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Volume 46,Issue 8,2019 Table of Contents
2019, 46(8):1-10, 30.
Abstract:
In recent years, the theory and technology of model predictive control (MPC) had been greatly developed, enjoying a wide application prospect. Basic principles of MPC were summarized. Current research situation of MPC technology in the motor system was briefly compared and analyzed. The control scheme of finite control set model predictive control (FCSMPC) applied in the field of motor drive was researched. The research ideas of FCSMPC were summarized on several aspects such as value function design, reduction of computation, vector action number and improvement of robustness. In the end, some new ideas and new trends were recommended to be studied on the technology of FCSMPC for further research.
In recent years, the theory and technology of model predictive control (MPC) had been greatly developed, enjoying a wide application prospect. Basic principles of MPC were summarized. Current research situation of MPC technology in the motor system was briefly compared and analyzed. The control scheme of finite control set model predictive control (FCSMPC) applied in the field of motor drive was researched. The research ideas of FCSMPC were summarized on several aspects such as value function design, reduction of computation, vector action number and improvement of robustness. In the end, some new ideas and new trends were recommended to be studied on the technology of FCSMPC for further research.
2 Application and Development of Model Predictive Control in PermanentMagnet Synchronous Motor System
2019, 46(8):11-17.
Abstract:
With the development of digital technology, the model predictive control (MPC) has been widely used in AC drive systems. Firstly, the principles of classical MPC strategies including finite control set MPC strategy and continuous control set MPC strategy were described. Secondly, the research status of the common improved MPC was summarized, such as multistep predictive control, multivector predictive control, predictive control with parameter robustness, generalized model prediction and explicit model prediction, and the relevant research ideas were put forward. Finally, according to the application requirements and research status of MPC, the future research directions that needed to be further deepened and expanded were prospected.
With the development of digital technology, the model predictive control (MPC) has been widely used in AC drive systems. Firstly, the principles of classical MPC strategies including finite control set MPC strategy and continuous control set MPC strategy were described. Secondly, the research status of the common improved MPC was summarized, such as multistep predictive control, multivector predictive control, predictive control with parameter robustness, generalized model prediction and explicit model prediction, and the relevant research ideas were put forward. Finally, according to the application requirements and research status of MPC, the future research directions that needed to be further deepened and expanded were prospected.
2019, 46(8):18-23, 58.
Abstract:
In the direct thrust control system of permanent magnet linear synchronous motor (PMLSM), it was difficult for traditional mechanical sensors to accurately obtain the feedback information of the control system under harsh conditions. The model reference adaptive algorithm was applied to PMLSM. A speed sensorless direct thrust control system based on model reference adaptive system (MRAS) was designed, and a flux linkage observer was reconstructed according to the identified flux position. The flux linkage was compensated to reduce the fluctuation of thrust response of direct thrust control. The simulation results showed that the sensorless PMLSM direct thrust control system based on MRAS and flux compensation could accurately identify the primary speed and position information, and obtain better dynamic and static performance.
In the direct thrust control system of permanent magnet linear synchronous motor (PMLSM), it was difficult for traditional mechanical sensors to accurately obtain the feedback information of the control system under harsh conditions. The model reference adaptive algorithm was applied to PMLSM. A speed sensorless direct thrust control system based on model reference adaptive system (MRAS) was designed, and a flux linkage observer was reconstructed according to the identified flux position. The flux linkage was compensated to reduce the fluctuation of thrust response of direct thrust control. The simulation results showed that the sensorless PMLSM direct thrust control system based on MRAS and flux compensation could accurately identify the primary speed and position information, and obtain better dynamic and static performance.
4 Method of Dead Time Compensation for Permanent Magnet Traction MotorBased on Adaptive Notch Filter
2019, 46(8):24-30.
Abstract:
In train traction inverter, to prevent simultaneous breakover of the up and down switches, dead time should be added in the turnon time of the switch. The fifth and seventh current harmonics would be produced by permanent magnet synchronous motor (PMSM). Obviously, it was necessary to study the suppression of harmonics. Firstly, the fifth and seventh harmonics caused by dead time were analyzed. Secondly, the adaptive notch filter was used to extract the harmonic components of the current to compensate the dead time, and the stability was analyzed. Finally, the effectiveness of the proposed method was verified on the MATLAB/Simulink platform.
In train traction inverter, to prevent simultaneous breakover of the up and down switches, dead time should be added in the turnon time of the switch. The fifth and seventh current harmonics would be produced by permanent magnet synchronous motor (PMSM). Obviously, it was necessary to study the suppression of harmonics. Firstly, the fifth and seventh harmonics caused by dead time were analyzed. Secondly, the adaptive notch filter was used to extract the harmonic components of the current to compensate the dead time, and the stability was analyzed. Finally, the effectiveness of the proposed method was verified on the MATLAB/Simulink platform.
2019, 46(8):31-36.
Abstract:
Due to the strong nonlinearity of the servo drive, the stator current of permanent magnet synchronous motor (PMSM) contained a large number of higher harmonics and caused a large torque ripple. To solve this problem, a harmonic suppression method based on cascaded secondorder generalized integrator (SOGI) was proposed. Cascaded SOGI was parallel to current loop dqaxis PI controllers. The sixth harmonic component of dqaxis current was extracted by cascaded SOGI and injected into the output voltage of PI controllers, which could offset the harmonic in reference voltage. The simulation results showed that the distortion of current waveform had been greatly reduced by using voltage compensation method based on cascaded SOGI, which confirmed the effectiveness of the algorithm.
Due to the strong nonlinearity of the servo drive, the stator current of permanent magnet synchronous motor (PMSM) contained a large number of higher harmonics and caused a large torque ripple. To solve this problem, a harmonic suppression method based on cascaded secondorder generalized integrator (SOGI) was proposed. Cascaded SOGI was parallel to current loop dqaxis PI controllers. The sixth harmonic component of dqaxis current was extracted by cascaded SOGI and injected into the output voltage of PI controllers, which could offset the harmonic in reference voltage. The simulation results showed that the distortion of current waveform had been greatly reduced by using voltage compensation method based on cascaded SOGI, which confirmed the effectiveness of the algorithm.
2019, 46(8):37-40, 46.
Abstract:
Due to deadtime effect, the output of voltage source inverter was nonnormalized and deformed. Deadtime effect affected the control accuracy of induction motor, especially for the speed sensorless vector control. It also caused the loss of power on the grid side. In order to reduce the influence of deadtime effect, the output voltage error calculation formula was listed to find out the total delay time. In addition, adaptive identification of stator resistance was carried out to increase the accuracy of delay time, which could apply to motor vector control as well. By compensating the error voltage, the control performance was improved and the influence on the control system was reduced. The results showed that the compensation strategy could improve the current waveform and total harmonic distortion.
Due to deadtime effect, the output of voltage source inverter was nonnormalized and deformed. Deadtime effect affected the control accuracy of induction motor, especially for the speed sensorless vector control. It also caused the loss of power on the grid side. In order to reduce the influence of deadtime effect, the output voltage error calculation formula was listed to find out the total delay time. In addition, adaptive identification of stator resistance was carried out to increase the accuracy of delay time, which could apply to motor vector control as well. By compensating the error voltage, the control performance was improved and the influence on the control system was reduced. The results showed that the compensation strategy could improve the current waveform and total harmonic distortion.
2019, 46(8):41-46.
Abstract:
In view of the fact that the simplified flux linkage method of switched reluctance motor (SRM) could only realize singlephase online operation and the conduction interval was fixed, a sensorless control technology combining fixed turnoff angle and adaptive adjustment of turnon angle was proposed. Using the curvefitting turnoff position flux to replace the traditional stored data table, the turnoff position signal and the estimated speed and other positions were determined by comparing the realtime calculated dynamic flux linkage and the curvefitted static flux linkage. Considering the nonlinear characteristics of the impedance and inductance of the motor, the conduction interval was determined by optimizing the selfregulating model of the opening angle in the minimum inductance region. The simulation results verified the feasibility and correctness of the scheme, which could realize the indirect detection of rotor position and further optimize the operation efficiency of the motor.
In view of the fact that the simplified flux linkage method of switched reluctance motor (SRM) could only realize singlephase online operation and the conduction interval was fixed, a sensorless control technology combining fixed turnoff angle and adaptive adjustment of turnon angle was proposed. Using the curvefitting turnoff position flux to replace the traditional stored data table, the turnoff position signal and the estimated speed and other positions were determined by comparing the realtime calculated dynamic flux linkage and the curvefitted static flux linkage. Considering the nonlinear characteristics of the impedance and inductance of the motor, the conduction interval was determined by optimizing the selfregulating model of the opening angle in the minimum inductance region. The simulation results verified the feasibility and correctness of the scheme, which could realize the indirect detection of rotor position and further optimize the operation efficiency of the motor.
2019, 46(8):47-54.
Abstract:
In the butanol production by liquid fermentation of straw, in order to achieve highefficiency fermentation, the distribution of the bacteria in the fermentation liquid should be uniform, and the added materials needed to be stirred in time. Due to the large size of the fermenter for industrial production of butanol, the agitation process required a higher output torque of the drive motor. Therefore, a straw fermenter with high efficiency, small volume, low speed and high torque was of great significance for the industrial fermentation of butanol. A statorrotor permanent magnet vernier motor was designed for fermentation liquid agitation. The specific selection of the slotpole combinations of the motor and the electromagnetic performance were studied. A prototype was built and hysteresis control was used to achieve rapid response to liquid fermentation objects, enabling a lowenergy and efficient fermentation process.
In the butanol production by liquid fermentation of straw, in order to achieve highefficiency fermentation, the distribution of the bacteria in the fermentation liquid should be uniform, and the added materials needed to be stirred in time. Due to the large size of the fermenter for industrial production of butanol, the agitation process required a higher output torque of the drive motor. Therefore, a straw fermenter with high efficiency, small volume, low speed and high torque was of great significance for the industrial fermentation of butanol. A statorrotor permanent magnet vernier motor was designed for fermentation liquid agitation. The specific selection of the slotpole combinations of the motor and the electromagnetic performance were studied. A prototype was built and hysteresis control was used to achieve rapid response to liquid fermentation objects, enabling a lowenergy and efficient fermentation process.
2019, 46(8):55-58.
Abstract:
In order to improve the energy efficiency of DC motor starting, the unique rotational speed extremum trajectory in the shape of concave parabola was obtained by using variational method. Simulation verified that the energy efficiency extremum of this was the lowest. To find the optimal energy efficiency trajectory, several other starting trajectories were considered, especially the convex parabola trajectory relative to the variational extremum trajectory, which was proved to have a higher energy efficiency. The simulation also proved that the simple starting method with a constant high current could further improve the energy efficiency of DC motor starting.
In order to improve the energy efficiency of DC motor starting, the unique rotational speed extremum trajectory in the shape of concave parabola was obtained by using variational method. Simulation verified that the energy efficiency extremum of this was the lowest. To find the optimal energy efficiency trajectory, several other starting trajectories were considered, especially the convex parabola trajectory relative to the variational extremum trajectory, which was proved to have a higher energy efficiency. The simulation also proved that the simple starting method with a constant high current could further improve the energy efficiency of DC motor starting.
10 Analysis of Electromagnetic Loss Characteristics of Electric VehicleInWheel Motor Based on Maxwell
2019, 46(8):59-64.
Abstract:
Electric vehicle inwheel motor often operated in complex operating conditions and harsh environments, resulting in constant changes of the current and internal electromagnetic losses of inwheel motor. The serious impact on the motor temperature rise analysis and reliable operation had happened. Taking a 4 kW inwheel motor as an example, using Maxwell electromagnetic finite element analysis software, the electromagnetic finite element model of the inwheel motor was established, and the electromagnetic field was calculated. By choosing eight common working conditions of acceleration and overload, the distribution of electromagnetic losses and the law of numerical variation of each component of inwheel motor were analyzed. From the analysis results, it could be seen that the stator iron loss increased with the increase of rotational speed, but did not change with the increase of overload multiple. The core loss of rotor could be neglected. The eddy current loss of permanent magnet increased with the increase of acceleration and overload at the same time, but the effect of acceleration condition on it was stronger. The copper loss of windings was mainly affected by the change of overload multiple, which accounted for the largest proportion of total loss and was the main heat source. An important reference for the analysis of temperature field and the design of cooling structure of inwheel motor was provided.
Electric vehicle inwheel motor often operated in complex operating conditions and harsh environments, resulting in constant changes of the current and internal electromagnetic losses of inwheel motor. The serious impact on the motor temperature rise analysis and reliable operation had happened. Taking a 4 kW inwheel motor as an example, using Maxwell electromagnetic finite element analysis software, the electromagnetic finite element model of the inwheel motor was established, and the electromagnetic field was calculated. By choosing eight common working conditions of acceleration and overload, the distribution of electromagnetic losses and the law of numerical variation of each component of inwheel motor were analyzed. From the analysis results, it could be seen that the stator iron loss increased with the increase of rotational speed, but did not change with the increase of overload multiple. The core loss of rotor could be neglected. The eddy current loss of permanent magnet increased with the increase of acceleration and overload at the same time, but the effect of acceleration condition on it was stronger. The copper loss of windings was mainly affected by the change of overload multiple, which accounted for the largest proportion of total loss and was the main heat source. An important reference for the analysis of temperature field and the design of cooling structure of inwheel motor was provided.
11 Winding Design Scheme of SingleWinding DoubleSpeed AsynchronousMotor Based on Unified Design Method
2019, 46(8):65-69, 86.
Abstract:
The AC windings of 72slot 8/10pole motor were analyzed and studied by constructing twodimensional slot number diagram and using the unified design method. Two winding design schemes with higher distribution coefficient for 8 poles were obtained. The fundamental phase bandwidths of the two schemes were 60°/165° and 120°/120°, respectively. The reverse pole changing structure YY/Δ was adopted. After calculating the harmonics of the magnetic potential of the windings, the pitch selection of the two windings and the magnetic potential harmonic analysis were performed, and the optimal scheme with high threephase balance and low harmonics was obtained.
The AC windings of 72slot 8/10pole motor were analyzed and studied by constructing twodimensional slot number diagram and using the unified design method. Two winding design schemes with higher distribution coefficient for 8 poles were obtained. The fundamental phase bandwidths of the two schemes were 60°/165° and 120°/120°, respectively. The reverse pole changing structure YY/Δ was adopted. After calculating the harmonics of the magnetic potential of the windings, the pitch selection of the two windings and the magnetic potential harmonic analysis were performed, and the optimal scheme with high threephase balance and low harmonics was obtained.
2019, 46(8):70-75.
Abstract:
YKS series highvoltage and highspeed motor had the characteristics of high single unit capacity and large local temperature rise. A YKS5602 3 000 kW highvoltage and highspeed motor was taken as an example. According to the actual size of the motor, the motor end winding and statorrotor models were established. The finite element method was used to simulate the fluid field and temperature field. The flow of cooling gas in each ventilation slot was calculated during motor operation. The fluidsolid coupling analysis of the whole motor was carried out to obtain the temperature field distribution of the end winding and stator of the highvoltage motor. The simulation results were analyzed and compared with the experimental data. The results showed that the method of coupling the fluid field and temperature field could accurately acquire the gas flow in each ventilation slot of the YKS motor and the local temperature rise distribution in the motor.
YKS series highvoltage and highspeed motor had the characteristics of high single unit capacity and large local temperature rise. A YKS5602 3 000 kW highvoltage and highspeed motor was taken as an example. According to the actual size of the motor, the motor end winding and statorrotor models were established. The finite element method was used to simulate the fluid field and temperature field. The flow of cooling gas in each ventilation slot was calculated during motor operation. The fluidsolid coupling analysis of the whole motor was carried out to obtain the temperature field distribution of the end winding and stator of the highvoltage motor. The simulation results were analyzed and compared with the experimental data. The results showed that the method of coupling the fluid field and temperature field could accurately acquire the gas flow in each ventilation slot of the YKS motor and the local temperature rise distribution in the motor.
2019, 46(8):76-81.
Abstract:
As an important part of the flywheel system, magnetic bearings (MBs) worked in a vacuum environment with poor heat dissipation and high temperature, which would seriously affect the operation and reliability of the flywheel system. The loss of hybrid magnetic bearing (HMB) for flywheel energy storage was analyzed. Based on this, the 3D thermal model of HMB was established by using ANSYS finite element software. The losses of the MBs under different operating conditions were introduced into the temperature field as heat source. The temperature distribution of the MBs under different operating conditions was obtained, which provided an important basis for the design and temperature rise control of the MBs.
As an important part of the flywheel system, magnetic bearings (MBs) worked in a vacuum environment with poor heat dissipation and high temperature, which would seriously affect the operation and reliability of the flywheel system. The loss of hybrid magnetic bearing (HMB) for flywheel energy storage was analyzed. Based on this, the 3D thermal model of HMB was established by using ANSYS finite element software. The losses of the MBs under different operating conditions were introduced into the temperature field as heat source. The temperature distribution of the MBs under different operating conditions was obtained, which provided an important basis for the design and temperature rise control of the MBs.
2019, 46(8):82-86.
Abstract:
Compared with traditional threephase inverters, highpower multiphase variable frequency drive system could reduce the voltage by increasing the number of phases under the condition of unchanged power. It could speed flying start in a very short period of time, and operate under grid connection and bypass modes in the absence of under phase loss. The whole system had the advantages of safety and reliability, high system efficiency, low vibration, low noise, low cost, energy saving and environmental protection. The topology structure of starshaped multiphase variable frequency drive system with highlow voltage conversion was described in detail, and the parameters and structure of highpower multiphase variable frequency drive system were designed. Through the test and verification of the engineering prototype, the advantages nature of the product were proved based on data analysis, test results and field operation.
Compared with traditional threephase inverters, highpower multiphase variable frequency drive system could reduce the voltage by increasing the number of phases under the condition of unchanged power. It could speed flying start in a very short period of time, and operate under grid connection and bypass modes in the absence of under phase loss. The whole system had the advantages of safety and reliability, high system efficiency, low vibration, low noise, low cost, energy saving and environmental protection. The topology structure of starshaped multiphase variable frequency drive system with highlow voltage conversion was described in detail, and the parameters and structure of highpower multiphase variable frequency drive system were designed. Through the test and verification of the engineering prototype, the advantages nature of the product were proved based on data analysis, test results and field operation.
2019, 46(8):87-95, 109.
Abstract:
The foreign and domestic technology research and industry application status of permanent magnet synchronous traction system for rail transit field were introduced, involving highspeed train, light rail, subway and so on. The technology advantages, risk analysis and preventive measures of permanent magnet synchronous traction system were demonstrated. The design ideas, key technology and analysis simulation test for prototype design of permanent synchronous traction system were described in detail using CRH5 as prototype. Ground joint test and loading assessment results showed that the system core technologies such as traction control unit, auxiliary control unit and control algorithm were safe and reliable, and the system efficiency was improved by above 3%.
The foreign and domestic technology research and industry application status of permanent magnet synchronous traction system for rail transit field were introduced, involving highspeed train, light rail, subway and so on. The technology advantages, risk analysis and preventive measures of permanent magnet synchronous traction system were demonstrated. The design ideas, key technology and analysis simulation test for prototype design of permanent synchronous traction system were described in detail using CRH5 as prototype. Ground joint test and loading assessment results showed that the system core technologies such as traction control unit, auxiliary control unit and control algorithm were safe and reliable, and the system efficiency was improved by above 3%.
2019, 46(8):96-104.
Abstract:
When a threephase shortcircuit fault occured on the ship shaft with a brushless doublyfed generator (BDFG), the shortcircuit current would cause a great hazard to the system. Therefore, it was necessary to design a special protection circuit to ensure the safety of the system. Based on the space rotating coordinate system, the dynamic equation of the threephase short circuit on the power winding of the ship shaft with BDFG was established, and the variation characteristics of the system shortcircuit current were studied according to the law of magnetic flux conservation by analyzing the components of the shortcircuit current. It was proposed to add the crowbar resistor and the DC unloading circuit to unload the overcurrent, and the current variation characteristics were further studied after adding the protection circuit. A 30 kVA BDFG was used as the simulation object. Model simulation and theoretical value calculation were carried out by MATLAB/Simulink. The effectiveness of the protection circuit was verified. It was instructive for the electrical safety design of the ship shaft with BDFG.
When a threephase shortcircuit fault occured on the ship shaft with a brushless doublyfed generator (BDFG), the shortcircuit current would cause a great hazard to the system. Therefore, it was necessary to design a special protection circuit to ensure the safety of the system. Based on the space rotating coordinate system, the dynamic equation of the threephase short circuit on the power winding of the ship shaft with BDFG was established, and the variation characteristics of the system shortcircuit current were studied according to the law of magnetic flux conservation by analyzing the components of the shortcircuit current. It was proposed to add the crowbar resistor and the DC unloading circuit to unload the overcurrent, and the current variation characteristics were further studied after adding the protection circuit. A 30 kVA BDFG was used as the simulation object. Model simulation and theoretical value calculation were carried out by MATLAB/Simulink. The effectiveness of the protection circuit was verified. It was instructive for the electrical safety design of the ship shaft with BDFG.
2019, 46(8):105-109.
Abstract:
The running characteristics and controller output characteristics of permanent magnet synchronous motor (PMSM) for electric vehicle were introduced. According to the technical conditions and test methods specified in GB/T 18488-2015 “drive motor system for electric vehicle”, the online inspection process for electric vehicle PMSM was designed in combination with the production process planning of PMSM for electric vehicle. On this basis, the online performance inspection system for electric vehicle PMSM was designed, and the advanced frequency conversion measurement technology and computer control measurement technology were applied in the system. Experimental results showed that the system was accurate, stable, easy to operate and highly automatic, and had high design reference value.
The running characteristics and controller output characteristics of permanent magnet synchronous motor (PMSM) for electric vehicle were introduced. According to the technical conditions and test methods specified in GB/T 18488-2015 “drive motor system for electric vehicle”, the online inspection process for electric vehicle PMSM was designed in combination with the production process planning of PMSM for electric vehicle. On this basis, the online performance inspection system for electric vehicle PMSM was designed, and the advanced frequency conversion measurement technology and computer control measurement technology were applied in the system. Experimental results showed that the system was accurate, stable, easy to operate and highly automatic, and had high design reference value.
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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.
