2008 14th Symposium on Electromagnetic Launch Technology最新文献

{"title":"Double 7.5-kW Three-Phase Switched Reluctance Motors Parallel Drive System for Electric Locomotive Traction","authors":"H. Chen, G. Xie","doi":"10.1109/ELT.2008.98","DOIUrl":"https://doi.org/10.1109/ELT.2008.98","url":null,"abstract":"This paper has proposed an electric locomotive in coal mine drawn by the parallel drive system of the switched reluctance dual motors. The principles of the Switched Reluctance motor drive operated at four quadrants with the fixed conducting angles PWM control strategy, the scheme of the symmetrical traction at I-quadrant and at Ill-quadrant, and the scheme of the symmetrical regenerative braking control at II- quadrant and at IV-quadrant, are given. The major components of the prototype are explained in detail. The closed-loop rotor speed control of the main motor, synchronization of the rotor speed and balance distribution of loads between the main motor and the subordinate motor have been implemented by the fuzzy logic algorithm. The experimental results of the prototype are included. It is shown that the rotor speed error of the subordinate motor is within 5% and the error of the output torque of the subordinate motor is within 10%.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126541945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stress Wave Measurements in an Electromagnetic Launcher","authors":"A.J. Johnson, T. Haran, F. Moon, W. Robinson","doi":"10.1109/ELT.2008.77","DOIUrl":"https://doi.org/10.1109/ELT.2008.77","url":null,"abstract":"This paper discusses strain measurements that were conducted on the electromagnetic rail launcher at the Georgia Institute of Technology. The dynamic strain in the rails of the launcher was measured using fiber Bragg grating strain sensors with an interrogation system developed by micron optics. The fiber optic sensors are immune to the large pulsed electromagnetic fields in the bore of the launcher. The immunity of this system to electromagnetic interference allowed for dynamic strain measurements to be made during launch. These measurements show changes in the dynamic strain that are indicative of a critical velocity of the rails. These changes include wave radiation, wave reflection and strain amplification above the critical velocity. The magnitude of the stress waves are large enough for plastic deformation of the rails to occur. This plastic deformation could directly affect the lifetime of the rails in the electromagnetic launcher. The apparent critical velocity seen in these experiments is lower than the value from the Bernoulli-Euler beam theory. This is believed to be caused by a combination of the nonlinear load-deflection curve and effective mass of the containment. In addition to these phenomena, jerk effect waves and asymmetries between the two different rails were also observed.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134542756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"StarTram: The Magnetic Launch Path to Very Low Cost, Very High Volume Launch to Space","authors":"J. Powell, G. Maise","doi":"10.1109/ELT.2008.76","DOIUrl":"https://doi.org/10.1109/ELT.2008.76","url":null,"abstract":"Rocket based Earth to space launch systems are limited to a few hundred tons of payload annually at $~10,000 per kilogram. Over the past 30 years only marginal cost reductions have been achieved. Electromagnetic launch to space can greatly reduce launch cost and increase launch volume. StarTram uses superconducting maglev to accelerate heavy payloads ~20 to 30 tons, to orbital speed, ~8 kms/sec, in evacuated tunnels at ground level. Superconducting 20 ton Maglev passenger vehicles using the 1966 inventions of Powell and Danby now operate in Japan at 360 mph in the open atmosphere limited only by air drag. In evacuated tunnels, orbital speeds are possible. Two StarTram systems are described. The near term Gen-1 system launches 35 ton cargo craft from the surface at a high altitude location, e.g., ~4000 meters. The cargo craft ascends to orbit, where a small delta V rocket burn establishes orbit. Launch energy cost is only ~$0.50 per kilogram of payload. Adding costs of the cargo craft, operating personnel, and the amortized launch facility, total launch cost is only ~$50 per kg, compared to $10,000 per kg using rockets. A single Gen-1 facility can launch over 100,000 tons per year to orbit, 500 times current world capacity. Applications for the Gen-1 system includes greatly expanded Earth monitoring and communications, national defense, beamed power to Earth and robust space exploration. The Gen-1 system is described including Maglev levitation and propulsion, superconducting energy storage, the exit into the atmosphere, and the cargo craft design. Also described are the aerodynamic heating and deceleration forces on the cargo craft as it ascends to orbit. The initial deceleration is ~10 g and nose heating rate is ~20 kW/cm2. Both decrease to zero in a few seconds. Delta V loss through the atmosphere is about 500 meters/sec. Technology for the Gen-1 systems already exists and a Gen-1 facility could operate within 10 years. The U.S., Russia, China and Europe each have the technical capability and suitable high-altitude sites for a Gen-1 system. Potential sites are described. The Gen-2 StarTram system to launch both cargo and passengers is also described. It is a longer term, and requires a magnetically levitated launch tube to reach high altitude.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131640052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Rail's Material on Railgun Inductance Gradient and Losses","authors":"S. Bayati, A. Keshtkar","doi":"10.1109/ELT.2008.33","DOIUrl":"https://doi.org/10.1109/ELT.2008.33","url":null,"abstract":"Inductance Gradient is one of the most important and effective factors in the efficiency of a railgun. This factor is, in turn, a function of various parameters such as railgun geometry, dimensions and materials. In this paper, we will discuss the effects of rail's material conductivity (sigma) and permeability (mu) on the inductance gradient (L') and the ohmic losses of railgun. By simulation of the railgun using two dimensional Finite Element Method (2D-FEM), for different values of sigma and mu, the stored magnetic energy and ohmic losses are calculated and then L' obtained and tabulated. Increasing the material conductivity (sigma) of rails, or choosing a good conductors for rails fabrication, will decrease inductance gradient. However, in this case, we can reduce ohmic losses. High value of permeability (mu) results the increasing of L' and decreasing of losses. In this paper, we will present two dimensional finite element models for railgun, electromagnetic equations and the boundary conditions, field and current distributions, L' and losses tables for different materials of the rail and some useful graphs.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114206683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Concepts of Electromagnetic Railgun: Synchronous Multi-Barrel-Launch Powered by Single Power Supply","authors":"Ying Wang, Jiange Zhang, Guoan Zhang, L. Shu","doi":"10.1109/ELT.2008.62","DOIUrl":"https://doi.org/10.1109/ELT.2008.62","url":null,"abstract":"Synchronously launching lots of projectiles to form barrage against missile is necessary in some occasions . This paper presents four new concept of electromagnetic rail launchers volleying projectiles powered by single high-power pulsed power supply, named respectively as multi-barrel parallel, common armature, multi-barrel serial, armature serial. This paper gives their work principles, equivalent circuits for analysis in theory, basic equations, and compares them with each other. At last it is indicated that these inventions are significant and valuable for the development of electromagnetic launch technology and science, and they have a lot of potential applications.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125850912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Design and Testing of a Large-Caliber Railgun","authors":"M. Crawford, R. Subramanian, T. Watt, D. Surls, D. Motes, J. Mallick, D. Barnette, S. Satapathy, J. Campos","doi":"10.1109/ELT.2008.84","DOIUrl":"https://doi.org/10.1109/ELT.2008.84","url":null,"abstract":"A large-caliber railgun was developed to demonstrate the supersonic launch of 120 mm projectiles. A trade study that evaluated over 70 different railgun configurations and geometries resulted in the selection of a high-inductance-gradient, multi-turn configuration as the best overall choice. Subscale tests were performed on both the railgun and launch package configurations. A full-scale laboratory system was installed that included a dedicated high-current, large-caliber breech and gunline. A full-scale launcher was successfully tested to beyond the design conditions.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125888279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Railguns through Numerical Simulations","authors":"W. Yuan, P. Yan","doi":"10.1109/ELT.2008.22","DOIUrl":"https://doi.org/10.1109/ELT.2008.22","url":null,"abstract":"Up to date, the armature transition is still a big problem in railgunnery. Many kinds of mechanism were proposed by researchers to predict or explain armature transition phenomena. And many types of railgun were invented. In this paper, three types of railgun, including simple railgun, parallel-augmented railgun and muzzle-fed railgun, are investigated with numerical simulations. Since current density is the decisive factor to transition velocity, this study focuses on the current distribution in armature. The inductance gradient of railgun and magnetic field distribution are also investigated. In order to simplify simulations, rails and armature are considered in each simulation, and armatures of railgun are same. The Maxwell 3D modular of Ansoft corp. was utilized as the program code. The simple railgun is selected as the benchmark, and the other two types were compared with it. In the simulation of parallel-augmented railgun, two current sources (500 kA, 60 Hz) were connected to inner rails and outer rail independently. In muzzle-fed railgun simulation, the same current source as in simple railgun was connected to rails. Based on simulation results, conclusions are drawn that augmented railgun has the highest inductance gradient and the largest launcher efficiency. But the current density at rear part of armature is larger than that of simple railgun if the currents flowing through inner rails and outer rail are equal. The inductance gradient of muzzle-fed railgun is the smallest, but the current density at armature shoulder is the largest. Projectiles of muzzle-fed railgun will face the greatest magnetic flux density.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"160 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123458067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ETC Ignition Research on 120 mm Gun in Korea","authors":"Seong-Ho Kim, Kyung-Seung Yang, Young Hyun Lee, Jin Sung Kim, Byung-Ha Lee","doi":"10.1109/ELT.2008.37","DOIUrl":"https://doi.org/10.1109/ELT.2008.37","url":null,"abstract":"An electrothermal-chemical (ETC) propulsion with the control of a combustion process yet requires large electrical energies for an appreciable effect. Referring to the changed tendency of focusing ETC researches on the early ignition phase, ADD (Agency for Defense Development), Korea has been studying an electrothermal ignition for a 120 mm gun using a capillary plasma injector. Under the condition of a limited capillary geometry, design efforts with various liner materials have been done to achieve robust capillary discharges capable of transferring energies around 100 kJ. Electrical properties were estimated with the help of plasma theories and compared with experimental results. Experiments using a closed vessel and a gun chamber simulator have been done to investigate the burning behaviors and the early phase of an electrothermal ignition, respectively. The closed vessel was designed for both a plasma and a conventional ignition. The burning rates could be obtained up to 70 MPa. The gun chamber simulator was designed in the shape of the chamber of a 120 mm gun except for an acrylic chamber wall withstanding up to 30 MPa. Through prior tests using the closed vessel and the gun chamber simulator appropriate electrical energies and propellant have been selected. Firings of the full-scale 120 mm gun have been done using JA2 propellant. Electrical pulses of 1 - 2.5 ms duration in the energy from 20 kJ to 120 kJ were applied. Besides an ignition capability, the results showed a possibility of a control on the peak pressure. Currently, ADD, Korea continues the research to enhance the efficiency of the plasma injector, to compact the pulse forming network, and to investigate the electrothermal ignition properties of LOVA propellant.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130084468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Permanent Magnet DC Linear Motor for Aircraft Electromagnetic Launcher","authors":"M. Mirzaei, S. E. Abdollahi, A. Vahedi","doi":"10.1109/ELT.2008.63","DOIUrl":"https://doi.org/10.1109/ELT.2008.63","url":null,"abstract":"This paper presents design and analysis of DC linear motor with permanent magnet excitation for aircraft launcher application. The detailed calculation of the motor performance is described. The main advantage of this system is removing of electronic switches and replacing it with a modified brush and commutator system. The rectangular permanent magnets and coils and coreless and ironless stator are used to achieve maximum output with minimum losses. 2D finite element and analytical methods are operated for electromagnetic field calculations.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132865559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Driving Current's Wave on Accelerative Performance of Induction Coil Launcher","authors":"Ke-yi Zhao, Shukang Cheng, Ruiping Zhang","doi":"10.1109/ELT.2008.51","DOIUrl":"https://doi.org/10.1109/ELT.2008.51","url":null,"abstract":"It is a goal for the investigator pursuing to how to improve the efficiency of the induction coil launcher (ICL). In order to enhance the efficiency, the influences of the driving current's wave on the accelerative performance in single-stage ICL are investigated. Combined the bipolar driving manner and the single-polar driving manner, the dynamic working process of the single-stage induction coil launcher are simulated. The waves of the driving current and the waves of the armature's force, speed and position are presented. For the two driving manner, the waves of their corresponding driving current are not identical. The driving current in the bipolar driving manner is bipolar, and the driving current in the single-polar driving manner is single-polar. Under the condition of the bipolar driving manner, the armature will be decelerated because of the braking force when it has not been leaved from the driving coil completely. Under the condition of the single-polar driving manner, the armature will be suffered from the action of the braking force when it has leaved from the driving coil completely. Therefore the braking force will be produced lower negative effect in the single-polar driving manner than in the bipolar driving manner, which means that higher efficiency is achieved from the single-polar driving manner. Under the same working conditions (Z=5, C=1000 mu F, f/=3000V), the maximum velocities obtained in the bipolar driving manner and in the single-polar driving manner are 7.8 m/s and 14.0008 m/s respectively. Analysis shows that the braking effect of the armature is not only related with the driving current wave but also with the armature's position.","PeriodicalId":170049,"journal":{"name":"2008 14th Symposium on Electromagnetic Launch Technology","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131298078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}