基于MFC的单文档界面平台,采用C++语言和MFC类库设计了适用于电磁式双凸极轮毂电机的有限元分析程序,包括实现电机的尺寸确定、有限元前处理、有限元计算及有限元后处理功能模块。同时,设计了一台5 k W、12/8极的电磁式双凸极轮毂电机,...基于MFC的单文档界面平台,采用C++语言和MFC类库设计了适用于电磁式双凸极轮毂电机的有限元分析程序,包括实现电机的尺寸确定、有限元前处理、有限元计算及有限元后处理功能模块。同时,设计了一台5 k W、12/8极的电磁式双凸极轮毂电机,计算分析不同运行情况时的电机性能,获得相应的电机特性曲线。结果表明,程序设计合理、适用,且具有良好的扩展性,为复杂和特殊情况下的电机磁场分析提供了开发途径。展开更多
The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet （DSPM） motor. Compared with common three-phase bridge inverters, the proposed inve...The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet （DSPM） motor. Compared with common three-phase bridge inverters, the proposed inverter works under more complicated conditions with different principles for special winding back EMFs, position signals of hall sensors, and the given mode of switches. The ideal steady driving principles of the inverter for the motor are given. The working state with asymmetric winding back EMFs, inaccurate position signals of hall sensors, and the changing input voltage is analyzed. Finally, experimental results vertify that the given anal ysis is correct.展开更多
The inductances in d-q axis have an important influence on the behavior of PMSM （PM （permanent-magnet） synchronous machines）. Their calculation is fundamental not only to evaluate the performance such as torque an...The inductances in d-q axis have an important influence on the behavior of PMSM （PM （permanent-magnet） synchronous machines）. Their calculation is fundamental not only to evaluate the performance such as torque and field weakening capability but also to design the control system to maximize performance and power factor. This paper presents a study of inductance in the d-q axis for buried （i.e., IPMSM （interior） PM Synchronous Machines）. This study is achieved using 2-D （two-dimensional） FEM （finite-element method） and Park＇s transformation.展开更多
We report a hybrid nanogenerator that includes a triboelectric nanogenerator （TENG） and an electromagnetic generator （EMG） for scavenging mechanical energy. This nanogenerator operates in a hybrid mode using both ...We report a hybrid nanogenerator that includes a triboelectric nanogenerator （TENG） and an electromagnetic generator （EMG） for scavenging mechanical energy. This nanogenerator operates in a hybrid mode using both the triboelectric and electromagnetic induction effects. Under a vibration frequency of 14 Hz, the fabricated TENG can deliver an open-circuit voltage of about 84 V, a short-circuit current of 43 μA, and a maximum power of 1.2 mW （the corresponding power per unit mass and volume are 1.82 mW/g and 3.4 W/m^3, respectively） under a loading resistance of 2 MΩ, whereas the fabricated EMG can produce an opencircuit voltage of about 9.9 V, a short-circuit current of 7 mA, and a maximum power of 17.4 mW （the corresponding power per unit mass and volume are 0.53 mW/g and 3.7 W/m^3, respectively） under a loading resistance of 2 kΩ. Impedance matching between the TENG and EMG can be achieved using a transformer to decrease the impedance of the TENG. Moreover, the energy produced by the hybrid nanogenerator can be stored in a home-made Li-ion battery. This research represents important progress toward practical applications of vibration energy generation for realizing self-charging power cells.展开更多
A MHD generator with different arrangements of electromagnetic fields will lead the generator working in three modes.A quasi-one-dimensional approximation is used for the model of the MHD generator to analyze the inne...A MHD generator with different arrangements of electromagnetic fields will lead the generator working in three modes.A quasi-one-dimensional approximation is used for the model of the MHD generator to analyze the inner mechanism of operation modes.For the MHD generator with a uniform constant magnetic field,a specific critical electric field E_(cr) is required to decelerate a supersonic entrance flow into a subsonic exit flow.Otherwise,the generator works in a steady mode with a larger electric field than E_(cr) in which a steady supersonic flow is provided at the exit,or the generator works in a choked mode with a smaller electric field than E_(cr) in which the supersonic entrance flow is choked in the channel.The detailed flow field characteristics in different operation modes are discussed,demonstrating the relationship of operation modes with electromagnetic fields.展开更多
文摘基于MFC的单文档界面平台,采用C++语言和MFC类库设计了适用于电磁式双凸极轮毂电机的有限元分析程序,包括实现电机的尺寸确定、有限元前处理、有限元计算及有限元后处理功能模块。同时,设计了一台5 k W、12/8极的电磁式双凸极轮毂电机,计算分析不同运行情况时的电机性能,获得相应的电机特性曲线。结果表明,程序设计合理、适用,且具有良好的扩展性,为复杂和特殊情况下的电机磁场分析提供了开发途径。
文摘The three-phase bridge inverter is used as the converter topology in the power controller for a 9 kW doubly salient permanent magnet （DSPM） motor. Compared with common three-phase bridge inverters, the proposed inverter works under more complicated conditions with different principles for special winding back EMFs, position signals of hall sensors, and the given mode of switches. The ideal steady driving principles of the inverter for the motor are given. The working state with asymmetric winding back EMFs, inaccurate position signals of hall sensors, and the changing input voltage is analyzed. Finally, experimental results vertify that the given anal ysis is correct.
文摘The inductances in d-q axis have an important influence on the behavior of PMSM （PM （permanent-magnet） synchronous machines）. Their calculation is fundamental not only to evaluate the performance such as torque and field weakening capability but also to design the control system to maximize performance and power factor. This paper presents a study of inductance in the d-q axis for buried （i.e., IPMSM （interior） PM Synchronous Machines）. This study is achieved using 2-D （two-dimensional） FEM （finite-element method） and Park＇s transformation.
基金This work was supported by Beijing Natural Science Foundation （No. 2154059）, National Natural Science Foundation of China （Nos. 51472055 and 61404034）, and the ＂Thousands Talents＂ program for pioneer researcher and his innovation team, China.
文摘We report a hybrid nanogenerator that includes a triboelectric nanogenerator （TENG） and an electromagnetic generator （EMG） for scavenging mechanical energy. This nanogenerator operates in a hybrid mode using both the triboelectric and electromagnetic induction effects. Under a vibration frequency of 14 Hz, the fabricated TENG can deliver an open-circuit voltage of about 84 V, a short-circuit current of 43 μA, and a maximum power of 1.2 mW （the corresponding power per unit mass and volume are 1.82 mW/g and 3.4 W/m^3, respectively） under a loading resistance of 2 MΩ, whereas the fabricated EMG can produce an opencircuit voltage of about 9.9 V, a short-circuit current of 7 mA, and a maximum power of 17.4 mW （the corresponding power per unit mass and volume are 0.53 mW/g and 3.7 W/m^3, respectively） under a loading resistance of 2 kΩ. Impedance matching between the TENG and EMG can be achieved using a transformer to decrease the impedance of the TENG. Moreover, the energy produced by the hybrid nanogenerator can be stored in a home-made Li-ion battery. This research represents important progress toward practical applications of vibration energy generation for realizing self-charging power cells.
基金supported in part by the National Natural Science Foundation of China under Grant 51006027,Grant 50925625,and Grant 51437002the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology under Grant HIT.NSRIF.2009091the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant 20102302120047
文摘A MHD generator with different arrangements of electromagnetic fields will lead the generator working in three modes.A quasi-one-dimensional approximation is used for the model of the MHD generator to analyze the inner mechanism of operation modes.For the MHD generator with a uniform constant magnetic field,a specific critical electric field E_(cr) is required to decelerate a supersonic entrance flow into a subsonic exit flow.Otherwise,the generator works in a steady mode with a larger electric field than E_(cr) in which a steady supersonic flow is provided at the exit,or the generator works in a choked mode with a smaller electric field than E_(cr) in which the supersonic entrance flow is choked in the channel.The detailed flow field characteristics in different operation modes are discussed,demonstrating the relationship of operation modes with electromagnetic fields.
