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Volume 47,Issue 4,2020 Table of Contents
2020, 47(4):1-9.
DOI: 10.12177/emca.2019.180
Abstract:
The continuous time mathematical model of electrically excited linear synchronous motor is established, which is suitable for the design of speed controller. A singleinputsingleoutput transfer function between the primary quadrature axis voltage and the primary mechanical speed is established with reasonable assumptions. An adaptive speed controller is designed by using local parameter optimization gradient method, which consists of only one integrator, one multiplier and two proportional elements. The adaptive speed controller without the traditional current loop accelerates the response speed and simplifies the system structure. The controller designed by MATLAB numerical simulation software is used to analyze the influence of the factors such as the adaptive gain adjustment coefficient and the generalized error feedback coefficient on the stability and convergence of the adaptive speed control system. Simulation results show the effectiveness of the adaptive speed control strategy.
The continuous time mathematical model of electrically excited linear synchronous motor is established, which is suitable for the design of speed controller. A singleinputsingleoutput transfer function between the primary quadrature axis voltage and the primary mechanical speed is established with reasonable assumptions. An adaptive speed controller is designed by using local parameter optimization gradient method, which consists of only one integrator, one multiplier and two proportional elements. The adaptive speed controller without the traditional current loop accelerates the response speed and simplifies the system structure. The controller designed by MATLAB numerical simulation software is used to analyze the influence of the factors such as the adaptive gain adjustment coefficient and the generalized error feedback coefficient on the stability and convergence of the adaptive speed control system. Simulation results show the effectiveness of the adaptive speed control strategy.
2020, 47(4):10-17.
DOI: 10.12177/emca.2019.190
Abstract:
Traditional model predictive control (MPC) uses all 7 voltage vectors generated by voltage source inverter (VSI) as candidate voltage vectors, which results in heavy calculation burden. But traditional model predictive torque control (MPTC) does not utilize 7 voltage vectors equally under some conditions. The MPTC system for surface permanent magnet synchronous motor (SPMSM) is built. Considering different stator flux sectors, flux and torque control commands and torque angles, the utilization rate of 7 voltage vectors is studied. Based on the principle of utilization rate of voltage vectors, simplified candidate voltage vector sets are proposed which can dynamically adjust candidate voltage vectors. Simulation results show that compared with traditional candidate voltage vectors sets, the proposed sets maintain the performance equivalently and decrease the number of candidate voltage vectors, and therefore can improve the realtime performance of the system.
Traditional model predictive control (MPC) uses all 7 voltage vectors generated by voltage source inverter (VSI) as candidate voltage vectors, which results in heavy calculation burden. But traditional model predictive torque control (MPTC) does not utilize 7 voltage vectors equally under some conditions. The MPTC system for surface permanent magnet synchronous motor (SPMSM) is built. Considering different stator flux sectors, flux and torque control commands and torque angles, the utilization rate of 7 voltage vectors is studied. Based on the principle of utilization rate of voltage vectors, simplified candidate voltage vector sets are proposed which can dynamically adjust candidate voltage vectors. Simulation results show that compared with traditional candidate voltage vectors sets, the proposed sets maintain the performance equivalently and decrease the number of candidate voltage vectors, and therefore can improve the realtime performance of the system.
2020, 47(4):18-23.
DOI: 10.12177/emca.2020.007
Abstract:
An adaptive PID controller based on disturbance observer is designed to deal with the problem of speed tracking accuracy of permanent magnet synchronous linear motor (PMSLM). A nonlinear disturbance observer is designed for the linear motor model based on vector control. Based on Lyapunov function, the overload compensation controller is designed and the projection adaptive law is updated on line. These make the PID control law follow the feedback control law. Experimental results show that the control strategy has better dynamic performance and robustness.
An adaptive PID controller based on disturbance observer is designed to deal with the problem of speed tracking accuracy of permanent magnet synchronous linear motor (PMSLM). A nonlinear disturbance observer is designed for the linear motor model based on vector control. Based on Lyapunov function, the overload compensation controller is designed and the projection adaptive law is updated on line. These make the PID control law follow the feedback control law. Experimental results show that the control strategy has better dynamic performance and robustness.
2020, 47(4):24-29.
DOI: 10.12177/emca.2019.186
Abstract:
Traditional position sensorless control systems generally adopt PI regulator for position information processing. A new adaptive Luenberger observer is proposed to solve the drawbacks of PI regulator such as parameter setting, poor tracking performance and weak interference suppression ability. This method uses pulsating high frequency current injection method to obtain the high frequency pulse vibration position signal, and then establishes Luenberger observer for speed and load disturbances according to the dynamic equation of the motor. Neural network is adopted to build the autotuning parameters controller for replacing the PID controller in Luenberger observer. The control of permanent magnet linear synchronous motor (PMLSM) without position sensor is realized. The simulation results show that the maximum error of velocity estimation is 2×10-3m/s，and the maximum error of position estimation is -3×10-5rad. PMLSM control system based on the adaptive Luenberger observer has good tracking performance and antiinterference performance.
Traditional position sensorless control systems generally adopt PI regulator for position information processing. A new adaptive Luenberger observer is proposed to solve the drawbacks of PI regulator such as parameter setting, poor tracking performance and weak interference suppression ability. This method uses pulsating high frequency current injection method to obtain the high frequency pulse vibration position signal, and then establishes Luenberger observer for speed and load disturbances according to the dynamic equation of the motor. Neural network is adopted to build the autotuning parameters controller for replacing the PID controller in Luenberger observer. The control of permanent magnet linear synchronous motor (PMLSM) without position sensor is realized. The simulation results show that the maximum error of velocity estimation is 2×10-3m/s，and the maximum error of position estimation is -3×10-5rad. PMLSM control system based on the adaptive Luenberger observer has good tracking performance and antiinterference performance.
2020, 47(4):30-34.
DOI: 10.12177/emca.2019.168
Abstract:
In order to improve the control performance of brushless DC motor (BLDCM), a new integral separation PID control algorithm based on traditional PID control method is proposed. The new integral separation PID control algorithm is applied to BLDCM speed and current closedloop control. The control method not only has strong antiloaddisturbance ability, but also can effectively solve the problem existing in traditional PID control that system oscillation may occur when the control quantity of the system exceeds that of the controlled object. The new integral separation PID control algorithm combines the advantages of the integral separation PID control algorithm and the PID control algorithm with dead zone. It can not only prolong the service life of the control system, but also limit the system deviation. The effectiveness and practicability of the proposed method are verified by MATLAB/Simulink simulation and experiment.
In order to improve the control performance of brushless DC motor (BLDCM), a new integral separation PID control algorithm based on traditional PID control method is proposed. The new integral separation PID control algorithm is applied to BLDCM speed and current closedloop control. The control method not only has strong antiloaddisturbance ability, but also can effectively solve the problem existing in traditional PID control that system oscillation may occur when the control quantity of the system exceeds that of the controlled object. The new integral separation PID control algorithm combines the advantages of the integral separation PID control algorithm and the PID control algorithm with dead zone. It can not only prolong the service life of the control system, but also limit the system deviation. The effectiveness and practicability of the proposed method are verified by MATLAB/Simulink simulation and experiment.
2020, 47(4):35-39.
DOI: 10.12177/emca.2019.185
Abstract:
With the advantages of high power density, high efficiency, high controllability, and low noise, brushless DC motors (BLDCMs) are especially suitable for mini unmanned underwater vehicle (UUV) whose interior space is strictly limited. Hardware miniaturization design is carried out for the power drive system of mini UUV. On the premise of meeting the power requirements, the integrated functional chips are used to reduce the space of functional module to achieve the compactness of the control circuits and drive circuits of the system. It is verified by experiments that the speed control accuracy and load performance of the drive control system with satisfactory compactness can meet the requirements of the mini UUV.
With the advantages of high power density, high efficiency, high controllability, and low noise, brushless DC motors (BLDCMs) are especially suitable for mini unmanned underwater vehicle (UUV) whose interior space is strictly limited. Hardware miniaturization design is carried out for the power drive system of mini UUV. On the premise of meeting the power requirements, the integrated functional chips are used to reduce the space of functional module to achieve the compactness of the control circuits and drive circuits of the system. It is verified by experiments that the speed control accuracy and load performance of the drive control system with satisfactory compactness can meet the requirements of the mini UUV.
2020, 47(4):40-43.
DOI: 10.12177/emca.2019.184
Abstract:
The traditional offline inertia identification methods have low calculation accuracy and limited application occasions. Aiming at this problem, an improved off-line inertia identification method is proposed. Acceleration and deceleration programming with the torque calculation method is introduced into the identification process, and the effects of friction and load are eliminated, so that the accuracy of identification results is improved. A calculation model is established for the offline inertia identification of servo system. The proposed method is experimentally verified. The results show that this method can effectively improve the identification accuracy, and it also applies to the loaded case.
The traditional offline inertia identification methods have low calculation accuracy and limited application occasions. Aiming at this problem, an improved off-line inertia identification method is proposed. Acceleration and deceleration programming with the torque calculation method is introduced into the identification process, and the effects of friction and load are eliminated, so that the accuracy of identification results is improved. A calculation model is established for the offline inertia identification of servo system. The proposed method is experimentally verified. The results show that this method can effectively improve the identification accuracy, and it also applies to the loaded case.
2020, 47(4):44-48.
DOI: 10.12177/emca.2019.167
Abstract:
Aiming at online identification of permanent magnet synchronous motor (PMSM) parameters, a small speed disturbance injection method based on forgetting factor recursive least square (FFRLS) is proposed for online identifying both electrical and mechanical parameters of PMSM. The estimation can be separated into two parts. Electrical parameters such as stator resistance, inductance and flux linkage can be identified in real time by using FFRLS. Considering the operation condition of a constant speed, it is hard to identify the rotational inertia online because the derivative of angular velocity is nearly zero. To solve the problem, the small speed disturbance injection method is used to identify the mechanical parameters. Simulation results show that the proposed method can identify the electrical and mechanical parameters of PMSM accurately and rapidly.
Aiming at online identification of permanent magnet synchronous motor (PMSM) parameters, a small speed disturbance injection method based on forgetting factor recursive least square (FFRLS) is proposed for online identifying both electrical and mechanical parameters of PMSM. The estimation can be separated into two parts. Electrical parameters such as stator resistance, inductance and flux linkage can be identified in real time by using FFRLS. Considering the operation condition of a constant speed, it is hard to identify the rotational inertia online because the derivative of angular velocity is nearly zero. To solve the problem, the small speed disturbance injection method is used to identify the mechanical parameters. Simulation results show that the proposed method can identify the electrical and mechanical parameters of PMSM accurately and rapidly.
2020, 47(4):49-53.
DOI: 10.12177/emca.2019.179
Abstract:
Space vector pulse width modulation (SVPWM) and selected harmonic elimination PWM (SHEPWM) are applied simultaneously in the PWM process of AC speed regulation system. SVPWM is adopted at low frequency and SHEPWM is used at medium frequency. This hybrid modulation method avoids the problems of large storage of SHEPWM at low frequency and variation of SVPWM harmonic characteristics at medium frequency. A zerocrossing point switching method is proposed for harmonic current switching, which guarantees the smooth transition of switching angle number from 5 to 1 in SHEPWM technology. In the switching process from SHEPWM to SVPWM, a reference voltage vector inphase switching method is adopted to achieve smooth transition. Simulation results prove the validity of the theory.
Space vector pulse width modulation (SVPWM) and selected harmonic elimination PWM (SHEPWM) are applied simultaneously in the PWM process of AC speed regulation system. SVPWM is adopted at low frequency and SHEPWM is used at medium frequency. This hybrid modulation method avoids the problems of large storage of SHEPWM at low frequency and variation of SVPWM harmonic characteristics at medium frequency. A zerocrossing point switching method is proposed for harmonic current switching, which guarantees the smooth transition of switching angle number from 5 to 1 in SHEPWM technology. In the switching process from SHEPWM to SVPWM, a reference voltage vector inphase switching method is adopted to achieve smooth transition. Simulation results prove the validity of the theory.
2020, 47(4):54-58.
DOI: 10.12177/emca.2019.183
Abstract:
A standing wave type ultrasonic motor working on radial vibration mode is studied. Firstly, the structure of the motor is analyzed. Secondly, a finite element model of the stator is built with finite element analysis software ANSYS. The impacts of piezoelectric ceramic structural parameters on the vibration characteristics of the stator are investigated based on the finite element model. The structural parameters of the stator is determined. Transient response of the stator is further analyzed. Finally, a prototype motor is manufactured according to the theoretical results. Experimental tests are conducted on the prototype motor. The test results show that the designed motor has good output performances.
A standing wave type ultrasonic motor working on radial vibration mode is studied. Firstly, the structure of the motor is analyzed. Secondly, a finite element model of the stator is built with finite element analysis software ANSYS. The impacts of piezoelectric ceramic structural parameters on the vibration characteristics of the stator are investigated based on the finite element model. The structural parameters of the stator is determined. Transient response of the stator is further analyzed. Finally, a prototype motor is manufactured according to the theoretical results. Experimental tests are conducted on the prototype motor. The test results show that the designed motor has good output performances.
2020, 47(4):59-63.
DOI: 10.12177/emca.2019.191
Abstract:
A high-voltage high-efficiency tube flameproof type threephase asynchronous motor is designed. The design advantages of the whole structure and the stator, frame, rotor, fan, bearing and junction box of the motor are introduced. The motor design shows innovation in the aspects of efficiency, circumferential eccentric tube arrangement, high strength flameproof parts, shaft through winding, thin oil lubricated rolling bearing, high protection, low vibration, low noise, etc. The advancement of the designed motor is proved by analyzing the test data of the product prototype.
A high-voltage high-efficiency tube flameproof type threephase asynchronous motor is designed. The design advantages of the whole structure and the stator, frame, rotor, fan, bearing and junction box of the motor are introduced. The motor design shows innovation in the aspects of efficiency, circumferential eccentric tube arrangement, high strength flameproof parts, shaft through winding, thin oil lubricated rolling bearing, high protection, low vibration, low noise, etc. The advancement of the designed motor is proved by analyzing the test data of the product prototype.
2020, 47(4):64-70.
DOI: 10.12177/emca.2020.006
Abstract:
Aiming at the problems of low efficiency andlow power factor of the motor in the permanent magnet synchronous power generation system of diesel locomotive, the maximum torque per ampere (MTPA) control strategy is adopted to control the traction converter, and the MTPA control under the limitation of voltage limit ellipse is analyzed. The power angle, power factor and efficiency are compared under the unity power factor control and id=0 control strategies. The simulation and comparison analysis shows that the speed regulation range of the id=0 control is very narrow, the unity power factor control is unstable at high speeds, while the MTPA control can run stably in the full speed range. Furthermore, the power factor and efficiency of the permanent magnet synchronous generator are improved with MTPA control，and the stability of the system is improved.
Aiming at the problems of low efficiency andlow power factor of the motor in the permanent magnet synchronous power generation system of diesel locomotive, the maximum torque per ampere (MTPA) control strategy is adopted to control the traction converter, and the MTPA control under the limitation of voltage limit ellipse is analyzed. The power angle, power factor and efficiency are compared under the unity power factor control and id=0 control strategies. The simulation and comparison analysis shows that the speed regulation range of the id=0 control is very narrow, the unity power factor control is unstable at high speeds, while the MTPA control can run stably in the full speed range. Furthermore, the power factor and efficiency of the permanent magnet synchronous generator are improved with MTPA control，and the stability of the system is improved.
2020, 47(4):71-76.
DOI: 10.12177/emca.2019.181
Abstract:
Torque fluctuation coefficient is an important index to measure the quality of brushless torque motor. In the process of development and production of motors, the measured value of the torque fluctuation coefficient of the prototype is higher than the designed value. Through the prototype test and simulation, the causes of the difference are analyzed from the aspects of winding coil, three-phase currents, and eccentricity of stator and rotor in the production process of the prototype. The results show that eccentricity is the main reason for the measured value to be higher than the designed value, while three-phase current and winding coil have less effects on the difference. By optimizing the structure design of the motor to reduce the eccentricity of stator and rotor and correcting the design value according to the torque fluctuation caused by the eccentricity, the consistency between the design value and the measured value can be improved.
Torque fluctuation coefficient is an important index to measure the quality of brushless torque motor. In the process of development and production of motors, the measured value of the torque fluctuation coefficient of the prototype is higher than the designed value. Through the prototype test and simulation, the causes of the difference are analyzed from the aspects of winding coil, three-phase currents, and eccentricity of stator and rotor in the production process of the prototype. The results show that eccentricity is the main reason for the measured value to be higher than the designed value, while three-phase current and winding coil have less effects on the difference. By optimizing the structure design of the motor to reduce the eccentricity of stator and rotor and correcting the design value according to the torque fluctuation caused by the eccentricity, the consistency between the design value and the measured value can be improved.
2020, 47(4):77-80.
DOI: 10.12177/emca.2019.182
Abstract:
Permanent magnet roller eddy current sorter is an important device for extracting metal slag at the fire site, but the existing sorting equipment has problems such as low sorting efficiency and large volume and weight, and it needs to be optimized. The magnetic system space of the core components of the sorter is studied. The magnetic system space structure model of the sorter is established. The working principle of the sorter is explained, and the calculation equation of the magnetic system space of the magnetic block for a certain magnetic roller is given. Then, the law of the magnetic induction intensity distribution of the original magnetic system space is analyzed by using the finite element method, and the magnetic induction intensities of the magnetic roller under different outer diameters, different inner diameters, and different iron ring thicknesses are compared. An optimization design scheme for the original eddy current sorter is proposed, which reduces the weight and improves the efficiency of the sorter.
Permanent magnet roller eddy current sorter is an important device for extracting metal slag at the fire site, but the existing sorting equipment has problems such as low sorting efficiency and large volume and weight, and it needs to be optimized. The magnetic system space of the core components of the sorter is studied. The magnetic system space structure model of the sorter is established. The working principle of the sorter is explained, and the calculation equation of the magnetic system space of the magnetic block for a certain magnetic roller is given. Then, the law of the magnetic induction intensity distribution of the original magnetic system space is analyzed by using the finite element method, and the magnetic induction intensities of the magnetic roller under different outer diameters, different inner diameters, and different iron ring thicknesses are compared. An optimization design scheme for the original eddy current sorter is proposed, which reduces the weight and improves the efficiency of the sorter.
2020, 47(4):81-86.
DOI: 10.12177/emca.2019.189
Abstract:
In order to study the fluid flow and heat transfer characteristics in a megawatt wind power generator, based on the basic principles of computational fluid dynamics (CFD) and numerical heat transfer (NHT), the finite volume method is used to model the generator, and the flow and temperature fields are calculated numerically. The correctness and accuracy of the calculation method are verified by comparing the calculation results with the experimental data. The temperature field of the internal flow field of the generator is analyzed, and the flow characteristics of the cooling medium of the megawatt wind power generator are revealed. Based on the analysis, the generator ventilation duct layout scheme is optimized, effectively reducing the temperature rise at the generator hot spots.
In order to study the fluid flow and heat transfer characteristics in a megawatt wind power generator, based on the basic principles of computational fluid dynamics (CFD) and numerical heat transfer (NHT), the finite volume method is used to model the generator, and the flow and temperature fields are calculated numerically. The correctness and accuracy of the calculation method are verified by comparing the calculation results with the experimental data. The temperature field of the internal flow field of the generator is analyzed, and the flow characteristics of the cooling medium of the megawatt wind power generator are revealed. Based on the analysis, the generator ventilation duct layout scheme is optimized, effectively reducing the temperature rise at the generator hot spots.
2020, 47(4):87-91.
DOI: 10.12177/emca.2019.188
Abstract:
Aiming at extending the output speed range of fourphase switched reluctance motors, a new asymmetric Ttype power converter is proposed. The power converter is composed of modified Ttype threelevel converters and auxiliary circuits. Ttype converter is a multilevel converter which can provide more flexible phase control. The DClink capacitors in the auxiliary circuits are used for voltage level clamping as well as DC voltageboosting capacitors to produce additional voltage during the rise and fall period of a motor phase current. The operation and analysis are detailed for different operation modes. Comparisons are made between the proposed converter and diode neutralpoint clamped (NPC) multilevel converters on efficiency and cost. The simulation results show that the proposed new Ttype power converter increases both speed and output power, improves the efficiency of SRM system, and is suitable for high speed applications.
Aiming at extending the output speed range of fourphase switched reluctance motors, a new asymmetric Ttype power converter is proposed. The power converter is composed of modified Ttype threelevel converters and auxiliary circuits. Ttype converter is a multilevel converter which can provide more flexible phase control. The DClink capacitors in the auxiliary circuits are used for voltage level clamping as well as DC voltageboosting capacitors to produce additional voltage during the rise and fall period of a motor phase current. The operation and analysis are detailed for different operation modes. Comparisons are made between the proposed converter and diode neutralpoint clamped (NPC) multilevel converters on efficiency and cost. The simulation results show that the proposed new Ttype power converter increases both speed and output power, improves the efficiency of SRM system, and is suitable for high speed applications.
2020, 47(4):92-96.
DOI: 10.12177/emca.2020.003
Abstract:
Heavy-duty automated guided vehicles (AGVs) are widely used in intelligent manufacturing, but most of them are less flexible. An omni-directional AGV composed of eight Mecanum wheels, DC servo motor, DC servo motor drives and retarding mechanism is designed. The weighing capability of the eight wheels is strong, which solves the weighing problem. The characteristics of the Mecanum wheel makes movement more flexible. CANopen is used for the control and information acquisition of DC servo drivers. Through the kinematics calculation of the Mecanum wheels, the speed of each wheel can be obtained, so as to realize high precision control of the AGV.
Heavy-duty automated guided vehicles (AGVs) are widely used in intelligent manufacturing, but most of them are less flexible. An omni-directional AGV composed of eight Mecanum wheels, DC servo motor, DC servo motor drives and retarding mechanism is designed. The weighing capability of the eight wheels is strong, which solves the weighing problem. The characteristics of the Mecanum wheel makes movement more flexible. CANopen is used for the control and information acquisition of DC servo drivers. Through the kinematics calculation of the Mecanum wheels, the speed of each wheel can be obtained, so as to realize high precision control of the AGV.
2020, 47(4):97-102.
DOI: 10.12177/emca.2019.187
Abstract:
48 V i-BSG(intelligent belt driven starter generator) motor is one of the core parts in hybrid vehicle system. It has comprehensive functions of starting, generating, energy recovering and power assisting. Therefore, it can improve performance of low speed region of engine，which makes vehicle get better performance of emission and better fuel economy. In order to achieve excellent performance indicators, the design of motor’s electromagnetism is optimized with the finite element software. The motor working model and control strategy are expounded in detail. A motor prototype is manufactured and successfully passes the test verification. The results of experiment show that the motor can realize the design objectives. Compared with Valeo’s motor, it has the advantages of small volume and low cost, which lays a solid foundation for marketing.
48 V i-BSG(intelligent belt driven starter generator) motor is one of the core parts in hybrid vehicle system. It has comprehensive functions of starting, generating, energy recovering and power assisting. Therefore, it can improve performance of low speed region of engine，which makes vehicle get better performance of emission and better fuel economy. In order to achieve excellent performance indicators, the design of motor’s electromagnetism is optimized with the finite element software. The motor working model and control strategy are expounded in detail. A motor prototype is manufactured and successfully passes the test verification. The results of experiment show that the motor can realize the design objectives. Compared with Valeo’s motor, it has the advantages of small volume and low cost, which lays a solid foundation for marketing.
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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.
