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Volume 49,Issue 4,2022 Table of Contents
2022, 49(4):1-9.
DOI: 10.12177/emca.2022.003
Abstract:
Motor is the core equipment of electric energy conversion. It is used to drive various production equipment. The safe and continuous operation of motor directly affects the national economy and social development. Among different kinds of motors, asynchronous motors have wide applications and are operated under different conditions, so the fault diagnosis of asynchronous motors have attracted much attention. The importance and main problems of fault diagnosis of asynchronous motors are summarized, and the artificial intelligence technology of fault detection in this field in recent years is discussed detailedly. The key directions and work in the near future are also put forward.
Motor is the core equipment of electric energy conversion. It is used to drive various production equipment. The safe and continuous operation of motor directly affects the national economy and social development. Among different kinds of motors, asynchronous motors have wide applications and are operated under different conditions, so the fault diagnosis of asynchronous motors have attracted much attention. The importance and main problems of fault diagnosis of asynchronous motors are summarized, and the artificial intelligence technology of fault detection in this field in recent years is discussed detailedly. The key directions and work in the near future are also put forward.
2022, 49(4):10-15.
DOI: 10.12177/emca.2021.208
Abstract:
The position tracking accuracy of permanent magnet linear synchronous motor (PMLSM) servo system is susceptible to uncertain factors such as friction and load disturbance. In view of the problem, a nonsingular fast terminal sliding mode control (NFTSMC) method based on friction and disturbance compensation is used to design the position controller. Firstly, the PMLSM dynamic model with Stribeck friction model is established, and the natural selection particle swarm optimization (PSO) algorithm is used to identify the off\|line parameters of the friction model. Secondly, the NFTSMC method is used to ensure the rapid convergence of the system state and avoid singular problems, and the identified friction model is used for compensation. Finally, the sliding mode observer is used to observe and compensate the total uncertainty, which weakens the chattering phenomenon. Simulation results verify that the control strategy improves the position tracking accuracy, and has fast convergence and strong disturbance immunity.
The position tracking accuracy of permanent magnet linear synchronous motor (PMLSM) servo system is susceptible to uncertain factors such as friction and load disturbance. In view of the problem, a nonsingular fast terminal sliding mode control (NFTSMC) method based on friction and disturbance compensation is used to design the position controller. Firstly, the PMLSM dynamic model with Stribeck friction model is established, and the natural selection particle swarm optimization (PSO) algorithm is used to identify the off\|line parameters of the friction model. Secondly, the NFTSMC method is used to ensure the rapid convergence of the system state and avoid singular problems, and the identified friction model is used for compensation. Finally, the sliding mode observer is used to observe and compensate the total uncertainty, which weakens the chattering phenomenon. Simulation results verify that the control strategy improves the position tracking accuracy, and has fast convergence and strong disturbance immunity.
2022, 49(4):16-23,59.
DOI: 10.12177/emca.2021.192
Abstract:
In order to realize the quantitative control of the flux and torque in permanent magnet synchronous motor (PMSM), based on the simplified models of flux and torque variation, the deadbeat (DB) control for PMSM is proposed. The torque angle is important to DB control. It can be obtained through look\|up table or the d and q components of stator flux. However, the former needs lots of memory space and the latter needs rotor flux position information. To solve these problems, the back propagation (BP) neural network is used to predict torque angle. Another BP neural network is used to predict the angle of ideal voltage vector to replace conventional calculation. Thus, the DB control of stator flux and torque for PMSM with dual BP neural networks is established. Simulation results show that the BP neural networks can be used to output torque angle and the angle of ideal voltage vector and the motor system works properly.
In order to realize the quantitative control of the flux and torque in permanent magnet synchronous motor (PMSM), based on the simplified models of flux and torque variation, the deadbeat (DB) control for PMSM is proposed. The torque angle is important to DB control. It can be obtained through look\|up table or the d and q components of stator flux. However, the former needs lots of memory space and the latter needs rotor flux position information. To solve these problems, the back propagation (BP) neural network is used to predict torque angle. Another BP neural network is used to predict the angle of ideal voltage vector to replace conventional calculation. Thus, the DB control of stator flux and torque for PMSM with dual BP neural networks is established. Simulation results show that the BP neural networks can be used to output torque angle and the angle of ideal voltage vector and the motor system works properly.
2022, 49(4):24-30.
DOI: 10.12177/emca.2021.213
Abstract:
In the permanent magnet synchronous motor (PMSM) double-closed-loop speed control system, the current loop as the inner loop restricts the dynamic responsiveness of the control system directly. Deadbeat predictive current control (DPCC) has the advantages of simple algorithm and fast dynamic response, but DPCC requires an accurate motor model. The mismatch of parameters can cause current static error and distortion, especially the mismatch of inductance. It can cause instability of the control system. To solve the above problems, an improved DPCC algorithm is proposed. The discrete transfer function of traditional DPCC is deduced, and the influence of its parameter sensitivity is analyzed. The DPCC algorithm is further improved to achieve better inductance parameter sensitivity, effectively expand the applicable range of inductance, and reduce current distortion. The effectiveness of the improved DPCC under inductance mismatch is verified by MATLAB/Simulink simulation and experiments.
In the permanent magnet synchronous motor (PMSM) double-closed-loop speed control system, the current loop as the inner loop restricts the dynamic responsiveness of the control system directly. Deadbeat predictive current control (DPCC) has the advantages of simple algorithm and fast dynamic response, but DPCC requires an accurate motor model. The mismatch of parameters can cause current static error and distortion, especially the mismatch of inductance. It can cause instability of the control system. To solve the above problems, an improved DPCC algorithm is proposed. The discrete transfer function of traditional DPCC is deduced, and the influence of its parameter sensitivity is analyzed. The DPCC algorithm is further improved to achieve better inductance parameter sensitivity, effectively expand the applicable range of inductance, and reduce current distortion. The effectiveness of the improved DPCC under inductance mismatch is verified by MATLAB/Simulink simulation and experiments.
2022, 49(4):31-38.
DOI: 10.12177/emca.2021.218
Abstract:
The non-zero vector pulse width modulation (NZVPWM) wave technology suppresses the common-mode voltage (CMV) of the three-phase inverter. But its dead zone effect can cause the failure of common-mode suppression. An improved active zero space vector pulse width modulation (AZSVPWM) technology is proposed, and the dead zone constraint conditions which can achieve full modulation are analyzed. By setting a reasonable dead zone range, the common mode voltage can be effectively suppressed in a wide modulation range. The simulation and experimental results verify the validity of the analysis.
The non-zero vector pulse width modulation (NZVPWM) wave technology suppresses the common-mode voltage (CMV) of the three-phase inverter. But its dead zone effect can cause the failure of common-mode suppression. An improved active zero space vector pulse width modulation (AZSVPWM) technology is proposed, and the dead zone constraint conditions which can achieve full modulation are analyzed. By setting a reasonable dead zone range, the common mode voltage can be effectively suppressed in a wide modulation range. The simulation and experimental results verify the validity of the analysis.
2022, 49(4):39-44，65.
DOI: 10.12177/emca.2021.209
Abstract:
Homopolar inductor machines (HIMs) have broad application prospects in the fields of flywheel energy storage system, pulsed alternator and so on with the characteristics of brushless excitation and simple structure. Firstly, the topology and operating principle of the HIM are given. Seconldy, the influences of rotor with the rectangular, arc and sinusoidal slots on the electromagnetic properties such as air-gap flux density, back electromotive force (EMF) and torque are studied by finite element method. Thirdly, the stress distribution of rotors with different slot shapes under high-speed rotation is studied. Considering the electromagnetic and mechanical characteristics, an HIM with an arc slot rotor structure is selected as the object to analyze its performance. Finally, a prototype of HIM is tested to verify the rationality of the analysis. The results show that although the sinusoidal slot rotor can obtain a more sinusoidal air-gap flux density, its fundamental wave component is about 25.2% and 24.3% less than those of the rectangular and arc slots under the same slot depth, and the output torque is low. In addition, the rectangular and sinusoidal slots have obvious stress concentration, which are located at the root of the rotor salient pole and the slot surface respectively, while the rotor with arc slot has a more uniform stress distribution.
Homopolar inductor machines (HIMs) have broad application prospects in the fields of flywheel energy storage system, pulsed alternator and so on with the characteristics of brushless excitation and simple structure. Firstly, the topology and operating principle of the HIM are given. Seconldy, the influences of rotor with the rectangular, arc and sinusoidal slots on the electromagnetic properties such as air-gap flux density, back electromotive force (EMF) and torque are studied by finite element method. Thirdly, the stress distribution of rotors with different slot shapes under high-speed rotation is studied. Considering the electromagnetic and mechanical characteristics, an HIM with an arc slot rotor structure is selected as the object to analyze its performance. Finally, a prototype of HIM is tested to verify the rationality of the analysis. The results show that although the sinusoidal slot rotor can obtain a more sinusoidal air-gap flux density, its fundamental wave component is about 25.2% and 24.3% less than those of the rectangular and arc slots under the same slot depth, and the output torque is low. In addition, the rectangular and sinusoidal slots have obvious stress concentration, which are located at the root of the rotor salient pole and the slot surface respectively, while the rotor with arc slot has a more uniform stress distribution.
2022, 49(4):45-52.
DOI: 10.12177/emca.2021.210
Abstract:
In response to the issues of complex manufacturing and hard maintenance caused by the large volume flat-|type permanent magnet linear motor in the low speed and large thrust linear drive field, a polygon combined permanent magnet linear synchronous motor (PCPMLSM) is described. PCPMLSM laminated along the circumferential direction eliminates eddy current effect. A 20-pole 24-slot PCPMLSM is analyzed by the 3D finite element method (FEM). Aiming at the problems of limited location accuracy and deterioration of thrust characteristics caused by the end force of the motor with this structure, the non-periodic variation rule of single end force caused by asymmetry of the end flux is studied. This phenomenon is weakened by using the mean value of the single end forces when the number of magnetic poles connected with the primary core is odd and even. On this basis, the method of reducing the end force by combining the optimization of the primary core length and the unequal width dislocation of the end teeth on each side is proposed. Finally, the effectiveness of the proposed strategy is verified by FEM.
In response to the issues of complex manufacturing and hard maintenance caused by the large volume flat-|type permanent magnet linear motor in the low speed and large thrust linear drive field, a polygon combined permanent magnet linear synchronous motor (PCPMLSM) is described. PCPMLSM laminated along the circumferential direction eliminates eddy current effect. A 20-pole 24-slot PCPMLSM is analyzed by the 3D finite element method (FEM). Aiming at the problems of limited location accuracy and deterioration of thrust characteristics caused by the end force of the motor with this structure, the non-periodic variation rule of single end force caused by asymmetry of the end flux is studied. This phenomenon is weakened by using the mean value of the single end forces when the number of magnetic poles connected with the primary core is odd and even. On this basis, the method of reducing the end force by combining the optimization of the primary core length and the unequal width dislocation of the end teeth on each side is proposed. Finally, the effectiveness of the proposed strategy is verified by FEM.
2022, 49(4):53-59.
DOI: 10.12177/emca.2021.223
Abstract:
The rotor eccentricity of permanent magnet wind generator will cause uneven distribution of generator air gap and magnetic field imbalance, which aggravate the vibration of the generator, and even cause rotor scrapping in serious cases and result in generator damage and failure. Taking a MW-class permanent magnet wind generator as the analysis object, the influence of air gap eccentricity on generator air gap flux density and radial electromagnetic force is analyzed theoretically. Finite element analysis of transient electromagnetic field of wind generators under different air gap eccentricities is performed, and the distribution characteristics of air gap flux density and radial electromagnetic force under different air gap eccentricities are obtained. Harmonic response analysis of the stator under the radial electromagnetic force is conducted to obtain the response characteristics of the stator caused by air gap eccentricity. The results show that with the increase of air gap eccentricity, the amplitude of air gap density is increased, and new side band components of radial electromagnetic force appear. The amplitudes of harmonics of the operating frequency in the vibration response of generator stator also increase, and the amplitude of the second order radial mode response is the largest. The results can provide a certain theoretical basis for the research of generator air gap monitoring method.
The rotor eccentricity of permanent magnet wind generator will cause uneven distribution of generator air gap and magnetic field imbalance, which aggravate the vibration of the generator, and even cause rotor scrapping in serious cases and result in generator damage and failure. Taking a MW-class permanent magnet wind generator as the analysis object, the influence of air gap eccentricity on generator air gap flux density and radial electromagnetic force is analyzed theoretically. Finite element analysis of transient electromagnetic field of wind generators under different air gap eccentricities is performed, and the distribution characteristics of air gap flux density and radial electromagnetic force under different air gap eccentricities are obtained. Harmonic response analysis of the stator under the radial electromagnetic force is conducted to obtain the response characteristics of the stator caused by air gap eccentricity. The results show that with the increase of air gap eccentricity, the amplitude of air gap density is increased, and new side band components of radial electromagnetic force appear. The amplitudes of harmonics of the operating frequency in the vibration response of generator stator also increase, and the amplitude of the second order radial mode response is the largest. The results can provide a certain theoretical basis for the research of generator air gap monitoring method.
2022, 49(4):60-65.
DOI: 10.12177/emca.2021.212
Abstract:
Different from conventional natural cooling or housing water cooling motor, water is directly used by the internal submersible motor to cool the inside of the motor, which leads to the strong coupling of fluid-solid conjugate heat transfer of the whole machine. In order to improve the reliability and safety of the motor, the coupled heat transfer analysis of flow and temperature fields is very necessary. For a marine air-gap water cooling internal submersible permanent magnet motor, based on the principle of computational fluid dynamics (CFD), the three-dimensional flow and temperature fields are numerically simulated and the geometric structure is improved, eleminating the countercurrent phenomenon of the internal flow field of the motor, improving the heat dissipation efficiency of the whole machine, and optimizing the flow field and temperature rise of the motor. The result has a certain reference significance for the geometric structure design of the internal submersible motor.
Different from conventional natural cooling or housing water cooling motor, water is directly used by the internal submersible motor to cool the inside of the motor, which leads to the strong coupling of fluid-solid conjugate heat transfer of the whole machine. In order to improve the reliability and safety of the motor, the coupled heat transfer analysis of flow and temperature fields is very necessary. For a marine air-gap water cooling internal submersible permanent magnet motor, based on the principle of computational fluid dynamics (CFD), the three-dimensional flow and temperature fields are numerically simulated and the geometric structure is improved, eleminating the countercurrent phenomenon of the internal flow field of the motor, improving the heat dissipation efficiency of the whole machine, and optimizing the flow field and temperature rise of the motor. The result has a certain reference significance for the geometric structure design of the internal submersible motor.
10 Influence of Wind Friction Loss of Rotor on Temperature Rise of High-Speed Permanent Magnet Motor
2022, 49(4):66-70，82.
DOI: 10.12177/emca.2021.216
Abstract:
The high-speed permanent magnet motor has compact structure, high power density and difficult heat dissipation, which would easily cause irreversible demagnetization of the rotor permanent magnet due to excessive temperature rise. Taking a high-speed permanent magnet motor with the rated speed of 30 000 r/min as an example, based on the principles of computational fluid dynamics and numerical heat transfer, from the perspective of practical engineering applications, the wind friction loss of the rotor and temperature rise are calculated and analyzed under different ventilation rates, and compared with the motor temperature rise test results. The research shows that the wind friction loss of rotor accounts for a large proportion of total wind friction loss in the high-speed permanent magnet motor, and the proportion increases with the increase of flow rate. After the ventilation rate reaches a certain value, the heat dissipation of the motor reaches a balance, and the wind friction loss of the rotor increases sharply with the increase of flow rate, which causes the temperature of the permanent magnet to rise. After using water cooling for the motor base, the ventilation rate can be reduced, so that the motor can reach the ideal temperature rise level.
The high-speed permanent magnet motor has compact structure, high power density and difficult heat dissipation, which would easily cause irreversible demagnetization of the rotor permanent magnet due to excessive temperature rise. Taking a high-speed permanent magnet motor with the rated speed of 30 000 r/min as an example, based on the principles of computational fluid dynamics and numerical heat transfer, from the perspective of practical engineering applications, the wind friction loss of the rotor and temperature rise are calculated and analyzed under different ventilation rates, and compared with the motor temperature rise test results. The research shows that the wind friction loss of rotor accounts for a large proportion of total wind friction loss in the high-speed permanent magnet motor, and the proportion increases with the increase of flow rate. After the ventilation rate reaches a certain value, the heat dissipation of the motor reaches a balance, and the wind friction loss of the rotor increases sharply with the increase of flow rate, which causes the temperature of the permanent magnet to rise. After using water cooling for the motor base, the ventilation rate can be reduced, so that the motor can reach the ideal temperature rise level.
2022, 49(4):71-76.
DOI: 10.12177/emca.2021.220
Abstract:
In order to further improve the power density and heat dissipation capacity of the mine-used concentrated winding permanent magnet motor, a new winding cooling structure with cooling water pipe and winding wound parallelly is proposed. Taking a 315 kW concentrated winding permanent magnet motor as an example, a three-dimensional model of the motor is established through reasonable equivalence and assumptions, and the temperature field of the motor is analyzed based on computational fluid dynamics (CFD) method. The effects of different parallel winding methods and different inlet speeds under the same parallel winding method on the heat dissipation of the motor are analyzed, and the optimal heat dissipation method is determined. The simulation analysis shows that the parallel winding of cooling water pipe and winding effectively improves the heat dissipation capacity.
In order to further improve the power density and heat dissipation capacity of the mine-used concentrated winding permanent magnet motor, a new winding cooling structure with cooling water pipe and winding wound parallelly is proposed. Taking a 315 kW concentrated winding permanent magnet motor as an example, a three-dimensional model of the motor is established through reasonable equivalence and assumptions, and the temperature field of the motor is analyzed based on computational fluid dynamics (CFD) method. The effects of different parallel winding methods and different inlet speeds under the same parallel winding method on the heat dissipation of the motor are analyzed, and the optimal heat dissipation method is determined. The simulation analysis shows that the parallel winding of cooling water pipe and winding effectively improves the heat dissipation capacity.
2022, 49(4):77-82.
DOI: 10.12177/emca.2021.217
Abstract:
In order to reduce the temperature rise of high voltage induction motor and strengthen the convective heat transfer inside the motor, taking a high voltage induction motor with the rated power of 1 250 kW as the research object, a new rotor ventilation structure is designed based on computational fluid dynamics theory and convective heat transfer optimization. The three\|dimensional coupling analysis model is established to analyze fluid thermal coupling of the motor. With the help of digital simulation technology, the fluid flow and heat transfer characteristics of each ventilation duct of the motor under the ventilation structure of new and old rotors are calculated and compared. From the perspective of field synergy of convection heat transfer optimization, the temperature rise and temperature distribution of the motor under different rotor ventilation structures are obtained, providing a reference for the optimization design of the ventilation structure of high voltage induction motors. Finally, the temperature rise calculation results of the new motor structure are compared with the type test results of the prototype, and the temperature rise error is only 4%, which verifies the accuracy and validity of the calculation method.
In order to reduce the temperature rise of high voltage induction motor and strengthen the convective heat transfer inside the motor, taking a high voltage induction motor with the rated power of 1 250 kW as the research object, a new rotor ventilation structure is designed based on computational fluid dynamics theory and convective heat transfer optimization. The three\|dimensional coupling analysis model is established to analyze fluid thermal coupling of the motor. With the help of digital simulation technology, the fluid flow and heat transfer characteristics of each ventilation duct of the motor under the ventilation structure of new and old rotors are calculated and compared. From the perspective of field synergy of convection heat transfer optimization, the temperature rise and temperature distribution of the motor under different rotor ventilation structures are obtained, providing a reference for the optimization design of the ventilation structure of high voltage induction motors. Finally, the temperature rise calculation results of the new motor structure are compared with the type test results of the prototype, and the temperature rise error is only 4%, which verifies the accuracy and validity of the calculation method.
2022, 49(4):83-88.
DOI: 10.12177/emca.2021.214
Abstract:
Aiming at the problems that the high-speed motor rotor of fuel cell air compressor is easy to be damaged due to high-speed instability and the accelerated wear of air bearing due to rotor overload, the rotor stress and critical speed of different rotor structures are studied by using the finite element method, and a hollow rotor structure with axially preloaded and fixed magnetic steel is presented. Then, taking an ultra-high-speed permanent magnet motor with the rated power of 35 kW and the peak speed of 100 000 r/min as an example, the advantages and disadvantages of different rotor structures in strength, critical speed, mass, moment of inertia, assembly manufacturability and reliability are compared and analyzed comprehensively. The comparison results show that although the new rotor structure is slightly inferior in rotor strength in comparison with several common rotor structures, it has great advantages in other aspects. Finally, an air compressor prototype is manufactured according to the new rotor structure, and experimental results show that the prototype can run stably at the speed of 100 000 r/min, which verifies the rationality of the new rotor structure.
Aiming at the problems that the high-speed motor rotor of fuel cell air compressor is easy to be damaged due to high-speed instability and the accelerated wear of air bearing due to rotor overload, the rotor stress and critical speed of different rotor structures are studied by using the finite element method, and a hollow rotor structure with axially preloaded and fixed magnetic steel is presented. Then, taking an ultra-high-speed permanent magnet motor with the rated power of 35 kW and the peak speed of 100 000 r/min as an example, the advantages and disadvantages of different rotor structures in strength, critical speed, mass, moment of inertia, assembly manufacturability and reliability are compared and analyzed comprehensively. The comparison results show that although the new rotor structure is slightly inferior in rotor strength in comparison with several common rotor structures, it has great advantages in other aspects. Finally, an air compressor prototype is manufactured according to the new rotor structure, and experimental results show that the prototype can run stably at the speed of 100 000 r/min, which verifies the rationality of the new rotor structure.
2022, 49(4):89-94.
DOI: 10.12177/emca.2021.211
Abstract:
For small hydropower stations using direct\|drive permanent magnet synchronous generators (PMSGs), there exist the needs of adapting to the changes of the external environment such as the change of flow water and the unstable speed of rotation, and improving the efficiency of the power generation. Based on the control algorithm of the direct-drive PMSG on the generator side, a sliding mode observer (SMO) with feedback automatic gain control algorithm is designed to estimate the rotor position of PMSG, so as to improve the estimation error at low speed. We design a set of 37 kW PMSG generator and carry out experiment tests. The results verify that the algorithm can effectively control the rotor position estimation error of the direct-drive PMSG at low speed, and quickly converge at high speed, meeting the control requirements of PMSG.
For small hydropower stations using direct\|drive permanent magnet synchronous generators (PMSGs), there exist the needs of adapting to the changes of the external environment such as the change of flow water and the unstable speed of rotation, and improving the efficiency of the power generation. Based on the control algorithm of the direct-drive PMSG on the generator side, a sliding mode observer (SMO) with feedback automatic gain control algorithm is designed to estimate the rotor position of PMSG, so as to improve the estimation error at low speed. We design a set of 37 kW PMSG generator and carry out experiment tests. The results verify that the algorithm can effectively control the rotor position estimation error of the direct-drive PMSG at low speed, and quickly converge at high speed, meeting the control requirements of PMSG.
2022, 49(4):95-102.
DOI: 10.12177/emca.2021.203
Abstract:
Aiming at the typical faults of current sensors in permanent magnet synchronous motor (PMSM) drive system, a fault diagnosis method of current sensors based on the second-order difference is proposed. The fault sensor is located by judging the relationship between the current residual and the threshold, and the fault type is identified by calculating the second-order difference and periodic current integral of the output current. The proposed method can accurately identify four typical current sensor faults, providing accurate information for fault tolerance and maintenance. Meanwhile, the robustness of the algorithm is enhanced due to the periodic reconstruction of current residual. Simulation and experimental results show that the proposed method can locate and identify fault sensors accurately, and it is robust to parameter mismatches and current disturbances.
Aiming at the typical faults of current sensors in permanent magnet synchronous motor (PMSM) drive system, a fault diagnosis method of current sensors based on the second-order difference is proposed. The fault sensor is located by judging the relationship between the current residual and the threshold, and the fault type is identified by calculating the second-order difference and periodic current integral of the output current. The proposed method can accurately identify four typical current sensor faults, providing accurate information for fault tolerance and maintenance. Meanwhile, the robustness of the algorithm is enhanced due to the periodic reconstruction of current residual. Simulation and experimental results show that the proposed method can locate and identify fault sensors accurately, and it is robust to parameter mismatches and current disturbances.
2022, 49(4):103-108.
DOI: 10.12177/emca.2021.221
Abstract:
In the problem of high voltage ride through (HVRT) of doubly\|fed induction generator (DFIG), the transient overcurrent caused by voltage swell is not enough to trigger crowbar protection action, which makes the short\|circuit current characteristics of stator and rotor under HVRT more complex than those in the case of low voltage ride through (LVRT). Different from the inherent analysis of stator and rotor current, the expressions which take into account the combined influence of electromagnetic transient transition process and rotor side converter (RSC) regulation are derived. On this basis, considering the requirements of grid connection specification for DFIG reactive current support, the outputs of RSC and grid side converter (GSC) related to the swell amplitude are controlled, so as to make DFIG work in the reactive support state. The simulation results show that the expressions of stator and rotor current accurately describe the fault current during HVRT, and the results are more general and are of great significance to the calculation of fault electrical quantity. The improved reactive current configuration realizes the HVRT of DFIG. This research has a certain reference value for mastering the dynamic process of DFIG.
In the problem of high voltage ride through (HVRT) of doubly\|fed induction generator (DFIG), the transient overcurrent caused by voltage swell is not enough to trigger crowbar protection action, which makes the short\|circuit current characteristics of stator and rotor under HVRT more complex than those in the case of low voltage ride through (LVRT). Different from the inherent analysis of stator and rotor current, the expressions which take into account the combined influence of electromagnetic transient transition process and rotor side converter (RSC) regulation are derived. On this basis, considering the requirements of grid connection specification for DFIG reactive current support, the outputs of RSC and grid side converter (GSC) related to the swell amplitude are controlled, so as to make DFIG work in the reactive support state. The simulation results show that the expressions of stator and rotor current accurately describe the fault current during HVRT, and the results are more general and are of great significance to the calculation of fault electrical quantity. The improved reactive current configuration realizes the HVRT of DFIG. This research has a certain reference value for mastering the dynamic process of DFIG.
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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.
