EMI Filter Design and Performance for isolated full bridge buck converter is developed in this paper. In order to design a high performance EMI filter, many issues need to be considered beforehand. Some important issu...EMI Filter Design and Performance for isolated full bridge buck converter is developed in this paper. In order to design a high performance EMI filter, many issues need to be considered beforehand. Some important issues including accurate model of converter components, parasitic elements, its effect on EMI noise and impedance mismatch are included in this paper. A numerical prediction of EMI/EMC has the potential to evaluate EMI performances at the design stage and before prototyping. It can also help reduce the post-prototype EMC cost by minimizing late redesign and modifications of a design implementation. Saber simulator is used to analyze the EMI noises and EMI filter’s performance. Conducted EMI noise measurement and EMI filter design of isolated full bridge buck converter has been achieved while successfully satisfying the FCC class B limits in the frequency range from 150 kHz to 30 MHz. Simulation results are compared with experimental data and the effectiveness of the EMI simulation approach is demonstrated.展开更多
Modeling and simulation of induction motor drive system to investigate and mitigate the adverse effects of PWM inverter based on analysis, modeling and simulation are presented. The estimation of conducted disturbance...Modeling and simulation of induction motor drive system to investigate and mitigate the adverse effects of PWM inverter based on analysis, modeling and simulation are presented. The estimation of conducted disturbances and other adverse effects of PWM inverter by simulation offer a considerable gain from the economic point of view. For an accurate model of the motor drive system including mains, rectifier, inverter, motor and its long cables, the high frequency parasitic current paths are taken into account. The novel model and its parasitic values for three-phase induction motor system are presented. Finally a new solution for suppressing EMI, common mode voltage, leakage current, bearing current and shaft voltages is proposed and the results show the excellent performances of proposed solution including active and passive filters.展开更多
The radiation dose received by patients undergoing chest radiography was included. 200 patients who attended these investigations in 10 hospitals in Iran were randomly selected from all ages groups and both female and...The radiation dose received by patients undergoing chest radiography was included. 200 patients who attended these investigations in 10 hospitals in Iran were randomly selected from all ages groups and both female and male. Critically ill patients were excluded.This paper presents the work, which was implemented on 200 patients and evaluated using the entrance skin dose (ESD) in the posterior anterior (PA) chest projection measured directly at the center of the X-ray field. In addition, the machine room, and dark room parameters, as well as work practices and repeat rates were studied. The quality control (QC) parameters and the ESD before and after QC were evaluated utilizing an anthropomorphic phantom to define the optimal exposure condition at all hospitals. This research shows that after using the QC parameters and after optimization of the exposure conditions, the ESD was decreased by 42% on average. Also the quality of the radiographs generally increased. The reported method is easily implemented in any clinical situation where optimization of chest radiography is needed.展开更多
基金Sponsored by the National Science Foundation of China (Grant No.50477009).
文摘EMI Filter Design and Performance for isolated full bridge buck converter is developed in this paper. In order to design a high performance EMI filter, many issues need to be considered beforehand. Some important issues including accurate model of converter components, parasitic elements, its effect on EMI noise and impedance mismatch are included in this paper. A numerical prediction of EMI/EMC has the potential to evaluate EMI performances at the design stage and before prototyping. It can also help reduce the post-prototype EMC cost by minimizing late redesign and modifications of a design implementation. Saber simulator is used to analyze the EMI noises and EMI filter’s performance. Conducted EMI noise measurement and EMI filter design of isolated full bridge buck converter has been achieved while successfully satisfying the FCC class B limits in the frequency range from 150 kHz to 30 MHz. Simulation results are compared with experimental data and the effectiveness of the EMI simulation approach is demonstrated.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50477009).
文摘Modeling and simulation of induction motor drive system to investigate and mitigate the adverse effects of PWM inverter based on analysis, modeling and simulation are presented. The estimation of conducted disturbances and other adverse effects of PWM inverter by simulation offer a considerable gain from the economic point of view. For an accurate model of the motor drive system including mains, rectifier, inverter, motor and its long cables, the high frequency parasitic current paths are taken into account. The novel model and its parasitic values for three-phase induction motor system are presented. Finally a new solution for suppressing EMI, common mode voltage, leakage current, bearing current and shaft voltages is proposed and the results show the excellent performances of proposed solution including active and passive filters.
文摘The radiation dose received by patients undergoing chest radiography was included. 200 patients who attended these investigations in 10 hospitals in Iran were randomly selected from all ages groups and both female and male. Critically ill patients were excluded.This paper presents the work, which was implemented on 200 patients and evaluated using the entrance skin dose (ESD) in the posterior anterior (PA) chest projection measured directly at the center of the X-ray field. In addition, the machine room, and dark room parameters, as well as work practices and repeat rates were studied. The quality control (QC) parameters and the ESD before and after QC were evaluated utilizing an anthropomorphic phantom to define the optimal exposure condition at all hospitals. This research shows that after using the QC parameters and after optimization of the exposure conditions, the ESD was decreased by 42% on average. Also the quality of the radiographs generally increased. The reported method is easily implemented in any clinical situation where optimization of chest radiography is needed.
