We propose a position sensorless control scheme for a four-switch,three-phase brushless DC motor drive,based on the zero crossing point detection of phase back-EMF voltages using newly defined error functions(EFs). Th...We propose a position sensorless control scheme for a four-switch,three-phase brushless DC motor drive,based on the zero crossing point detection of phase back-EMF voltages using newly defined error functions(EFs). The commutation in-stants are 30° after detected zero crossing points of the EFs. Developed EFs have greater magnitude rather than phase or line voltages so that the sensorless control can work at a lower speed range. Moreover,EFs have smooth transitions around zero voltage level that reduces the commutation errors. EFs are derived from the filtered terminal voltages vao and vbo of two low-pass filters,which are used to eliminate high frequency noises for calculation of the average terminal voltages. The feasibility of the proposed sensorless control is demonstrated by simulation and experimental results.展开更多
The permanent-magnet(PM) spherical motor has special configuration and complicated distribution of electromagnetic field.The spatial distribution of the effective flux density produced by permanent magnets is obtained...The permanent-magnet(PM) spherical motor has special configuration and complicated distribution of electromagnetic field.The spatial distribution of the effective flux density produced by permanent magnets is obtained,and the end-effect of the permanent magnets is analyzed.In the 3-dimensional(3-D) finite element(FE) analysis,the calculation of Back-EMF charac-teristics of the PM spherical motor needs to be conducted by steps,which leads to large computational burden.A novel ana-lyzing method to quantize the end-effect of the PM spherical motor is proposed,that is,the end-effect coefficient of the PM spherical motor is calculated to revise the back-EMF waveform obtained from the 2-D FE model.Under different outer radii of the stator coil and different pole arc coefficients of the PM spherical motor,the revised 2-D results are validated by the results obtained from the 3-D FE model and the experimental results.With this method,the special structural feature of the PM spherical motor is fully considered;the pure 3-D calculation of electromagnetic field is conducted only once;higher precision and less computational burden can be achieved.The method provides a new approach to investigating the back-EMF charac-teristic of the PM spherical motor.展开更多
In this paper,an improved rotor position estimation strategy based on third harmonic back-EMF for single-and dual-three-phase permanent magnet synchronous machines(PMSMs)under imbalanced situation is proposed.Due to t...In this paper,an improved rotor position estimation strategy based on third harmonic back-EMF for single-and dual-three-phase permanent magnet synchronous machines(PMSMs)under imbalanced situation is proposed.Due to the imbalanced machine impedance,back-EMF or sensing resistor network,the measured triplen harmonic back-EMF will contain certain fundamental component distortion which may severely deteriorate the performance of rotor position estimation.With the aid of the fundamental component compensator,this distortion can be significantly compensated,and the rotor position estimation error can be minimized considerably.The proposed strategy has been implemented on a dSPACE platform with a prototype of dual-three-phase PMSM with serious imbalanced parameters,and operate at single-and dual-three-phase conditions.The experimental results prove that the proposed strategy can significantly improve the steady-state and dynamic performance of rotor position estimation under imbalanced situation.展开更多
In order to solve the problem of asymmetric bidirectional flux control capability in hybrid excitation machine,a novel structure called dual consequent hybrid excitation synchronous(DCHES)machine is presented in this ...In order to solve the problem of asymmetric bidirectional flux control capability in hybrid excitation machine,a novel structure called dual consequent hybrid excitation synchronous(DCHES)machine is presented in this paper.Generally,the analysis of back-EMF for the machine with complex electromagnetic structure such as DCHES machine should utilize 3-D finite element analysis(FEA),which will require huge resources and computing time.In order to avoid using 3-D FEA to analyze the back-EMF of complex structure,an analytical method of calculating back-EMF is presented in this paper.The electromagnetic field in 3-D space can be simplified as a 2-D field by dividing the 3-D field into several simple zones,the resultant effect equals to the summation of every single 2-D field's effect.According to electromagnetic theory,the analytical formula of back-EMF is obtained on the basis of Fourier series.The influence of main parameters on back-EMF waveform under sine and trapezoidal flux distribution is discussed respectively.The theoretical result shows that the trapezoidal air-gap flux distribution would generate a sine back-EMF.Finally,the presented analytical method is verified and evaluated with experimental results.展开更多
采用转矩环取代传统的电流环,可减小非理想反电势无刷直流电机(brushless DC motor,BLDCM)的转矩脉动,提高其控制性能,而转矩环中反馈转矩计算的关键在于绕组反电势的准确获取。建立考虑参数偏差的滑模观测器(sliding-mode observer,SMO...采用转矩环取代传统的电流环,可减小非理想反电势无刷直流电机(brushless DC motor,BLDCM)的转矩脉动,提高其控制性能,而转矩环中反馈转矩计算的关键在于绕组反电势的准确获取。建立考虑参数偏差的滑模观测器(sliding-mode observer,SMO)对反电势进行实时观测,定量分析了定子电阻偏差对观测结果的影响,分析表明反电势观测的稳态误差等于电阻偏差量与电流的乘积。为消除这一影响,利用李雅普诺夫(Lyapunov)稳定性理论,设计了定子电阻参数辨识的自适应率,在线辨识得到的电阻参数用于调整SMO的系数矩阵,构成了新型的自适应滑模观测器。最后,利用RT-LAB实时控制器进行实验,验证了上述分析结果的正确性,证明了所提方法能够正确快速地观测无刷直流电机反电势。展开更多
文摘We propose a position sensorless control scheme for a four-switch,three-phase brushless DC motor drive,based on the zero crossing point detection of phase back-EMF voltages using newly defined error functions(EFs). The commutation in-stants are 30° after detected zero crossing points of the EFs. Developed EFs have greater magnitude rather than phase or line voltages so that the sensorless control can work at a lower speed range. Moreover,EFs have smooth transitions around zero voltage level that reduces the commutation errors. EFs are derived from the filtered terminal voltages vao and vbo of two low-pass filters,which are used to eliminate high frequency noises for calculation of the average terminal voltages. The feasibility of the proposed sensorless control is demonstrated by simulation and experimental results.
基金supported by the National Scientific Fund for Distinguished Young Scholars (Grant NO.50825701) the Key Program of National Natural Science Foundation of China (Grant NO.51037004)+1 种基金the National Natural Science Foundation of China (Grant NO.51077097)the Key Technologies Research and Development Program of Tianjin (Grant Nos:10ZCKFGX02300,10ZCKFGX02800)
文摘The permanent-magnet(PM) spherical motor has special configuration and complicated distribution of electromagnetic field.The spatial distribution of the effective flux density produced by permanent magnets is obtained,and the end-effect of the permanent magnets is analyzed.In the 3-dimensional(3-D) finite element(FE) analysis,the calculation of Back-EMF charac-teristics of the PM spherical motor needs to be conducted by steps,which leads to large computational burden.A novel ana-lyzing method to quantize the end-effect of the PM spherical motor is proposed,that is,the end-effect coefficient of the PM spherical motor is calculated to revise the back-EMF waveform obtained from the 2-D FE model.Under different outer radii of the stator coil and different pole arc coefficients of the PM spherical motor,the revised 2-D results are validated by the results obtained from the 3-D FE model and the experimental results.With this method,the special structural feature of the PM spherical motor is fully considered;the pure 3-D calculation of electromagnetic field is conducted only once;higher precision and less computational burden can be achieved.The method provides a new approach to investigating the back-EMF charac-teristic of the PM spherical motor.
文摘In this paper,an improved rotor position estimation strategy based on third harmonic back-EMF for single-and dual-three-phase permanent magnet synchronous machines(PMSMs)under imbalanced situation is proposed.Due to the imbalanced machine impedance,back-EMF or sensing resistor network,the measured triplen harmonic back-EMF will contain certain fundamental component distortion which may severely deteriorate the performance of rotor position estimation.With the aid of the fundamental component compensator,this distortion can be significantly compensated,and the rotor position estimation error can be minimized considerably.The proposed strategy has been implemented on a dSPACE platform with a prototype of dual-three-phase PMSM with serious imbalanced parameters,and operate at single-and dual-three-phase conditions.The experimental results prove that the proposed strategy can significantly improve the steady-state and dynamic performance of rotor position estimation under imbalanced situation.
基金Supported in part by the Natural Science Foundation of Henan Province under Grant 162300410319the Education Department of Henan Province under Grant 16A470026,Zhengzhou University of Light Industry under Grant 2014BSJJ040the office of Science and Technology in Henan Province under Grant 172102310254.
文摘In order to solve the problem of asymmetric bidirectional flux control capability in hybrid excitation machine,a novel structure called dual consequent hybrid excitation synchronous(DCHES)machine is presented in this paper.Generally,the analysis of back-EMF for the machine with complex electromagnetic structure such as DCHES machine should utilize 3-D finite element analysis(FEA),which will require huge resources and computing time.In order to avoid using 3-D FEA to analyze the back-EMF of complex structure,an analytical method of calculating back-EMF is presented in this paper.The electromagnetic field in 3-D space can be simplified as a 2-D field by dividing the 3-D field into several simple zones,the resultant effect equals to the summation of every single 2-D field's effect.According to electromagnetic theory,the analytical formula of back-EMF is obtained on the basis of Fourier series.The influence of main parameters on back-EMF waveform under sine and trapezoidal flux distribution is discussed respectively.The theoretical result shows that the trapezoidal air-gap flux distribution would generate a sine back-EMF.Finally,the presented analytical method is verified and evaluated with experimental results.
文摘采用转矩环取代传统的电流环,可减小非理想反电势无刷直流电机(brushless DC motor,BLDCM)的转矩脉动,提高其控制性能,而转矩环中反馈转矩计算的关键在于绕组反电势的准确获取。建立考虑参数偏差的滑模观测器(sliding-mode observer,SMO)对反电势进行实时观测,定量分析了定子电阻偏差对观测结果的影响,分析表明反电势观测的稳态误差等于电阻偏差量与电流的乘积。为消除这一影响,利用李雅普诺夫(Lyapunov)稳定性理论,设计了定子电阻参数辨识的自适应率,在线辨识得到的电阻参数用于调整SMO的系数矩阵,构成了新型的自适应滑模观测器。最后,利用RT-LAB实时控制器进行实验,验证了上述分析结果的正确性,证明了所提方法能够正确快速地观测无刷直流电机反电势。
