Yoke Search-Coil Based Interturn Short-Circuit Fault Diagnosis of Dual-Redundancy PM Assisted Synchronous Reluctance Machine
Hao Shengqiao1, Liang Ziyi1, Cheng Yi2, Li Dawei1, Qu Ronghai1
1. State Key Laboratory of High-Density Electrical Energy Conversion Huazhong University of Science and Technology Wuhan 430074 China; 2. China Aero Engine Control System Institute of AECC Wuxi 214063 China
Abstract：A dual-redundancy permanent magnet assisted synchronous reluctance machine (PMA-SynRM) integrates the redundancy concept with multi-phase winding technology. By enhancing the reluctance torque proportion and reducing permanent magnet flux linkage, PMA-SynRMs significantly improve fault-tolerant capability, making them suitable for aerospace starter-generator applications. To further enhance reliability in aerospace applications, this paper proposes an interturn short-circuit fault (ISCF) diagnosis method based on a yoke search coil (SC). Wound on the stator yoke, these SCs effectively mitigate interference from tooth saturation and end-winding leakage, improve diagnostic reliability, reduce the number of required SCs, and enhance flexibility in coil configuration. In addition, the proposed method can identify the redundancy associated with the fault source. It amplifies the detection signal, increasing sensitivity and improving the speed and accuracy of diagnosing ISCF. This paper studies the ISCF model of the PMA-SynRM, analyzes three major design rules and methods of yoke SCs, and establishes a simulation model. The proposed diagnosis method is verified under various fault conditions and the influence of non-ideal factors. Yoke SCs are designed following three key rules. (1) The SCs must detect faults at all positions while minimizing the number of SCs. (2) The SCs should output zero voltage under normal operation. (3) The search coil group (SCG) corresponding to the faulty redundancy should output a larger voltage signal than that of the healthy redundancy. Using a 48-slot 8-pole PMA-SynRM, these rules guide the design of coil structure, placement, series connection, and grouping. Compared with traditional tooth- mounted SCs, the proposed yoke SCs reduce interference from tooth saturation and leakage flux, enhancing diagnostic reliability for aerospace applications. The fault diagnosis process is as follows. When an ISCF occurs, the yoke SCGs detect voltage signals at frequencies of 1fe and 3fe. The sum of these components is defined as the fault characteristic parameter χr. To detect the most challenging single-turn short-circuit fault (STSCF), the threshold χval is set based on χr value generated by the rated current during STSCF. The ratio between the threshold χval and rotor speed nr is 23.3 mV/kr/min. Simulation results show that for STSCF in different coils of Redundancy-1, an alternative signal is generated in SCG-1, while SCG-2 remains zero. The fault signature in SCG-1 is significantly larger than χval, enabling STSCF detection and localization. Non-ideal factors, such as eccentricity and current asymmetry, induce voltages below χval, preventing false alarms. A prototype and a test bed were constructed. Experimental results align with simulations. (1) As contact resistance rsc decreases from 100 mΩ to 10 mΩ, the measured χr in SCG-1 increases from 0.21 V to 1.18 V, both exceeding the 6 000 r/min STSCF threshold χval=0.14 V. (2) For ISCFs in different coils of Redundancy-1, the short-circuit loop current remains nearly constant. However, the χr reaches the highest 0.98 V when the fault is in coil T3 (closest to SCs) and minimizes at 0.37 V for a fault in coil T1. Both values exceed 0.14 V. (3) As load increases from 0 N·m to 8 N·m, the χr of SCG-1 increases from 0.38 V to 0.47 V, remaining above 0.14 V. The experimental results show that the proposed yoke SC provides a practical solution for high-reliability ISCF diagnosis in aerospace applications.
[1] 汪波, 徐文翰, 查陈诚, 等. 多三相分布式绕组和集中式绕组永磁磁阻电机对比研究[J]. 电工技术学报, 2024, 39(10): 2984-2994. Wang Bo, Xu Wenhan, Zha Chencheng, et al.Comparative study on triple 3-phase PMA-SynRM with distributed winding and concentrated winding[J]. Transactions of China Electrotechnical Society, 2024, 39(10): 2984-2994. [2] Xu Peilin, Feng J H, Guo S Y, et al.Analysis of dual three-phase permanent-magnet synchronous machines with different angle displacements[J]. IEEE Transa- ctions on Industrial Electronics, 2017, 65(3): 1941-1954. [3] 孙鹏程, 贾少锋, 梁得亮, 等. 冗余电机拓扑与应用综述及发展展望[J]. 电工技术学报, 2025, 40(6): 1729-1745. Sun Pengcheng, Jia Shaofeng, Liang Deliang, et al.Overview and prospect of redundancy machines: topologies and applications[J]. Transactions of China Electrotechnical Society, 2025, 40(6): 1729-1745. [4] Bonnett A H, Yung C.Increased efficiency versus increased reliability[J]. IEEE Industry Applications Magazine, 2008, 14(1): 29-36. [5] Faiz J, Nejadi-Koti H, Valipour Z.Comprehensive review on inter-turn fault indexes in permanent magnet motors[J]. IET Electric Power Applications, 2017, 11(1): 142-156. [6] 黄建, 尹佐生, 王天乙, 等. 基于容错齿磁通的五相永磁电机匝间短路故障诊断[J]. 电工技术学报, 2023, 38(14): 3733-3744. Huang Jian, Yin Zuosheng, Wang Tianyi, et al.Diagnosis of inter-turn short-circuit fault for five- phase permanent magnet machine based on fault- tolerant tooth flux[J]. Transactions of China Electro- technical Society, 2023, 38(14): 3733-3744. [7] 谢颖, 胡圣明, 陈鹏, 等. 永磁同步电机匝间短路故障温度场分析[J]. 电工技术学报, 2022, 37(2): 322-331. Xie Ying, Hu Shengming, Chen Peng, et al.Thermal field analysis on inter-turn short circuit fault of permanent magnet synchronous motor[J]. Transa- ctions of China Electrotechnical Society, 2022, 37(2): 322-331. [8] Zeng Chong, Huang Song, Yang Yongming, et al.Inter-turn fault diagnosis of permanent magnet synchronous machine based on tooth magnetic flux analysis[J]. IET Electric Power Applications, 2018, 12(6): 837-844. [9] Infantraj A, Kumaran M S.Evaluation and classi- fication of stator turn-to-turn faults using electrical equivalent circuits for surface permanent magnet brushless direct current motors[J]. Journal of Power Electronics, 2023, 23(11): 1703-1711. [10] Zafarani M, Bostanci E, Qi Yuan, et al.Interturn short-circuit faults in permanent magnet synchronous machines: an extended review and comprehensive analysis[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2018, 6(4): 2173-2191. [11] 张鹏, 赵国新, 崔效源, 等. 匝间短路故障对永磁同步电机定子侧电流影响分析[J]. 电机与控制应用, 2024, 51(6): 78-87. Zhang Peng, Zhao Guoxin, Cui Xiaoyuan, et al.Analysis of the effect of inter-turn short-circuit fault on the stator current of permanent magnet syn- chronous motor[J]. Electric Machines & Control Application, 2024, 51(6): 78-87. [12] Lü Ke, Wang Dong, Huang Wen, et al.Research on fault indicator for integrated fault diagnosis system of PMSM based on stator tooth flux[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2024, 12(1): 985-996. [13] Orviz M, Laborda D F, Reigosa D, et al.Demagne- tization detection and severity assessment in PMSMs using search coils exploiting machine's symmetry[J]. IEEE Transactions on Industry Applications, 2023, 59(4): 4021-4034. [14] Da Yao, Shi Xiaodong, Krishnamurthy M.A new approach to fault diagnostics for permanent magnet synchronous machines using electromagnetic signature analysis[J]. IEEE Transactions on Power Electronics, 2012, 28(8): 4104-4112. [15] 杭俊, 孙无双, 赖江龙, 等. 基于跨极式探测线圈的双三相永磁同步电机故障诊断方法[J]. 电机与控制学报, 2023, 27(7): 163-173. Hang Jun, Sun Wushuang, Lai Jianglong, et al.Fault diagnosis method of dual three phase permanent magnet synchronous motor based on transpolar search coil[J]. Electric Machines and Control, 2023, 27(7): 163-173. [16] 杭俊, 孙无双, 赖江龙, 等. 基于跨极式探测线圈的双三相永磁同步电机故障诊断方法[J]. 电机与控制学报, 2023, 27(7): 163-173. Hang Jun, Sun Wushuang, Lai Jianglong, et al.Fault diagnosis method of dual three phase permanent magnet synchronous motor based on transpolar search coil[J]. Electric Machines and Control, 2023, 27(7): 163-173. [17] Li Tiannan, Du Bochao, Huang Wan, et al.Diagnostic technique for inter-turn faults of PMSMs based on search coils using high-frequency negative sequence components[C]//2021 IEEE 16th Conference on Industrial Electronics and Applications (ICIEA), Chengdu, China, 2021: 718-723. [18] Sui Yi, Zheng Ping, Wu Fan, et al. A novel five-phase fault-tolerant modular in-wheel permanent-magnet synchronous machine for electric vehicles[J]. Journal of Applied Physics, 2015, 117(17): 17B521. [19] Huang Wan, Du Bochao, Li Tiannan, et al.Interturn short-circuit fault diagnosis of interior permanent magnet synchronous motor for electric vehicle based on search coil[J]. IEEE Transactions on Power Electronics, 2023, 38(2): 2506-2515. [20] Li Rui, Fang Haiyang, Li Dawei, et al.A search coil design method of PMSM for detection of inter-turn short-circuit fault[J]. IEEE Transactions on Industrial Electronics, 2024, 71(4): 3964-3974. [21] Wang Runyu, Li Dawei, Fan Xinggang, et al.Analysis of short-circuit current automatic suppression for toroidal winding PM machines[J]. IEEE Transactions on Power Electronics, 2024, 39(6): 7510-7524.
2026, Vol. 41 
