1,720,986 research outputs found
Design of Improved Efficiency Induction Motors for Minimum Additional cost
No full textAim of the paper is to present the approach for manufacturing higher efficiency ranges of induction motors with minimum additional costs. The analysis concerns with industrial low voltage three-phase induction motors, in the 0.75 ̧90 kW power range. Examples of improved efficiency motors are given, based on the new Induction Motors European Classification Scheme
Flux-Weakening Control of Surface Mounted PM Synchronous Motors Accounting for Resistive Voltage Drop
No full textThis paper deals with the flux-weakening control of surface mounted permanent magnet synchronous motors, taking into account the influence of the resistive voltage drop in the stator windings, an effect which is usually neglected in similar studies. At first, the motor equations exploiting the optimal torque-speed limits in the flux-weakening region are evaluated and discussed. Then, the influence of the resistive voltage drop is pointed out, evidencing the mismatches related to its neglecting in the set-up of the flux-weakening strategy. Hence, a simplified approach to flux-weakening motor control is presented, useful for the practical implementation in micro-controlled drives. Finally, experimental results are shown, using a position-tracking application as a test case
Some practical issues of the transputer based real-time systems
No full textAn overview of the real-time features of transputers and Occam is presented. Real-time issues such as scheduling, timing, concurrence, low level support, communication, and exception handling are studied. Based on the shortcomings of transputers and Occam, some compensating methods have been proposed and implemented. Some test results are reported. It is concluded that transputers and Occam provide quite good support for implementing real-time systems. The ability to allow for both genuine and quasi-parallel processing gives the transputer a distinct advantage over conventional computer systems for real-time use. Occam, which was designed to execute on the transputer type of architecture, directly addresses issues of real-time system programming, such as the representations of parallelism, timing, assigning priorities to processes, resource allocation, low-level machine access, and flexible device interfacin
ADAPTIVE CONTROL OF D.C. ACTUATORS FOR ROBOTICS
No full textThis paper presents a model reference adaptive control method which is particularly appropriate in the control of electrical drives. The control algorithm has been developed taking into account both the control problems (such as the influence of a discrete control action on the behavior of a continuous system) and the hardware and software structures of the computing device, which is generally a multiple processor system in order to satisfy real-time requirements.
This approach allows the realization of simple and modular microprocessor-based adaptive controllers.
To evaluate the effectiveness of the adaptive control method, the paper presents the results of simulations which bave been carried out in the case of a D.C. drive and compares performances obtained with the adaptive controller and a P.I.D. regulator. To obtain from the simulations results which match with the actual behavior of the D.C. motor, its mathematical
model takes into account the saturation of the magnetic care and the parameter variations
Analysis of fault-tolerant five-phase IPM synchronous motor
No full textThe choice of a multi-phase motor is a potentially
fault-tolerant solution and gives rise to many advantages,
respect to the traditional three-phase motor drives. In this paper an high torque density five-phase IPM synchronous motor has
been studied, and the motor performance have been evaluated in the case of healthy-mode and faulty-mode operation
High-performance low-cost Hall probe measuring head
No full textAn electronic circuit is described that allows the use of an inexpensive Hall probe as a high-performance magnetic-field sensor. The circuit contains a high-precision voltage reference, a proportional control thermostat, a 16 bit serial analog-to-digital converter, and a digital control subsystem integrated into a single programmable logic device. The precision of the probe is of about 4 μT. © 1997 American Institute of Physics
Experience in Design Optimization of High Efficiency Induction Motors
No full textThe problem of designing high efficiency induction motors is approached using nonlinear programming. A software has been developed whose capacities are pointed out by showing some significant and original applications. Different design strategies have been considered in order to evaluate the effects of groups of variables on the chosen "Objective Function" and motor performance. Moreover an appropriate use of the proposed methodology has allowed to optimize an induction motor line with the same stator and rotor shapes.
The optimization results point out how an accurate motor design allows to achieve significant reductions on the operating cost (from 36% for 1.5 kW to 19% for the 18.5 kW) without affecting the manufacturing costs.
Based on the optimization results, several prototypes have been built and tested
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