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The thermal analysis of a high performance brushless synchronous electric motor with permanent magnets and water jacket cooling is presented. The analysis is carried out following a lumped parameter thermal network approach which allows to identify the most important thermal paths in the motor and the main parameters influencing them. Thanks to its...
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... There is no indication of how data would change for different aspect ratio motors. The same shortcoming applies to References [33,34], which are computational and experimental studies of a single motor design. A conceptual designer cannot extend their findings to an arbitrarily shaped motor. ...
Heat transfer affects a motor’s sizing, its performance, and, ultimately, the overall vehicle’s range and endurance. However, the thermal literature does not have early-stage models for outrunner brushless DC (BLDC) motors found in small unmanned aerial systems (UASs). To address this gap, we have developed a non-dimensional heat transfer model (Nusselt correlation). Parametric experiments of four different-sized BLDC motors under load in Reynolds-matched wind tunnel tests generated data for model correlation. The motors’ aspect ratios (diameter/length) ranged from 0.9 to 1.5. The freestream Reynolds number of the axial flow over the motors ranged from 20,000 to 40,000. The rotational Reynolds number ranged from 10,000 to 20,000. The results showed that aspect ratio had the largest influence on heat transfer, followed by rotational and freestream Reynolds numbers. A steady-state model used the correlation to predict the motor’s ambient temperature differential within 10 K of experimental data. A case study applied the correlation to predict a hypothetical motor’s continuous torque in different environments. The correlation enables conceptual designers to capture thermally-driven trade-offs in early design stages and reduce costly revisions in later stages.
... Currently, temperature prediction methods mainly include lumped parameter thermal 2 of 13 networks and numerical analysis [8,9]. Lumped parameter thermal networks depend excessively on empirical formulas and coefficients and cannot predict the flow characteristics of the cooling medium in the motor [10]. In contrast, the numerical calculation method can accurately predict the fluid movement and rotor temperature distribution in the complex cooling system of the rotor [11,12]. ...
With the continuous growth of energy demand, the advantages of nuclear power, such as high energy density, low emissions, and cleanliness, are gradually highlighted. However, the increasing capacity of the turbine generator in nuclear power plants has led to greater losses and critical heating issues. Designing an effective cooling system plays an important role in improving the rotor’s heat dissipation ability, especially under the condition of limited rotor space. In this study, the cooling effects of the rotor using a radial straight-type cooling structure and a composited radial–axial–radial cooling structure are compared and analyzed for a 1555 MVA hydrogen-cooled nuclear turbine generator. Three-dimensional fluid thermal coupled models of the rotor with both cooling structures are established, and corresponding boundary conditions are provided. The models are solved using the finite volume method. The flow law of cooling hydrogen gas inside the rotor and the temperature distribution of various parts of the rotor are studied in detail. Compared with the radial straight-type cooling structure, adopting the composited radial–axial–radial cooling structure can reduce the average temperature of the rotor field windings by 4.5 °C. The research results provide a reference for the design and optimization of the rotor cooling system for large-capacity nuclear turbine generators.
... The main losses of the motor include copper loss, iron loss, eddy current loss of permanent magnet, mechanical loss, and stray loss [1][2][3]. The copper loss is the main part of the motor loss [4][5][6]. However, due to the higher copper loss of hairpin winding, the heat dissipation issue of motors with hairpin winding should be addressed. ...
... According to the above method, the average of the CHTA and CHTC at various levels is shown in Figure 17. When the CHTA is at its maximum, the combination of parameters is d 1 (2), d 2 (2), d 3 (2), d 4 (4). When the CHTC is at its maximum, the combination of parameters is d 1 (1), d 2 (1), d 3 (4), d 4 (3). ...
In this paper, the cooling performance of oil-cooling PMSM with hairpin winding under various oil parameters is analyzed via a simulation and an experiment. The effects of oil jet positions, oil temperatures, and oil flow rates on the cooling performance are analyzed. It is found that increasing the oil temperature in the range of 20 °C to 60 °C, increasing the flow rate of oil jets whose position angle is from 15° to 45°, and increasing the flow rate in the range of 1 L/min to 2 L/min will significantly improve the cooling performance. The apertures of the oil spray ring are optimized using the Taguchi algorithm. The cooling performance is the best when the flow ratio is m(0°):m(15°):m(30°):m(45°):m(60°):m(75°) = 4%:19%:10%:10%:4%:4%. This study provides a guide for the design of the oil-cooling system for the hairpin winding of the PMSM.
... Given this situation, electric vehicle (EVs) was being considered as a potential replacement for vehicles powered by ICE [1]. The current state of EVs still offers opportunities for improvement, with vehicle performance being a central focus of research and development efforts [2][3][4]. According to Wang et al. [5], high power density in motor design leads to an increase in loss density, making thermal management more challenging and becoming a significant obstacle to efficiency. ...
... In this study, the optimum number of coolant flow passes is also specified. Cavazzuti et al. [12] studied the conduction resistance between stator teeth and water jackets by developing the Lumped Parameter Thermal Network (LPTN) model for water-cooled PMSM. The winding, stator, rotor, and magnet properties are temperature-dependent, and due to that; the electromagnetic losses of the motor are coupled with the thermal characteristics. ...
... As summarized in Fig. (1), most of the studies taken into account in the literature on the synchronous motor are performed for low power scales [4,11,12,. After a detailed literature survey, limited studies are found for high motor powers such as above 200 kW. ...
In this study, 250 kW, 9 phase, outer rotor types of Permanent Magnet Synchronous Motor (PMSM) are taken into consideration. To optimize the cooling efficiency of the motor, firstly, the motor geometry is obtained, and the e-magnetic model of the geometry is validated with the manufacturer`s data. Secondly, by using the validated e-magnetic model, the cooling system of the motor was analyzed by using the thermal model of the Motor-CAD. The thermal model is also validated with the real-time experiments which are held on an electric bus at constant speed experimentally. For finding the best cooling strategy for the motor, after validation, the effect of the mass flow rate, the type of the cooling refrigerant, the cooling pipe diameter size, and the change of torque are analyzed on the validated model. The results showed us that mass flow rate and torque have a significant effect on winding temperature, and the Taguchi method showed that [mass flow rate (A)=50 l/min, pipe diameter (B) = 17.7 mm, number of turns (C)=20, type of fluid (D)= EGW50/50, torque (E)=2000 Nm] is the best cooling design parameters for the cooling strategy of the considered PMSM.
... Although these studies effectively analyze the internal temperature distribution of the motor, it is difficult to apply them to lower the motor's internal temperature directly. Therefore, studies to lower the internal temperature of motors have been actively conducted [9][10][11]. ...
... Chen et al. [9] optimized the stator shaft diameter and the position of the rotor axial vent holes to lower the motor's internal temperature. Cavazzut et al. [10] analyzed the main parameters affecting the motor winding temperature and optimized the stator geometries. Lim et al. [11] optimized the rotor shape to improve the torque performance of interior permanent magnet motors by considering the thermal properties of permanent magnets. ...
Electrical losses are converted into thermal energy in motors, which heats each component. It is a significant factor in decreasing motor mechanical performance. In this paper, the motor cooling characteristics were analyzed according to the design factors of the water jacket to investigate the cooling performance of a permanent magnet synchronous motor (PMSM). First, the electrical losses generated in PMSM were calculated using electromagnetic finite element (FE) analysis. Secondly, a 3D electromagnetic–thermal fluid coupled FE analysis was performed to analyze the temperature distribution inside the motor by applying electrical loss as the heat source. Finally, the motor cooling performance according to the design factors of the water jacket was statistically analyzed using the design of experiment (DOE) method. It was found that the mass flow rate of 0.02547 kg/s and six passes of the water jacket with one inlet and two outlets could be considered the optimum conditions in terms of the maximum motor temperature.
... The requirement for high [40]. extract the detailed distribution [21,22]. While the numerical methods including finite element analysis (FEA) and computational fluid dynamics (CFD) have the capability to consider a complex configuration with high accuracy however come at the cost of long computation time [23]. ...
... Hence, the performance and life span of the induction motor ar pendent on its thermal conditions. The induction motor's temperature rises as a resu heat sources such as stator's iron losses, mechanical and windage loss, and winding loss [3,4]. Currently, induction motors are cooled using techniques such as air coo water cooling, and air-water cooling. ...
... Hence, the performance and life span of the induction motor are dependent on its thermal conditions. The induction motor's temperature rises as a result of heat sources such as stator's iron losses, mechanical and windage loss, and winding joule loss [3,4]. Currently, induction motors are cooled using techniques such as air cooling, water cooling, and air-water cooling. ...
The driving motor is one of the most crucial components of an electric vehicle (EV). The most commonly used type of motor in EVs is the induction motor. These motors generate heat during operation due to the flow of electrical current through the motor’s coils, as well as friction and other factors. For long-run and high efficiency of the motor, cooling becomes more important. This article utilized ANSYS Motor-CAD to map the temperature signature of an induction motor and investigated the thermal efficiency of using nanofluids as a cooling medium. The thermal conductivity of nanofluids has been found to be superior to that of more conventional cooling fluids such as air and water. This research explores the effect of using Al2O3, ZnO, and CuO concentrations in nanofluids (water as a base fluid) on the thermal efficacy and performance of motor. According to the findings, using nanofluids may considerably increase the efficiency of the motor, thereby lowering temperature rise and boosting system effectiveness. Based on the simulation analysis using ANSYS Motor-CAD, the results demonstrate that the utilization of CuO nanofluid as a cooling medium in the induction motor led to a reduction of 10% in the temperature of the motor housing. The maximum reduction in the temperature was found up to 10% when nanofluids were used, which confirms CuO as an excellent option of nanofluids for use as motor cooling and other applications where effective heat transmission is crucial.
... Hence, the performance and life span of the induction motor ar pendent on its thermal conditions. The induction motor's temperature rises as a resu heat sources such as stator's iron losses, mechanical and windage loss, and winding loss [3,4]. Currently, induction motors are cooled using techniques such as air coo water cooling, and air-water cooling. ...
... Hence, the performance and life span of the induction motor are dependent on its thermal conditions. The induction motor's temperature rises as a result of heat sources such as stator's iron losses, mechanical and windage loss, and winding joule loss [3,4]. Currently, induction motors are cooled using techniques such as air cooling, water cooling, and air-water cooling. ...
Based on the simulation analysis using ANSYS Motor-CAD, the results demonstrate that the utilization of CuO nanofluid as a cooling medium in the induction motor led to a reduction of 10% in the temperature of the motor housing. The maximum reduction in the temperature was found up to 10% when nanofluids were used, which confirms CuO as an excellent option of nanofluids for use as motor cooling and other applications where effective heat transmission is crucial.
... When the motor functions at 22000rpm under full load conditions, the PM temperature can go up to 120°C. This in turn induces thermal expansion resulting stress in risers in various components [7]. The laminated rotor back iron is stacked with layers of laminated sheet and adhesives, which when exposed to a thermal gradience, will expand. ...
div class="section abstract"> Transport electrification is pushing the automotive and aerospace industries to enhance the power density of their powertrains further and further. One of the technologies currently pursued by some companies is high-speed electric motors. For instance, the new Model S Plaid motor by Tesla has a carbon-fiber wrapped IPM (Interior Permanent Magnet) rotor which can exceed 20,000 rpm . The SPX88-120 made by Helix company shows a power density of about 18 kW/kg at 50,000 rpm . However, such high rotating speeds result is huge mechanical stresses in the entire rotating assembly, thus making the structural design of these parts extremely challenging. The primary goal of this paper is to provide a scientific rationale for the effective Finite Element Modeling (FEM) and integration strategies to maximize the rotating assembly durability of a 150 kW radial flux SPMSM (surface-mounted permanent magnet synchronous motor) considered as a case-study. A non-linear simulation requires the input of a stress-strain curve and modified power law hardening study is conducted. The secondary goal of the paper is to analyze the thermal stress risers for multiphysics optimization of components. An analytical methodology to estimate the fatigue life for fully reverse cyclic loading is expressed. An extensive study on the eigen mode shape and frequency was performed to understand the dominant frequency of the system. A comparative performance study is conducted on shaft critical speeds, modal analysis, and stiffness interaction between components. Multiphysics optimization of topology is undertaken, the principal stresses in significant load-bearing components are reduced by 10 to 33%.
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