Analysis on Harmonic Loss of IPMSM for the Variable DC-link Voltage through the FEM-Control Coupled Analysis

Hyun Soo Park,Tae Chul Jeung,Jae Kwang Lee,Byoung Kuk Lee 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

This paper describes the loss analysis based on load conditions of the air conditioning compressor motors using variable dc-link voltage. The losses of PMSM (Permanent Magnet Synchronous Motor) should be analyzed by the PWM (Pulse Width Modulation) output of inverter. The harmonic loss by the PWM cannot consider that using the current source analysis of the inverter. In addition, when the voltage of dc-link is variable with the condition of variable speed and load conditions in motor, the losses of motor are also changeable, however it is hard to analyze those losses by only electromagnetic finite element method (FEM). Therefore, this paper proposes the analysis method considering the carrier frequency of the inverter and the varying state of the dc-link voltage through the FEM-control coupled analysis. Using proposed analysis method, additional core loss and eddy current loss of permanent magnet caused by PWM could be analyzed. Finally, the validity of the proposed analysis method is verified through the comparison the result of coupled analysis with experiment.

중환자에서 동맥혈 가스분석 횟수와 그로인한 실혈량에 대한 연구

이석열,전철우,정영수,오희숙,마분란,이정미,정혜영,이만복,이길노 순천향의학연구소;Soonchunhyang Medical Research Institute 2000 Journal of Soonchunhyang Medical Science Vol.6 No.1

Background : Arterial blood gas analysis is the most comon exam in intensive care unit. In this study, the frequency of blood gas analysis and the amount of blood loss after Blood Gas Analysis in Intensive Care Unit were observed. Methods : From November 1999 to February 2000, 115 patients admitted to intensive care unit at Soonchunhyang university Kumi hospital were studied prospectively for the frequency of blood gas analysis and the amount of blood loss after blood gas analysis in Intensive Care Unit. Results : The mean value of frequency of blood gas analysis was 6.41±6.49 and the mean value of amount of blood loss after blood gas analysis was 0.78ml. This was lower than that of other foreign reports. The patients with ventilator therapy above 24 hours showed higher frequency of blood gas analysis than that of not applied ventilator patients. Pulse oxymetry was applied to all patients and the frequency of blood gas analysis was decreased due to the use of strict pulse oxymetry. Conclusion : Doctors and nurses in intensive care unit keep in mind that adequate blood sampling is needed for the decrease of blood loss. Education and protocol for the decrease of blood loss after arterial blood gas analysis may be necessary.

Analysis on Harmonic Loss of IPMSM for the Variable DC-link Voltage through the FEM-Control Coupled Analysis

Park, Hyun Soo,Jeung, Tae Chul,Lee, Jae Kwang,Lee, Byoung Kuk The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

This paper describes the loss analysis based on load conditions of the air conditioning compressor motors using variable dc-link voltage. The losses of PMSM (Permanent Magnet Synchronous Motor) should be analyzed by the PWM (Pulse Width Modulation) output of inverter. The harmonic loss by the PWM cannot consider that using the current source analysis of the inverter. In addition, when the voltage of dc-link is variable with the condition of variable speed and load conditions in motor, the losses of motor are also changeable, however it is hard to analyze those losses by only electromagnetic finite element method (FEM). Therefore, this paper proposes the analysis method considering the carrier frequency of the inverter and the varying state of the dc-link voltage through the FEM-control coupled analysis. Using proposed analysis method, additional core loss and eddy current loss of permanent magnet caused by PWM could be analyzed. Finally, the validity of the proposed analysis method is verified through the comparison the result of coupled analysis with experiment.

Analysis on Harmonic Loss of IPMSM for the Variable DC-link Voltage through the FEM-Control Coupled Analysis

박현수,정태철,이재광,이병국 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

This paper describes the loss analysis based on load conditions of the air conditioning compressor motors using variable dc-link voltage. The losses of PMSM (Permanent Magnet Synchronous Motor) should be analyzed by the PWM (Pulse Width Modulation) output of inverter. The harmonic loss by the PWM cannot consider that using the current source analysis of the inverter. In addition, when the voltage of dc-link is variable with the condition of variable speed and load conditions in motor, the losses of motor are also changeable, however it is hard to analyze those losses by only electromagnetic finite element method (FEM). Therefore, this paper proposes the analysis method considering the carrier frequency of the inverter and the varying state of the dc-link voltage through the FEM-control coupled analysis. Using proposed analysis method, additional core loss and eddy current loss of permanent magnet caused by PWM could be analyzed. Finally, the validity of the proposed analysis method is verified through the comparison the result of coupled analysis with experiment.

Analysis of Synchronous Rectification Discontinuous PWM for SiC MOSFET Three Phase Inverters

Peng Dai,Congcong Shi,Lei Zhang,Jiahang Zhang 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

Wide band gap semiconductor devices such as SiC MOSFETs are becoming the preferred devices for high frequency and high power density converters due to their excellent performances. However, the proportion of the switching loss that accounts for the whole inverter loss is growing along with an increase of the switching frequency. In view of the third quadrant working characteristics of a SiC MOSFET, synchronous rectification discontinuous pulse-width modulation is proposed (SRDPWM) to further reduce system losses. The SRDPWM has been analyzed in detail. Based on a frequency domain mathematical model, a quantitative mathematical analysis of the harmonic characteristic is conducted by double Fourier transform. Meanwhile, a switching loss model and a conduction loss model of inverter for SRDPWM have been built. Simulation and experimental results verify the result of the harmonic analysis of the double Fourier analysis and the accuracy of the loss models. The efficiencies of the SRDPWM and the SVPWM are compared. The result indicates that the SRDPWM has fewer losses and a higher efficiency than the SVPWM under high switching frequency and light load conditions as a result of the reduced number of switching transitions. In addition, the SRDPWM is more suitable for SiC MOSFET converters.

춘천 마라톤 출전 탈모자의 미네럴 함량 분석 연구

문영숙 코리아뷰티디자인학회 2015 코리아뷰티디자인학회지 Vol.9 No.1

Nutritional treatments and solutions for hair loss by hair analysis have been securing its position as the general hair loss control approach in the western world. Hair testing has been used as a preventive measure to identify the reasons of hair loss and so prevent hair loss as well as ultimately for good health. Hair analysis is a problem solution by scientific approach and the analysis data is important to identify the specific features in a certain area. This paper analyzed the mineral contents of marathon runners with hair loss through hair testing. The subjects were runners with visually identifiable hair loss among runners in Chuncheon Marathon in March 2006. In accordance with the analysis, there were more male runners with hair loss than female runners with hair loss. Subjects in their 40s to 50s had more hair loss. The heavy metal contamination figures among the subjects were higher in the order of aluminum, mercury and barium. The mineral contents among the Korean runners were lower in the order of selenium, manganese, phosphorous and sulfur. The mineral contents among the runners with hair loss were higher in the sequence of potassium, calcium, zinc, sodium, copper and chrome.

전류집전 방법에 따른 원통형 고체산화물 연료전지의 성능 변화 수치해석

유건,박석주,이종원,이승복,임탁형,송락현,신동열,김호영 한국수소및신에너지학회 2011 한국수소 및 신에너지학회논문집 Vol.22 No.2

Performance changes of an anode-supported tubular SOFC including current collectors are analyzed at different current collecting methods using numerical simulation. From the two dimensional numerical model of the solid oxide fuel cell with nickel felts as anodic current collectors and silver wires as cathodic ones,the performance curves and the distributions of temperature, concentration, current density are obtained. Also,the voltage loss of the cell is divided into three parts: activation loss, concentration loss and ohmic loss. The results show that the performance change of the cell is dominantly influenced by the ohmic loss. Although the temperature and concentration distributions are different, the total activation loss and concentration loss are nearly same. And the ohmic loss is divided into each parts of the cell components. The ohmic loss of the anodic current collectorreaches about 60~80% of the cell’s total ohmic loss. Therefore, the reduction of the ohmic loss of the anodic current collector is very important for stack power enhancement. It is also recommended that the load should be connected to the both ends of the anodic current collector.

Early radiographic diagnosis of peri-implantitis enhances the outcome of peri-implantitis treatment: a 5-year retrospective study after non-surgical treatment

Chang, Hee-Yung,Park, Shin-Young,Kim, Jin-Ah,Kim, Young-Kyun,Lee, Hyo-Jung Korean Academy of Periodontology 2015 Journal of Periodontal & Implant Science Vol.45 No.3

Purpose: This retrospective study evaluated the relationship between the timing of peri-implantitis diagnosis and marginal bone level after a 5-year follow-up of non-surgical peri-implantitis treatment. Methods: Thirty-three patients (69 implants) were given peri-implantitis diagnosis in 2008-2009 in Seoul National University Bundang Hospital. Among them, 31 implants from 16 patients were included in this study. They were treated non-surgically in this hospital, and came for regular maintenance visits for at least 5 years after peri-implantitis treatment. Radiographic marginal bone levels at each interval were measured and statistical analysis was performed. Results: Timing of peri-implantitis was one of the significant factors affecting initial bone loss and total bone loss not additional bone after peri-implantitis diagnosis. Patients with cardiovascular disease and diabetic mellitus were positively influenced on both initial bone loss and total bone loss. Patients who needed periodontal treatment after implant placement showed a negative effect on bone loss compared to those who needed periodontal treatment before implant placement during entire periods. Implant location also significantly influenced on amounts of bone loss. Mandibular implants showed less bone loss than maxillary implants. Among surgical factors, combined use of autogenous and xenogenic bone graft materials showed a negative effect on bone loss compared to autogenous bone graft materials. Use of membrane negatively affected on initial bone loss but positively on additional bone loss and total bone loss. Thread exposure showed positive effects on initial bone loss and total bone loss. Conclusions: Early peri-implantitis diagnosis led to early non-surgical intervention for peri-implantitis treatment, which resulted in the maintenance of the bone level as well as preservation of the implant.

Early radiographic diagnosis of periimplantitis enhances the outcome of peri-implantitis treatment: a 5-year retrospective study after non-surgical treatment

장희영,이효정,김진아,김영균,박신영 대한치주과학회 2015 Journal of Periodontal & Implant Science Vol.45 No.3

Purpose: This retrospective study evaluated the relationship between the timing of periimplantitis diagnosis and marginal bone level after a 5-year follow-up of non-surgical periimplantitis treatment. Methods: Thirty-three patients (69 implants) were given peri-implantitis diagnosis in 2008- 2009 in Seoul National University Bundang Hospital. Among them, 31 implants from 16 patients were included in this study. They were treated non-surgically in this hospital, and came for regular maintenance visits for at least 5 years after peri-implantitis treatment. Radiographic marginal bone levels at each interval were measured and statistical analysis was performed. Results: Timing of peri-implantitis was one of the significant factors affecting initial bone loss and total bone loss not additional bone after peri-implantitis diagnosis. Patients with cardiovascular disease and diabetic mellitus were positively influenced on both initial bone loss and total bone loss. Patients who needed periodontal treatment after implant placement showed a negative effect on bone loss compared to those who needed periodontal treatment before implant placement during entire periods. Implant location also significantly influenced on amounts of bone loss. Mandibular implants showed less bone loss than maxillary implants. Among surgical factors, combined use of autogenous and xenogenic bone graft materials showed a negative effect on bone loss compared to autogenous bone graft materials. Use of membrane negatively affected on initial bone loss but positively on additional bone loss and total bone loss. Thread exposure showed positive effects on initial bone loss and total bone loss. Conclusions: Early peri-implantitis diagnosis led to early non-surgical intervention for periimplantitis treatment, which resulted in the maintenance of the bone level as well as preservation of the implant.

Electromagnetic, Vibration and Thermal Analysis of 1.1 kw Switched Reluctance Motor for Electric Vehicle Application

Karunakaran Vijayalakshmi,Kandadai Nagaratnam Srinivas 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

This paper presents the electromagnetic analysis, vibration analysis and thermal analysis of a 6/4 pole, 1.1 kW switched reluctance motor (SRM), focusing on its application to EV, in the sense that the vibration and thermal analyses are carried out at speeds of range more than 1000 rpm, which usually experienced by EV SRM. At first, electromagnetic analysis is performed for six different silicon steel materials viz., 35JN210, 35JN300, 50JN470, 50JNA350, 50JNA600 and 50JNE350, and from the results, it has been noted that the material 35JN210 has less torque ripple and a good efficiency compared to all other materials. So this material is selected for SRM structure to perform thermal and vibration analysis. SRM proves to be a suitable candidate in electric vehicle application with the limitation with respect to its vibration and noise. The noise generation during motor operation is a major concern for SRM. The main source of vibration, the radial force, is calculated using two- dimensional (2D) transient finite-element analysis (FEA).The electromagnetic analysis is performed to find out the force exerted on the stator and deformations due to that. Using these nodal forces as input, transient analysis is performed to examine the motor's vibration characteristics. By this analysis, the motor modal frequencies are examined so that the motor operation could be skipped from operating in this vibrating region when it is used in electric vehicle applications. For thermal analysis, FEA is used to calculate the heat generation and temperature distribution on different parts of the machine to estimate the thermal behaviour of the motor.