Mobile website
- News
Electric Machines & Control Application (CN 31-1959/TM, ISSN 1673-6540) was founded in 1959 in title of Technical Information of Small and Medium-sized Electric Machines. The title was changed to Small and Medium-sized Electric Machines in 1977, and then changed to its current title in 2005. The journal is sponsored by Shanghai Electrical Apparatus Research Institute (Group) Co., Ltd., aims to publish cutting-edge achievements in various research fields related to the electrical science. The journal is a source journal of the Comprehensive Evaluation Database of Chinese Academic Journals, and the full text articles are included in Chinese Academic Journals (CD). It has been included in Chinese Core Journals and Key Magazine of China Technology for years. Recently, it has also been included in Scopus, EBSCO, DOAJ, EuroPub, Research4Life, ICI world of Jourmals, ICI Journal Master Lister, Japan Science and Technology Agency database (JST, Japan) and Abstract Journals (AJ, Russia). The impact factor is steadily increasing year by year. Electric Machines and Control Application is published on the 10th of each month and is publicly distributed domestically and internationally. The post issuing code is 4-199.
More
- Current Issue
- Special issue
- Archive
- Most Downloaded
- Browse by Issues
Article Search
Search by issue
Display Method:
2025,52(11):1148-1159, DOI: 10.12177/emca.2025.108
Abstract:
[Objective] Single-rotor compressors are widely used in household air-conditioners because of their compact size, high reliability and significant cost-effectiveness. However, the unbalanced centrifugal forces generated by the rotor rotation of single-rotor compressor lead to periodic load fluctuations, consequently resulting in speed ripples and associated vibration noise. These issues are particularly pronounced at low-frequency operation of the compressor. To address these issues, this paper proposes a speed ripple suppression method for compressors based on extremum seeking algorithm(ESA), aiming to enhance speed stability of the compressor under low-frequency operating conditions. [Methods] Firstly, the load characteristics of the single-rotor compressor during normal operation were analyzed. Based on this analysis, a control method was proposed to construct a feedforward compensation current based on the superimposed value of the DC component and fundamental component of the load torque. Then, the existence of extremum of motor speed fluctuation amplitude as the compensation gain and phase offset angle varied was demonstrated, and the ESA was used to dynamically adjust the amplitude and phase offset angle of the compensation current according to the speed fluctuation amplitude, so as to realize adaptive speed ripple suppression. Finally, an improved ESA based on incomplete derivative proportional integral derivative control was proposed to improve the response speed in view of the slow convergence speed problem of the traditional ESA. [Results] Using Plecs software for simulation, the results showed that in the low and medium speed or variable torque conditions, the compressor speed ripple was greatly suppressed after using the current compensation method based on the traditional ESA. The current compensation method based on the improved ESA proposed in this paper, compared with the traditional ESA, improved the convergence speed of the algorithm and optimized the dynamic performance while guaranteeing the steady state performance. [Conclusion] The speed ripple suppression method for compressors based on improved ESA proposed in this paper can achieve the optimal regulation of feedforward compensation current amplitude and phase offset angle under various operating conditions, effectively reduce the speed ripple caused by the load torque fluctuation, and provide a new perspective for optimizing compressor drive system control and integrating advanced control algorithms.
[Objective] Single-rotor compressors are widely used in household air-conditioners because of their compact size, high reliability and significant cost-effectiveness. However, the unbalanced centrifugal forces generated by the rotor rotation of single-rotor compressor lead to periodic load fluctuations, consequently resulting in speed ripples and associated vibration noise. These issues are particularly pronounced at low-frequency operation of the compressor. To address these issues, this paper proposes a speed ripple suppression method for compressors based on extremum seeking algorithm(ESA), aiming to enhance speed stability of the compressor under low-frequency operating conditions. [Methods] Firstly, the load characteristics of the single-rotor compressor during normal operation were analyzed. Based on this analysis, a control method was proposed to construct a feedforward compensation current based on the superimposed value of the DC component and fundamental component of the load torque. Then, the existence of extremum of motor speed fluctuation amplitude as the compensation gain and phase offset angle varied was demonstrated, and the ESA was used to dynamically adjust the amplitude and phase offset angle of the compensation current according to the speed fluctuation amplitude, so as to realize adaptive speed ripple suppression. Finally, an improved ESA based on incomplete derivative proportional integral derivative control was proposed to improve the response speed in view of the slow convergence speed problem of the traditional ESA. [Results] Using Plecs software for simulation, the results showed that in the low and medium speed or variable torque conditions, the compressor speed ripple was greatly suppressed after using the current compensation method based on the traditional ESA. The current compensation method based on the improved ESA proposed in this paper, compared with the traditional ESA, improved the convergence speed of the algorithm and optimized the dynamic performance while guaranteeing the steady state performance. [Conclusion] The speed ripple suppression method for compressors based on improved ESA proposed in this paper can achieve the optimal regulation of feedforward compensation current amplitude and phase offset angle under various operating conditions, effectively reduce the speed ripple caused by the load torque fluctuation, and provide a new perspective for optimizing compressor drive system control and integrating advanced control algorithms.
2025,52(11):1160-1169, DOI: 10.12177/emca.2025.107
Abstract:
[Objective] Aiming at the wind power grid-connected power fluctuation problem, this paper proposes a wind turbine rotor kinetic power smoothing strategy based on extended Kalman filter (EKF) and linear active disturbance rejection control (LADRC), in order to solve the problems of phase lag and insufficient disturbance rejection capabilities of the traditional methods. [Methods] Firstly, the aerodynamic model and mathematical model of the permanent magnet direct drive wind power generation system were established. Secondly, the LADRC was designed for the speed loop control, and the rotor kinetic energy algorithm based on EKF was proposed to dynamically update the noise statistical characteristics and optimize the power command estimation. Finally, the simulation model was constructed, and the proposed EKF-LADRC strategy was compared and analyzed with the traditional proportional integral (PI) control and active disturbance rejection control (ADRC) under the turbulence conditions of the high wind speed region and the rated wind speed region. [Results] The simulation results showed that, under turbulent condition in the high wind speed region, EKF-LADRC reduced the power standard deviation by 87.5% and 69.5%, respectively, compared to PI control and ADRC, and suppressed the speed fluctuation to 0.02 r/min. And the power output smoothing was significantly improved under turbulent condition in the rated wind speed region. Simulation results verified the effectiveness of the proposed strategy in suppressing power fluctuations under different wind conditions. [Conclusion] The synergistic strategy of EKF-based rotor kinetic energy algorithm and LADRC proposed in this paper can significantly reduce the power fluctuation and enhance the system robustness. The adaptive noise estimation capability of EKF successfully eliminates the phase lag in traditional filter, and LADRC disturbance compensation mechanism ensures rapid response to turbulent wind conditions. The strategy not only outperforms the traditional methods in terms of dynamic performance, but also maintains operational stability under extreme operating conditions, and its computationally efficient and engineering realizability are of great value for applications in high percentage renewable energy grids that require stringent power quality standards.
[Objective] Aiming at the wind power grid-connected power fluctuation problem, this paper proposes a wind turbine rotor kinetic power smoothing strategy based on extended Kalman filter (EKF) and linear active disturbance rejection control (LADRC), in order to solve the problems of phase lag and insufficient disturbance rejection capabilities of the traditional methods. [Methods] Firstly, the aerodynamic model and mathematical model of the permanent magnet direct drive wind power generation system were established. Secondly, the LADRC was designed for the speed loop control, and the rotor kinetic energy algorithm based on EKF was proposed to dynamically update the noise statistical characteristics and optimize the power command estimation. Finally, the simulation model was constructed, and the proposed EKF-LADRC strategy was compared and analyzed with the traditional proportional integral (PI) control and active disturbance rejection control (ADRC) under the turbulence conditions of the high wind speed region and the rated wind speed region. [Results] The simulation results showed that, under turbulent condition in the high wind speed region, EKF-LADRC reduced the power standard deviation by 87.5% and 69.5%, respectively, compared to PI control and ADRC, and suppressed the speed fluctuation to 0.02 r/min. And the power output smoothing was significantly improved under turbulent condition in the rated wind speed region. Simulation results verified the effectiveness of the proposed strategy in suppressing power fluctuations under different wind conditions. [Conclusion] The synergistic strategy of EKF-based rotor kinetic energy algorithm and LADRC proposed in this paper can significantly reduce the power fluctuation and enhance the system robustness. The adaptive noise estimation capability of EKF successfully eliminates the phase lag in traditional filter, and LADRC disturbance compensation mechanism ensures rapid response to turbulent wind conditions. The strategy not only outperforms the traditional methods in terms of dynamic performance, but also maintains operational stability under extreme operating conditions, and its computationally efficient and engineering realizability are of great value for applications in high percentage renewable energy grids that require stringent power quality standards.
2025,52(11):1170-1181, DOI: 10.12177/emca.2025.115
Abstract:
[Objective] To address the issues of voltage fluctuations and increased network losses in distribution network caused by high photovoltaic penetration, this paper proposes an optimal configuration strategy of energy storage power source based on time-series comprehensive voltage-active power sensitivity. [Methods] Firstly, a static comprehensive sensitivity matrix between nodal voltage and active power variation was established to quantify the impact of power injection on voltage deviation across all nodes. Then, to reflect the time-series characteristics of photovoltaic output and load fluctuation, a time-series weighting factor was introduced to correct the influence of voltage deviations at different time periods, thereby forming a time-series comprehensive sensitivity index that determined the priority of energy storage system installation locations. On this basis, a multi-objective optimization model was formulated that simultaneously minimized the comprehensive operating costs of the energy storage system, voltage deviation of the distribution network, and total network losses. Subsequently, the optimization model was solved using an improved particle swarm optimization algorithm, which enhanced convergence speed and avoided local optimal by dynamically adjusting inertia weight and learning factors. Finally, generative adversarial network was employed to generate diverse distribution network operational scenarios, thereby enriching the optimization dataset and improving the robustness of solutions under photovoltaic and load uncertainty. [Results] The case study results demonstrated that, compared with conventional voltage sensitivity analysis method, the proposed time-series sensitivity analysis method effectively enhanced the precision and targeted nature of node voltage regulation. The optimized energy storage system configuration achieved collaborative improvement in both economic performance and renewable energy utilization capability while ensuring that nodal voltages remained within permissible limits. [Conclusion] The proposed strategy significantly accelerates the energy storage planning process of distribution network, enhances its ability to maintain voltage stability under photovoltaic fluctuations, and promotes the economic and reliable operation of distribution network with high proportion photovoltaic.
[Objective] To address the issues of voltage fluctuations and increased network losses in distribution network caused by high photovoltaic penetration, this paper proposes an optimal configuration strategy of energy storage power source based on time-series comprehensive voltage-active power sensitivity. [Methods] Firstly, a static comprehensive sensitivity matrix between nodal voltage and active power variation was established to quantify the impact of power injection on voltage deviation across all nodes. Then, to reflect the time-series characteristics of photovoltaic output and load fluctuation, a time-series weighting factor was introduced to correct the influence of voltage deviations at different time periods, thereby forming a time-series comprehensive sensitivity index that determined the priority of energy storage system installation locations. On this basis, a multi-objective optimization model was formulated that simultaneously minimized the comprehensive operating costs of the energy storage system, voltage deviation of the distribution network, and total network losses. Subsequently, the optimization model was solved using an improved particle swarm optimization algorithm, which enhanced convergence speed and avoided local optimal by dynamically adjusting inertia weight and learning factors. Finally, generative adversarial network was employed to generate diverse distribution network operational scenarios, thereby enriching the optimization dataset and improving the robustness of solutions under photovoltaic and load uncertainty. [Results] The case study results demonstrated that, compared with conventional voltage sensitivity analysis method, the proposed time-series sensitivity analysis method effectively enhanced the precision and targeted nature of node voltage regulation. The optimized energy storage system configuration achieved collaborative improvement in both economic performance and renewable energy utilization capability while ensuring that nodal voltages remained within permissible limits. [Conclusion] The proposed strategy significantly accelerates the energy storage planning process of distribution network, enhances its ability to maintain voltage stability under photovoltaic fluctuations, and promotes the economic and reliable operation of distribution network with high proportion photovoltaic.
2025,52(11):1182-1192, DOI: 10.12177/emca.2025.116
Abstract:
[Objective] In traditional electromagnetic field simulation software, numerical calculation methods such as finite difference and finite element method are mainly used to solve problems. Although these methods can obtain numerical solutions closer to the experimental results, their computational accuracy heavily depends on the number of meshes and the quality of the dividing. While improving the solution accuracy, it also leads to a significant in computation time and cost, especially when using software for large-scale optimization design. [Methods] Therefore, this paper proposed a development strategy for electromagnetic simulation software that integrated artificial intelligence technology. Artificial neural network (ANN) models were used in pre-processing, solving, and post-processing to accelerate the entire solving process. In the modeling process, multimodal parametric modeling techniques based on images, speech, and text were used. In the mesh dividing and matrix solving, ANN models were used for classification judgment or regression prediction. In the processing and visualization stages of calculation results, machine learning fitting and interpolation methods were used for smoothing the computational results and improving the resolution. [Results] Based on electromagnetic simulation software, a large amount of finite element data could be obtained for specific problems. In a data-driven environment, it was possible to achieve the prediction of electromagnetic field distribution, the prediction of AC copper consumption based on surrogate models, the full performance prediction of motors with multiple input/output and operating conditions, multi-objective accelerated optimization with the help of classifiers, as well as multi-objective optimization and motor modeling based entirely on surrogate models. [Conclusion] This study constructs digital twins of electromagnetic products through data-driven approaches, providing effective support for their status monitoring, predictive maintenance and performance optimization.
[Objective] In traditional electromagnetic field simulation software, numerical calculation methods such as finite difference and finite element method are mainly used to solve problems. Although these methods can obtain numerical solutions closer to the experimental results, their computational accuracy heavily depends on the number of meshes and the quality of the dividing. While improving the solution accuracy, it also leads to a significant in computation time and cost, especially when using software for large-scale optimization design. [Methods] Therefore, this paper proposed a development strategy for electromagnetic simulation software that integrated artificial intelligence technology. Artificial neural network (ANN) models were used in pre-processing, solving, and post-processing to accelerate the entire solving process. In the modeling process, multimodal parametric modeling techniques based on images, speech, and text were used. In the mesh dividing and matrix solving, ANN models were used for classification judgment or regression prediction. In the processing and visualization stages of calculation results, machine learning fitting and interpolation methods were used for smoothing the computational results and improving the resolution. [Results] Based on electromagnetic simulation software, a large amount of finite element data could be obtained for specific problems. In a data-driven environment, it was possible to achieve the prediction of electromagnetic field distribution, the prediction of AC copper consumption based on surrogate models, the full performance prediction of motors with multiple input/output and operating conditions, multi-objective accelerated optimization with the help of classifiers, as well as multi-objective optimization and motor modeling based entirely on surrogate models. [Conclusion] This study constructs digital twins of electromagnetic products through data-driven approaches, providing effective support for their status monitoring, predictive maintenance and performance optimization.
Research on Variable Parameter PI and Load Torque Compensation Control of AC Servo System Speed Loop
2025,52(11):1193-1204, DOI: 10.12177/emca.2025.110
Abstract:
[Objective] In the field of modern industrial automation, the dynamic performance of the speed loop of permanent magnet synchronous motors directly affects the operational efficiency and stability of the system. Currently, factors such as load torque disturbances and parameter variations have a significant impact on the dynamic performance of the speed loop, limiting the application of the motor in high-precision and high-dynamic response scenarios. [Methods] To address this problem, this paper proposed a variable parameter proportional integral (PI) control strategy based on the adaptive sliding mode load torque observer. This strategy innovatively combined the high-precision estimation capability of the sliding mode observer with the adaptive characteristics of variable parameter PI control. By capturing the transient changes in load torque in real-time through the sliding mode observer, the PI controller was driven to dynamically adjust the proportional and integral parameters, enabling the system to maintain optimal control under different operating conditions and achieve global dynamic optimization. [Results] The effectiveness of the proposed control strategy was verified through simulation and experiment. The results showed that the variable parameter PI control improved the dynamic response speed by approximately 27.5% compared with the traditional fixed-parameter PI control. Compared with the normal PI dual closed-loop control, the system overshoot was reduced by 20.6%, the recovery time was reduced by 56.6%, and the response time was reduced by 50% through the speed loop variable parameter PI control with load torque identification compensation. [Conclusion] The proposed control strategy effectively enhances the dynamic response speed, steady-state accuracy and anti-disturbance capability of the speed loop of permanent magnet synchronous motor, significantly enhances the system control effect, and shows good engineering application prospects in the fields of new energy vehicles and industrial robots.
[Objective] In the field of modern industrial automation, the dynamic performance of the speed loop of permanent magnet synchronous motors directly affects the operational efficiency and stability of the system. Currently, factors such as load torque disturbances and parameter variations have a significant impact on the dynamic performance of the speed loop, limiting the application of the motor in high-precision and high-dynamic response scenarios. [Methods] To address this problem, this paper proposed a variable parameter proportional integral (PI) control strategy based on the adaptive sliding mode load torque observer. This strategy innovatively combined the high-precision estimation capability of the sliding mode observer with the adaptive characteristics of variable parameter PI control. By capturing the transient changes in load torque in real-time through the sliding mode observer, the PI controller was driven to dynamically adjust the proportional and integral parameters, enabling the system to maintain optimal control under different operating conditions and achieve global dynamic optimization. [Results] The effectiveness of the proposed control strategy was verified through simulation and experiment. The results showed that the variable parameter PI control improved the dynamic response speed by approximately 27.5% compared with the traditional fixed-parameter PI control. Compared with the normal PI dual closed-loop control, the system overshoot was reduced by 20.6%, the recovery time was reduced by 56.6%, and the response time was reduced by 50% through the speed loop variable parameter PI control with load torque identification compensation. [Conclusion] The proposed control strategy effectively enhances the dynamic response speed, steady-state accuracy and anti-disturbance capability of the speed loop of permanent magnet synchronous motor, significantly enhances the system control effect, and shows good engineering application prospects in the fields of new energy vehicles and industrial robots.
2025,52(11):1205-1214, DOI: 10.12177/emca.2025.111
Abstract:
[Objective] High-power permanent magnet direct-drive motors for port transmissions are usually designed with high voltage ratings. However, this solution poses significant challenges in terms of electromagnetic design, manufacturing precision and maintenance reliability. For variable-speed drive systems, relying on high-cost power electronics for frequency conversion greatly increases the production cost. To address these problems, a low-voltage multi-branch structure design for permanent magnet direct-drive motors is proposed in this paper. [Methods] Firstly, according to the design requirements of high-power permanent magnet direct-drive motor for port transmissions, the electromagnetic scheme of the motor was designed to use multiple low-voltage inverters to supply power, and the total current of the whole motor was shared by each branch circuit. Then, the stator winding of the motor was designed with multi-branch structure, and the coupling between different branch windings and the electromagnetic performance of the motor when different branches were put into operation were analyzed by finite element simulation to theoretically verify the feasibility of the multi-branch motor. When different branches were put into operation, it increased the unevenness of the air-gap magnetic field and affected the stability of the motor. Finally, the cogging torque of the motor was optimized by opening an auxiliary slot in the rotor. [Results] Simulation results showed that the low-voltage multi-branch structure scheme, which effectively solved the problem of high current in the low-voltage scheme, put different branches into operation according to the load demand and improved the overall efficiency of the motor. When a certain inverter failed, the reliability of the motor drive system was greatly improved by controlling other inverters and increasing the current so that the motor output the rated torque. The peak-to-peak value of cogging torque of the un-slotted motor was 2 419.5 N·m, and after opening the rotor auxiliary slot optimization, the peak-to-peak value of cogging torque was reduced to 1 136.7 N·m, a reduction of 53.02%. [Conclusion] The low-voltage multi-branch structure optimization scheme proposed in this paper effectively solves the high cost and high current problems of high-power permanent magnet direct-drive motors for port transmission. The scheme can decide the number of branches to be put into operation according to the load requirements, which improves the efficiency of the motor and provides a certain reference for the design of high-power motors.
[Objective] High-power permanent magnet direct-drive motors for port transmissions are usually designed with high voltage ratings. However, this solution poses significant challenges in terms of electromagnetic design, manufacturing precision and maintenance reliability. For variable-speed drive systems, relying on high-cost power electronics for frequency conversion greatly increases the production cost. To address these problems, a low-voltage multi-branch structure design for permanent magnet direct-drive motors is proposed in this paper. [Methods] Firstly, according to the design requirements of high-power permanent magnet direct-drive motor for port transmissions, the electromagnetic scheme of the motor was designed to use multiple low-voltage inverters to supply power, and the total current of the whole motor was shared by each branch circuit. Then, the stator winding of the motor was designed with multi-branch structure, and the coupling between different branch windings and the electromagnetic performance of the motor when different branches were put into operation were analyzed by finite element simulation to theoretically verify the feasibility of the multi-branch motor. When different branches were put into operation, it increased the unevenness of the air-gap magnetic field and affected the stability of the motor. Finally, the cogging torque of the motor was optimized by opening an auxiliary slot in the rotor. [Results] Simulation results showed that the low-voltage multi-branch structure scheme, which effectively solved the problem of high current in the low-voltage scheme, put different branches into operation according to the load demand and improved the overall efficiency of the motor. When a certain inverter failed, the reliability of the motor drive system was greatly improved by controlling other inverters and increasing the current so that the motor output the rated torque. The peak-to-peak value of cogging torque of the un-slotted motor was 2 419.5 N·m, and after opening the rotor auxiliary slot optimization, the peak-to-peak value of cogging torque was reduced to 1 136.7 N·m, a reduction of 53.02%. [Conclusion] The low-voltage multi-branch structure optimization scheme proposed in this paper effectively solves the high cost and high current problems of high-power permanent magnet direct-drive motors for port transmission. The scheme can decide the number of branches to be put into operation according to the load requirements, which improves the efficiency of the motor and provides a certain reference for the design of high-power motors.
2025,52(11):1215-1227, DOI: 10.12177/emca.2025.106
Abstract:
[Objective] High-precision vector control of permanent magnet synchronous motor (PMSM) faces problems such as dependence on position sensors, response lag of sudden load change, and start-up out-of-step. During PMSM operation, the time-varying factors such as stator internal resistance partial voltage, back electro motive force and dq-axis coupling term will degrade the control accuracy. [Methods] In order to meet the demands of high-precision applications, this paper proposed a method integrated speed identification, load disturbance suppression, and precise magnetic field orientation for speed sensorless control. Firstly, a model reference adaptive system (MRAS) was constructed based on Popov superstability theory, and an adaptive law was designed to identify the speed through the output error of the reference model and the adjustable model of the stator voltage equation to achieve the speed sensorless operation. Secondly, a full order state observer (FOSO) was constructed based on MRAS. The system state space was reconstructed by using the measured voltages, currents and the estimated rotational speeds. A feedback gain matrix was configured to suppress speed fluctuations caused by sudden load changed, forming a virtual speed loop to enhance disturbance rejection capability. Finally, open-loop starting was used to solve the motor out-of-step problem caused by the randomness of rotor position during motor starting, the stator internal resistance voltage division compensation and the dynamic compensation of dq-axis cross-coupling term were introduced into the dq-axis control voltage, which reduced the control voltage loss and realized the precise orientation of the stator magnetic field. [Results] The experimental results showed that the virtual speed ring composed of FOSO could effectively suppress the load disturbance, and the magnetic chain circle after the precise magnetic field orientation was closer to the ideal circle. [Conclusion] The integrated control method proposed in this paper effectively solves the control difficulties of PMSM in the areas of speed sensorless operation, response lag of sudden load change and start-up out-of-step, and significantly improves the system response speed and control accuracy.
[Objective] High-precision vector control of permanent magnet synchronous motor (PMSM) faces problems such as dependence on position sensors, response lag of sudden load change, and start-up out-of-step. During PMSM operation, the time-varying factors such as stator internal resistance partial voltage, back electro motive force and dq-axis coupling term will degrade the control accuracy. [Methods] In order to meet the demands of high-precision applications, this paper proposed a method integrated speed identification, load disturbance suppression, and precise magnetic field orientation for speed sensorless control. Firstly, a model reference adaptive system (MRAS) was constructed based on Popov superstability theory, and an adaptive law was designed to identify the speed through the output error of the reference model and the adjustable model of the stator voltage equation to achieve the speed sensorless operation. Secondly, a full order state observer (FOSO) was constructed based on MRAS. The system state space was reconstructed by using the measured voltages, currents and the estimated rotational speeds. A feedback gain matrix was configured to suppress speed fluctuations caused by sudden load changed, forming a virtual speed loop to enhance disturbance rejection capability. Finally, open-loop starting was used to solve the motor out-of-step problem caused by the randomness of rotor position during motor starting, the stator internal resistance voltage division compensation and the dynamic compensation of dq-axis cross-coupling term were introduced into the dq-axis control voltage, which reduced the control voltage loss and realized the precise orientation of the stator magnetic field. [Results] The experimental results showed that the virtual speed ring composed of FOSO could effectively suppress the load disturbance, and the magnetic chain circle after the precise magnetic field orientation was closer to the ideal circle. [Conclusion] The integrated control method proposed in this paper effectively solves the control difficulties of PMSM in the areas of speed sensorless operation, response lag of sudden load change and start-up out-of-step, and significantly improves the system response speed and control accuracy.
2025,52(11):1228-1241, DOI: 10.12177/emca.2025.112
Abstract:
[Objective] Aiming at the four-motor synchronous drive servo system, this paper investigates an event-triggered finite-time command filtering control (ET-FNCFC) strategy to ensure servo control performance while reducing control signal update frequency, addressing bandwidth resource constraints in network control applications such as teleoperation and high-power multi-axis servo systems. [Methods] Firstly, the dynamics model of the four-motor synchronous drive servo system was established, and the finite-time controller was constructed by employing the command filtering backstepping control technique. Combined with the improved cross-coupling synchronization architecture, synchronization feedback signals between the two sets of motors were designed to enhance inter-motor synchronization performance. Secondly, the event-triggered conditions were formulated to avoid the Zeno phenomenon, thereby reducing control signal update frequency while minimising the impact on control performance. Subsequently, the closed-loop system stability was rigorously proved using Lyapunov stability theory and finite-time stability lemma. Finally, simulation and analysis were carried out based on Matlab/Simulink to compare the proposed ET-FNCFC with the time-triggered finite-time command filtering control (TT-FNCFC). [Results] The sine signal was selected as the system tracking signal. The load tracking effect, tracking error, synchronization error, and trigger times of ET-FNCFC and TT-FNCFC were compared and analyzed. The results demonstrated that the proposed ET-FNCFC strategy rapidly converged to the desired reference signal, achieved lower synchronization error compared to TT-FNCFC, while significantly reducing event-induced communication frequency to conserve system resources. The simulation results validated both the effectiveness and advantages of the proposed strategy. [Conclusion] The event-triggered control strategy can effectively reduce the occupation of communication resources, and the finite-time synchronization control not only accelerates the convergence speed, but also achieves precise load tracking and motor synchronization, providing a new solution for the high-performance control of multi-motor drive systems.
[Objective] Aiming at the four-motor synchronous drive servo system, this paper investigates an event-triggered finite-time command filtering control (ET-FNCFC) strategy to ensure servo control performance while reducing control signal update frequency, addressing bandwidth resource constraints in network control applications such as teleoperation and high-power multi-axis servo systems. [Methods] Firstly, the dynamics model of the four-motor synchronous drive servo system was established, and the finite-time controller was constructed by employing the command filtering backstepping control technique. Combined with the improved cross-coupling synchronization architecture, synchronization feedback signals between the two sets of motors were designed to enhance inter-motor synchronization performance. Secondly, the event-triggered conditions were formulated to avoid the Zeno phenomenon, thereby reducing control signal update frequency while minimising the impact on control performance. Subsequently, the closed-loop system stability was rigorously proved using Lyapunov stability theory and finite-time stability lemma. Finally, simulation and analysis were carried out based on Matlab/Simulink to compare the proposed ET-FNCFC with the time-triggered finite-time command filtering control (TT-FNCFC). [Results] The sine signal was selected as the system tracking signal. The load tracking effect, tracking error, synchronization error, and trigger times of ET-FNCFC and TT-FNCFC were compared and analyzed. The results demonstrated that the proposed ET-FNCFC strategy rapidly converged to the desired reference signal, achieved lower synchronization error compared to TT-FNCFC, while significantly reducing event-induced communication frequency to conserve system resources. The simulation results validated both the effectiveness and advantages of the proposed strategy. [Conclusion] The event-triggered control strategy can effectively reduce the occupation of communication resources, and the finite-time synchronization control not only accelerates the convergence speed, but also achieves precise load tracking and motor synchronization, providing a new solution for the high-performance control of multi-motor drive systems.
2025,52(11):1242-1250, DOI: 10.12177/emca.2025.114
Abstract:
[Objective] To enhance the performance stability of robot joint motors in high-radiation environments, a design and prototype development are carried out for radiation-resistant robot joint motors to meet the long-term operation and maintenance requirements of nuclear industrial robots in high-radiation conditions. [Methods] Firstly, according to the basic performance parameters required for the joint motor, simulation was carried out by finite element method to get the ideal design value. Then, the main components of the joint motor were analyzed, and it was determined that the metal materials were less affected by nuclear radiation, while non-metallic materials were the weak links. Through radiation experimental verification of paint-coated wire, heat-shrinkable tube, adhesive material, lubricating grease, outgoing line, etc., the radiation-resistant performance limits of the materials used in the motor were analyzed. Finally, the appropriate materials were selected for the physical verification of the robot joint motor, so that the joint motor could withstand the γ-ray radiation level of 5 MGy. [Results] Through the designed and analysised of the joint motor, the rated torque of the motor was more than 1.5 N·m, and the rated speed of 240 r/min met the use requirements. The joint motor remained in a controlled state after 5 MGy γ-ray radiation, with a significant decrease in internal resistance, a decrease in rotational speed, an increase in current, and a decrease in the overall performance of the motor of about 15%. [Conclusion] Through the design and prototype test verification of the joint motor, it can ensure that the nuclear industrial robot can perform long-term operation and maintenance in a high-radiation environment, and the test magnitude reaches 5 MGy, which fully meets the current application requirements of radiation environment robots. With the increase of radiation level, the performance of the motor shows a decreasing trend, but it is still in a controlled state. This study provides certain reference and support for the development of motors in the nuclear field.
[Objective] To enhance the performance stability of robot joint motors in high-radiation environments, a design and prototype development are carried out for radiation-resistant robot joint motors to meet the long-term operation and maintenance requirements of nuclear industrial robots in high-radiation conditions. [Methods] Firstly, according to the basic performance parameters required for the joint motor, simulation was carried out by finite element method to get the ideal design value. Then, the main components of the joint motor were analyzed, and it was determined that the metal materials were less affected by nuclear radiation, while non-metallic materials were the weak links. Through radiation experimental verification of paint-coated wire, heat-shrinkable tube, adhesive material, lubricating grease, outgoing line, etc., the radiation-resistant performance limits of the materials used in the motor were analyzed. Finally, the appropriate materials were selected for the physical verification of the robot joint motor, so that the joint motor could withstand the γ-ray radiation level of 5 MGy. [Results] Through the designed and analysised of the joint motor, the rated torque of the motor was more than 1.5 N·m, and the rated speed of 240 r/min met the use requirements. The joint motor remained in a controlled state after 5 MGy γ-ray radiation, with a significant decrease in internal resistance, a decrease in rotational speed, an increase in current, and a decrease in the overall performance of the motor of about 15%. [Conclusion] Through the design and prototype test verification of the joint motor, it can ensure that the nuclear industrial robot can perform long-term operation and maintenance in a high-radiation environment, and the test magnitude reaches 5 MGy, which fully meets the current application requirements of radiation environment robots. With the increase of radiation level, the performance of the motor shows a decreasing trend, but it is still in a controlled state. This study provides certain reference and support for the development of motors in the nuclear field.
2025,52(11):1251-1261, DOI: 10.12177/emca.2025.118
Abstract:
[Objective] High voltage direct current system is a common scheme for far-offshore wind power and has already been implemented in practical engineering projects. But this scheme is still facing the problems of high cost of offshore converter station platforms and large losses in the collector system. To address this problem, this paper investigated the optimal frequency selection for the far-offshore wind power medium frequency gathering system. [Methods] Firstly, finite element modeling was used to accurately calculate the distribution parameters and current carrying capacity of submarine three-core cables at different frequencies. According to the calculation results, referred to the wiring scheme of similar scale offshore wind farms for the selection of submarine cables. Then, the power losses in the collector system and the losses in the offshore diode rectifier platform were calculated, and converted the losses to the price of electricity. Finally, the optimal operating frequency of the offshore wind power high voltage direct current transmission system was selected by integrating the economic analyses of submarine cables, collector losses and offshore converter platforms. [Results] The increase in operating frequency would increase the investment cost of the collector system and the loss of the converter platform, would reduce the investment cost of the converter platform, and the optimization of the submarine cable selection could prevent the excessive increase in the investment cost of the collector system. [Conclusion] In this paper, the economic analyses of submarine cables, collector losses and offshore converter platforms are synthesised to conclude that the optimal operating frequency of the offshore wind power high voltage direct current system is 180 Hz, which achieves a good balance between technical feasibility, cost-effectiveness and operational efficiency.
[Objective] High voltage direct current system is a common scheme for far-offshore wind power and has already been implemented in practical engineering projects. But this scheme is still facing the problems of high cost of offshore converter station platforms and large losses in the collector system. To address this problem, this paper investigated the optimal frequency selection for the far-offshore wind power medium frequency gathering system. [Methods] Firstly, finite element modeling was used to accurately calculate the distribution parameters and current carrying capacity of submarine three-core cables at different frequencies. According to the calculation results, referred to the wiring scheme of similar scale offshore wind farms for the selection of submarine cables. Then, the power losses in the collector system and the losses in the offshore diode rectifier platform were calculated, and converted the losses to the price of electricity. Finally, the optimal operating frequency of the offshore wind power high voltage direct current transmission system was selected by integrating the economic analyses of submarine cables, collector losses and offshore converter platforms. [Results] The increase in operating frequency would increase the investment cost of the collector system and the loss of the converter platform, would reduce the investment cost of the converter platform, and the optimization of the submarine cable selection could prevent the excessive increase in the investment cost of the collector system. [Conclusion] In this paper, the economic analyses of submarine cables, collector losses and offshore converter platforms are synthesised to conclude that the optimal operating frequency of the offshore wind power high voltage direct current system is 180 Hz, which achieves a good balance between technical feasibility, cost-effectiveness and operational efficiency.
Article Search
Search by issue
Article Search
Search by issue
Display Method:
Abstract:
The impact of largescale access of wind farms on the transient stability of power grids could not be ignored. Taking the extended twomachine system with doublyfed wind turbines as an example, the equivalent model of doublyfed induction generator was established, and the twomachine system could be equivalent to a singlemachine infinity system. Based on the law of equal area, the analytic formula of critical clearing angle of the system was deduced in detail after wind power accessed. The analytic formula was used to quantitatively analyze the variation trends of the critical clearing angle with wind power ratio, wind turbine grid connection position, fault location and load access position. The influence laws of the above four factors on the stability of transient power angle were summarized. The simulation models of the extended twomachine system with doublyfed induction generator was established in BPA and FASTEST, and the accuracy of the theoretical analysis was verified.
The impact of largescale access of wind farms on the transient stability of power grids could not be ignored. Taking the extended twomachine system with doublyfed wind turbines as an example, the equivalent model of doublyfed induction generator was established, and the twomachine system could be equivalent to a singlemachine infinity system. Based on the law of equal area, the analytic formula of critical clearing angle of the system was deduced in detail after wind power accessed. The analytic formula was used to quantitatively analyze the variation trends of the critical clearing angle with wind power ratio, wind turbine grid connection position, fault location and load access position. The influence laws of the above four factors on the stability of transient power angle were summarized. The simulation models of the extended twomachine system with doublyfed induction generator was established in BPA and FASTEST, and the accuracy of the theoretical analysis was verified.
Abstract:
Multimotor synchronous and coordinate system was widely used in the field of motor control. The control strategy played a important role in the performance of multimotor synchronization system. Domestic and foreign scholars had conducted deep research, who aimed at the problem of multimotor synchronization.They put forward a variety of synchronization control strategies. The control strategies proposed at home and abroad were reviewed. The accuracy of tracking, robustness and capacity of antiload of the control object were analyzed. The new prospect of multimotor synchronization control was proposed.
Multimotor synchronous and coordinate system was widely used in the field of motor control. The control strategy played a important role in the performance of multimotor synchronization system. Domestic and foreign scholars had conducted deep research, who aimed at the problem of multimotor synchronization.They put forward a variety of synchronization control strategies. The control strategies proposed at home and abroad were reviewed. The accuracy of tracking, robustness and capacity of antiload of the control object were analyzed. The new prospect of multimotor synchronization control was proposed.
Abstract:
Inwheel motor drive technology represents an essential development direction in new energy vehicle drive system. The technical requirements and drive form were introduced. The technical requirements and drive form of inwheel motor drive were summarized. Current research situation of inwheel motor drive technology was compared and analyzed briefly. The key technique problems of inwheel motor technology were proposed. The essential technologies in descreasing unsprung mass, restraining vertical vibration effect and reducing torque ripple of inwheel motor were discussed, which were supposed to be solved urgently. The development trend of inwheel motor drive technology was predicted.
Inwheel motor drive technology represents an essential development direction in new energy vehicle drive system. The technical requirements and drive form were introduced. The technical requirements and drive form of inwheel motor drive were summarized. Current research situation of inwheel motor drive technology was compared and analyzed briefly. The key technique problems of inwheel motor technology were proposed. The essential technologies in descreasing unsprung mass, restraining vertical vibration effect and reducing torque ripple of inwheel motor were discussed, which were supposed to be solved urgently. The development trend of inwheel motor drive technology was predicted.
2024,51(9):70-79, DOI: 10.12177/emca.2024.090
Abstract:
To address the issue of high torque ripple in permanent magnet assisted synchronous reluctance motor (PMA-SynRM), a multi-objective optimization design method based on the non-dominated sorting genetic algorithm II (NSGA-II) was proposed. First, the basic structure and working principle of the PMA-SynRM were introduced. Next, the rotor structure of the PMA-SynRM was improved by constructing air barriers and designing asymmetric auxiliary slots. Then, sensitivity analysis was conducted to identify the parameters that had the most significant impact on the optimization objectives of the PMA-SynRM, and multi-objective optimization was performed using NSGA-II. The optimal topology was selected from the generated Pareto front. Finally, the torque performance of the optimized motor was compared with that of the initial motor using finite element analysis software. Simulation results showed that the performance of the PMA-SynRM optimized through NSGA-II was significantly improved.
To address the issue of high torque ripple in permanent magnet assisted synchronous reluctance motor (PMA-SynRM), a multi-objective optimization design method based on the non-dominated sorting genetic algorithm II (NSGA-II) was proposed. First, the basic structure and working principle of the PMA-SynRM were introduced. Next, the rotor structure of the PMA-SynRM was improved by constructing air barriers and designing asymmetric auxiliary slots. Then, sensitivity analysis was conducted to identify the parameters that had the most significant impact on the optimization objectives of the PMA-SynRM, and multi-objective optimization was performed using NSGA-II. The optimal topology was selected from the generated Pareto front. Finally, the torque performance of the optimized motor was compared with that of the initial motor using finite element analysis software. Simulation results showed that the performance of the PMA-SynRM optimized through NSGA-II was significantly improved.
Contact Us
Download Center
You are thevisitor
沪ICP备16038578号-3
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.
