Auto-Test on Motor Temperature Rising in Electric Vehicles with Mutual MRAS

A new method to calculate the motor temperature rising in electric vehicle （EV） is proposed based on the stator resistance identification. The measure theory of the motor temperature rising with the stator resistance is discussed at first. An enhanced magnetism motor dynamic math model is built which is the research object. Then the resistance identification system model is built on the mutual model reference adaptive,system （MRAS） theory. The simulation diagram of the mutual MRAS model is constructed and the resistance identification performance is studied in different motor states. Simulation results indicate that the stator resistance identification model with the mutual MRAS is effective. At the same time, the identification of motor temperature rising is possible with the identification of the stator resistance.

On-line Temperature Rise Measurement of Submersible Motors

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Analysis of Temperature Rise in High-Speed Permanent Magnet Synchronous Traction Motors by Coupling the Equivalent Thermal Circuit Method and Computational Fluid Dynamics

To solve the problem of temperature rise caused by the high power density of high-speed permanent magnet synchronous traction motors,the temperature rise of various components in the motor is analyzed by coupling the equivalent thermal circuit method and computational fluid dynamics.Also,a cooling strategy is proposed to solve the problem of temperature rise,which is expected to prolong the service life of these devices.First,the theoretical bases of the approaches used to study heat transfer and fluid mechanics are discussed,then the fluid flow for the considered motor is analyzed,and the equivalent thermal circuit method is introduced for the calculation of the temperature rise.Finally,the stator,rotor loss,motor temperature rise,and the proposed cooling method are also explored through experiments.According to the results,the stator temperature at 50,000 r/min and 60,000 r/min at no-load operation is 68℃ and 76℃,respectively.By monitoring the temperature of the air outlets inside and outside the motor at different speeds,it is also found that the motor reaches a stable temperature rise after 65 min of operation.Coupling of the thermal circuit method and computational fluid dynamics is a strategy that can provide the average temperature rise of each component and can also comprehensively calculate the temperature of each local point.We conclude that a hybrid cooling strategy based on axial air cooling of the inner air duct of the motor and water cooling of the stator can meet the design requirements for the ventilation and cooling of this type of motors.

Temperature Rise Calculation and Velocity Planning of Permanent Magnet Linear Synchronous Motor under Trapezoidal Speed

For permanent magnet linear synchronous motor(PMLSM) working at trapezoidal speed for long time, high thrust brings high temperature rise, while low thrust limits dynamic performance. Thus, it is crucial to find a balance between temperature rise and dynamic performance. In this paper, a velocity planning model of the PMLSM at trapezoidal speed based on electromagnetic-fluid-thermal(EFT) field is proposed to obtain the optimal dynamic performance under temperature limitation. In this model, the winding loss is calculated considering the acceleration and deceleration time. The loss model is indirectly verified by the temperature rise experiment of an annular winding sample. The actual working conditions of the PMLSM are simulated by dynamic grid technology to research the influence of acceleration and deceleration on fluid flow in the air gap, and the variation rule of the thermal boundary condition is analyzed. Combined with the above conditions, the temperature rise of a coreless PMLSM(CPMLSM) under the rated working condition is calculated and analyzed in detail. Through this method and several iterations, the optimal dynamic performance under the temperature limitation is achieved. The result is verified by a comparison between simulation and prototype tests, which can help improve the dynamic performance.

Temperature Field Analysis of Mine Flameproof Outer Rotor Permanent Magnet Synchronous Motor with Different Cooling Schemes

Aiming at the problem of temperature rise of mine flameproof outer rotor permanent magnet synchronous motor,based on the fluid structure coupling method,the temperature distribution of motor under three cooling schemes of air cooling and water cooling are calculated respectively.For the structure I air cooling system,the influence of different number of heat sink on the maximum temperature rise and pressure drop of fluid channel is analyzed,and the parameters of heat sink are optimized.For the structure II air cooling system,the influence of setting fillet at the turn back of the fluid channel on the head loss in the fluid domain of the motor is analyzed,and the influence of different fillet radius on the head loss and the maximum temperature rise in the fluid domain is obtained.For the structure II water cooling system,the influence of different water flow speed on the maximum temperature rise of the motor is analyzed,and the influence of different assembly clearance of modular stator teeth and yoke on the maximum temperature rise of the motor is analyzed.The cooling effect and temperature rise distribution characteristics of the three cooling schemes are compared and analyzed.Finally,a water-cooled prototype is manufactured,and the temperature rise experiment is carried out,and the influence of the thermal deformation of fluid channel,stator yoke and stator teeth on the maximum temperature of the motor is analyzed.The results show that the calculated temperature field after considering the thermal deformation is closer to the experimental value,which verifies the accuracy of the calculation results,It also provides a reference for the selection and design of the cooling structure of the same type of PMSM electric roller.

Cooling System Design and Thermal Analysis of Modular Stator Hybrid Excitation Synchronous Motor

Hybrid excitation synchronous motor has the advantages of uniform and adjustable electromagnetic field, wide speed range and high power density. It has broad application prospects in new energy electric vehicles, wind power generation and other fields. This paper introduces the basic structure of hybrid excitation motor with modular stator, and analyzes the operation principle of hybrid excitation motor. The cooling structure of the water-cooled plate is designed, and the effects of the thickness of the water-cooled plate and the number of water channels in the water-cooled plate on the heat dissipation capacity of the water-cooled plate are analyzed by theoretical and computational fluid dynamics methods. The effects of different water cooling plate structures on water velocity, pressure drop, water pump power consumption and heat dissipation capacity were compared and analyzed. The influence of different inlet flow velocity on the maximum temperature rise of each part of the motor is analyzed, and the temperature of each part of the motor under the optimal water flow is analyzed. The influence of the traditional spiral water jacket cooling structure and the water-cooled plate cooling structure on the maximum temperature rise of the motor components is compared and analyzed. The results show that the water-cooled plate cooling structure is more suitable for the modular stator motor studied in this paper. Based on the water-cooled plate cooling structure, the air-water composite cooling structure is designed, and the effects of the air-water composite cooling structure and the water-cooled plate cooling structure on the maximum temperature rise of each component of the motor are compared and analyzed. The results show that the maximum temperature rise of each component of the motor is reduced under the air-water composite cooling structure.

S-Zorb汽油精制装置降烯烃操作

介绍了S-Zorb工艺技术的原理及生产方法,针对国六汽油对烯烃含量的控制要求,延安石油化工厂汽油精制装置反向操作,开展降烯烃操作,通过提高循环氢量配比、降低反应器进口温度、控制反应器温升等措施,实现了预期目标。

二次水断供核主泵屏蔽电机冷却水瞬态热分析

核主泵屏蔽电机在热态极端环境参数额定(简称热态额定)工况下,二次水突然断供(secondary water supply outage,SWSO)300 s时刻,一次下导轴承润滑水温不超过警报温度95℃是产品出厂的重要指标,研究该情况下热流场计算方法及各种参数随时间演变特性对于电机热安全非常重要。首先,以北方工厂冷态环境参数下额定(简称冷态额定)工况该电机SWSO前后稳/瞬态厂内测量入出口试验数据为边界条件,采用有限体积法,进行流场和温度场的流固耦合数值模拟,模拟值与试验值300 s时的误差为5.97%,验证了计算方法准确性。然后,数值反演热态额定工况SWSO一/二次冷却水的温度场随时间变化规律。结果表明:SWSO 300 s内,二次水流速及对流传热系数随时间变化存在特征明显不同的2个阶段,二次水与螺旋槽壁面间对流换热系数h由稳态时7808.06 W/(m^(2)⋅K),13 s内减少到480.07 W/(m^(2)⋅K),随后h变化很小;热态额定参数时,下导轴承润滑水温远低于报警值95℃。为核主泵屏蔽电机轴承润滑水热安全计算提供参考。

定子通风槽钢结构对提高中型高压电机散热性能分析

为降低YJK450-6、400kW中型高压电机的通风散热性能,本文对该电机不同通风槽钢结构进行了散热性能研究。首先,在现有电机的直线标准型通风结构基础上,提出单列缩放型、双列直线型、双列缩放型3种轴-径向混合通风结构形式;在SpaceClaim软件中建立电机3维温度场数值计算模型,根据基本假设和边界条件结合电机内部热量传递公式计算出电机仿真设置参数,并导入Fluent软件进行仿真模拟,其中,计算温度场所用热源通过AnsoftMaxwell平台计算的电机损耗值获取。其次,通过网格无关性和温升试验验证本文建立的电机3维温度场数值计算模型;通过仿真模拟对比分析3种轴-径向混合通风结构与直线标准型结构对电机流场和温度场的影响;采用正交试验法对轴-径向混合通风结构进行参数优化,得到最佳散热结构和参数方案;进一步探究冷却风速对双列缩放型槽钢的电机换热性能的影响;结合定子绕组温升和电机整体的温升均匀性系数,对最佳散热结构和参数方案电机进行散热效果评价。仿真结果表明:本文建立的计算模型是有效的;双列缩放型通风槽钢结构的各项散热性能指标均最好,是最优通风槽钢结构;径向风道高度为6mm且数量为13的双列缩放型通风槽钢结构为最佳散热结构和参数方案;双列缩放型通风槽钢结构两侧的平均对流换热系数随冷却风速增大而增大,且槽钢迎风面的平均对流换热系数明显大于背风面;径向风道高度为6mm且数量为13的双列缩放型通风槽钢结构电机的内/外层绕组温升分布均匀性系数比直线标准型电机分别提高88.13%、20.11%。因此,优化设计通风槽钢结构有利于电机内部空气流动和散热,可实现有效降低电机内部温升的目的。

面向短时/断续工作制的电机系统固–液相变热管理技术及应用发展

固–液相变现象表现出的潜热特性可有效平抑瞬时温升,将其应用于航天航空、奔越式机器人、新能源汽车、数控机床等电机热管理系统,可有效提高短时工作制或断续周期性工作制(S2—S8)下运行的伺服电驱动系统的瞬态性能。为了总结归纳固–液相变材料的电机系统热管理技术及其应用现状,该文针对固–液相变材料特性、系统数值计算与仿真模拟、样机实验测试方法、相变热管理系统结构等4个方面开展调研,并提出亟待解决的关键技术问题。研究发现:目前阶段石蜡和低温熔盐是适合电机系统的最佳相变介质,但仍存在导热系数较低的问题,需通过改性强化解决;通过机壳灌注相变材料,可有效实现温升平抑,但尚缺乏有针对性的热路拓扑设计;采用焓–多孔方法是模拟相变过程的理想手段,但糊状区参数的取值缺乏理论指导;最后,固–液相变过程的测试中侵入式传感器易对电磁、热、流场的自然演变过程产生干扰。

基于Flowmaster牵引电机冷却系统建模分析

电机温度升高会对牵引电机性能的稳定产出生不利影响,为使牵引电机在温升限度内安全运行,保证牵引电机具有良好的散热条件,一般都为电机设计独立的冷却系统。基于牵引电机冷却系统性能和结构特点,建立牵引电机冷却系统计算模型,对冷却系统管网进行解算,分析散热器迎风面积、通风流量、空气温度等对牵引电机温升的影响,为冷却系统各部件的选型提供理论参考。搭建牵引电机温升试验平台,获得电机内温度随负载和冷却液流量变化的关系。通过试验对仿真结果进行了可靠性验证,可以看出,数值模拟是研究牵引电机冷却系统流动与传热问题的重要手段,对冷却系统的设计具有重要指导意义。

真空泵用反凸极永磁同步电机设计与性能分析

针对真空泵用驱动电机运行过程中存在转子温度高、散热难的问题,根据真空泵驱动工况的实际要求,设计了一台反凸极永磁同步电机和一台常规永磁同步电机。首先,利用有限元软件,分析了转子磁障尺寸对电机转矩的影响以及磁障层数对电感的影响,从而得出了转子磁障尺寸和磁障层数的合适值;其次,对两台电机的气隙磁密波形、空载反电动势和损耗等电磁性能进行了对比分析;最后,通过仿真对比分析了两台电机的温度场以及两者转子和转轴处的温升。结果表明,相比于常规永磁同步电机,反凸极永磁同步电机的转矩性能更好、转子损耗和转子温升更小,为新产品研发提供了科学的参考依据。

轴向磁通永磁电机混合冷却结构设计与分析

针对轴向磁通永磁电机损耗大和散热困难的问题,提出了风冷结构和混合冷却结构,其中混合冷却结构由端盖风冷结构和定子水冷结构组成。建立了电机的三维模型,采用流固耦合法对电机进行仿真分析,通过对比两种冷却结构的冷却效果,选择了混合冷却结构作为电机的冷却系统。通过仿真分析了流速对电机温升的影响,并根据仿真结果确定了混合冷却结构最佳的入口风速以及水速,证明了混合冷却结构的有效性,为轴向磁通永磁电机的冷却系统设计提供了一定的参考。

400 kW永磁同步电机磁-流-热耦合特性分析

为准确分析大功率永磁同步电机运行时的温升特性,对400 kW,9 000 r/min的大功率永磁同步电机进行磁-流-热多物理场耦合分析。首先,对电机进行结构设计,分析其空载及负载的运行特性。其次,将损耗作为热源加载到温度场中,采用流热耦合,计算冷却流道中的冷却液对电机温度的影响。最后,考虑电机材料的温度特性对热性能的影响,提出双向耦合的方法,将电机磁场损耗实际分布加载到温度场中,再将绕组和永磁体温度变化情况反代至电磁场,通过有限元方法实现电机磁-流-热多物理场耦合。结果表明,双向耦合方法下,绕组的温升比单向耦合高6.27%,永磁体温升增加2.27%,提高了该类电机损耗和温升计算精度。

驱动电机轴承热特性分析系统设计与验证

针对新能源汽车驱动电机轴承热特性分析过程中,其温升及接触分析计算过于复杂、计算效率低的问题,采用MATLAB App Designer软件开发工具,在建立驱动电机轴承温升及接触分析模型和编制其数值求解程序的基础上,设计一套新能源汽车驱动电机轴承热特性分析系统。该系统使用方便,只需输入轴承的相关参数,便可直接计算出轴承相应的温升、发热功耗和接触载荷等性能参数,且计算结果可在系统界面以图表的形式进行显示和输出。与试验数据的对比结果表明,该系统高效可靠,为工程设计中其他复杂计算系统的开发提供了参考。

车用驱动电机损耗温升分析与多目标优化

基于微型厢式货车用驱动电机的运行工况建立其各类损耗的分析模型,结合有限元软件对电机铜耗、铁心损耗、永磁体涡流损耗等进行计算,并进一步得到机壳水冷散热结构下的电机温度分布;计算结果与实验结果较吻合,验证了电机损耗与温升求解过程的准确性。应用智能优化算法对电机电磁与水道结构中的多个参数进行磁热耦合多目标优化,优化后的电机整体模型与初始方案相比,综合性能得到有效提高。

低齿槽转矩低温升电机技术研究与设计

齿槽转矩影响电机的转动平稳性,温升影响电机自身绝缘可靠性,同时也影响系统工作运行环境。针对低齿槽转矩低温升电机的需求,文章围绕低齿槽转矩、低温升等电机设计的关键技术,通过理论分析及有限元仿真优化设计,研制出一款额定输出转矩不低于25Nm,齿槽转矩不大于80mNm,机壳表面温度不大于35℃的低齿槽转矩低温升液冷电机,并通过试验数据验证了理论分析与仿真方法的准确性。相关工作为低齿槽转矩低温升液冷电机的设计开发提供一定参考价值。

基于转子永磁分段优化的轴向磁通永磁电机涡流损耗分析与试验

轴向磁通永磁电机永磁体中的涡流损耗将使转子温度升高,致使永磁体产生不可逆退磁风险,影响电机的正常运行。该文推导了轴向磁通永磁电机永磁体涡流损耗的数学模型,分析得到永磁体表面涡流路径长度及永磁体表面积对涡流损耗的影响规律;结合理论分析,在永磁体完全分段的基础上,提出了三种永磁体部分分段的优化新方法;利用有限元软件建立了电机有限元分析模型,对永磁体的电流密度分布、涡流损耗、抗退磁能力、静力学强度等进行了仿真分析与比较,获得了较合适的永磁体部分分段数和永磁体保留尺寸。最后制作了样机,测试了电机效率、永磁体磁性能和永磁体温升情况,验证了所提优化方法的有效性及理论分析的准确性。

外转子永磁直驱电动机水冷系统传热特性

随着对电动机高效节能要求的提高,外转子永磁直驱电动机凭借其起动转矩大、高效节能的优点得到了广泛的应用,但散热困难是外转子永磁直驱电动机普遍存在的问题。为解决外转子永磁直驱电动机散热困难的问题,以45 kW的外转子永磁直驱电动机为研究对象,在定子支架中设计安装水冷系统。基于周向Z型水冷结构,建立了水冷电动机的三维模型,通过CFD流体流动与传热相耦合的分析方法,分析不同冷却水流速对电动机温升的影响规律。结果表明,随着冷却水流速的增加,水冷系统散热效果得到提升,但增大到一定的流速后,进一步增大冷却水流速对水冷系统散热效果的改善很小。以上结论可以为外转子永磁直驱电动机水冷系统设计提供一定的理论依据。