The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The heating and cooling is very complex process for winding in large power transformer, which involves fluid dynamic, manufacture technology and numerical heat transfer and other related disciplines. Recently, the electromagnetic-Fluid-thermal coupled method and thermal network method are widely used by domestic and foreign researchers, whereas the oil flow distribution can not be taken into account...
The numerical prediction of the main state of the equipment is the first step in the prognostic and health management (PHM) study. Temperature is one of the most important health indicators of segment — powered linear motor. A nonlinear autoregressive with exogenous input neural network (NARXNN) model is trained to predict the temperature of the segment-powered linear motor. Based on the single —...
This paper presents an electro-thermal based junction temperature (Tj) estimation method of insulated gate bipolar transistor (IGBT) power module. Firstly, the internal structure of IGBT and its transient characteristics are researched, through which the factors affecting the power loss as well as its basic influence rule are analyze and the multivariable loss calculation model is obtained. And then...
Spray cooling is a new type of high heat flux heat transfer cooling technology. In the process, cooling medium is dispersed certain microscale droplets through the nozzles and injected to the stator core and winding. The spray characteristics will affect directly the heat transfer coefficient. So in the paper a test rig using a nozzle was constructed to explore the atomization characteristics of spray...
In this paper, the effect of changes in the width of teeth and yoke on stator temperature characteristics was analyzed. An initial model of fill factor 45% was produced. The validity of the temperature analysis using the thermal equivalent circuit method was experimentally verified. A basic model was selected as the initial model. Also, a temperature characteristic analysis was performed for various...
When designing a very-high-speed (VHS) machine, it is crucial to evaluate the windage losses accurately, because they are an important part of the total losses. It is therefore important to validate a reliable model, further used for the design and optimization of the motor. In this paper, an empirical windage loss model has been compared to measurements on a motor running up to 155 krpm in a pressure...
Monitoring of diesel generators is an important part of the management program of electricity utilities as well as telecommunication companies' in-order to have their cellular towers and base transmitter stations up all the time. A reliable remote monitoring method over the on-site method is always desirable so that managing of time and resources can take place as efficiently as possible. This paper...
A three-dimensional finite element model of miniature circuit breaker is established. The steady state temperature field is obtained by the method of electrothermal coupling, and the mechanism of overload protection is analyzed. The influence of wire size on the temperature of bimetal is studied. A simple and effective method to reduce the influence of external wire size is presented. The influence...
The evaporative cooling technology has high cooling efficiency and high reliability and it is a promising cooling method which can be applied to switching mode power supply (SMPS). Thermal simulation is an effective way to analyze the performance of the cooling system, and can provide guidance for the optimization of SMPS. In this paper, thermal simulation models of fully-immersed evaporative cooling...
Compared to permanent magnet motors using rare-earth metals, a wound field synchronous motors tends to generate more heat due to increased windings, so it is required to consider cooling measures in design. In this study, a 3D computational fluid dynamics simulation and experimental verification of an 80kW Wound Field Synchronous Motor was performed to investigate the cooling performance of dual cooling...
The core temperature of power cables is a key supervising factor which concerns the operation safety of transmission line. However, direct measurement influences insulation performance due to embedding instruments into the cable. In this paper a measurement method using temperature retrieval is proposed. The finite element models of the cable are established for excavating the implicit relationships...
In this paper, based on the special requirements and rigor conditions of the power air cooling island motor for fan, a 115kW 67.9RPM 380V low-speed high-torque direct-driven PMSM with fractional-slot winding for fan used on power air cooling island was designed to state design feature and difficulties. For the air cooling island vertical motor for fan, due to space and weight restricted, cooling difficulties,...
This paper presents a developed copper-iron alloy which made as the rotor sleeve in a high speed permanent magnetic machine (HSPMG), whist investigating its benefits in improve machine thermal performance. The features of the new alloy is experimental tested against the performance, which includes the conductivity, the permeability, and thermal conductivity, and the variation of loss distribution...
In this paper, more than ten different iron loss models are experimentally evaluated, which covers alternating and rotating fields, influence of temperature, DC bias flux density and distorted flux density due to PWM inverter. Iron loss models considering alternating fields are evaluated by the measured results of a lamination ring specimen. The iron loss model considering rotating field and nonsinusoidal...
This paper proposes a method to estimate the stator winding temperature of permanent magnet synchronous motor (PMSM) driven by direct torque control (DTC) strategy, where the stator resistance is used as a direct indicator of the temperature. In this method, the quantitative relationship between the dc current offset and the corresponding changes in torque is derived. The dc current offset is generated...
In this paper, a multi-channel temperature transmitter is designed, aiming at temperature measurement of rotors, which can also be extended to other parameter measurements of rotating objets. The device receives power with contactless power transfer technology. And the measured temperature data is transferred through wireless data communication. The problem of electromagnetic interference between...
This paper studies the characteristics and design concept of low-speed high-torque direct-driven PMSM with fractional-slot concentrated winding used in coal mine belt conveyor system. The fractional slot concentrated winding PMSM with high efficiency, high power density and simple windings type is used widely, and more attention is paid to the influence of cogging torque with different slots and poles,...
With the increase of the electrical machines capacity and voltage level, the main insulation of the stator coil becomes thicker. Heat dissipation and voltage endurance becomes a contradiction. The traditional cooling, such as air-cooling and water-cooling, will not well meet design needs. New cooling methods with both advantages of good cooling effect and good insulation are in keen demand in industry...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.