Abstract：The wound rotor synchronous generator (WRSG), with its convenient magnetic field adjustment and brushless power generation features, is widely used in aircraft power systems. The electromagnetic load of the aircraft WRSG is high, leading to high loss density and temperature rise, and the high-temperature environment of the engine compartment also increases the risk of WRSG overheating. Excessive temperature rise can reduce the reliability and even cause WRSG failure in severe cases. Therefore, accurate temperature field modeling and efficient heat dissipation are critical to ensure the safe and stable operation of the WRSG and can also guide heat dissipation design. This paper analyzes the composition and distribution characteristics of WRSG losses and constructs a hybrid cooling method combined with spray oil cooling and cycling oil cooling. Based on the fluid-solid coupled heat transfer model, the uneven distribution characteristics of temperature are studied, and the spray oil method is further optimized to improve heat dissipation. This study focuses on the oil-spray-cooled WRSG as the research object. Firstly, the electromagnetic models of the main generator (MG), main exciter (ME), and permanent magnet generator (PMG) are established through the finite element method. Combined with the theoretical formulas, the loss composition and distribution characteristics of the WRSG are obtained. Considering the heat source distribution, a hybrid cooling structure combining spray oil cooling and cycling oil cooling is designed. The oil flows along the cycling cooling channel to cool the stator assembly of the MG and then enters the hollow shaft. Multiple sets of spray holes are set up in the hollow shaft. Under rotation, oil is sprayed into the WRSG cavity from the spray holes, which can directly contact the heat source of the WRSG, achieving efficient cooling. Then, the fluid-solid coupling model is established based on the parameter transfer relationship of multi-physics fields, and the fluid field of gas-liquid two-phase flow under rotation is numerically simulated based on the Realizable k-ε turbulence model and Euler multiphase flow model. The oil friction loss is supplemented by analyzing the mixed distribution state of oil and gas. A three-dimensional temperature field model of the WRSG is established to obtain the temperature rise characteristics of each-stage generator under different working conditions, and the uneven temperature distribution characteristics of the WRSG are studied. The research found that the highest temperature appears at the end of the MG armature winding, followed by the MG excitation winding. In contrast, the temperature of the rotating rectifier and permanent magnet is lower, with a larger temperature rise margin. Further, an optimized method of oil-spray cooling based on the rotor-integrated oil slinger is proposed. Based on the original oil spray cooling, two oil slingers are installed on the spray oil holes on both sides of the MG. The oil slingers are installed coaxially. After the oil sprayed from the spray oil holes at both ends of the MG hits the oil slinger, it is atomized and thrown out by the centrifugal action of the high-speed rotation of the oil slinger. As a result, the situation where the MG excitation winding blocks the single straight-line jet is avoided, which can improve the oil distribution in the cavity. The heat source contacts more oil, improving the heat dissipation effect. Numerical analysis results show that this optimization method improves the oil volume fraction at the end of the MG armature winding and enhances the heat dissipation capacity. The highest temperature rise under rated load and overload has decreased by 18.5% and 12.9%, respectively, and the highest temperature rise of the WRSG has decreased from 71.9℃ to 62.6℃. Finally, prototype experiments verify the accuracy of fluid-solid coupling heat transfer research and the effectiveness of oil-spray optimization methods.
李进才, 李涵琪, 张卓然, 李立强, 王一未, 廖晨东. 航空油冷三级式无刷发电机流固耦合传热研究及散热优化[J]. 电工技术学报, 2024, 39(22): 7030-7044.
Li Jincai, Li Hanqi, Zhang Zhuoran, Li Liqiang, Wang Yiwei, Liao Chendong. Research on Fluid-Solid Coupling Heat Transfer and Optimization of Heat Dissipation in the Aircraft Oil-Cooled Wound Rotor Synchronous Generator. Transactions of China Electrotechnical Society, 2024, 39(22): 7030-7044.
[1] Jiao Ningfei, Li Zijie, Mao Shuai, et al.Aircraft brushless wound-rotor synchronous starter-generator: a technology review[J]. IEEE Transactions on Power Electronics, 2023, 38(6): 7558-7574. [2] 马鹏, 刘卫国, 彭纪昌, 等. 三级式同步电机转子初始位置在线检测方法[J]. 中国电机工程学报, 2015, 35(18): 4771-4778. Ma Peng, Liu Weiguo, Peng Jichang, et al.An on-line initial rotor position estimation method for three- stage brushless synchronous machines[J]. Proceedings of the CSEE, 2015, 35(18): 4771-4778. [3] Madonna V, Giangrande P, Lusuardi L, et al.Thermal overload and insulation aging of short duty cycle, aerospace motors[J]. IEEE Transactions on Industrial Electronics, 2020, 67(4): 2618-2629. [4] Boglietti A, Cavagnino A, Staton D, et al.Evolution and modern approaches for thermal analysis of electrical machines[J]. IEEE Transactions on Indu- strial Electronics, 2009, 56(3): 871-882. [5] 丁树业, 江欣, 朱敏, 等. 基于集总参数热网络法的永磁同步电机启动及稳态温升分析[J]. 电机与控制学报, 2020, 24(5): 143-150. Ding Shuye, Jiang Xin, Zhu Min, et al.Starting and steady temperature rise investigation for permanent magnet synchronous motor based on lumped- parameter thermal-network[J]. Electric Machines and Control, 2020, 24(5): 143-150. [6] 师蔚, 骆凯传, 张舟云. 基于热网络法的永磁电机温度在线估计[J]. 电工技术学报, 2023, 38(10): 2686-2697. Shi Wei, Luo Kaichuan, Zhang Zhouyun.On-line temperature estimation of permanent magnet motor based on lumped parameter thermal network method[J]. Transactions of China Electrotechnical Society, 2023, 38(10): 2686-2697. [7] Zhang Fengyu, Gerada D, Xu Zeyuan, et al.A thermal modeling approach and experimental validation for an oil spray-cooled hairpin winding machine[J]. IEEE Transactions on Transportation Electrification, 2021, 7(4): 2914-2926. [8] Sciascera C, Giangrande P, Papini L, et al.Analytical thermal model for fast stator winding temperature prediction[J]. IEEE Transactions on Industrial Electronics, 2017, 64(8): 6116-6126. [9] 佟文明, 孙静阳, 舒圣浪, 等. 不同数值方法在自扇冷永磁同步电机三维热分析中的应用[J]. 电工技术学报, 2017, 32(增刊1): 151-159. Tong Wenming, Sun Jingyang, Shu Shenglang, et al.Application of different numerical methods in 3D thermal analysis for fan-ventilated permanent magnet synchronous machines[J]. Transactions of China Electrotechnical Society, 2017, 32(S1): 151-159. [10] 王立坤, 毕晓帅, 朱志佳, 等. 特高压输电用同步调相机端部涡流损耗及流固耦合传热研究[J]. 中国电机工程学报, 2022, 42(5): 1968-1981. Wang Likun, Bi Xiaoshuai, Zhu Zhijia, et al.Research on eddy current loss and fluid-solid coupling heat transfer in the end region of syn- chronous condenser for UHV transmission[J]. Pro- ceedings of the CSEE, 2022, 42(5): 1968-1981. [11] 程自然, 王宇, 高剑, 等. 计及电磁-传热影响的蒸发冷却风力发电机定子铁心穿管结构优化设计研究[J]. 电工技术学报, 2024, 39(6): 1684-1697. Cheng Ziran, Wang Yu, Gao Jian, et al.Optimization design of stator core pipe for evaporative cooling wind generators considering the influence of elec- tromagnetic and heat transfer[J]. Transactions of China Electrotechnical Society, 2024, 39(6): 1684-1697. [12] 李涛, 张幽彤, 梁玉秀, 等. 轴向磁通轮毂电机热分析及研究[J]. 工程热物理学报, 2021, 42(6): 1561-1568. Li Tao, Zhang Youtong, Liang Yuxiu, et al.Thermal analysis and research of axial flux in-wheel motor[J]. Journal of Engineering Thermophysics, 2021, 42(6): 1561-1568. [13] 汪波, 黄珺, 查陈诚, 等. 多三相分数槽集中式绕组容错电机匝间短路故障温度场分析[J]. 电工技术学报, 2023, 38(19): 5101-5111. Wang Bo, Huang Jun, Zha Chencheng, et al.Thermal analysis of multiple 3-phase fractional slot con- centrated winding fault tolerant machine with turn fault[J]. Transactions of China Electrotechnical Society, 2023, 38(19): 5101-5111. [14] 朱高嘉, 朱英浩, 朱建国, 等. 永磁电机温度场的改进有限公式迭代算法[J]. 电工技术学报, 2017, 32(16): 136-144. Zhu Gaojia, Zhu Yinghao, Zhu Jianguo, et al.A modified thermal rewind model of permanent magnet motors based on finite formulation method[J]. Transactions of China Electrotechnical Society, 2017, 32(16): 136-144. [15] 张琦, 李增亮, 董祥伟, 等. 水下电机损耗加载方式及温度场耦合分析[J]. 电工技术学报, 2018, 33(5): 1007-1014. Zhang Qi, Li Zengliang, Dong Xiangwei, et al.Study of the loss loading method and coupling analysis of temperature distribution of the underwater motor[J]. Transactions of China Electrotechnical Society, 2018, 33(5): 1007-1014. [16] 陈鹏, 谢颖, 李道璐. 感应电机定子匝间短路故障温升特性研究[J]. 电工技术学报, 2023, 38(18): 4875-4888. Chen Peng, Xie Ying, Li Daolu.Research on the temperature rise characteristics of induction motors with stator inter-turn fault[J]. Transactions of China Electrotechnical Society, 2023, 38(18): 4875-4888. [17] 于占洋, 胡旭阳, 李岩, 等. 新型强迫风冷散热结构在高功率密度外转子表贴式PMSM上应用分析[J]. 电工技术学报, 2023, 38(24): 6668-6678. Yu Zhanyang, Hu Xuyang, Li Yan, et al.Application analysis of novel forced air-cooled in outer rotor surface-mounted PMSM with high power density[J]. Transactions of China Electrotechnical Society, 2023, 38(24): 6668-6678. [18] 王俊杰, 魏佳丹, 郁钧豪, 等. 基于间接二次谐波注入的三级式同步电机低速阶段无位置传感器起动控制[J]. 中国电机工程学报, 2022, 42(24): 9031-9042. Wang Junjie, Wei Jiadan, Yu Junhao, et al.Sensorless starting control of three-stage synchronous machines at low speed based on indirectly injected second harmonic signals[J]. Proceedings of the CSEE, 2022, 42(24): 9031-9042. [19] Wei Jiadan, Wang Junjie, Zhang Zhuoran, et al.Frequency-insensitive rotor position estimation method for three-stage synchronous machine based on indirect high-frequency signal injection[J]. IEEE Transactions on Transportation Electrification, 2022, 8(2): 1785-1793. [20] Wang Yinli, Nuzzo S, Zhang He, et al.Challenges and opportunities for wound field synchronous generators in future more electric aircraft[J]. IEEE Transactions on Transportation Electrification, 2020, 6(4): 1466-1477. [21] 李立毅, 张江鹏, 闫海媛, 等. 高功率密度电机三维温度场计算及导热优化研究[J]. 中国电机工程学报, 2016, 36(13): 3642-3650, 3384. Li Liyi, Zhang Jiangpeng, Yan Haiyuan, et al.Study on the optimization of thermal conductivity and 3D temperature filed calculation for the high power density motor[J]. Proceedings of the CSEE, 2016, 36(13): 3642-3650, 3384. [22] 江善林. 高速永磁同步电机的损耗分析与温度场计算[D]. 哈尔滨: 哈尔滨工业大学, 2010. Jiang Shanlin.High-speed permanent magnet syn- chronous motor loss analysis and temperature field calculation[D]. Harbin: Harbin Institute of Tech- nology, 2010. [23] 张文校, 胡岩, 曹力, 等. 高速永磁屏蔽电机摩擦损耗分析与计算[J]. 电工技术学报, 2023, 38(12): 3122-3129. Zhang Wenxiao, Hu Yan, Cao Li, et al.Analysis and calculation of friction loss of high-speed permanent magnetic shielding motor[J]. Transactions of China Electrotechnical Society, 2023, 38(12): 3122-3129. [24] 张凤阁, 杜光辉, 王天煜, 等. 兆瓦级高速永磁电机通风系统设计与转子表面风摩耗研究[J]. 电机与控制学报, 2014, 18(2): 50-55. Zhang Fengge, Du Guanghui, Wang Tianyu, et al.Ventilation system design and research on wind friction loss of rotor surface of MW high-speed permanent magnet motor[J]. Electric Machines and Control, 2014, 18(2): 50-55. [25] 韩雪岩, 张华伟, 徐昕, 等. 基于计算流体力学的非晶合金轴向磁通永磁电机冷却系统设计[J]. 电工技术学报, 2017, 32(20): 189-197. Han Xueyan, Zhang Huawei, Xu Xin, et al.Design of cooling system for amorphous alloy axial flux permanent magnet motor based on computational fluid dynamics[J]. Transactions of China Elec- trotechnical Society, 2017, 32(20): 189-197. [26] 张淑佳, 李贤华, 朱保林, 等. k-ε 涡粘湍流模型用于离心泵数值模拟的适用性[J]. 机械工程学报, 2009, 45(4): 238-242. Zhang Shujia, Li Xianhua, Zhu Baolin, et al.Applicability of k-ε eddy viscosity turbulence models on numerical simulation of centrifugal pump[J]. Journal of Mechanical Engineering, 2009, 45(4): 238-242. [27] 刘震, 王晓玲, 刘长欣, 等. 复杂长竖井引水隧洞施工通风两相流模拟研究[J]. 天津大学学报 (自然科学与工程技术版), 2018, 51(11): 1139-1146. Liu Zhen, Wang Xiaoling, Liu Changxin, et al.Two-phase flow simulation of construction venti- lation in the complex diversion tunnels with long vertical shafts[J]. Journal of Tianjin University (Science and Technology), 2018, 51(11): 1139-1146.
2024, Vol. 39 
