Abstract:The high-frequency injection method is widely used for inductance identification and low-speed sensorless control of permanent magnet synchronous motors. However, no existing research realizes both functions simultaneously through a shared injection sequence. This paper proposes a current component- separation method based on high-frequency square-wave injection to identify the d- and q-axis incremental inductances and the coupling inductance online. The high-precision sensorless control can be achieved without position sensors. The method has been validated on both interior three-phase and surface dual three-phase (30-degree phase shift) permanent magnet synchronous motors. The paper introduces a mathematical representation of cross-coupling inductance into the voltage model in the synchronous rotating frame and establishes a traditional reactance model as a reference. A novel four-stage square-wave voltage-injection waveform is designed. By tuning voltage amplitude coefficients, the waveform enables clear separation of self-excited and coupling-excited current components, and averaging is used to suppress high-frequency disturbances. To mitigate loss of estimation accuracy due to position uncertainty, a correction method for the angular deviation between the injection reference frame and the actual synchronous rotating frame is developed. By modeling the coupling-excited current and deriving the relation between the cross-coupling angle and the d- and q-axis currents, an online fitting strategy is proposed. A cross-coupling angle map is created from real position sensor input. For dual three-phase motors, a harmonic subspace-based inductance identification path is established via vector space decomposition. High-frequency voltage is injected into this subspace, and inductance is identified using the same component separation strategy. Different sensorless control structures are developed for different motor types. For interior-motors with high saturation and strong coupling, dual-axis injection in the synchronous rotating frame is used, and a corrected third-order control structure is implemented based on cross-coupling current. For surface dual three-phase motors, a phase-locked loop in the stationary reference frame estimates position directly from response current without angle compensation. Experimental validation is carried out on a 35 kW three-phase motor and a 400 W dual three-phase motor test bench. Tests include accuracy under static and dynamic conditions, position tracking performance, and convergence speed during step current. The proposed method exhibits reliable real-time performance with inductance estimation error under 6%, convergence within 10 ms, and position error below 10 degrees. The theoretical foundation of the proposed method is developed based on the voltage equations in the synchronous rotating reference frame. In theory, different multiphase motor configurations (such as five-phase, seven-phase, and multi-three-phase machines) differ only in neutral-point currents and harmonic-order plane currents, which do not affect the current-voltage equations in the synchronous rotating frame. Therefore, variations in winding configurations, power ratings, or saliency ratios do not affect the applicability of the proposed method. However, the coupling relationship between the cross-coupling angle and the injection reference frame makes the calibration process dependent on a physical position sensor. Achieving high-accuracy calibration of the cross-coupling angle under sensorless conditions remains to be further investigated. In conclusion, the proposed high-frequency square-wave injection and current-separation method enables accurate inductance estimation and sensorless control, which is suitable for deployment in automotive-grade motor controllers.
朱元, 徐世寒, 孟令, 金昶明, 王伟达. 基于高频电流成分分离的PMSM电感辨识与无位置控制[J]. 电工技术学报, 2026, 41(12): 4066-4080.
Zhu Yuan, Xu Shihan, Meng Ling, Jin Changming, Wang Weida. Inductance Identification and Sensorless Control of PMSM Based on Separation of High-Frequency Current Components. Transactions of China Electrotechnical Society, 2026, 41(12): 4066-4080.
[1] Kim H S, Sul S K.Real-time torque control of IPMSM under flux variations[J]. IEEE Journal of Emerging and Selected Topics in Power Electronics, 2022, 10(3): 3345-3356. [2] 张国强, 杜锦华. 永磁同步电机无位置传感器控制技术综述[J]. 电机与控制应用, 2024, 51(1): 1-13. Zhang Guoqiang, Du Jinhua.Review of position sensorless control technology for permanent magnet synchronous motors[J]. Electric Machines & Control Application, 2024, 51(1): 1-13. [3] 陈瑞, 吴悠, 杜荣华, 等. 一种基于特征模型的永磁同步电机协调控制策略[J]. 电气工程学报, 2025, 20(1): 54-64. Chen Rui, Wu You, Du Ronghua, et al.A coordinated control strategy for the permanent magnet syn-chronous motor based on the characteristic model[J]. Journal of Electrical Engineering, 2025, 20(1): 54-64. [4] Jung H S, Kim H, Sul S K, et al.Permanent magnet temperature estimation in a mass-produced traction motor for an electric vehicle[J]. IEEE Transactions on Transportation Electrification, 2021, 8(2): 1863-1873. [5] Li Silong, Sarlioglu B, Jurkovic S, et al.Analysis of temperature effects on performance of interior permanent magnet machines for high variable temperature applications[J]. IEEE Transactions on Industry Applications, 2017, 53(5): 4923-4933. [6] Li Xinyue, Kennel R.General formulation of Kalman-filter-based online parameter identification methods for VSI-fed PMSM[J]. IEEE Transactions on Industrial Electronics, 2021, 68(4): 2856-2864. [7] Feng Guodong, Lai Chunyan, Tan Xiaojun, et al.Multi-parameter estimation of PMSM using differential model with core loss compensation[J]. IEEE Transac-tions on Transportation Electrification, 2022, 8(1): 1105-1115. [8] Reigosa D D, Fernandez D, Yoshida H, et al.Permanent-magnet temperature estimation in PMSMs using pulsating high-frequency current injection[J]. IEEE Transactions on Industry Applications, 2015, 51(4): 3159-3168. [9] Reigosa D, Fernández D, Martínez M, et al.Magnet temperature estimation in permanent magnet syn-chronous machines using the high frequency indu-ctance[C]//2018 IEEE Energy Conversion Congress and Exposition (ECCE), Portland, OR, USA, 2018: 5029-5034. [10] Shuang Bo, Zhu Ziqiang.Simultaneous sensorless rotor position and torque estimation for IPMSM at standstill and low speed based on high-frequency square wave voltage injection[J]. IEEE Transactions on Industrial Electronics, 2022, 69(9): 8791-8802. [11] 王奇维, 李斌兴, 潘冠丞, 等. 基于转子位置误差解耦阻抗建模的永磁同步电机电感在线辨识方法[J]. 电工技术学报, 2025, 40(2): 439-451. Wang Qiwei, Li Binxing, Pan Guancheng, et al.Impedance model based online inductance identi-fication method of permanent magnet synchronous motor decoupled from rotor position error[J]. Transactions of China Electrotechnical Society, 2025, 40(2): 439-451. [12] Zapico M O, Reigosa D D, Laborda D F, et al.Use HF signal injection for simultaneous rotor angle, torque and temperature estimation in PMSMs[C]//2021 IEEE Energy Conversion Congress and Exposition (ECCE), Vancouver, BC, Canada, 2021: 5084-5091. [13] International Organization for Standardization (ISO). ISO 26262:2018 Road vehicles-Functional safety[A]. 2018. [14] Ortombina L, Berto M, Alberti L.Sensorless drive for salient synchronous motors based on direct fitting of elliptical-shape high-frequency currents[J]. IEEE Transactions on Industrial Electronics, 2022, 70(4): 3394-3403. [15] 李东昇, 袁杰, 王坤东. SOGI级联SFNF的高频注入无传感器电机控制方法[J]. 电机与控制学报, 2024, 28(3): 24-32. Li Dongsheng, Yuan Jie, Wang Kundong.High frequ-ency injection sensor-less motor control method with cascade of SOGI and SFNF[J]. Electric Machines and Control, 2024, 28(3): 24-32. [16] 刘小青, 王晋, 刘开元, 等. 基于高频注入法的同步磁阻电机无位置传感器控制[J]. 微电机, 2024, 57(5): 28-32. Liu Xiaoqing, Wang Jin, Liu Kaiyuan, et al.Research on sensorless control of synchronous reluctance motor based on high frequency signal injection[J]. Micro-motors, 2024, 57(5): 28-32. [17] Kang Yegu, Reigosa D, Sarlioglu B, et al.D-and Q-axis inductance estimation and self-sensing condition monitoring using 45° angle high-frequency injection[J]. IEEE Transactions on Industry Appli-cations, 2020, 57(1): 506-515. [18] Wang Jinke, Gao Qiang, Rahman F, et al.Fast on-line inductance estimation for interior permanent magnet synchronous machines based on the modified square-wave injection[C]//2021 IEEE International Electric Machines & Drives Conference (IEMDC), Hartford, CT, USA, 2021: 1-6. [19] Zhou Jiaxin, Huang Keyuan, Huang Shoudao, et al.Inductance parameter identification method of permanent magnet synchronous motor based on the HF rotating square wave voltage injection[C]//2019 22nd International Conference on Electrical Machines and Systems (ICEMS), Harbin, China, 2019: 1-4. [20] Yoo J, Kim H S, Sul S K.MTPA tracking control of sensorless IPMSM based on square-wave voltage signal injection[J]. IEEE Transactions on Power Electronics, 2022, 37(10): 12525-12537. [21] 葛健, 宫逸凡, 徐伟, 等. 基于在线参数辨识及自适应谐波提取滤波器的改进型直线振荡电机无位置传感器控制[J]. 电工技术学报, 2024, 39(22): 7099-7110. Ge Jian, Gong Yifan, Xu Wei, et al.Improved sensorless control of linear oscillatory machine based on online parameter identification and adaptive harmonic extraction filter[J]. Transactions of China Electrotechnical Society, 2024, 39(22): 7099-7110. [22] 王建渊, 李英杰, 景航辉, 等. 基于静止轴系改进高频方波注入同步磁阻电机无传感器控制[J]. 电工技术学报, 2024, 39(12): 3658-3669. Wang Jianyuan, Li Yingjie, Jing Hanghui, et al.Sensorless control of high frequency square wave injection synchronous reluctance motor based on static axis system improvement[J]. Transactions of China Electrotechnical Society, 2024, 39(12): 3658-3669. [23] Xu P L, Zhu Z Q.Novel square-wave signal injection method using zero-sequence voltage for sensorless control of PMSM drives[J]. IEEE Transactions on Industrial Electronics, 2016, 63(12): 7444-7454. [24] 周林, 林珊, 王孝洪, 等. 基于高频正交方波注入法的永磁同步电机控制研究[J]. 电机与控制学报, 2024, 28(2): 64-74. Zhou Lin, Lin Shan, Wang Xiaohong, et al.Permanent magnet synchronous motor based on high-frequency orthogonal square wave injection method[J]. Electric Machines and Control, 2024, 28(2): 64-74. [25] Wang Gaolin, Xiao Dianxun, Zhang Guoqiang, et al.Sensorless control scheme of IPMSMs using HF orthogonal square-wave voltage injection into a stationary reference frame[J]. IEEE Transactions on Power Electronics, 2019, 34(3): 2573-2584. [26] Kim S, Ha J I, Sul S K.PWM switching frequency signal injection sensorless method in IPMSM[J]. IEEE Transactions on Industry Applications, 2012, 48(5): 1576-1587. [27] Wang Gaolin, Yang Lei, Yuan Bihe, et al.Pseudo-random high-frequency square-wave voltage injection based sensorless control of IPMSM drives for audible noise reduction[J]. IEEE Transactions on Industrial Electronics, 2016, 63(12): 7423-7433. [28] Huang Chao, Li Liang.Architectural design and analysis of a steer-by-wire system in view of functional safety concept[J]. Reliability Engineering & System Safety, 2020, 198: 106822. [29] 艾星全, 肖岚, 伍群芳. 基于谐波注入的双三相PMSM全转矩范围最小铜耗缺相容错控制策略[J]. 电工技术学报, 2025, 40(10): 3157-3169. Ai Xingquan, Xiao Lan, Wu Qunfang.Fault-tolerant control strategy of open-phase fault with minimum loss in full torque operation range for DTP-PMSM based on harmonic current injection[J]. Transactions of China Electrotechnical Society, 2025, 40(10): 3157-3169. [30] 刘伟, 刘磊. 基于电流预测及谐波抑制的双三相永磁同步电动机容错控制研究[J]. 电气技术, 2023, 24(7): 20-25, 33. Liu Wei, Liu Lei.Research on fault-tolerant control of dual three-phase permanent magnet synchronous motor based on current prediction and harmonic suppression[J]. Electrical Engineering, 2023, 24(7): 20-25, 33. [31] Wang Qiwei, Zhang Guoqiang, Wang Gaolin, et al.Offline parameter self-learning method for general-purpose PMSM drives with estimation error com-pensation[J]. IEEE Transactions on Power Electronics, 2019, 34(11): 11103-11115. [32] 黄科元, 周佳新, 刘思美, 等. 考虑逆变器非线性永磁同步电机高频注入电感辨识方法[J]. 电工技术学报, 2021, 36(8): 1607-1616. Huang Keyuan, Zhou Jiaxin, Liu Simei, et al.Inductance identification method of permanent magnet synchronous motor considering inverter nonlinearity based on high-frequency injection[J]. Transactions of China Electrotechnical Society, 2021, 36(8): 1607-1616. [33] Li Yi, Zhu Z Q, Howe D, et al.Improved rotor-position estimation by signal injection in brushless AC motors, accounting for cross-coupling magnetic saturation[J]. IEEE Transactions on Industry Appli-cations, 2009, 45(5): 1843-1850. [34] Choi C H, Seok J K.Compensation of zero-current clamping effects for sensorless drives based on high-frequency signal injection[C]//Conference Record of the 2006 IEEE Industry Applications Conference Forty-First IAS Annual Meeting, Tampa, FL, USA, 2006: 2466-2471.