针对高速电机磁悬浮转子受不平衡扰动时位移精度下降的问题，提出一种基于最小位移原则的变极性最小均方误差（least mean square，LMS）反馈不平衡补偿策略，通过在线辨识位移信号中的转速同频分量，引入反馈补偿来增加系统对同频分量的广义动刚度，实现不平衡补偿。利用广义根轨迹分析了引入补偿后系统的闭环稳定性，同时针对仅以负极性或正极性引入补偿后，闭环系统均存在临界转频以上或以下发散的问题，设计了通过切换引入补偿的极性来穿越临界转频，从而实现引入LMS反馈补偿后全转速范围闭环稳定。实验结果表明，该方法在全转速范围内均能大幅减小位移信号中的转速同频分量。
Variable Polarity LMS Feedback Based on Displace Nulling to Compensate Unbalance of Magnetic Bearing
Because of the decrease of high-speed motor magnetic rotor displace accuracy generated by unbalance vibration, a LMS feedback algorithm based on the principle of displace nulling is proposed. The system generalized dynamic stiffness is improved by online identifying the same-frequency component of displace signal and adding feedback compensation to achieve unbalance compensation. In addition, the stability of close loop system is analyzed by generalized root locus; meanwhile, to cross the critical frequency and achieve the displace compensation among the whole speed range, a variable polarity strategy is raised. Experiment results demonstrates it can suppress the displace same-frequency vibration effectively among the whole speed range.
1. Science and Technology on Inertial Laboratory (Beihang University), Haidian District, Beijing 100191, China;
2. Fundamental Science on Novel Inertial Instrument & Navigation System Technology Laboratory (Beihang University), Haidian District, Beijing 100191, China
摘要针对高速电机磁悬浮转子受不平衡扰动时位移精度下降的问题，提出一种基于最小位移原则的变极性最小均方误差（least mean square，LMS）反馈不平衡补偿策略，通过在线辨识位移信号中的转速同频分量，引入反馈补偿来增加系统对同频分量的广义动刚度，实现不平衡补偿。利用广义根轨迹分析了引入补偿后系统的闭环稳定性，同时针对仅以负极性或正极性引入补偿后，闭环系统均存在临界转频以上或以下发散的问题，设计了通过切换引入补偿的极性来穿越临界转频，从而实现引入LMS反馈补偿后全转速范围闭环稳定。实验结果表明，该方法在全转速范围内均能大幅减小位移信号中的转速同频分量。
Abstract：Because of the decrease of high-speed motor magnetic rotor displace accuracy generated by unbalance vibration, a LMS feedback algorithm based on the principle of displace nulling is proposed. The system generalized dynamic stiffness is improved by online identifying the same-frequency component of displace signal and adding feedback compensation to achieve unbalance compensation. In addition, the stability of close loop system is analyzed by generalized root locus; meanwhile, to cross the critical frequency and achieve the displace compensation among the whole speed range, a variable polarity strategy is raised. Experiment results demonstrates it can suppress the displace same-frequency vibration effectively among the whole speed range.
宋腾1,2，韩邦成1,2，郑世强1,2，冯锐1,2. 基于最小位移的磁悬浮转子变极性LMS反馈不平衡补偿[J]. 振动与冲击, 2015, 34(7): 24-32.
SONG Teng1,2 HAN Bangcheng1,2 ZHENG Shiqiang1,2 FENG Rui1,2. Variable Polarity LMS Feedback Based on Displace Nulling to Compensate Unbalance of Magnetic Bearing. JOURNAL OF VIBRATION AND SHOCK, 2015, 34(7): 24-32.
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