Topic

# Copper loss

About: Copper loss is a research topic. Over the lifetime, 1638 publications have been published within this topic receiving 15786 citations.

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18 Jun 1979TL;DR: In this paper, an improvement to a recently reported theory for the analysis of the pattern and impedance loci of microstrip antennas is developed, which yields a theory which is simple and inexpensive to apply.

Abstract: An improvement to a recently reported theory for the analysis of the pattern and impedance loci of microstrip antennas is developed. It yields a theory which is simple and inexpensive to apply. The fields in the interior of the antennas are characterized in terms of a discrete set of modes. The poles corresponding to these modes are complex and depend on the losses in the antenna. The representation of the fields in terms of these modes is rigorous only for a bona fide cavity with no copper loss. The proper shift in the complex poles due to the addition of copper and radiative losses is approximated by lumping the latter two together with the dielectric loss to form an effective loss tangent. By so doing, it is found that the resulting expressions for impedance of the microstrip antenna are in good agreement with measured results for all modes and feed locations. The theory is applied to the evaluation of impedance variation with feed location, to multiport analysis, and to the design of circularly polarized microstrip antennas.

565 citations

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01 May 1979

TL;DR: In this article, an improvement to a recently reported theory for the analysis of the pattern and impedance loci of microstrip antennas is developed, which yields a theory which is simple and inexpensive to apply.

Abstract: : An improvement to a recently reported theory for the analysis of the pattern and impedance loci of microstrip antennas is developed. It yields a theory which is simple and inexpensive to apply. The fields in the interior of the antennnas are characterized in terms of a discrete set of modes. The poles corresponding to these modes are complex and depend on the losses in the antenna. The representation of the fields in terms of these modes in rigorous only for a bona fide cavity with no copper loss. The proper shift in the complex poles due to the addition of copper and radiative losses is approximated by lumping the latter two together with the dielectric loss to form an effective loss tangent. By so doing, it is found that the resulting expressions for impedance of the microstrip antenna is in good agreement with measured results for all modes and feed locations. The theory is applied to the evaluation of impedance variation with feed location, multiport analysis, and to design of circularly polarized microstrip antennas. (Author)

556 citations

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TL;DR: The proposed control algorithm is applied to the experimental PM motor drive system, in which one digital signal processor is employed to execute the control algorithms, and several drive tests are carried out.

Abstract: This paper aims to improve efficiency in permanent magnet synchronous (PM) motor drives. The controllable electrical loss which consists of the copper loss and the iron loss can be minimized by the optimal control of the armature current vector. The control algorithm of the current vector minimizing the electrical loss is proposed and the optimal current vector can be decided according to the operating speed and the load conditions. The proposed control algorithm is applied to the experimental PM motor drive system, in which one digital signal processor is employed to execute the control algorithms, and several drive tests are carried out. The operating characteristics controlled by the loss minimization control algorithm are examined in detail by computer simulations and experimental results. >

391 citations

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TL;DR: In this article, two improved torque sharing functions for implementing torque ripple minimization (TRM) control are presented, which are dependent on the turn-on angle, overlap angle, and the expected torque.

Abstract: Two improved torque-sharing functions for implementing torque ripple minimization (TRM) control are presented in this paper. The proposed torque-sharing functions are dependent on the turn-on angle, overlap angle, and the expected torque. This study shows that for a given torque the turn-on angle and the overlap angle have significant effects upon speed range, maximum speed, copper loss, and efficiency. Hence, genetic algorithm is used to optimize the turn-on angle and the overlap angle at various expected torque demands operating under the proposed TRM control in order to maximize the speed range and minimize the copper loss. Furthermore, four torque-sharing functions are used to derive the optimized results. At the same time, a fast and accurate online approach to compute the optimal turn-on and overlap angles is proposed. Therefore, this paper provides a valuable method to improve the performances of switched reluctance motor drives operating under TRM control.

320 citations

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01 Jan 2001TL;DR: In this paper, the authors take a high level look at multiphase induction machines in order to examine those aspects that are not design-specific, and they show that for a machine in which the only design variable is the phase number, the main target for loss reduction is the stator copper loss, which by the use of more than three phases may be attenuated by as much as 8.5%.

Abstract: In this paper the authors take a high level look at multiphase induction machines in order to examine those aspects that are not design-specific. They show that for a machine in which the only design variable is the phase number, the main target for loss reduction is the stator copper loss, which by the use of more than three phases may be attenuated by as much as 8.5%. In addition, a general expression for the harmonic fields produced when a machine having any phase number is excited from a PWM inverter is derived, and the sources of torque pulsation are identified.

287 citations