1,720,969 research outputs found
Adaptive Control Strategy to Regulate Continuously the Position of the Pneumatic Cylinder
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Implementations of Model Reference Adaptive Control Strategies to Control Continuously the Position of the Pneumatic Cylinder
No full textEfficiency Increase In The Extraction of Sugar Cane Juice In The Sugar Cane Mills By Means Of The Regulation Of Hydraulic Pressures
No full textAutomatic Control Strategy In The Sugar Cane Mills To Increase The Efficient In The Extraction of Sugar Cane Juice
No full textRotor on cone-shaped active magnetic bearings with three-phases power drivers
No full textThis paper presents the modeling, the control design and the experimental results obtained on a rotor suspended by means of cone-shaped active magnetic bearings controlled by an innovative three-phases drive technique. The machine reproduces a turbo-compressor group of a conditioning unit used in high performance jet aircrafts. The conical geometry of magnetic bearings allows to perform a compact design of actuation stage which is composed of only four pairs of electromagnets instead of five of conventional cylindrical solution, resulting of great interest for the application in small machines. The modeling phases of the system are illustrated along with the drive technique and control design procedure. The mechanical subsystem has been reproduced starting from the finite element (FE) model, reduced to its first bending modes. The electromechanical interaction has been modeled considering each electromagnet as a two-port element (electrical and mechanical) exerting a force expressed as function of displacement and current in equations linearized around the working point. The control design takes into account the axial and radial coupled actions of the actuators and performs a SISO decentralized technique with five PID filters. The overall system results to be compact in the actuation subsystem as well as in the power divers equipment, being this performed with an innovative technique based on a three-phases configuration to drive a couple of electromagnets instead of standard H-bridge configuration. The control and drive schemes are presented and the reference generation for power drivers switches is illustrated in details. This approach allows to save 25% of power electronics components and reduce losses on the switches although the design phases result quite more complex than classical solutions. The paper concludes on the exposition of experimental results aiming to validate and prove the correctness of drive technique and control design approache
SENSORLESS CONTROL DESIGN FOR HIGH-SPEED PMSM AUTOMOTIVE APPLICATION
No full textNowadays electrical drives are widely used in industrial applications like energy production, management and recovery. In this paper the control of IPMSM and SPMSM motors is investigated for very high speed automotive applications. The standard DQ control is improved with additional features to guarantee high efficiency. Moreover a sensorless observer based on Sliding Mode is developed and tested experimentally. The proposed control method is designed and validated starting from modeling and simulation, fast prototyping on a custom testbench and final deployment on the target automotive application. A comparison between the results obtained during the three steps is also presen
Turbomolecular pumps on conical active magnetic bearings
No full textThe adoption of magnetic levitation is experiencing a steady growth in the vacuum industry and, in particular, in turbomolecular pumps. Nowadays, the most common solutions for pumps of small and medium pumping capacity are based on hybrid architectures where passive magnetic bearings are combined to ceramic ball bearings. By converse, fully active magnetic suspensions with cylindrical configuration represent the standard for medium to high pumping rate machines. Although simple, the cylindrical configuration is prone to drawbacks related in particular to the strains growing in the disc of the axial actuator that motivate the investigation of alternative architectures. As shown in previous literature, the use of conical configuration, besides compacting driving electronics, seems to be promising considering that the control of the radial and axial degree of freedom is performed simultaneously by the same devices acting in two actuation planes.This paper describes the development and the experimental characterization of a turbomolecular pump supported by conical active magnetic bearings. The control design is based on a SISO decentralized technique with position and control embedded loops. A rotor centering technique based on the characterization of the current loops is exposed. The external position loop is tuned by measuring relevant transfer functions to refine the controller and allow a safe critical speed crossing. The power actuation of the eight electromagnets is performed with a three-phase configuration drive technique instead of standard H-bridges to minimize the number of power switches. Experimental results along with numerical computations obtained with simulation models are reported as proof of the validity of the modeling approach and of the conical architecture effectiveness
Characterization of Belt Drive Systems in Hybrid Powertrains
Full text linkThe present work is intended to describe the concept and realization of a test rig for the characterization of the efficiency of front end accessory drives. The study is in particular addressed to those systems where the traditional alternator is replaced with a Belt Starter Generator (BSG). A BSG is an electric machine capable of working both as generator (to function as traditional alternator and regenerate energy during braking) and as motor (to start the engine and provide electric traction and boosting). The utilization of such device is among the solutions adopted by mild hybrid technologies that are addressed to the reduction of fuel consumption and pollutant emissions typical of ICEs by the application of electric machines. The introduction of a BSG into a belt drive system leads to strong variations of the belt tension due to the alternation of tight and slack span. The study of the efficiency of such system is crucial in defining the best operating strategy of mild hybrid systems comprising a Belt Drive System (BDS) equipped with a BS
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