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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 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.
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2025,52(9):924-934, DOI: 10.12177/emca.2025.088
Abstract:
[Objective] To address the transient stability challenges in grid-following and grid-forming (GFL-GFM) converters parallel system, this paper proposes a transient stability control method based on dynamic adjustment of inertia-damping. [Methods] Firstly, a two-stage transient control framework was established for the GFL-GFM converters parallel system. During the fault period, fault current limiters were rapidly activated to mitigate overcurrent, while in the post-fault recovery stage, the phase-locked loop (PLL) of GFL converter and the inertia-damping parameters of GFM converter were dynamically adjusted. Secondly, the Sigmoid function was adopted to achieve inertia-damping coordination tuning, and the controller parameters were adaptively adjusted by the trend of the power angle of the parallel system. Finally, a time-domain simulation model of the parallel system of GFL-GFM converters was established based on the Matlab/Simulink platform. Through comparisons with traditional control methods and tests under voltage sag conditions of varying degrees, the effectiveness of the proposed transient control method was verified from multiple aspects. [Results] The results showed that compared with the traditional PLL freezing of GFL converter and the additional power control strategy of GFM converter, the proposed control method significantly reduced the amplitude of the power angle oscillation of GFL-GFM converters, greatly shortened the oscillation period, and adapted well to both mild and severe voltage sag conditions. The proposed control method effectively ensured the transient stability of the GFL-GFM converters parallel system during the whole fault process, and it also reduced the power angle oscillation deviation by more than 5%. [Conclusion] The proposed method enhances the adaptability and robustness of GFL-GFM converters parallel system under voltage sag of varying degrees, providing a new idea for the stable operation of grid-connected system with high proportion of power electronic equipment, which has good application value.
[Objective] To address the transient stability challenges in grid-following and grid-forming (GFL-GFM) converters parallel system, this paper proposes a transient stability control method based on dynamic adjustment of inertia-damping. [Methods] Firstly, a two-stage transient control framework was established for the GFL-GFM converters parallel system. During the fault period, fault current limiters were rapidly activated to mitigate overcurrent, while in the post-fault recovery stage, the phase-locked loop (PLL) of GFL converter and the inertia-damping parameters of GFM converter were dynamically adjusted. Secondly, the Sigmoid function was adopted to achieve inertia-damping coordination tuning, and the controller parameters were adaptively adjusted by the trend of the power angle of the parallel system. Finally, a time-domain simulation model of the parallel system of GFL-GFM converters was established based on the Matlab/Simulink platform. Through comparisons with traditional control methods and tests under voltage sag conditions of varying degrees, the effectiveness of the proposed transient control method was verified from multiple aspects. [Results] The results showed that compared with the traditional PLL freezing of GFL converter and the additional power control strategy of GFM converter, the proposed control method significantly reduced the amplitude of the power angle oscillation of GFL-GFM converters, greatly shortened the oscillation period, and adapted well to both mild and severe voltage sag conditions. The proposed control method effectively ensured the transient stability of the GFL-GFM converters parallel system during the whole fault process, and it also reduced the power angle oscillation deviation by more than 5%. [Conclusion] The proposed method enhances the adaptability and robustness of GFL-GFM converters parallel system under voltage sag of varying degrees, providing a new idea for the stable operation of grid-connected system with high proportion of power electronic equipment, which has good application value.
2025,52(9):935-943, DOI: 10.12177/emca.2025.083
Abstract:
[Objective] Laser communication, laser tracking and measurement, and anti-unmanned aerial vehicle system require high servo performance in optoelectronic tracking systems. However, the existing solutions based on industrial computers or commercial controllers are often constrained by closed technology, limited potential for secondary development, and large physical footprints, thereby failing to meet the demand for miniaturization and integration. There is a strong need for a more portable and efficient servo control system. [Methods] This paper designed an embedded integrated servo controller based on a microcontroller, which adopted the synergistic architecture of field programmable gate array and STM32, and offered high customizability and flexible interface expansion. At the same time, a switching control algorithm incorporating a smoothing factor was introduced to improve the traditional proportional integral derivative (PID) control, which effectively optimized the overshoot and dynamic tracking error of the optoelectronic tracking turntable. [Results] Based on the designed servo control system and the improved servo control algorithm, the design of a high-precision servo control system for optoelectronic tracking system was realized, which solved the problems of the limitations of the encoder feedback rate on the servo frequency as well as the insufficient number of interfaces of commercial control board. And the experiments were carried out on a two-axis turntable. The experimental results showed that compared with the traditional PID control, the proposed switching PID control incorporating a smoothing factor resulted in a 23.36% reduction in the overshoot and a 59.2% reduction in the sine tracking error. [Conclusion] The servo control system designed in this paper can meet the demand of miniaturization and integration of the modern optoelectronic tracking system and has good expandability, and the proposed algorithm can effectively reduce the overshoot of the system and improve the dynamic performance of the system.
[Objective] Laser communication, laser tracking and measurement, and anti-unmanned aerial vehicle system require high servo performance in optoelectronic tracking systems. However, the existing solutions based on industrial computers or commercial controllers are often constrained by closed technology, limited potential for secondary development, and large physical footprints, thereby failing to meet the demand for miniaturization and integration. There is a strong need for a more portable and efficient servo control system. [Methods] This paper designed an embedded integrated servo controller based on a microcontroller, which adopted the synergistic architecture of field programmable gate array and STM32, and offered high customizability and flexible interface expansion. At the same time, a switching control algorithm incorporating a smoothing factor was introduced to improve the traditional proportional integral derivative (PID) control, which effectively optimized the overshoot and dynamic tracking error of the optoelectronic tracking turntable. [Results] Based on the designed servo control system and the improved servo control algorithm, the design of a high-precision servo control system for optoelectronic tracking system was realized, which solved the problems of the limitations of the encoder feedback rate on the servo frequency as well as the insufficient number of interfaces of commercial control board. And the experiments were carried out on a two-axis turntable. The experimental results showed that compared with the traditional PID control, the proposed switching PID control incorporating a smoothing factor resulted in a 23.36% reduction in the overshoot and a 59.2% reduction in the sine tracking error. [Conclusion] The servo control system designed in this paper can meet the demand of miniaturization and integration of the modern optoelectronic tracking system and has good expandability, and the proposed algorithm can effectively reduce the overshoot of the system and improve the dynamic performance of the system.
2025,52(9):944-956, DOI: 10.12177/emca.2025.091
Abstract:
[Objective] BUCK circuits are widely used in new energy vehicle on-board power systems, industrial motor drives and other scenarios. In the application and realization of doubly-fed linear motor (DFLM), it is necessary to design a BUCK circuit for level shifting between the on-board battery pack and the DC bus capacitor of the motor to realize its contactless feeding function. However, the ringing of this BUCK circuit introduces high-frequency noise to the DC bus capacitor, which affects the current control of the driver side of the DFLM. To address this problem, this paper proposes a ringing simulation method and suppression strategy, aiming at suppressing high-frequency ringing to provide a basis for the current control of the driver side. [Methods] Firstly, the causes of high-frequency ringing of silicon carbide metal-oxide-silicon field effect transistor (SiC MOSFET) with Kelvin source in a BUCK circuit topology were analyzed. Then, specific values of each parasitic parameter were obtained by fitting the experimental data. Finally, for the ringing suppression objective, the selection of RCD snubber circuit was optimally designed through simulation to reduce the time cost of experimenting with different selections. [Results] The error of the system simulation results obtained through parameter identification was reduced by about 20% compared to the error caused by empirical value selection. According to the proposed value selection method, the turn-off ringing overshoot voltage was reduced by 83.0% and the turn-on ringing overshoot voltage was reduced by 83.6%. [Conclusion] In this paper, a method to optimize the snubber circuit selection is proposed. Simulation and experimental results show that this method can accurately obtain the circuit parasitic parameters through a small amount of experimental data, and select components to meet the requirements for SiC MOSFET switch ringing suppression, so that the spike voltage and device switching speed are operated in the system optimal range.
[Objective] BUCK circuits are widely used in new energy vehicle on-board power systems, industrial motor drives and other scenarios. In the application and realization of doubly-fed linear motor (DFLM), it is necessary to design a BUCK circuit for level shifting between the on-board battery pack and the DC bus capacitor of the motor to realize its contactless feeding function. However, the ringing of this BUCK circuit introduces high-frequency noise to the DC bus capacitor, which affects the current control of the driver side of the DFLM. To address this problem, this paper proposes a ringing simulation method and suppression strategy, aiming at suppressing high-frequency ringing to provide a basis for the current control of the driver side. [Methods] Firstly, the causes of high-frequency ringing of silicon carbide metal-oxide-silicon field effect transistor (SiC MOSFET) with Kelvin source in a BUCK circuit topology were analyzed. Then, specific values of each parasitic parameter were obtained by fitting the experimental data. Finally, for the ringing suppression objective, the selection of RCD snubber circuit was optimally designed through simulation to reduce the time cost of experimenting with different selections. [Results] The error of the system simulation results obtained through parameter identification was reduced by about 20% compared to the error caused by empirical value selection. According to the proposed value selection method, the turn-off ringing overshoot voltage was reduced by 83.0% and the turn-on ringing overshoot voltage was reduced by 83.6%. [Conclusion] In this paper, a method to optimize the snubber circuit selection is proposed. Simulation and experimental results show that this method can accurately obtain the circuit parasitic parameters through a small amount of experimental data, and select components to meet the requirements for SiC MOSFET switch ringing suppression, so that the spike voltage and device switching speed are operated in the system optimal range.
2025,52(9):957-970, DOI: 10.12177/emca.2025.082
Abstract:
[Objective] To provide important theoretical basis and technical references for the selection of open phase fault diagnosis methods and the formulation of fault-tolerant control strategies for the dual three-phase permanent magnet synchronous motor (DTP-PMSM), this paper investigates the fault characteristics of the DTP-PMSMs with open phase, including the current, voltage, torque, copper loss, and efficiency, as well as the impacts of the faults on the motor. [Methods] Firstly, the vector space completely decoupling control of DTP-PMSM was briefly introduced. Secondly, based on the dual three-phase vector space completely decoupling theory and dual-dq transform theory, the general expression of the current of DTP-PMSM with open phase fault was given by using the symmetric component method according to the asymmetric system characteristics of the motor during the fault. Then, the torque, copper loss, efficiency and voltage in different coordinate systems were systematically analyzed and evaluated and compared with the performance of the motor during normal operation. Finally, experiments were conducted on the DTP-PMSM under both normal and open phase operation, comparing the experimental results with theoretical analysis and simulation results from time-domain and vector diagram perspectives. [Results] The experimental results indicated that when the DTP-PMSM adopted vector space completely decoupling control and experienced an open phase fault, the amplitude of the remaining healthy phase currents increased. The trajectory of iαβ and uαβ in the fundamental subspace became distorted, and the harmonic currents and voltages escalated. At the same time, the DC component of copper loss increased by 38. 09%, the second harmonic torque increased up to 40.76% of its DC component, and the efficiency decreased by 11.85%. [Conclusion] The experimental results validate the correctness of the theoretical analysis and simulation results on the open phase fault characteristics of the DTP-PMSM proposed in this paper, and provide support for subsequent fault-tolerant control and fault detection in DTP-PMSM under open phase fault conditions.
[Objective] To provide important theoretical basis and technical references for the selection of open phase fault diagnosis methods and the formulation of fault-tolerant control strategies for the dual three-phase permanent magnet synchronous motor (DTP-PMSM), this paper investigates the fault characteristics of the DTP-PMSMs with open phase, including the current, voltage, torque, copper loss, and efficiency, as well as the impacts of the faults on the motor. [Methods] Firstly, the vector space completely decoupling control of DTP-PMSM was briefly introduced. Secondly, based on the dual three-phase vector space completely decoupling theory and dual-dq transform theory, the general expression of the current of DTP-PMSM with open phase fault was given by using the symmetric component method according to the asymmetric system characteristics of the motor during the fault. Then, the torque, copper loss, efficiency and voltage in different coordinate systems were systematically analyzed and evaluated and compared with the performance of the motor during normal operation. Finally, experiments were conducted on the DTP-PMSM under both normal and open phase operation, comparing the experimental results with theoretical analysis and simulation results from time-domain and vector diagram perspectives. [Results] The experimental results indicated that when the DTP-PMSM adopted vector space completely decoupling control and experienced an open phase fault, the amplitude of the remaining healthy phase currents increased. The trajectory of iαβ and uαβ in the fundamental subspace became distorted, and the harmonic currents and voltages escalated. At the same time, the DC component of copper loss increased by 38. 09%, the second harmonic torque increased up to 40.76% of its DC component, and the efficiency decreased by 11.85%. [Conclusion] The experimental results validate the correctness of the theoretical analysis and simulation results on the open phase fault characteristics of the DTP-PMSM proposed in this paper, and provide support for subsequent fault-tolerant control and fault detection in DTP-PMSM under open phase fault conditions.
2025,52(9):971-984, DOI: 10.12177/emca.2025.079
Abstract:
[Objective] AC microgrid back-to-back DC interconnect converters have significant power stability differences between the AC and DC sides in bidirectional power transmission, which may lead to a decrease in system stability and easily cause system instability. [Methods] The impedance characteristics of each port were analyzed through small signal modeling, and the bidirectional power stability of the AC and DC sides of the system was compared and analyzed by combining impedance expressions and Nyquist stability criteria. Aiming at the problems of negative impedance and bidirectional power stability differences under the traditional control, a port impedance coordinated optimization control strategy was proposed to simultaneously optimize the impedance of the three ports in the system. A voltage-power cooperative adjustment mechanism was introduced for the negative impedance on the AC side to achieve adaptive correction of the equivalent impedance characteristics through multivariate dynamic coupling. [Results] A Matlab/Simulink simulation model and a low-power prototype experimental platform were constructed, the simulation and experimental results showed that the proposed optimization control not only optimized the negative impedance of both the AC and DC sides of the system to the positive impedance, but also reduced the phase difference between the impedances on the DC side to zero, which greatly improved the stability margin of the system and enhanced the system bidirectional power stability. [Conclusion] The proposed port impedance coordinated optimization control strategy can effectively solve the problem of bidirectional power stability differences in back-to-back converter systems.
[Objective] AC microgrid back-to-back DC interconnect converters have significant power stability differences between the AC and DC sides in bidirectional power transmission, which may lead to a decrease in system stability and easily cause system instability. [Methods] The impedance characteristics of each port were analyzed through small signal modeling, and the bidirectional power stability of the AC and DC sides of the system was compared and analyzed by combining impedance expressions and Nyquist stability criteria. Aiming at the problems of negative impedance and bidirectional power stability differences under the traditional control, a port impedance coordinated optimization control strategy was proposed to simultaneously optimize the impedance of the three ports in the system. A voltage-power cooperative adjustment mechanism was introduced for the negative impedance on the AC side to achieve adaptive correction of the equivalent impedance characteristics through multivariate dynamic coupling. [Results] A Matlab/Simulink simulation model and a low-power prototype experimental platform were constructed, the simulation and experimental results showed that the proposed optimization control not only optimized the negative impedance of both the AC and DC sides of the system to the positive impedance, but also reduced the phase difference between the impedances on the DC side to zero, which greatly improved the stability margin of the system and enhanced the system bidirectional power stability. [Conclusion] The proposed port impedance coordinated optimization control strategy can effectively solve the problem of bidirectional power stability differences in back-to-back converter systems.
2025,52(9):985-994, DOI: 10.12177/emca.2025.087
Abstract:
[Objective] The aim of this paper is to investigate whether the voltage amplitude of the high-frequency square wave injection signals used in oriented silicon steel permanent magnet synchronous linear motor (PMSLM) can be lower than that of non-oriented silicon steel PMSLM when a high-frequency injection method is used for sensorless control to estimate the motor position. [Methods] Firstly, the mathematical model of PMSLM was established based on Simulink. Then, the position estimation of the PMSLM mathematical model was performed using a control method combining vector control, position velocity current triple closed-loop proportional integral control and high-frequency injection method. Finally, the model in Simulink was imported into the PMSLM through the RTU-BOX fast model for experiment, and the experimental results of the oriented silicon steel PMSLM and the non-oriented silicon steel PMSLM were compared. [Results] The initial injection voltage amplitude was set to 4.8 V. At this time, the absolute value of the estimated position error of the non-oriented silicon steel PMSLM obtained by the high-frequency injection method was less than 15%. Decreasing the injected voltage amplitude in steps of 0.1 V, the absolute values of the estimated position errors of the non-oriented silicon steel PMSLM were all less than 15% when the voltage amplitude was in the range of 4.8~0.4 V. The absolute value of the estimated position error of the non-oriented silicon steel PMSLM was greater than 15% when the voltage amplitude was reduced to 0.3 V, while the absolute value of the position error of the oriented silicon steel PMSLM was less than 15% at this point. [Conclusion] The anisotropy of oriented silicon steel can change the magnetic permeability, and the amplitude of the injection voltage for position estimation using the high-frequency injection method can be lower compared to that of non-oriented silicon steel.
[Objective] The aim of this paper is to investigate whether the voltage amplitude of the high-frequency square wave injection signals used in oriented silicon steel permanent magnet synchronous linear motor (PMSLM) can be lower than that of non-oriented silicon steel PMSLM when a high-frequency injection method is used for sensorless control to estimate the motor position. [Methods] Firstly, the mathematical model of PMSLM was established based on Simulink. Then, the position estimation of the PMSLM mathematical model was performed using a control method combining vector control, position velocity current triple closed-loop proportional integral control and high-frequency injection method. Finally, the model in Simulink was imported into the PMSLM through the RTU-BOX fast model for experiment, and the experimental results of the oriented silicon steel PMSLM and the non-oriented silicon steel PMSLM were compared. [Results] The initial injection voltage amplitude was set to 4.8 V. At this time, the absolute value of the estimated position error of the non-oriented silicon steel PMSLM obtained by the high-frequency injection method was less than 15%. Decreasing the injected voltage amplitude in steps of 0.1 V, the absolute values of the estimated position errors of the non-oriented silicon steel PMSLM were all less than 15% when the voltage amplitude was in the range of 4.8~0.4 V. The absolute value of the estimated position error of the non-oriented silicon steel PMSLM was greater than 15% when the voltage amplitude was reduced to 0.3 V, while the absolute value of the position error of the oriented silicon steel PMSLM was less than 15% at this point. [Conclusion] The anisotropy of oriented silicon steel can change the magnetic permeability, and the amplitude of the injection voltage for position estimation using the high-frequency injection method can be lower compared to that of non-oriented silicon steel.
2025,52(9):995-1005, DOI: 10.12177/emca.2025.086
Abstract:
[Objective] With the continuous development and improvement of microgrid technology, the use of renewable energy is increasingly valued. The impact of source-load uncertainty on microgrid security as well as economic operation cannot be ignored, and in order to solve the problem of optimal economic operation of microgrid, a hybrid Harris Hawk optimization (HHHO) algorithm is proposed. [Methods] Firstly, an optimal microgrid scheduling model considering source-load uncertainty was developed. Secondly, a HHHO algorithm combining elite strategy and differential learning mechanism was proposed. The elite strategy improved the convergence speed of the algorithm by retaining the elite individuals in the population. The differential learning mechanism optimized the accuracy of the algorithm’s search by enhancing the dissemination of valid information. Then, a hybrid scene reduction method based on Latin hypercubic sampling-probabilistic distance was proposed, and the reduced equivalent scene was used as the basis for the economic operation of the microgrid. Finally, the superiority of the proposed HHHO algorithm was verified by test functions and scene simulations. [Results] The test function experimental results showed that the proposed HHHO algorithm had high solution accuracy and fast convergence speed. Simulation results in scenarios such as wind and photovoltaic fluctuations showed that the HHHO algorithm was highly superior and significantly reduced the overall operating cost of the microgrid. [Conclusion] The proposed HHHO algorithm enables optimal economic operation of microgrids and provides theoretical support for long-term economic operation of microgrid.
[Objective] With the continuous development and improvement of microgrid technology, the use of renewable energy is increasingly valued. The impact of source-load uncertainty on microgrid security as well as economic operation cannot be ignored, and in order to solve the problem of optimal economic operation of microgrid, a hybrid Harris Hawk optimization (HHHO) algorithm is proposed. [Methods] Firstly, an optimal microgrid scheduling model considering source-load uncertainty was developed. Secondly, a HHHO algorithm combining elite strategy and differential learning mechanism was proposed. The elite strategy improved the convergence speed of the algorithm by retaining the elite individuals in the population. The differential learning mechanism optimized the accuracy of the algorithm’s search by enhancing the dissemination of valid information. Then, a hybrid scene reduction method based on Latin hypercubic sampling-probabilistic distance was proposed, and the reduced equivalent scene was used as the basis for the economic operation of the microgrid. Finally, the superiority of the proposed HHHO algorithm was verified by test functions and scene simulations. [Results] The test function experimental results showed that the proposed HHHO algorithm had high solution accuracy and fast convergence speed. Simulation results in scenarios such as wind and photovoltaic fluctuations showed that the HHHO algorithm was highly superior and significantly reduced the overall operating cost of the microgrid. [Conclusion] The proposed HHHO algorithm enables optimal economic operation of microgrids and provides theoretical support for long-term economic operation of microgrid.
2025,52(9):1006-1015, DOI: 10.12177/emca.2025.080
Abstract:
[Objective] Aiming at the problems of designing and tuning the weighting factors of the model predictive torque control (MPTC) of dual three-phase permanent magnet synchronous motor (DTP-PMSM) and the high harmonic currents in the x-y plane, an improved MPTC method with fuzzy unweighted factor based on virtual vectors was proposed. [Methods] Firstly, the tracking errors of torque and flux linkage were constrained by fuzzy dynamic boundary conditions, respectively, and the selection of voltage vectors was carried out under the constraint boundaries. The selected voltage vectors were required to keep the tracking errors of the torque and flux linkage within the boundary conditions, respectively. The two sets of vectors that meet the two boundary conditions were intersected according to set rules to select the optimal vector. Secondly, a set of virtual voltage vectors synthesized from four vectors was introduced as an alternative set of vectors to suppress the harmonic currents of the system. Finally, the improved MPTC proposed in this paper was compared and analyzed with the traditional MPTC, virtual vector-based MPTC and relative error rate cost function-based MPTC through simulation. [Results] The simulation results showed that compared with the traditional MPTC, virtual vector-based MPTC and relative error rate cost function-based MPTC, the total harmonic distortion of phase current of the improved MPTC proposed in this paper was reduced by 87.53%, 26.57% and 35.05%, respectively. The root mean square error of flux linkage ripple was reduced by 69.23%, 50% and 20%, and the root mean square error of torque ripple was reduced by 6.15%, 4.95% and 3.89%, respectively. The regulation time at load start-up was reduced by 15.7%, 22.9% and 44.8%, respectively, with smaller steady-state error and faster response. [Conclusion] The control method proposed in this paper not only achieves effective control of torque and flux linkage in DTP-PMSMs, but also eliminates the uncertainty introduced by the weighting factor, improves the dynamic performance of the system, and effectively suppresses the harmonic currents in the x-y plane, which has good feasibility.
[Objective] Aiming at the problems of designing and tuning the weighting factors of the model predictive torque control (MPTC) of dual three-phase permanent magnet synchronous motor (DTP-PMSM) and the high harmonic currents in the x-y plane, an improved MPTC method with fuzzy unweighted factor based on virtual vectors was proposed. [Methods] Firstly, the tracking errors of torque and flux linkage were constrained by fuzzy dynamic boundary conditions, respectively, and the selection of voltage vectors was carried out under the constraint boundaries. The selected voltage vectors were required to keep the tracking errors of the torque and flux linkage within the boundary conditions, respectively. The two sets of vectors that meet the two boundary conditions were intersected according to set rules to select the optimal vector. Secondly, a set of virtual voltage vectors synthesized from four vectors was introduced as an alternative set of vectors to suppress the harmonic currents of the system. Finally, the improved MPTC proposed in this paper was compared and analyzed with the traditional MPTC, virtual vector-based MPTC and relative error rate cost function-based MPTC through simulation. [Results] The simulation results showed that compared with the traditional MPTC, virtual vector-based MPTC and relative error rate cost function-based MPTC, the total harmonic distortion of phase current of the improved MPTC proposed in this paper was reduced by 87.53%, 26.57% and 35.05%, respectively. The root mean square error of flux linkage ripple was reduced by 69.23%, 50% and 20%, and the root mean square error of torque ripple was reduced by 6.15%, 4.95% and 3.89%, respectively. The regulation time at load start-up was reduced by 15.7%, 22.9% and 44.8%, respectively, with smaller steady-state error and faster response. [Conclusion] The control method proposed in this paper not only achieves effective control of torque and flux linkage in DTP-PMSMs, but also eliminates the uncertainty introduced by the weighting factor, improves the dynamic performance of the system, and effectively suppresses the harmonic currents in the x-y plane, which has good feasibility.
2025,52(9):1016-1025, DOI: 10.12177/emca.2025.084
Abstract:
[Objective] Circumferential staggered switched reluctance motor (SRM) utilizes auxiliary winding to compensate for torque drop in the main winding during commutation, which is of positive significance in suppressing the inherent torque ripple problem of SRM. Sector division is a critical factor affecting the efficacy of direct instantaneous torque control (DITC). [Methods] Firstly, the torque ripple suppression effect as well as the switching losses were considered comprehensively, and the turn-on and turn-off angles of the auxiliary winding were optimized by parametric methods. Then, a twelve-sector DITC strategy was developed by introducing the main winding advance conduction mechanism. Finally, a field-circuit coupled co-simulation model of circumferential staggered SRM was established to compare the operating performance between the nine-sector DITC strategy and twelve-sector DITC strategy with optimized turn-on and turn-off angles. [Results] The simulation results showed that compared with the nine-sector DITC strategy, the twelve-sector DITC strategy with optimized turn-on and turn-off angles significantly reduced the torque ripple coefficient by about 84%, and the torque per ampere also improved considerably by about 54%. Moreover, the main winding current of the demagnetized phase exhibited no current spike at the end of commutation, thereby alleviating its torque output burden during commutation and ensuring smoother current and torque transitions throughout the process. [Conclusion] The proposed twelve-sector DITC strategy effectively reduces the torque ripple during the commutation process of circumferential staggered SRM and enhances the torque per ampere and the system operating efficiency. It significantly enhances the smoothness of current profiles in the commutation region and the steady-state performance of the motor.
[Objective] Circumferential staggered switched reluctance motor (SRM) utilizes auxiliary winding to compensate for torque drop in the main winding during commutation, which is of positive significance in suppressing the inherent torque ripple problem of SRM. Sector division is a critical factor affecting the efficacy of direct instantaneous torque control (DITC). [Methods] Firstly, the torque ripple suppression effect as well as the switching losses were considered comprehensively, and the turn-on and turn-off angles of the auxiliary winding were optimized by parametric methods. Then, a twelve-sector DITC strategy was developed by introducing the main winding advance conduction mechanism. Finally, a field-circuit coupled co-simulation model of circumferential staggered SRM was established to compare the operating performance between the nine-sector DITC strategy and twelve-sector DITC strategy with optimized turn-on and turn-off angles. [Results] The simulation results showed that compared with the nine-sector DITC strategy, the twelve-sector DITC strategy with optimized turn-on and turn-off angles significantly reduced the torque ripple coefficient by about 84%, and the torque per ampere also improved considerably by about 54%. Moreover, the main winding current of the demagnetized phase exhibited no current spike at the end of commutation, thereby alleviating its torque output burden during commutation and ensuring smoother current and torque transitions throughout the process. [Conclusion] The proposed twelve-sector DITC strategy effectively reduces the torque ripple during the commutation process of circumferential staggered SRM and enhances the torque per ampere and the system operating efficiency. It significantly enhances the smoothness of current profiles in the commutation region and the steady-state performance of the motor.
2025,52(9):1026-1038, DOI: 10.12177/emca.2025.090
Abstract:
[Objective] The high proportion of distributed photovoltaic (DPV) integration changes the operation of the active distribution network (ADN), and the randomness and volatility of PV output leads to excessive active losses, increased voltage fluctuations, and unbalanced reactive power allocation in the distribution network. Therefore, this paper proposes a network partition voltage control method based on improved electrical distance, aiming to achieve partition voltage control for ADN with high proportion DPV. [Methods] In view of the large scale and high computational complexity of the decision variables and constraints of the centralized voltage optimization model in a high percentage of PV scenarios, this paper firstly proposed a network partition method based on the improvement of the electrical distance, which divided the ADN into multiple controllable sub-regions to reduce the solution scale. Secondly, a distributed voltage control strategy was designed for the voltage coordination problem at the boundary nodes of adjacent sub-region in the partition. Finally, a distributed solution method based on the slime mold algorithm was used to achieve an efficient solution for this strategy. [Results] Simulation verification was carried out using the IEEE 33 node model and a 199 node real system in the Qujing of Yunnan Province. The results showed that the proposed partition-based distributed voltage control optimization method not only effectively maintained the system voltage level, but also its distributed solution efficiency was significantly better than the centralized optimization method. [Conclusion] The proposed method successfully realizes the cooperative control of voltage in each sub-region and effectively maintains the system voltage level.
[Objective] The high proportion of distributed photovoltaic (DPV) integration changes the operation of the active distribution network (ADN), and the randomness and volatility of PV output leads to excessive active losses, increased voltage fluctuations, and unbalanced reactive power allocation in the distribution network. Therefore, this paper proposes a network partition voltage control method based on improved electrical distance, aiming to achieve partition voltage control for ADN with high proportion DPV. [Methods] In view of the large scale and high computational complexity of the decision variables and constraints of the centralized voltage optimization model in a high percentage of PV scenarios, this paper firstly proposed a network partition method based on the improvement of the electrical distance, which divided the ADN into multiple controllable sub-regions to reduce the solution scale. Secondly, a distributed voltage control strategy was designed for the voltage coordination problem at the boundary nodes of adjacent sub-region in the partition. Finally, a distributed solution method based on the slime mold algorithm was used to achieve an efficient solution for this strategy. [Results] Simulation verification was carried out using the IEEE 33 node model and a 199 node real system in the Qujing of Yunnan Province. The results showed that the proposed partition-based distributed voltage control optimization method not only effectively maintained the system voltage level, but also its distributed solution efficiency was significantly better than the centralized optimization method. [Conclusion] The proposed method successfully realizes the cooperative control of voltage in each sub-region and effectively maintains the system voltage level.
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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.
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Electric Machines & Control Application ® 2025
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沪ICP备16038578号-3
Electric Machines & Control Application ® 2025
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
