At present, an automatic-mechanic contact tap-changer is widely used in power system, but it can not frequently operate. In addition, arc will occur when the switch changes. In order to solve these two problems, this ...At present, an automatic-mechanic contact tap-changer is widely used in power system, but it can not frequently operate. In addition, arc will occur when the switch changes. In order to solve these two problems, this paper presented an automatic on-load voltage-regulating distributing transformer which employed non-contact solid-state relay as tap-changer, and mainly introduced its structure, basic principal, design method of each key link and experimental results. Laboratory simulation experiments informed that the scheme was feasible. It was a smooth and effective experiment device, which was practical in application.展开更多
Welding transformer is widely used in industry manufacturing, depleting a large portion of electricity energy.Based on modern computer technology and mathematical programming, optimum design of electro-magnetic device...Welding transformer is widely used in industry manufacturing, depleting a large portion of electricity energy.Based on modern computer technology and mathematical programming, optimum design of electro-magnetic devices leads to highly efficient use of energy and materials. Are welding transformer is optimized here. A mathematical model,considering both productive cost and operating losses, which is called or Economical-through-Life transformer, is established. Mixed penalty function method, mixed dispersing variable method and improved orthogonal method have been applied to carry out the optimization calculations. Result shows that the power factor is quite important in an Economi-cal-through-Life transformer, and that some principles must be followed in the design work. Also discussed are the advantages and disadvantages of the three methods. In the end, the prospect of optimum design of welding transformer is forecast.展开更多
In order to detect and recognize infrared target with joint transform correlator,a modified Cassegrain optical system is designed.The main advantages of the system are large field-of-view,infrared dual-band common opt...In order to detect and recognize infrared target with joint transform correlator,a modified Cassegrain optical system is designed.The main advantages of the system are large field-of-view,infrared dual-band common optical path and compact structure.In the modified Cassegrain optical system,the working wavelengths are 3.7~4.8μm and 8~12μm,the field-of-view is 4° and the aperture is 240mm.The paraboloidal primary mirror and hyperboloidal secondary mirror are all replaced by spherical surfaces.So the problems of high machining accuracy and alignment become much easier.In order to balance the aberrations,three compensating lenses are used in the system.The total length of the system is 183mm,and the ratio of the total length to focal length is 0.68.Moreover,the system has a good performance of athermalization between negative 40℃ and positive 60℃.The design results of the system show that the MTF value of each field is greater than 0.72 when the cut-off frequency is 11lp/mm.Due to the excellent image quality of the modified optical system,the ability of Joint transform correlator(JTC)applied in target tracking and identification has been improved for further.展开更多
文摘At present, an automatic-mechanic contact tap-changer is widely used in power system, but it can not frequently operate. In addition, arc will occur when the switch changes. In order to solve these two problems, this paper presented an automatic on-load voltage-regulating distributing transformer which employed non-contact solid-state relay as tap-changer, and mainly introduced its structure, basic principal, design method of each key link and experimental results. Laboratory simulation experiments informed that the scheme was feasible. It was a smooth and effective experiment device, which was practical in application.
文摘Welding transformer is widely used in industry manufacturing, depleting a large portion of electricity energy.Based on modern computer technology and mathematical programming, optimum design of electro-magnetic devices leads to highly efficient use of energy and materials. Are welding transformer is optimized here. A mathematical model,considering both productive cost and operating losses, which is called or Economical-through-Life transformer, is established. Mixed penalty function method, mixed dispersing variable method and improved orthogonal method have been applied to carry out the optimization calculations. Result shows that the power factor is quite important in an Economi-cal-through-Life transformer, and that some principles must be followed in the design work. Also discussed are the advantages and disadvantages of the three methods. In the end, the prospect of optimum design of welding transformer is forecast.
文摘In order to detect and recognize infrared target with joint transform correlator,a modified Cassegrain optical system is designed.The main advantages of the system are large field-of-view,infrared dual-band common optical path and compact structure.In the modified Cassegrain optical system,the working wavelengths are 3.7~4.8μm and 8~12μm,the field-of-view is 4° and the aperture is 240mm.The paraboloidal primary mirror and hyperboloidal secondary mirror are all replaced by spherical surfaces.So the problems of high machining accuracy and alignment become much easier.In order to balance the aberrations,three compensating lenses are used in the system.The total length of the system is 183mm,and the ratio of the total length to focal length is 0.68.Moreover,the system has a good performance of athermalization between negative 40℃ and positive 60℃.The design results of the system show that the MTF value of each field is greater than 0.72 when the cut-off frequency is 11lp/mm.Due to the excellent image quality of the modified optical system,the ability of Joint transform correlator(JTC)applied in target tracking and identification has been improved for further.
