling of Switched Reluctance Motor (SRM) drive. Precise modeling of SRM is essential to analyse the performance of control strategies for variable speed drive application. In this work the suitability of Generalized Regression Neural Network (GRNN) and Extreme Learning Machine (ELM) in addition to conventional neural network are explored for improving the modeling accuracy of SRM. The neural structures are trained with the data obtained by modeling of SRM using Finite Element Analysis (FEA) and the trained neural network is incorporated in the model of SRM drive. The results signify the modeling accuracy with GRNN model. The closed loop drive simulation is performed in MATLAB/Simulink environment and the closeness of the results in comparison with the experimental prototype validates the modeling approach.

Performances of SR Drive for Electrical Power Steering Systems

  • Ahn, Jin-Woo;Lee, Dong-Hee;An, Young-Ju
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.3B no.4
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    • pp.188-194
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    • 2003
  • The SRM (Switched Reluctance Motor) has a more inherent simple mechanical structure, greater ruggedness and higher efficiency than a conventional AC motor. It is for these reasons that SRM is widely applied in an extensive range of industrial applications. In this paper, SRM is designed and analyzed for EPS (Electrical Power Steering) application. Electrical power steering in a vehicle plays the role of reducing a driver's handling control power. For proper design, a FEM analysis is implemented according to the rotor structure. Using both a FEM and a magnetic circuit analysis, a designed motor is simulated and tested. The effectiveness of the suggested SRM drive for EPS application is verified by the prototype motor drive tests.

Switching Angle Selection for Maximum Torque in Toroidal SRM (Toroidal SRM의 최대토크 스위칭각 선정)

  • 차현록;김현덕;김광헌;임영철;최유영;최강식;전흥기
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.135-138
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    • 1999
  • This paper analysis magnetic circuit of toroida SRM and simulate optimal switching angle. In this troidal SRM, two of three phase are energized at an arbitrary instance while it is with only one phase in case of typical SRM. It has many advantages in the size of machine and power efficiency. Not only typically Known topologies witched reluctance motors such as asymmetric converter but full bridge converter are safe to employ

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Characteristic Analysis of Two-Phase SRM with Single Diode Bridge Rectifier (단상 다이오드 브리지 정류기를 갖는 2상 SRM 특성해석)

  • Lee, Chan-Gyo;Oh, Ju-Hwan;Kwon, Byung-Il
    • Proceedings of the KIEE Conference
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    • 2005.10c
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    • pp.89-91
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    • 2005
  • In This paper the convertor topology using single diode bridge rectifier for the now two-phase switched reluctance motor is proposed. The single diode bridge rectifier is supplied by the Ac voltage source. The nonlinear model of two-phase SRM is implement by maxwell and result show the photographic.

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Characteristics Analysis of 4/6 pole High Speed Hybrid SRM (고속 하이브리드 4/6극 SRM의 특성 해석)

  • Ahn, Soo-yong;Jeong, Kwang-il;Ahn, Jin-woo
    • Proceedings of the KIPE Conference
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    • 2016.11a
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    • pp.111-112
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    • 2016
  • 본 논문에서는 일반적인 스위치드 릴럭턴스 전동기(Switched Reluctance Motor, SRM)의 고정자 철심에 영구자석과 조합된 구조를 가지는 하이브리드형 스위치드 릴럭턴스 전동기(Hybrid SRM, HSRM)을 제안하였다. 제안된 HSRM은 기존 블렌더용 2상 4/2극 SRM의 인덕턴스 및 토크 특성과 비교하였다. 그 결과 제안된 HSRM은 높은 토크 출력 및 소형화가 가능함을 확인하였다.

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