Description and Analysis of Switched Mode Chopper Amplifier for DC Attraction Type Levitation System
01 Dec 2006-pp 1542-1547
TL;DR: Shirazee et al. as discussed by the authors introduced a new single switch based switched mode power amplifier for electromagnetic levitation, which has some definite advantages over mostly reported asymmetrical H-bridge converter (N.A. Shirazee and A. Basak, 1995).
Abstract: Power amplifier plays most important part of the electromagnetic suspension system. The advances in the technology of attraction type magnetic levitation are attributable almost entirely to the development of solid state electronic and power semiconductor devices. The amplifier should have properties like fast dynamics, wide bandwidth, ability to handle large payload, energy efficient, high reliability and should be cost-effective. Both linear and switching mode power amplifiers have been used in the field of DC electromagnetic suspension system. In this paper different possible switched mode power circuits for single magnet based electromagnetic levitation system have been discussed and a comparative study has been made of the different topologies of power amplifiers based on their structure and some experimental results. In the actual work design, fabrication and testing of an electromagnetic levitation scheme has been made as a complete project. But in this paper the emphasis is given on power amplifier portion due to limitation of space. A new single switch based switched mode power amplifier for electromagnetic levitation has been introduced. This circuit is simpler in topology and has some definite advantages over mostly reported asymmetrical H-bridge converter (N.A. Shirazee and A. Basak, 1995).
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23 Oct 1973
TL;DR: In this paper, the rotor is made in the form of a rod placed between the poles of the electromagnets of an n-phase system, which can be used in gravimetry and gyroscopic devices.
Abstract: : The electromagnetic suspension suggested differs from known suspensions in that its rotor is made in the form of a rod placed between the poles of the electromagnets of an n-phase system. This invention can be used in gravimetry and gyroscopic devices. (Author)
16 citations
01 May 2019
TL;DR: To determine the appropriate control period of the current loop in the digital suspension system, the mathematical model of the suspension system and the maglev chopper is established, then the quantitative relationship between the current Loop control period and the coil current ripple is deduced.
Abstract: The cascade control strategy of current inner loop and airgap outer loop is usually adopted in electromagnetic suspension (EMS) system. The current loop and airgap loop adopt different control cycles in controller design, and the current loop control cycle is required to be shorter than the airgap loop control cycle. In theory, the shorter the control cycle of the inner loop, the better the following effect of the chopper current, and the more beneficial to the suspension system. However, it also needs the higher controller performance and control algorithm efficiency. With the suspension control performance permitted, reducing the current loop control frequency can effectively reduce the requirements of the controller performance and expand the selection range of the controller. In order to determine the appropriate control period of the current loop in the digital suspension system, the mathematical model of the suspension system and the maglev chopper is established, then the quantitative relationship between the current loop control period and the coil current ripple is deduced. Based on Simulink, the coupling simulation model of the maglev chopper and the suspension system is established, where the influence of the chopper control period on the performance of the suspension system is simulated and analyzed.
1 citations
Additional excerpts
...PWM modulation technology and feedback compensation are adopted to improve the response speed of the system, so that output current and control voltage of the chopper have a good linear relationship [3-5]....
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References
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TL;DR: A magnetic levitation control system is built as a classroom demonstration device for systems and control courses as mentioned in this paper, where linearization and phase-lead compensation techniques are used to control the unstable nonlinear system.
Abstract: A magnetic levitation control system is built as a classroom demonstration device for systems and control courses. System linearization and phase-lead compensation techniques are used to control the unstable nonlinear system.
128 citations
TL;DR: In this article, a single input single output (SISO) analytical model and closed-loop identification experiments are presented, with emphasis on design procedures of H/sub 2/ and H/ sub /spl infin// controllers applied to the electromagnetic levitation system.
Abstract: Many magnetically levitated transport systems have been constructed, tested, and improved. Various magnetic levitation (MagLev) system technologies are being developed, and some of them, including the prototype featured in this article, use electromagnets for vehicle levitation. Vehicle levitation is achieved by controlling the gaps of these electromagnets. The constructed prototype will have independent levitation and propulsion systems, but the focus of this article is on the levitation system only. The system is open-loop unstable, highly nonlinear, and it has a very restricted equilibrium region. A single input single output (SISO) analytical model and closed-loop identification experiments are presented, with emphasis on design procedures of H/sub 2/ and H/sub /spl infin// controllers applied to the electromagnetic levitation system. For the designs of these controllers, a special choice of weighting functions is employed to attenuate the resonance peak at low frequencies in the closed-loop system. The results show that closed-loop system responses with H/sub 2/ and H/sub /spl infin// controllers are very similar and present better performances when compared to the response obtained with a classical controller.
78 citations
TL;DR: In this paper, two major demonstration systems are now in operation, one in Germany and one in Japan, for electrodynamic suspension and levitation, following on from aircushion vehicles such as the Tracked Hovercraft and the Aerotrain.
Abstract: Defying gravity seems to have fascinated scientists and philosophers through the ages. Electromagnetic suspension and levitation, following on from aircushion vehicles, such as the Tracked Hovercraft and the Aerotrain, has been the focus of attention and research for passenger-carrying vehicles since the 1970s. Two major demonstration systems are now in operation : one in Germany and one in Japan. Besides application to passenger-carrying vehicles, controlled DC electromagnet technology has been applied to produce frictionless magnetic bearings, conveyor systems, flow meters, etc. This is becoming a rapidly expanding area, moving out of the realms of academe into one of considerable industrial importance. The applications now include high-speed machine tool spindles, ultra-centrifuges, turbo-alternators, corrosive-liquid pumps, gas compressors and high-vacuum pumps, fly wheels for energy storage, handling components for protective coating and weighing balances. New developments in superconducting materials have also aroused fresh interest in the electrodynamic levitation schemes such as the Japanese one.
72 citations
TL;DR: Although the results presented are for a quadratic optimal controller, the control system configuration used can cope with more advanced real-time control algorithms.
Abstract: In this paper, a digital control experiment using a magnetic suspension system is described. Although the results presented are for a quadratic optimal controller, the control system configuration used can cope with more advanced real-time control algorithms. Practical issues concerning parameter identification, computer simulation, discrete-time implementation, use of a digital signal processor based controller and filter design are addressed. Simulated and experimental responses are presented and analyzed. Finally, a detailed plan on reproducing the control experiment is included.
67 citations
TL;DR: A simple technique for obtaining the parameters of a linearized model for a didactic magnetic levitation system is introduced and is suitable for use in undergraduate control experiments.
Abstract: A simple technique for obtaining the parameters of a linearized model for a didactic magnetic levitation system is introduced. The proposed procedure only involves basic concepts of dynamic systems and is suitable for use in undergraduate control experiments. The project and validation of a digital lead compensator based on the linearized model are also presented.
36 citations