Topic
TEFC
About: TEFC is a research topic. Over the lifetime, 163 publications have been published within this topic receiving 3921 citations.
Papers published on a yearly basis
Papers
1 Sep 1991
TL;DR: In this paper, a lumped-parameter thermal model is described which provides both a steady-state and transient solution to the temperatures within an electrical machine of the TEFC design.
Abstract: A lumped-parameter thermal model is described which provides both a steady-state and transient solution to the temperatures within an electrical machine of the TEFC design. The model is sufficiently complex to identify the temperatures at most locations in the machine, including the peak temperatures in the endwinding and the surface temperatures of the rotor. It is formulated out of purely dimensional information and constant thermal coefficients and is therefore easily adapted to a range of frame sizes. The thermal behaviour of the TEFC machine is accurately described by the solution of just eight linear differential equations. The model is therefore suitable for application to online temperature estimation for protection and duty-cycle evaluation. The application of the thermal model to a medium (75 kW) and two small (5.5 kW) induction motors is described in detail. The model performance is confirmed by experimental temperature data obtained from varying load tests on each of the three induction motors.
917 citations
TL;DR: In this paper, the authors present a review of thermal design issues in electric motors and give advice on how to deal with them when developing algorithms for inclusion in design software, and highlight a number of thermal issues that are difficult to analyze.
Abstract: With the ever-increasing pressure on electric motor manufacturers to develop smaller and more efficient electric motors, there is a need for more thermal analysis in parallel with the traditional electromagnetic design. Attention to the thermal design can be rewarded by major improvements in the overall performance. Technical papers published to date highlight a number of thermal design issues that are difficult to analyze. This paper reviews some of these issues and gives advice on how to deal with them when developing algorithms for inclusion in design software.
566 citations
10 Dec 2002
TL;DR: In this article, a simplified thermal model for variable-speed self-cooled induction motors is proposed and experimentally verified, based on simple equations that are compared with more complex equations well known in the literature.
Abstract: In this paper, a simplified thermal model for variable-speed self-cooled induction motors is proposed and experimentally verified. The thermal model is based on simple equations that are compared with more complex equations well known in the literature. The proposed thermal model allows one to predict the over temperature in the main parts of the motor, starting from the measured or the estimated losses in the machine. In the paper, the description of the thermal model setup is reported in detail. Finally, the model is used to define the correct power derating for a variable-speed pulsewidth-modulation induction motor drive.
414 citations
TL;DR: The vast majority of totally enclosed fan cooled (TEFC) squirrel cage induction motors in the 1-to 20-hp range installed in the petroleum and chemical industries are National Electrical Manufacturers Association (NEMA) T" frames built prior to 1992, NEMA T" frame built in accordance with the Energy Policy Act of 1992 (commonly referred to as EPAct motors), and the NEMA Premium motors, introduced after the year 2000, that exceed the EPAct efficiency standards as mentioned in this paper.
Abstract: The vast majority of totally enclosed fan cooled (TEFC) squirrel cage induction motors in the 1-to 20-hp range installed in the petroleum and chemical industries are National Electrical Manufacturers Association (NEMA) "T" frames built prior to 1992, NEMA "T" frames built in accordance with the Energy Policy Act of 1992 (commonly referred to as EPAct motors), and the NEMA Premium motors, introduced after the year 2000, that exceed the EPAct efficiency standards. All three types are available in accordance with the IEEE 841 recommended practice and standards. The most obvious difference in these three generations of motors is their efficiency levels. There has been some concern expressed by the users of these motors that to achieve the premium levels of efficiency it was necessary to compromise other performance characteristics and the motor reliability. This article addresses these claims and shows that they are without basis.
356 citations
Dissertation•
1 Jan 1995
TL;DR: In this paper, thermal network models, suitable for totally enclosed fan cooled (TEFC) induction motors, are used to predict the machine temperatures. But the model is limited to 7 nodes.
Abstract: The loadability of electric machines is above all determined by temperature limits. In this work, thermal network models, suitable for totally enclosed fan cooled (TEFC) induction motors, are used to predict the machine temperatures. Two specific models are suggested: one with 107 nodes, which primarily is intended as a design tool, and one with 7 nodes, for increased simplicity. The steady-state solution method is valid in a broad speed-range and for variable load. Time-dependent solutions are obtained as a function of four input variables: frequency, stator voltage, torque and ambient temperature.
182 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2022 | 1 |
| 2021 | 3 |
| 2020 | 2 |
| 2019 | 9 |
| 2018 | 6 |
| 2017 | 3 |