A Sensorless Control Method for Permanent Magnet Synchronous Machine Based on Dual Position Observers at Low Speed
Wang Jing1, Yan Jianhu1, Ji Guodong1, Shan Liang1, Ying Zhanfeng2
1. School of Automation Nanjing University of Science and Technology Nanjing 210094 China; 2. School of Energy and Power Engineering Nanjing University of Science and Technology Nanjing 210094 China
Abstract：For low-speed sensorless control of permanent magnet synchronous machine (PMSM), high frequency (HF) pulsating voltage injection method has been widely adopted to obtain the rotor position. However, the HF noise signal caused by HF signal injection imposes a negative impact on system bandwidth and dynamic performance. To solve this problem, some methods are proposed by designing novel observers and filters, but there is still an unavoidable trade-off between low noise and fast response. Therefore, new solution is necessary to design different position observers to decouple the low noise steady state and fast response transient state. To this end, the closed-loop bandwidths, filter characteristics and operation models for different observers should be analyzed, and a solution to combine different observers is required. Firstly, a conventional HF pulsating voltage injection method is presented to obtain a phase-locked loop (PLL) position observer and its parameter design method. Secondly, a second-order sliding mode observer (SMO) with variable gains is used for another position observer to realize low noise or low delay operations by changing its gains. Thirdly, the control structure and parameter design of the speed loop are derived through the similar structure with PLL, and its dynamic performance and filter characteristic are close to first-order low pass filter by comparing their Bode plots, which means it is difficult to achieve the low noise and low delay operations together. Finally, to decouple the low noise and low delay operations, the sensorless control system with a PLL position observer and a SMO is built which can switch low and high bandwidth operation models utilizing variable parameters corresponding to low noise and low delay operations respectively. In the sensorless control system, HF signal is adopted to implement signal injection based on a PLL position observer. An independent position observation system with a high closed-loop bandwidth is constructed to guarantee that the position estimation error converges to zero fast. Based on fundamental signal processing, a field-oriented control (FOC) system is built which obtains the rotor position and speed from the SMO. The SMO can get the rotor position with low delay from the PLL and obtain new position and speed estimations, then provide estimations with low noise or low delay for the FOC system corresponding to steady state and transient state respectively. According to the differences of response speed between the PLL and SMO, the conditions are presented to determine the system states and switch the controller bandwidths and a strategy is proposed using the integrators of the speed loop and SMO to smooth the bandwidth switching process. The experimental results describe the performances of the sensorless control system with dual position observers at different operations. When the PMSM starts up from 0 to 100r/min, comparing with conventional method, the low bandwidth model has lower speed and current fluctuations but longer position error convergence time. While the maximum speed fluctuation of high bandwidth model is close to 40r/min but the average speed is still 100r/min and the system can keep steady state. When the PMSM starts up with a rated load, the low bandwidth model and conventional method need 5s to reach the reference value but the high bandwidth model only need 0.02s, which means that the high bandwidth model has better dynamic performance. When the load or reference speed has a sudden change, the system can switch to high bandwidth model to regulate speed fast then return to low bandwidth model smoothly based on the bandwidth switching strategy. The theoretical analysis and experimental results show that the HF and fundamental signal processing can be decoupled utilizing dual position observers and the sensorless control system can be divided into independent position observation and FOC systems. Based on variable bandwidth and smooth switching strategy, the system can realize low noise and fluctuation at steady state and fast response and regulating at transient state.
王菁, 颜建虎, 季国东, 单梁, 应展烽. 一种基于双位置观测器的永磁同步电机低速无位置传感器控制方法[J]. 电工技术学报, 2023, 38(2): 375-386.
Wang Jing, Yan Jianhu, Ji Guodong, Shan Liang, Ying Zhanfeng. A Sensorless Control Method for Permanent Magnet Synchronous Machine Based on Dual Position Observers at Low Speed. Transactions of China Electrotechnical Society, 2023, 38(2): 375-386.
[1] Yin Zhonggang, Gao Fengtao, Zhang Yanqing, et al.A review of nonlinear Kalman filter appling to sensorless control for AC motor drives[J]. CES Transactions on Electrical Machines and Systems, 2019, 3(4): 351-362. [2] 姜燕, 李博文, 吴轩, 等. 基于比例谐振滤波的改进永磁同步电机转子位置观测器[J]. 电工技术学报, 2020, 35(17): 3619-3630. Jiang Yan, Li Bowen, Wu Xuan, et al.An improved rotor position observer for permanent magnet synchronous motors based on proportional resonant filtering[J]. Transactions of China Electrotechnical Society, 2020, 35(17): 3619-3630. [3] 李垣江, 董鑫, 魏海峰, 等. 表贴式永磁同步电机转速环复合PI无位置传感器控制[J]. 电工技术学报, 2020, 35(10): 2119-2129. Li Yuanjiang, Dong Xin, Wei Haifeng, et al.Sensorless compound PI control for surface per-manent magnet synchronous motor speed regulation system[J]. Transactions of China Electrotechnical Society, 2020, 35(10): 2119-2129. [4] 麦志勤, 肖飞, 刘计龙, 等. 基于改进型自调整轴系幅值收敛电流解调算法的旋转高频电压注入法[J]. 电工技术学报, 2021, 36(10): 2049-2060. Mai Zhiqin, Xiao Fei, Liu Jilong, et al.Rotating high-frequency voltage injection method based on improved self-adjusting frame amplitude convergence current demodulation algorithm[J]. Transactions of China Electrotechnical Society, 2021, 36(10): 2049-2060. [5] 赵文祥, 刘桓, 陶涛, 等. 基于虚拟信号和高频脉振信号注入的无位置传感器内置式永磁同步电机MTPA控制[J]. 电工技术学报, 2021, 36(24): 5092-5100. Zhao Wengxiang, Liu Huan, Tao Tao, et al.MTPA control of sensorless IPMSM based on virtual signal and high-frequency pulsating signal injection[J]. Transactions of China Electrotechnical Society, 2021, 36(24): 5092-5100. [6] 吴春, 陈科, 南余荣, 等. 考虑交叉饱和效应的变角度方波电压注入永磁同步电机无位置传感器控制[J]. 电工技术学报, 2020, 35(22): 4678-4687. Wu Chun, Chen Ke, Nan Yurong, et al.Variable angle square-wave voltage injection for sensorless control of PMSM considering cross-saturation effect[J]. Transactions of China Electrotechnical Society, 2020, 35(22): 4678-4687. [7] Mai Zhiqin, Xiao Fei, Fu Kangzhuang, et al.HF pulsating carrier voltage injection method based on improved position error signal extraction strategy for PMSM position sensorless control[J]. IEEE Transa-ctions on Power Electronics, 2021, 36(8): 9348-9360. [8] Li Haoyuan, Zhang Xing, Yang Shuying, et al.Unified graphical model of high-frequency signal injection methods for PMSM sensorless control[J]. IEEE Transactions on Industrial Electronics, 2020, 67(6): 4411-4421. [9] Jin Xinhai, Ni Ronggang, Chen Wei, et al.High-frequency voltage-injection methods and observer design for initial position detection of permanent magnet synchronous machines[J]. IEEE Transactions on Power Electronics, 2018, 33(9): 7971-7979. [10] 李孟秋, 王龙. 一种改进的永磁同步电机低速无位置传感器控制策略[J]. 电工技术学报, 2018, 33(9): 1967-1974. Li Mengqiu, Wang Long.An improved low speed sensorless control strategy for permanent magnet synchronous motor[J]. Transactions of China Elec-trotechnical Society, 2018, 33(9): 1967-1974. [11] 刘兵, 周波, 倪天恒, 等. 基于广义二阶积分器的表贴式永磁同步电机低速转子位置检测方法[J]. 电工技术学报, 2017, 32(23): 23-33. Liu Bing, Zhou Bo, Ni Tianheng, et al.A novel position observer for SPMSM sensorless control based on second-order generalized integrators[J]. Transactions of China Electrotechnical Society, 2017, 32(23): 23-33. [12] 邵俊波, 王辉, 黄守道, 等. 一种表贴式永磁同步电机无位置传感器低速控制策略[J]. 中国电机工程学报, 2018, 38(5): 1534-1541. Shao Junbo, Wang Hui, Huang Shoudao, et al.A position sensorless control strategy of surface-mounted permanent-magnet synchronous motors for low-speed operation[J]. Proceedings of the CSEE, 2018, 38(5): 1534-1541. [13] Kim S I, Im J H, Song E Y, et al.A new rotor position estimation method of IPMSM using all-pass filter on high-frequency rotating voltage signal injection[J]. IEEE Transactions on Industrial Electronics, 2016, 63(10): 6499-6509. [14] 刘计龙, 付康壮, 麦志勤, 等. 基于双频陷波器的改进型高频脉振电压注入无位置传感器控制策略[J]. 中国电机工程学报, 2021, 41(2): 749-759. Liu Jilong, Fu Kangzhuang, Mai Zhiqin, et al.Sensor-less control strategy of improved HF pulsating voltage injection based on dual frequency notch filter[J]. Proceedings of the CSEE, 2021, 41(2): 749-759. [15] 郭磊, 杨中平, 林飞. 带误差补偿的高频信号注入永磁同步电机无传感器控制策略[J]. 电工技术学报, 2019, 34(21): 4458-4466. Guo Lei, Yang Zhongping, Lin Fei.A sensorless control strategy for high frequency signal injection permanent magnet synchronous motor with error compensation[J]. Transactions of China Electro-technical Society, 2019, 34(21): 4458-4466. [16] 刘兵, 周波. 脉振高频电压注入SPMSM无位置传感器控制的估计误差分析与抑制方法[J]. 中国电机工程学报, 2018, 38(14): 4232-4241, 4329. Liu Bing, Zhou Bo.Analysis and compensation of position estimation error in SPMSM sensor-less control based on high frequency pulsating voltage injection[J]. Proceedings of the CSEE, 2018, 38(14): 4232-4241, 4329. [17] 孙宜标, 杨雪, 夏加宽. 采用鲁棒微分器的永磁直线同步电机二阶滑模控制[J]. 中国电机工程学报, 2007, 27(33): 6-10. Sun Yibiao, Yang Xue, Xia Jiakuan.Second order sliding mode control for PMLSM using robust differentiator[J]. Proceedings of the CSEE, 2007, 27(33): 6-10.
2023, Vol. 38 
