Pub Date : 2023-09-01DOI: 10.30941/CESTEMS.2023.00051
THE rapid growth of new energy vehicles is accelerating the low-carbon transition in the global transportation sector. According to the international energy agency report, more than 10 million electric vehicles (EVs) including pure electric and hybrid models were sold worldwide in 2022, which means that the global share of electric vehicles in the overall automotive market has risen from less than 5% in 2020 to 14% in 2022. Adoption of these 10 million EVs has reduced greenhouse emissions by a net amount of about 80 million tons. Along with rapid deployment of battery charging and swapping stations, it is expected for EVs to reduce oil demand by at least 5 million barrels per day and more CO2 emissions by EVs in 2030.
{"title":"Message from Editors","authors":"","doi":"10.30941/CESTEMS.2023.00051","DOIUrl":"https://doi.org/10.30941/CESTEMS.2023.00051","url":null,"abstract":"THE rapid growth of new energy vehicles is accelerating the low-carbon transition in the global transportation sector. According to the international energy agency report, more than 10 million electric vehicles (EVs) including pure electric and hybrid models were sold worldwide in 2022, which means that the global share of electric vehicles in the overall automotive market has risen from less than 5% in 2020 to 14% in 2022. Adoption of these 10 million EVs has reduced greenhouse emissions by a net amount of about 80 million tons. Along with rapid deployment of battery charging and swapping stations, it is expected for EVs to reduce oil demand by at least 5 million barrels per day and more CO2 emissions by EVs in 2030.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873789/10272303/10272306.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68150013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Axial-flux magnetic-geared machine (MGM) is a promising solution for electric vehicle applications for combining the virtues of both axial-flux electric machine and magnetic gear. However, generalized MGMs are limited by the torque density issue, accordingly inapplicable to industrial applications. To solve the abovementioned issue, an improved axial-flux magnetic-geared machine with a dual-winding design is proposed. The key merit of the proposed design is to achieve enhanced torque performance and space utilization with the proposed design, which installs a set of auxiliary winding between modulation rings. With the proposed design, overload protection capability, and fault-tolerant capability can be also achieved, for the proposed machine can work with either the excitation of armature windings or auxiliary windings. The pole-pair, slot combination, and parametric design is studied and optimized by the 3d finite-element method and designed C++ optimization software. Electromagnetic analysis and performance comparison indicate that the proposed machine can achieve a torque enhancement of 68.6% compared to the comparison machine.
{"title":"An Enhanced Axial-Flux Magnetic-Geared Machine with Dual-Winding Design for Electric Vehicle Applications","authors":"Weinong Fu;Qinying Wu;Shuangxia Niu;Yuanxi Chen;Xinhua Guo","doi":"10.30941/CESTEMS.2023.00047","DOIUrl":"https://doi.org/10.30941/CESTEMS.2023.00047","url":null,"abstract":"Axial-flux magnetic-geared machine (MGM) is a promising solution for electric vehicle applications for combining the virtues of both axial-flux electric machine and magnetic gear. However, generalized MGMs are limited by the torque density issue, accordingly inapplicable to industrial applications. To solve the abovementioned issue, an improved axial-flux magnetic-geared machine with a dual-winding design is proposed. The key merit of the proposed design is to achieve enhanced torque performance and space utilization with the proposed design, which installs a set of auxiliary winding between modulation rings. With the proposed design, overload protection capability, and fault-tolerant capability can be also achieved, for the proposed machine can work with either the excitation of armature windings or auxiliary windings. The pole-pair, slot combination, and parametric design is studied and optimized by the 3d finite-element method and designed C++ optimization software. Electromagnetic analysis and performance comparison indicate that the proposed machine can achieve a torque enhancement of 68.6% compared to the comparison machine.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873789/10272303/10272304.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68150012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.30941/CESTEMS.2023.00049
Yixuan Shuai;Dong Jiang;Zhuo Chen;Zicheng Liu;Haijing Sun;Peng Li
In traction application, speed range of motor is an important index for motor drives. In AC motor control, the maximum speed of the motor is limited by the output voltage capability of the traditional three-phase inverter with star connenction of windings. Switching the star connection to delta connection in high-speed range can extend the speed range. In order to extend the speed operation region, star-delta switch proposed by many literatures relies on mechanical relay, which needs a dead zone of tens of milliseconds and seriously affects torque output. Besides, the traditional method will cause current overshoot during the switch transient process, decreasing the device security and reliability. Aiming at the defects existing in the star-delta hard switching, this paper proposes a star-delta soft switching method. Without adding extra power electronics devices, DC-bus capacitor is used to provide the path of zero axis current in the transient process, which helps to achieve the smooth torque output and zero current switch in the transient. Experiments have been done to validate the performance of the proposed method. The switching transient from star to delta connection in the motor drive can be much more stable than hard switching method.
{"title":"Study of Star-Delta Soft Switch to Extend AC Motor High Speed Operation Region","authors":"Yixuan Shuai;Dong Jiang;Zhuo Chen;Zicheng Liu;Haijing Sun;Peng Li","doi":"10.30941/CESTEMS.2023.00049","DOIUrl":"https://doi.org/10.30941/CESTEMS.2023.00049","url":null,"abstract":"In traction application, speed range of motor is an important index for motor drives. In AC motor control, the maximum speed of the motor is limited by the output voltage capability of the traditional three-phase inverter with star connenction of windings. Switching the star connection to delta connection in high-speed range can extend the speed range. In order to extend the speed operation region, star-delta switch proposed by many literatures relies on mechanical relay, which needs a dead zone of tens of milliseconds and seriously affects torque output. Besides, the traditional method will cause current overshoot during the switch transient process, decreasing the device security and reliability. Aiming at the defects existing in the star-delta hard switching, this paper proposes a star-delta soft switching method. Without adding extra power electronics devices, DC-bus capacitor is used to provide the path of zero axis current in the transient process, which helps to achieve the smooth torque output and zero current switch in the transient. Experiments have been done to validate the performance of the proposed method. The switching transient from star to delta connection in the motor drive can be much more stable than hard switching method.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873789/10272303/10272328.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68150011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-01DOI: 10.30941/CESTEMS.2023.00050
Xiaobao Feng;Bo Wang;Chaohui Liu;Jiayun Zeng;Zheng Wang
Inter-turn fault is a serious stator winding short-circuit fault of permanent magnet synchronous machine (PMSM). Once it occurs, it produces a huge short-circuit current that poses a great risk to the safe operation of PMSM. Thus, an inter-turn short-circuit fault (ITSCF) diagnosis method based on high frequency (HF) voltage residual is proposed in this paper with proper HF signal injection. First, the analytical models of PMSM after the ITSCF are deduced. Based on the model, the voltage residual at low frequency (LF) and HF can be obtained. It is revealed that the HF voltage residual has a stronger ITSCF detection capability compared to the LF voltage residual. To obtain optimal fault signature, a 3-phase symmetrical HF voltage is injected into the machine drive system, and the HF voltage residuals are extracted. The fault indicator is defined as the standard deviation of the 3-phase HF voltage residuals. The effectiveness of the proposed ITSCF diagnosis method is verified by experiments on a triple 3-phase PMSM. It is worth noting that no extra hardware equipment is required to implement the proposed method.
{"title":"Research on Inter-Turn Short-Circuit Fault Diagnosis Method Based on High Frequency Voltage Residual for PMSM","authors":"Xiaobao Feng;Bo Wang;Chaohui Liu;Jiayun Zeng;Zheng Wang","doi":"10.30941/CESTEMS.2023.00050","DOIUrl":"https://doi.org/10.30941/CESTEMS.2023.00050","url":null,"abstract":"Inter-turn fault is a serious stator winding short-circuit fault of permanent magnet synchronous machine (PMSM). Once it occurs, it produces a huge short-circuit current that poses a great risk to the safe operation of PMSM. Thus, an inter-turn short-circuit fault (ITSCF) diagnosis method based on high frequency (HF) voltage residual is proposed in this paper with proper HF signal injection. First, the analytical models of PMSM after the ITSCF are deduced. Based on the model, the voltage residual at low frequency (LF) and HF can be obtained. It is revealed that the HF voltage residual has a stronger ITSCF detection capability compared to the LF voltage residual. To obtain optimal fault signature, a 3-phase symmetrical HF voltage is injected into the machine drive system, and the HF voltage residuals are extracted. The fault indicator is defined as the standard deviation of the 3-phase HF voltage residuals. The effectiveness of the proposed ITSCF diagnosis method is verified by experiments on a triple 3-phase PMSM. It is worth noting that no extra hardware equipment is required to implement the proposed method.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/7873789/10272303/10272327.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68150007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-04DOI: 10.30941/CESTEMS.2023.00039
Shengnan Wu;Zhimin Li;Wenming Tong
Because of its simple structure, large torque and high efficiency, permanent magnet synchronous motor of low speed and high torque is widely adopted in many fields. In this paper, a 394.5kW mining low-speed high-torque permanent magnet synchronous motor (LSHTPMSM) is regarded as the study object. According to the physical model, a three-dimensional equivalent heat transfer temperature field calculation model of the motor is built to simulate the temperature distribution of the motor under rated conditions. In terms of the serious issue of stator winding temperature increase of permanent magnet synchronous motor of low speed and high torque, the heat conduction optimization of the end of the stator winding is studied, which enhances the heat dissipation effect of the stator end winding, effectively reduces its temperature increase and temperature gradient with the winding in the slot, and improves the practical efficiency and service life of the motor. Finally, the motor temperature rise test platform is constructed for the verification of the feasibility of the optimization scheme, which provides a reference direction for the heat dissipation optimization of permanent magnet synchronous motor of low speed and high torque.
{"title":"Research on Thermal Calculation and End Winding Heat Conduction Optimization of Low Speed High Torque Permanent Magnet Synchronous Motor","authors":"Shengnan Wu;Zhimin Li;Wenming Tong","doi":"10.30941/CESTEMS.2023.00039","DOIUrl":"10.30941/CESTEMS.2023.00039","url":null,"abstract":"Because of its simple structure, large torque and high efficiency, permanent magnet synchronous motor of low speed and high torque is widely adopted in many fields. In this paper, a 394.5kW mining low-speed high-torque permanent magnet synchronous motor (LSHTPMSM) is regarded as the study object. According to the physical model, a three-dimensional equivalent heat transfer temperature field calculation model of the motor is built to simulate the temperature distribution of the motor under rated conditions. In terms of the serious issue of stator winding temperature increase of permanent magnet synchronous motor of low speed and high torque, the heat conduction optimization of the end of the stator winding is studied, which enhances the heat dissipation effect of the stator end winding, effectively reduces its temperature increase and temperature gradient with the winding in the slot, and improves the practical efficiency and service life of the motor. Finally, the motor temperature rise test platform is constructed for the verification of the feasibility of the optimization scheme, which provides a reference direction for the heat dissipation optimization of permanent magnet synchronous motor of low speed and high torque.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10209559","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81159910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-04DOI: 10.30941/CESTEMS.2023.00040
Zhan Su;Libing Jing
To enhance the output torque and minimize the torque ripple of coaxial magnetic gear (CMG), a novel auxiliary flux modulator CMG with unequal magnetic poles is proposed. This design incorporates an inner rotor with an asymmetric sector and a trapezoidal combined N-S pole structure, featuring Halbach arrays for the arrangement of permanent magnets (PMs). The outer rotor PMs adopt a Spoke-type configuration. To optimize the CMG for high output torque and low torque ripple, a sensitivity analysis is conducted to identify key size parameters that significantly influence the optimization objectives. Based on the sensitivity hierarchy of these parameters, a multi-objective optimization analysis is performed using a genetic algorithm (GA) to determine the optimal structural parameter values of the CMG. In addition, a coaxial magnetic gear (CMG) topology with 4 inner and 17 outer pole pairs is adopted, and the parametric model is established. Finally, the electromagnetic properties of the CMG are evaluated using the finite element method. The results indicate a remarkable reduction in torque ripple, specifically by 46.15%.
{"title":"Multi-Objective Optimization Analysis of Auxiliary Flux Modulator Magnetic Gear with Unequal Magnetic Poles","authors":"Zhan Su;Libing Jing","doi":"10.30941/CESTEMS.2023.00040","DOIUrl":"10.30941/CESTEMS.2023.00040","url":null,"abstract":"To enhance the output torque and minimize the torque ripple of coaxial magnetic gear (CMG), a novel auxiliary flux modulator CMG with unequal magnetic poles is proposed. This design incorporates an inner rotor with an asymmetric sector and a trapezoidal combined N-S pole structure, featuring Halbach arrays for the arrangement of permanent magnets (PMs). The outer rotor PMs adopt a Spoke-type configuration. To optimize the CMG for high output torque and low torque ripple, a sensitivity analysis is conducted to identify key size parameters that significantly influence the optimization objectives. Based on the sensitivity hierarchy of these parameters, a multi-objective optimization analysis is performed using a genetic algorithm (GA) to determine the optimal structural parameter values of the CMG. In addition, a coaxial magnetic gear (CMG) topology with 4 inner and 17 outer pole pairs is adopted, and the parametric model is established. Finally, the electromagnetic properties of the CMG are evaluated using the finite element method. The results indicate a remarkable reduction in torque ripple, specifically by 46.15%.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10209560","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82373159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-04DOI: 10.30941/CESTEMS.2023.00035
G. Kovács
The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field, as well as the synchronous parasitic torques, radial magnetic forces have been discussed in great detail in the literature, but always separately, for a long time. However, systematization of the phenomenon still awaits. Therefore, it is worth summarizing the completeness of the phenomena in a single study – with a new approach at the same time - in order to reveal the relationships between them. The role of rotor slot number is emphasized much more than before. New formulas derived for both synchronous torques and radial magnetic forces are used for further investigation. It will be shown that both phenomena in subject must be treated together. Formulas will be provided to take into account attenuation. Design guide will be provided to avoid dangerous rotor slot numbers. It will be shown that the generation of synchronous torques and radial magnetic forces do not depend – in this new approach - on the slot combination, but on the rotor slot number itself.
{"title":"Harmonics in the Squirrel Cage Induction Motor, Analytic Calculation Part II: Synchronous Parasitic Torques, Radial Magnetic Forces","authors":"G. Kovács","doi":"10.30941/CESTEMS.2023.00035","DOIUrl":"10.30941/CESTEMS.2023.00035","url":null,"abstract":"The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field, as well as the synchronous parasitic torques, radial magnetic forces have been discussed in great detail in the literature, but always separately, for a long time. However, systematization of the phenomenon still awaits. Therefore, it is worth summarizing the completeness of the phenomena in a single study – with a new approach at the same time - in order to reveal the relationships between them. The role of rotor slot number is emphasized much more than before. New formulas derived for both synchronous torques and radial magnetic forces are used for further investigation. It will be shown that both phenomena in subject must be treated together. Formulas will be provided to take into account attenuation. Design guide will be provided to avoid dangerous rotor slot numbers. It will be shown that the generation of synchronous torques and radial magnetic forces do not depend – in this new approach - on the slot combination, but on the rotor slot number itself.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10209558","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79986178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-12DOI: 10.30941/CESTEMS.2023.00038
Long Chen;Lvsheng Cui;Tong Ben;Libing Jing
This paper presents an identification method of the scalar Preisach model to consider the effect of reversible magnetization in the process of distribution function identification. By reconsidering the identification process by stripping the influence of reversible components from the measurement data, the Preisach distribution function is identified by the pure irreversible components. In this way, the simulation accuracy of both limiting hysteresis loops and the inner internal symmetrical small hysteresis loop is ensured. Furthermore, through a discrete Preisach plane with a hybrid discretization method, the irreversible magnetic flux density components are computed more efficiently through the improved Preisach model. Finally, the proposed method results are compared with the traditional method and the traditional method considering reversible magnetization and validated by the laboratory test for the B30P105 electrical steel by Epstein frame.
{"title":"An Improved Preisach Distribution Function Identification Method Considering the Reversible Magnetization","authors":"Long Chen;Lvsheng Cui;Tong Ben;Libing Jing","doi":"10.30941/CESTEMS.2023.00038","DOIUrl":"10.30941/CESTEMS.2023.00038","url":null,"abstract":"This paper presents an identification method of the scalar Preisach model to consider the effect of reversible magnetization in the process of distribution function identification. By reconsidering the identification process by stripping the influence of reversible components from the measurement data, the Preisach distribution function is identified by the pure irreversible components. In this way, the simulation accuracy of both limiting hysteresis loops and the inner internal symmetrical small hysteresis loop is ensured. Furthermore, through a discrete Preisach plane with a hybrid discretization method, the irreversible magnetic flux density components are computed more efficiently through the improved Preisach model. Finally, the proposed method results are compared with the traditional method and the traditional method considering reversible magnetization and validated by the laboratory test for the B30P105 electrical steel by Epstein frame.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10181102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80202071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-12DOI: 10.30941/CESTEMS.2023.00037
Longnv Li;Nan Jia;Xizhe Wang;Yiran Yun;Gaojia Zhu
This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet (PM) traction motor utilized in the propulsion systems for subway trains. In order to analyze accurately the machine's inherent cooling capacity when the train is running, the ambient airflow and the related heat transfer coefficient (HTC) are numerically investigated considering synchronously the bogie installation structure. The machine is preliminary cooled with air ducts set on the motor shell, and the fluidic-thermal field distributions with only the shell air duct cooling are numerically calculated. During simulations, the HTC obtained in the former steps is applied to the external surface of the machine to model the inherent cooling characteristic caused by the train movement. To reduce the temperature rise and thus guarantee the motor's working reliability, an internal self-circulated air cooling system is proposed according to the machine temperature distribution. The air enclosed in the end-caps is driven by the blades mounted on both sides of the rotor core and forms two air circuits to bring the excessive power losses generated in the heating components to cool regions. The fluid flow and temperature rise distributions of the cooling system's structural parameters are further improved by the Taguchi method in order to confirm the efficacy of the internal air cooling system.
{"title":"Cooling System Design Optimization of an Enclosed PM Traction Motor for Subway Propulsion Systems","authors":"Longnv Li;Nan Jia;Xizhe Wang;Yiran Yun;Gaojia Zhu","doi":"10.30941/CESTEMS.2023.00037","DOIUrl":"10.30941/CESTEMS.2023.00037","url":null,"abstract":"This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet (PM) traction motor utilized in the propulsion systems for subway trains. In order to analyze accurately the machine's inherent cooling capacity when the train is running, the ambient airflow and the related heat transfer coefficient (HTC) are numerically investigated considering synchronously the bogie installation structure. The machine is preliminary cooled with air ducts set on the motor shell, and the fluidic-thermal field distributions with only the shell air duct cooling are numerically calculated. During simulations, the HTC obtained in the former steps is applied to the external surface of the machine to model the inherent cooling characteristic caused by the train movement. To reduce the temperature rise and thus guarantee the motor's working reliability, an internal self-circulated air cooling system is proposed according to the machine temperature distribution. The air enclosed in the end-caps is driven by the blades mounted on both sides of the rotor core and forms two air circuits to bring the excessive power losses generated in the heating components to cool regions. The fluid flow and temperature rise distributions of the cooling system's structural parameters are further improved by the Taguchi method in order to confirm the efficacy of the internal air cooling system.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10181101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76190611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Switched reluctance motor (SRM) usually adopts Direct Instantaneous Torque Control (DITC) to suppress torque ripple. However, due to the fixed turn-on angle and the control mode of the two-phase exchange region, the conventional DITC control method has low adaptability in different working conditions, which will lead to large torque ripple. For this problem, an improved DITC control method based on turn-on angle optimization is proposed in this paper. Firstly, the improved BP neural network is used to construct a nonlinear torque model, so that the torque can be accurately fed back in real time. Secondly, the turn-on angle optimization algorithm based on improved GRNN neural network is established, so that the turn-on angle can be adjusted adaptively online. Then, according to the magnitude of inductance change rate, the two-phase exchange region is divided into two regions, and the phase with larger inductance change rate and current is selected to provide torque in the sub- regions. Finally, taking a 3-phase 6/20 SRM as example, simulation and experimental verification are carried out to verify the effectiveness of this method.
{"title":"An Improved DITC Control Method Based on Turn-On Angle Optimization","authors":"Chaozhi Huang;Wensheng Cao;Zhou Chen;Yuliang Wu;Yongmin Geng","doi":"10.30941/CESTEMS.2023.00043","DOIUrl":"10.30941/CESTEMS.2023.00043","url":null,"abstract":"Switched reluctance motor (SRM) usually adopts Direct Instantaneous Torque Control (DITC) to suppress torque ripple. However, due to the fixed turn-on angle and the control mode of the two-phase exchange region, the conventional DITC control method has low adaptability in different working conditions, which will lead to large torque ripple. For this problem, an improved DITC control method based on turn-on angle optimization is proposed in this paper. Firstly, the improved BP neural network is used to construct a nonlinear torque model, so that the torque can be accurately fed back in real time. Secondly, the turn-on angle optimization algorithm based on improved GRNN neural network is established, so that the turn-on angle can be adjusted adaptively online. Then, according to the magnitude of inductance change rate, the two-phase exchange region is divided into two regions, and the phase with larger inductance change rate and current is selected to provide torque in the sub- regions. Finally, taking a 3-phase 6/20 SRM as example, simulation and experimental verification are carried out to verify the effectiveness of this method.","PeriodicalId":100229,"journal":{"name":"CES Transactions on Electrical Machines and Systems","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10181104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78883252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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