Structure of the octagon-type ultrasonic motor was proposed and designed so as to allow the motor to drive small actuator. The stator of the motor consisted of the octagon shape elastic body and four rectangular plate...Structure of the octagon-type ultrasonic motor was proposed and designed so as to allow the motor to drive small actuator. The stator of the motor consisted of the octagon shape elastic body and four rectangular plate ceramics. The four ceramics were attached to outer surfaces of the octagon elastic body. The same phase voltages were applied to the ceramics on horizontal surfaces, and 90° phase difference voltages were applied to the ceramics on vertical surfaces. When the AC voltage with 90° phase difference was applied in ceramics, the elliptical displacement of unimorph bars was generated by generating bending vibration. To find the maximum displacement model that generates elliptical displacement at the centers of the inner surfaces, the finite element analysis program ATILA was used. The analyzed results were compared to the experimental results. As a result, the speed and torque are increased linearly by increasing the input voltage and the speed of motors can be controlled by changing the applied voltages.展开更多
Generator synchronization is an important and frequent operation in rural small hydropower station. In order to ensure that generator can be paralleled in the grid automatically, efficiently, and stably in the rural s...Generator synchronization is an important and frequent operation in rural small hydropower station. In order to ensure that generator can be paralleled in the grid automatically, efficiently, and stably in the rural small hydropower station whose parallel in operation still needs to be accomplished manually. This paper described an automatic quasi-synchronizing device, based on 89C52 Single-chip Microcomputer （SCM）. Its hardware includes three modules and its software is structuralized. The device structure is simple, and its reliability is high and the maintenance is easy. Besides, convenient Human Machine Interface （HMI） makes the parameter setting simple and flexible展开更多
基金Project supported by the Second Stage of Brain Korea 21 Projectssupported by the National Research Foundation of Korea (NRF) Grant funded by the Korea government (MEST) [No.2011-0030806]
文摘Structure of the octagon-type ultrasonic motor was proposed and designed so as to allow the motor to drive small actuator. The stator of the motor consisted of the octagon shape elastic body and four rectangular plate ceramics. The four ceramics were attached to outer surfaces of the octagon elastic body. The same phase voltages were applied to the ceramics on horizontal surfaces, and 90° phase difference voltages were applied to the ceramics on vertical surfaces. When the AC voltage with 90° phase difference was applied in ceramics, the elliptical displacement of unimorph bars was generated by generating bending vibration. To find the maximum displacement model that generates elliptical displacement at the centers of the inner surfaces, the finite element analysis program ATILA was used. The analyzed results were compared to the experimental results. As a result, the speed and torque are increased linearly by increasing the input voltage and the speed of motors can be controlled by changing the applied voltages.
文摘Generator synchronization is an important and frequent operation in rural small hydropower station. In order to ensure that generator can be paralleled in the grid automatically, efficiently, and stably in the rural small hydropower station whose parallel in operation still needs to be accomplished manually. This paper described an automatic quasi-synchronizing device, based on 89C52 Single-chip Microcomputer （SCM）. Its hardware includes three modules and its software is structuralized. The device structure is simple, and its reliability is high and the maintenance is easy. Besides, convenient Human Machine Interface （HMI） makes the parameter setting simple and flexible
