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Volume 49,Issue 10,2022 Table of Contents
2022, 49(10):1-9,19.
DOI: 10.12177/emca.2022.111
Abstract:
Aiming at the open-circuit fault of surface-mount dual three-phase permanent magnet synchronous motora fault-tolerant control scheme based on current optimization is proposed. Firstlyaccording to the basic Park transformationa coordinate transformation matrix that can realize the decoupling of stator inductance is deduced. A mathematical model under one-phase open-circuit fault is establishedand it is analyzed that the harmonic component of stator current is the cause of torque rippleand the fault-tolerant control problem under open-circuit fault is transformed into a multi-objective optimization problem of the d-q axis reference currents. Secondlyaiming at the shortcomings of the traditional gray wolf optimization algorithmsuch as uneven initial population distribution and the tendency to fall into local optimizationa Kent mapping-particle swarm-gray wolf optimization algorithm is proposed to realize the rapid and accurate optimization of current parameters in fault stateand obtain the maximum average torque while minimizing the torque ripple. Finallythe simulation results verify the effectiveness of the proposed method.
Aiming at the open-circuit fault of surface-mount dual three-phase permanent magnet synchronous motora fault-tolerant control scheme based on current optimization is proposed. Firstlyaccording to the basic Park transformationa coordinate transformation matrix that can realize the decoupling of stator inductance is deduced. A mathematical model under one-phase open-circuit fault is establishedand it is analyzed that the harmonic component of stator current is the cause of torque rippleand the fault-tolerant control problem under open-circuit fault is transformed into a multi-objective optimization problem of the d-q axis reference currents. Secondlyaiming at the shortcomings of the traditional gray wolf optimization algorithmsuch as uneven initial population distribution and the tendency to fall into local optimizationa Kent mapping-particle swarm-gray wolf optimization algorithm is proposed to realize the rapid and accurate optimization of current parameters in fault stateand obtain the maximum average torque while minimizing the torque ripple. Finallythe simulation results verify the effectiveness of the proposed method.
2022, 49(10):10-19.
DOI: 10.12177/emca.2022.103
Abstract:
Aiming at the noise caused by the serious harmonic problem of dual three-phase motora hybrid pulse width modulation technology is proposed. This modulation technology is improved on the traditional continuous maximum four-vector space vector pulse width modulation (SVPWM) algorithm. The four kinds of zero vectors are used effectively and the time sequence of effective vectors is redistributed. The improved SVPWM method is combined with the periodic frequency modulation methodand a new hybrid pulse width modulation technology is proposed. Compared with the traditional continuous maximum four-vectors modulation methodthe modulation technology makes the distribution of switching frequency and its integral multiple harmonic content more uniform at the cost of increasing the switching times only onceand significantly reduces the high-frequency harmonic amplitude of phase current on the premise of ensuring the operation performance of vector control of dual three-phase motor. At the same timethe fluctuation of z1-z2 harmonic sub plane harmonic amplitude is suppressed greatly. The proposed method neither changes the fundamental wave characteristics nor uses additional circuits in the driver. Finallythe effectiveness of the proposed strategy is verified by simulation.
Aiming at the noise caused by the serious harmonic problem of dual three-phase motora hybrid pulse width modulation technology is proposed. This modulation technology is improved on the traditional continuous maximum four-vector space vector pulse width modulation (SVPWM) algorithm. The four kinds of zero vectors are used effectively and the time sequence of effective vectors is redistributed. The improved SVPWM method is combined with the periodic frequency modulation methodand a new hybrid pulse width modulation technology is proposed. Compared with the traditional continuous maximum four-vectors modulation methodthe modulation technology makes the distribution of switching frequency and its integral multiple harmonic content more uniform at the cost of increasing the switching times only onceand significantly reduces the high-frequency harmonic amplitude of phase current on the premise of ensuring the operation performance of vector control of dual three-phase motor. At the same timethe fluctuation of z1-z2 harmonic sub plane harmonic amplitude is suppressed greatly. The proposed method neither changes the fundamental wave characteristics nor uses additional circuits in the driver. Finallythe effectiveness of the proposed strategy is verified by simulation.
2022, 49(10):20-26,59.
DOI: 10.12177/emca.2022.097
Abstract:
A method is introduced to achieve position sensorless control and online stator resistance identification for PMSM in the full speed range. The high-frequency square wave injection method is utilized to accomplish position sensorless operation at zero and low speedwhile switching to the synchronous shaft sliding mode observer at medium and high speed. The stator resistance is closely related to winding temperature and control performanceand it can be calculated by Ohm′s law with the DC disturbance current injection and closed-loop control in the stationary two-phase coordinate system. The proposed method does not rely on other motor parametershas little impact on the system operation and is widely applicable. The simulation results show that the accuracy is ±5%which can be used to monitor the winding temperature and improve the performance of position sensorless control.
A method is introduced to achieve position sensorless control and online stator resistance identification for PMSM in the full speed range. The high-frequency square wave injection method is utilized to accomplish position sensorless operation at zero and low speedwhile switching to the synchronous shaft sliding mode observer at medium and high speed. The stator resistance is closely related to winding temperature and control performanceand it can be calculated by Ohm′s law with the DC disturbance current injection and closed-loop control in the stationary two-phase coordinate system. The proposed method does not rely on other motor parametershas little impact on the system operation and is widely applicable. The simulation results show that the accuracy is ±5%which can be used to monitor the winding temperature and improve the performance of position sensorless control.
2022, 49(10):27-33.
DOI: 10.12177/emca.2022.093
Abstract:
In order to reduce torque ripple of induction motor model predictive torque control (MPTC) system and further reduce the flux ripplea flux linkage and torque deadbeat control is proposed. The simulation results show that the induction motor system works properly under the flux linkage and torque deadbeat control. Compared with MPTCthe proposed strategy can decrease the root mean squared error (RMSE) of torque ripple by 87.84%the RMSE of flux ripple by 97.83%and the total harmonic distortion (THD) of current by 94.21%. And compared with torque deadbeat model predictive controlthe torque ripple of the proposed strategy is increased slightlybut the RMSE of flux ripple is reduced by 96.77%and the THD of current is reduced by 90.03%. The real-time experiment results show that the flux linkage and torque deadbeat control is simple to calculate and has good real-time performance. The calculation time is 4.79% of MPTC and 5.29% of torque deadbeat model predictive control.
In order to reduce torque ripple of induction motor model predictive torque control (MPTC) system and further reduce the flux ripplea flux linkage and torque deadbeat control is proposed. The simulation results show that the induction motor system works properly under the flux linkage and torque deadbeat control. Compared with MPTCthe proposed strategy can decrease the root mean squared error (RMSE) of torque ripple by 87.84%the RMSE of flux ripple by 97.83%and the total harmonic distortion (THD) of current by 94.21%. And compared with torque deadbeat model predictive controlthe torque ripple of the proposed strategy is increased slightlybut the RMSE of flux ripple is reduced by 96.77%and the THD of current is reduced by 90.03%. The real-time experiment results show that the flux linkage and torque deadbeat control is simple to calculate and has good real-time performance. The calculation time is 4.79% of MPTC and 5.29% of torque deadbeat model predictive control.
2022, 49(10):34-39.
DOI: 10.12177/emca.2022.100
Abstract:
Permanent magnet synchronous motor (PMSM) parameters are affected by the environment and other nonlinear factors. So it is necessary to adjust the control system according to the motor parameters to achieve better control performance. A new step-by-step parameter identification system for position sensorless PMSM is presented to solve the problems that the parameters of different motors are different and the fast manual measurement can not be realized. The resistance is calculated by volt-ampere method in stages and the inductance and magnetic chain of the motor are calculated by high-frequency voltage injection method. The parameters of the built-in PMSM can be identified automatically under the position sensorless control. Finallythe reliability of the new step-by-step parameter identification system is verified by building a simulation model with MATLAB/Simulink and the accuracy of the system is verified by experiments.
Permanent magnet synchronous motor (PMSM) parameters are affected by the environment and other nonlinear factors. So it is necessary to adjust the control system according to the motor parameters to achieve better control performance. A new step-by-step parameter identification system for position sensorless PMSM is presented to solve the problems that the parameters of different motors are different and the fast manual measurement can not be realized. The resistance is calculated by volt-ampere method in stages and the inductance and magnetic chain of the motor are calculated by high-frequency voltage injection method. The parameters of the built-in PMSM can be identified automatically under the position sensorless control. Finallythe reliability of the new step-by-step parameter identification system is verified by building a simulation model with MATLAB/Simulink and the accuracy of the system is verified by experiments.
2022, 49(10):40-45.
DOI: 10.12177/emca.2022.109
Abstract:
A DC/DC bidirectional active equalization circuit topology combined with fuzzy control theory is proposed for the problems of large number of lithium cells and serious inconsistency. Taking the state of charge (SOC) as the basis for equalization judgmentthe mean-difference method is used to carry out active equalizationwhich realizes the equalization of a single cell and the alternate equalization between multiple single cells. The simulation results show that the proposed cell active equalization strategy can effectively improve the inconsistency of multiple cells and has a fast equalization speedwhich effectively realizes the active SOC equalization among cells.
A DC/DC bidirectional active equalization circuit topology combined with fuzzy control theory is proposed for the problems of large number of lithium cells and serious inconsistency. Taking the state of charge (SOC) as the basis for equalization judgmentthe mean-difference method is used to carry out active equalizationwhich realizes the equalization of a single cell and the alternate equalization between multiple single cells. The simulation results show that the proposed cell active equalization strategy can effectively improve the inconsistency of multiple cells and has a fast equalization speedwhich effectively realizes the active SOC equalization among cells.
7 Transformer Iron Core Looseness Fault Diagnosis Model Based on CEEMDAN-Wavelet-Threshold and 3D-CNN
2022, 49(10):46-52.
DOI: 10.12177/emca.2022.083
Abstract:
In order to solve the identification and diagnosis of transformer iron core looseness faulta method of removing environmental noise based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN)-wavelet-threshold is proposedand a method of identifying transformer iron core looseness fault based on voiceprint using three-dimensional convolutional neural network (3D-CNN) is proposed. A transformer iron core looseness fault test platform is built to collect the noise signals of the iron core under different degrees of looseness. The voiceprint signal collected for fault identification is filtered by CEEMDAN-wavelet-threshold algorithmand the transformer voiceprint signal with high signal-to-noise ratio is obtained by using the difference between transformer body noise and environmental noise in kurtosis. Thenthe time-frequency matrix is generated by short-time Fourier transform of the filtered voiceprint signalthe Mel spectrogram is obtained by dimensionality reduction of Mel filterand the data set suitable for the input format of 3D-CNN is made. Each layer of the network is builtand 3D-CNN is used to classify and identify the transformer iron core looseness fault. The experimental results show that the recognition rate of transformer iron core looseness fault is more than 90% under the condition of considering environmental noiseand can be used for the recognition and diagnosis of transformer iron core looseness fault.
In order to solve the identification and diagnosis of transformer iron core looseness faulta method of removing environmental noise based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN)-wavelet-threshold is proposedand a method of identifying transformer iron core looseness fault based on voiceprint using three-dimensional convolutional neural network (3D-CNN) is proposed. A transformer iron core looseness fault test platform is built to collect the noise signals of the iron core under different degrees of looseness. The voiceprint signal collected for fault identification is filtered by CEEMDAN-wavelet-threshold algorithmand the transformer voiceprint signal with high signal-to-noise ratio is obtained by using the difference between transformer body noise and environmental noise in kurtosis. Thenthe time-frequency matrix is generated by short-time Fourier transform of the filtered voiceprint signalthe Mel spectrogram is obtained by dimensionality reduction of Mel filterand the data set suitable for the input format of 3D-CNN is made. Each layer of the network is builtand 3D-CNN is used to classify and identify the transformer iron core looseness fault. The experimental results show that the recognition rate of transformer iron core looseness fault is more than 90% under the condition of considering environmental noiseand can be used for the recognition and diagnosis of transformer iron core looseness fault.
8 Fault Diagnosis of Asynchronous Motor Based on BP Neural Network and Wavelet Packet Energy Analysis
2022, 49(10):53-59.
DOI: 10.12177/emca.2022.105
Abstract:
In order to efficiently solve the problem of asynchronous motor faulta fault diagnosis system of asynchronous motor based on back-propagation (BP) neural network and wavelet packet energy analysis is proposed. The stator current signal is used as the fault signal of asynchronous motorand the collected stator current signal is analyzed by wavelet packet energy analysis to extract the corresponding fault feature vector. In order to improve the accuracy of diagnosisthe time-domain and frequency-domain features of signals are extracted and input into BP neural network for training and learning. After enough trainingthe accuracy is tested with test samples. Through the proposed methodthe faults of asynchronous motor can be eliminated and corrected in timeand the economic benefits of the factory can be improved.
In order to efficiently solve the problem of asynchronous motor faulta fault diagnosis system of asynchronous motor based on back-propagation (BP) neural network and wavelet packet energy analysis is proposed. The stator current signal is used as the fault signal of asynchronous motorand the collected stator current signal is analyzed by wavelet packet energy analysis to extract the corresponding fault feature vector. In order to improve the accuracy of diagnosisthe time-domain and frequency-domain features of signals are extracted and input into BP neural network for training and learning. After enough trainingthe accuracy is tested with test samples. Through the proposed methodthe faults of asynchronous motor can be eliminated and corrected in timeand the economic benefits of the factory can be improved.
2022, 49(10):60-67.
DOI: 10.12177/emca.2022.067
Abstract:
In order to quickly and accurately calculate fault tolerant operation capability of multiphase permanent magnet synchronous motor (PMSM) at asymmetrical fault conditionan analytical model of no-load and on-load magnetic field of multiphase inner rotor surface permanent magnet synchronous motor (SPMSM) under asymmetrical fault condition is proposed by the Fourier series analysis method in the two-dimensional polar coordinate system. The performances such as air gap magnetic densityno-load back electromotive force (EMF) and electromagnetic output torque are calculated accurately. A 12-phase inner rotor SPMSM with 44-poles and 48-slots for ship is designed and manufacturedand theaccuracy of proposed model is validated by finite element analysis and test. On this basisin order to improve the fault tolerance ability of multiphase PMSMa fault tolerant control strategy for open circuit fault of one phase winding of multiphase motor drive system is established with minimum-phase current as the optimization goal. Taking the performances such as electromagnetic output torque and torque ripple as evaluation indexesthe fault tolerant performance of 12-phase SPMSM is analyzed to further improve the reliability of motor drive system.
In order to quickly and accurately calculate fault tolerant operation capability of multiphase permanent magnet synchronous motor (PMSM) at asymmetrical fault conditionan analytical model of no-load and on-load magnetic field of multiphase inner rotor surface permanent magnet synchronous motor (SPMSM) under asymmetrical fault condition is proposed by the Fourier series analysis method in the two-dimensional polar coordinate system. The performances such as air gap magnetic densityno-load back electromotive force (EMF) and electromagnetic output torque are calculated accurately. A 12-phase inner rotor SPMSM with 44-poles and 48-slots for ship is designed and manufacturedand theaccuracy of proposed model is validated by finite element analysis and test. On this basisin order to improve the fault tolerance ability of multiphase PMSMa fault tolerant control strategy for open circuit fault of one phase winding of multiphase motor drive system is established with minimum-phase current as the optimization goal. Taking the performances such as electromagnetic output torque and torque ripple as evaluation indexesthe fault tolerant performance of 12-phase SPMSM is analyzed to further improve the reliability of motor drive system.
2022, 49(10):68-76.
DOI: 10.12177/emca.2022.101
Abstract:
Firstlythe calculation methods of freight trains at the flat slope and variable slope points are analyzed. Aiming at reducing the traction energy consumption of freight trainsan energy-saving optimization model of freight trains is established with time and speed limit as constraints. Considering the existence of temporary speed limit in the linean energy-saving strategy based on different interval division is proposedwhich divides the interval according to the working condition sequence under the fastest speed curveinserts the idling working condition into the interval to form the energy-saving condition sequenceand use the improved whale optimization algorithm to solve the position of the condition conversion point in each interval. Finallythe effectiveness of the proposed energy-saving strategy is verified by comparing it with the classical four stage energy-saving strategy in simulation and actual lines.
Firstlythe calculation methods of freight trains at the flat slope and variable slope points are analyzed. Aiming at reducing the traction energy consumption of freight trainsan energy-saving optimization model of freight trains is established with time and speed limit as constraints. Considering the existence of temporary speed limit in the linean energy-saving strategy based on different interval division is proposedwhich divides the interval according to the working condition sequence under the fastest speed curveinserts the idling working condition into the interval to form the energy-saving condition sequenceand use the improved whale optimization algorithm to solve the position of the condition conversion point in each interval. Finallythe effectiveness of the proposed energy-saving strategy is verified by comparing it with the classical four stage energy-saving strategy in simulation and actual lines.
2022, 49(10):77-85.
DOI: 10.12177/emca.2022.104
Abstract:
The bus voltage plays a key role in the safe and stable operation of the DC microgrid system. The voltage regulation process of the bidirectional DC converter presents the characteristics of uncertaintynonlinearity and strong coupling. Meanwhilethe controllability of the system is significantly decreased due to sensor failure. These complicated factors greatly reduce the stability of the bus voltage under the dynamical changes of the system. To solve these problemsfirstlythe virtual operation scenario is constructed with the help of the state feedback linearization techniqueand an estimator is designed to simulate the state information to reconstruct the virtual scenario systematically. Secondlyby using the reconstructed state informationthe adaptive control method and the backstepping method are combined to obtain an adaptive nonlinear control schemewhich effectively ensures the safe and stable operation of the system in case of the complicated external factors and internal fails. Finallythe MATLAB/Simulink simulation results verify the effectiveness of the proposed scheme.
The bus voltage plays a key role in the safe and stable operation of the DC microgrid system. The voltage regulation process of the bidirectional DC converter presents the characteristics of uncertaintynonlinearity and strong coupling. Meanwhilethe controllability of the system is significantly decreased due to sensor failure. These complicated factors greatly reduce the stability of the bus voltage under the dynamical changes of the system. To solve these problemsfirstlythe virtual operation scenario is constructed with the help of the state feedback linearization techniqueand an estimator is designed to simulate the state information to reconstruct the virtual scenario systematically. Secondlyby using the reconstructed state informationthe adaptive control method and the backstepping method are combined to obtain an adaptive nonlinear control schemewhich effectively ensures the safe and stable operation of the system in case of the complicated external factors and internal fails. Finallythe MATLAB/Simulink simulation results verify the effectiveness of the proposed scheme.
2022, 49(10):86-94.
DOI: 10.12177/emca.2022.107
Abstract:
The accurate analysis of motor modal is an important part to realize the low noise drive design of motor. When the modal frequency of motor is close to the frequency of corresponding order radial electromagnetic force waveresonance will occur. Taking a 6-pole 36-slot 70 kW commercial vehicle owner driven permanent magnet synchronous motor as the research objectthe influence of the rotor with auxiliary slot and the rotor with segmental skewed pole method for the first-order tooth harmonic on the electromagnetic force wave is compared and analyzed. The amplitude of the 0-order 12-time frequency radial electromagnetic force wave can be reduced by 79% after adopting the optimized method of rotor with auxiliary slot and rotor with segmental skewed pole. The three-dimensional finite element modal simulation model of the motor is established. The influence of the motor structural components on the modal is analyzed. Combined with the installation and fixation methods of the common vehicle mounted drive motorthe shell is constrainedand the modal characteristics of the motor under different constraints are analyzed. The results show that under the working condition of peak power of 8 000 r/minthe amplitude of radial electromagnetic force with 0-order 12-time frequency under the optimized design scheme is largebut the frequency is 4 800 Hzfar away from the natural frequency of the motor modalso resonance will not occur and the electromagnetic noise is reduced.
The accurate analysis of motor modal is an important part to realize the low noise drive design of motor. When the modal frequency of motor is close to the frequency of corresponding order radial electromagnetic force waveresonance will occur. Taking a 6-pole 36-slot 70 kW commercial vehicle owner driven permanent magnet synchronous motor as the research objectthe influence of the rotor with auxiliary slot and the rotor with segmental skewed pole method for the first-order tooth harmonic on the electromagnetic force wave is compared and analyzed. The amplitude of the 0-order 12-time frequency radial electromagnetic force wave can be reduced by 79% after adopting the optimized method of rotor with auxiliary slot and rotor with segmental skewed pole. The three-dimensional finite element modal simulation model of the motor is established. The influence of the motor structural components on the modal is analyzed. Combined with the installation and fixation methods of the common vehicle mounted drive motorthe shell is constrainedand the modal characteristics of the motor under different constraints are analyzed. The results show that under the working condition of peak power of 8 000 r/minthe amplitude of radial electromagnetic force with 0-order 12-time frequency under the optimized design scheme is largebut the frequency is 4 800 Hzfar away from the natural frequency of the motor modalso resonance will not occur and the electromagnetic noise is reduced.
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Electric Machines & Control Application ® 2025
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
沪ICP备16038578号-3
Electric Machines & Control Application ® 2025
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
