The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field, as well as the related differential leakage, attenuation, asynch...The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field, as well as the related differential leakage, attenuation, asynchronous parasitic torques have been discussed in great detail in the literature, but always separately, for a long time. However, systematization of the phenomenon still awaits. Therefore, it is worth summarizing the completeness of the phenomena in a single study – with a new approach at the same time-in order to reveal the relationships between them. The role of rotor slot number is emphasized much more than before. An existing, commonly used, but still impractical basic figure has been modified to more clearly demonstrate the response of the rotor for the harmonics of the stator. The need to treat differential leakage, asynchronous parasitic torques and attenuation together will be demonstrated: new formula for asynchronous parasitic torque is derived;the long-used characteristic curves for differential leakage and attenuation used separately so far was merged into one, correct curve in order to provide a correct design guide for the engineers.展开更多
A general method of calculating the saturable leakage reactances of squirrelcage asynchronous motors is presented.The method synthesized the variety of effectswhich affect the saturation of leakage magnetic circuit.An...A general method of calculating the saturable leakage reactances of squirrelcage asynchronous motors is presented.The method synthesized the variety of effectswhich affect the saturation of leakage magnetic circuit.And the saturable reactances canbe precisely evaluated in any running condition.The computation results of Y-series mo-tors are in good agreement with the test ones.展开更多
For starting high-voltage asynchronous motor,the voltage regulator based on current-limiting transformer is presented in the paper. Its mathematical model needs to be established analyzing and designing voltage regula...For starting high-voltage asynchronous motor,the voltage regulator based on current-limiting transformer is presented in the paper. Its mathematical model needs to be established analyzing and designing voltage regulator of high-voltage asynchronous motor. The mathematical model of the current-limiting transformer is deduced based on basic circuit theory. It can be found that a continuous variation reactance can describe the current-limiting transformer during starting process. The two variables functions of current and voltage are transformed into one-variable functions,and thus system control is greatly simplified. The voltage regulator is simulated on the basis. The simulation results show that this model has enough accuracy. Finally, the high-voltage asynchronous motor voltage regulator based on current-limiting transformer is designed and tested on this model.展开更多
The heating calculation of three-phase squirrel- cage asynchronous motor on the condition of starting for a prescribed rotary angle is firstly studied with time dissection method and its corresponding algorithm is pro...The heating calculation of three-phase squirrel- cage asynchronous motor on the condition of starting for a prescribed rotary angle is firstly studied with time dissection method and its corresponding algorithm is provided. Then based upon the algorithm, a new method for motor power selection is established. Motor initial power determined by load power ischecked and modified in terms of time crit erion, heating criterion,and starting torque criterion.An appropriate motor power which meets three criterions is obtained at last, in the meantime, working displacement matrix andfrequency matrix used for control are acquired. Lifting motor of MDJ1800 low-level high- speed palletizer is taken as a reaI case in the paper.展开更多
In this study,a novel energy-efficient single-phase induction motor with three stator windings is proposed as shown in Fig 1.The winding A constitutes the first branch.The series connection of the capacitor C and the ...In this study,a novel energy-efficient single-phase induction motor with three stator windings is proposed as shown in Fig 1.The winding A constitutes the first branch.The series connection of the capacitor C and the winding B constitute the second branch,and the series connection of the capacitor C2 and the winding C constitute the third one.The above three branches are connected in parallel as shown in Fig.2.展开更多
This paper proposes and implements a model-free open-loop iterative learning control(ILC)strategy to realize the speed control of the single-phase flux switching motor(FSM)with an asymmetrical rotor.Base on the propos...This paper proposes and implements a model-free open-loop iterative learning control(ILC)strategy to realize the speed control of the single-phase flux switching motor(FSM)with an asymmetrical rotor.Base on the proposed winding control method,the asymmetrical rotor enables the motor to generate continuous positive torque for positive rotation,and relatively small resistance torque for negative rotation.An initial iteration coefficient and variable iteration coefficient optimized scheme was proposed based on the characteristics of the hardware circuit,thereby forming the model-free strategy.A series of prototype experiments was carried out.Experimental results verify the effectiveness and practicability of the proposed ILC strategy.展开更多
Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference ...Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference circuit was also introduced in the middle voltage link of inverter to avoid the shift of the optimum PF point caused by the change of the load and the reliable run of the control system was assured. The experi-ment results show that it has a good self-adaptation in the whole scope of speed ad-justment and an obvious economization on energy while it runs under load.展开更多
There are several problems existing in the direct starting of asynchronous motor such as large starting current,reactive power absorption from network side and weak interference-resistance,etc.Aiming at this,a compreh...There are several problems existing in the direct starting of asynchronous motor such as large starting current,reactive power absorption from network side and weak interference-resistance,etc.Aiming at this,a comprehensive energy-saving optimization model of asynchronous motor for voltage regulation based on static synchronous compensator(STATCOM)is put forward.By analyzing the working principle and operation performance of static synchronous compensator regulating voltage,a new energy-efficient optimization method for asynchronous motor is proposed based on the voltage regulator model to achieve soft start,continuous dynamic reactive power compensation and the terminal voltage stability control.The multi-objective optimal operation of asynchronous motor is realized by controlling the inverter to adjust the reactive current dynamically.The strategy reduces the influence of starting current and grid voltage by soft starting,and realizes the function of reactive power compensation and terminal voltage stabilization.The effectiveness and superiority of the proposed model is verified by the simulation analysis and the results of comparison with the motor started directly.展开更多
The HC-55 single-phase AC series-excitation commutator motor exported to Japan by the Linquan Motor Factory is an open-type motor characterized by simple structure, small volume, high rotary speed, large starting torq...The HC-55 single-phase AC series-excitation commutator motor exported to Japan by the Linquan Motor Factory is an open-type motor characterized by simple structure, small volume, high rotary speed, large starting torque, reliable operation and easy installation. It can be used as a driving component for various kinds of household electrical appliances, such as electric mills, pulverlizers, small stirrers, vacuum cleaners and electric hair dryers, an ideal product for electrical equipment.展开更多
In this paper, the relationship between the protection and control of asynchronous motor and all sorts of protection devices for asynchronous motor are briefly expounded. The protection of motor has mainly developed i...In this paper, the relationship between the protection and control of asynchronous motor and all sorts of protection devices for asynchronous motor are briefly expounded. The protection of motor has mainly developed in three stages： thermal relay, electronic integrated protector, and microcomputer protector. In terms of sampling methods, the protection can be divided into two types： （1） the sampling current detection, which is implemented using a thermal relay with circuit breaker for the thermomagnetic tripping motor protection, and an electronic and solid state relay with circuit breaker and sof~ starter for the thermomagnetic tripping motor protection; （2） the sampling temperature detection, which is to directly detect electromotor winding temperature using bimetallic strip temperature relay, thermal protector, detecting coil, and heat resistance temperature relay. However, the second method is very expensive and difficult to maintain because a motor winding is necessary to directly bury, so it is used only in the cases requiring some frequent operations. Finally, the harmonious cooperation between overload protection device and motor or between overload protection device and short circuit protection device must be considered regardless of the protection device model.展开更多
In the process of the continuous development of power electronics technology, motor control gradually toward more optimized, efficient direction. In this paper, the variable frequency asynchronous motor control system...In the process of the continuous development of power electronics technology, motor control gradually toward more optimized, efficient direction. In this paper, the variable frequency asynchronous motor control system as the research object, mainly discusses the design requirements and design content of PLC in the variable frequency asynchronous motor control system, to achieve the control effect of the motor.展开更多
A method of feedforward compensation for electromotive force(EMF) in the single-phase permanent magnet linear generation system and a research in the performance of the single-phase PMLG system are presented.A general...A method of feedforward compensation for electromotive force(EMF) in the single-phase permanent magnet linear generation system and a research in the performance of the single-phase PMLG system are presented.A general mathematical model for the single-phase permanet magnet linear generator(PMLG) system is established and the current loop,voltage loop and the feedforward control are studied based on it for the control system.Then this paper analyses the transfer function of the power system,optimizes current loop and voltage loop parameters by engineering algorithm,and calculates the optimal control parameters.An EMF feedforward compensation method is developed to optimize the control system which improves dynamic performance of the power system but does not affect the steady-state performance.The result of this research verifies the correctness and rationality of the design for the control system.展开更多
文摘The magnetic field generated in the air gap of the cage asynchronous machine and the harmonics of the magnetomotive forces creating that magnetic field, as well as the related differential leakage, attenuation, asynchronous parasitic torques have been discussed in great detail in the literature, but always separately, for a long time. However, systematization of the phenomenon still awaits. Therefore, it is worth summarizing the completeness of the phenomena in a single study – with a new approach at the same time-in order to reveal the relationships between them. The role of rotor slot number is emphasized much more than before. An existing, commonly used, but still impractical basic figure has been modified to more clearly demonstrate the response of the rotor for the harmonics of the stator. The need to treat differential leakage, asynchronous parasitic torques and attenuation together will be demonstrated: new formula for asynchronous parasitic torque is derived;the long-used characteristic curves for differential leakage and attenuation used separately so far was merged into one, correct curve in order to provide a correct design guide for the engineers.
文摘A general method of calculating the saturable leakage reactances of squirrelcage asynchronous motors is presented.The method synthesized the variety of effectswhich affect the saturation of leakage magnetic circuit.And the saturable reactances canbe precisely evaluated in any running condition.The computation results of Y-series mo-tors are in good agreement with the test ones.
基金Natural Science Foundation of Shanghai,China(No.14ZR1419100)Shanghai Science and Technology Commission,China(No.13160501500)+1 种基金Shanghai Maritime University Foundation,China(No.20130430)the Ministry of Transport Foundation of China(No.2013329 810350)
文摘For starting high-voltage asynchronous motor,the voltage regulator based on current-limiting transformer is presented in the paper. Its mathematical model needs to be established analyzing and designing voltage regulator of high-voltage asynchronous motor. The mathematical model of the current-limiting transformer is deduced based on basic circuit theory. It can be found that a continuous variation reactance can describe the current-limiting transformer during starting process. The two variables functions of current and voltage are transformed into one-variable functions,and thus system control is greatly simplified. The voltage regulator is simulated on the basis. The simulation results show that this model has enough accuracy. Finally, the high-voltage asynchronous motor voltage regulator based on current-limiting transformer is designed and tested on this model.
基金This project is supported by National 863 Foundation (863-512-9801-06)
文摘The heating calculation of three-phase squirrel- cage asynchronous motor on the condition of starting for a prescribed rotary angle is firstly studied with time dissection method and its corresponding algorithm is provided. Then based upon the algorithm, a new method for motor power selection is established. Motor initial power determined by load power ischecked and modified in terms of time crit erion, heating criterion,and starting torque criterion.An appropriate motor power which meets three criterions is obtained at last, in the meantime, working displacement matrix andfrequency matrix used for control are acquired. Lifting motor of MDJ1800 low-level high- speed palletizer is taken as a reaI case in the paper.
文摘In this study,a novel energy-efficient single-phase induction motor with three stator windings is proposed as shown in Fig 1.The winding A constitutes the first branch.The series connection of the capacitor C and the winding B constitute the second branch,and the series connection of the capacitor C2 and the winding C constitute the third one.The above three branches are connected in parallel as shown in Fig.2.
文摘This paper proposes and implements a model-free open-loop iterative learning control(ILC)strategy to realize the speed control of the single-phase flux switching motor(FSM)with an asymmetrical rotor.Base on the proposed winding control method,the asymmetrical rotor enables the motor to generate continuous positive torque for positive rotation,and relatively small resistance torque for negative rotation.An initial iteration coefficient and variable iteration coefficient optimized scheme was proposed based on the characteristics of the hardware circuit,thereby forming the model-free strategy.A series of prototype experiments was carried out.Experimental results verify the effectiveness and practicability of the proposed ILC strategy.
基金Supported by Liaoning Educational Foundation(202183386)
文摘Deduced the relationship between the power factor (PF) and the angular fre-quency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference circuit was also introduced in the middle voltage link of inverter to avoid the shift of the optimum PF point caused by the change of the load and the reliable run of the control system was assured. The experi-ment results show that it has a good self-adaptation in the whole scope of speed ad-justment and an obvious economization on energy while it runs under load.
文摘There are several problems existing in the direct starting of asynchronous motor such as large starting current,reactive power absorption from network side and weak interference-resistance,etc.Aiming at this,a comprehensive energy-saving optimization model of asynchronous motor for voltage regulation based on static synchronous compensator(STATCOM)is put forward.By analyzing the working principle and operation performance of static synchronous compensator regulating voltage,a new energy-efficient optimization method for asynchronous motor is proposed based on the voltage regulator model to achieve soft start,continuous dynamic reactive power compensation and the terminal voltage stability control.The multi-objective optimal operation of asynchronous motor is realized by controlling the inverter to adjust the reactive current dynamically.The strategy reduces the influence of starting current and grid voltage by soft starting,and realizes the function of reactive power compensation and terminal voltage stabilization.The effectiveness and superiority of the proposed model is verified by the simulation analysis and the results of comparison with the motor started directly.
文摘The HC-55 single-phase AC series-excitation commutator motor exported to Japan by the Linquan Motor Factory is an open-type motor characterized by simple structure, small volume, high rotary speed, large starting torque, reliable operation and easy installation. It can be used as a driving component for various kinds of household electrical appliances, such as electric mills, pulverlizers, small stirrers, vacuum cleaners and electric hair dryers, an ideal product for electrical equipment.
文摘In this paper, the relationship between the protection and control of asynchronous motor and all sorts of protection devices for asynchronous motor are briefly expounded. The protection of motor has mainly developed in three stages： thermal relay, electronic integrated protector, and microcomputer protector. In terms of sampling methods, the protection can be divided into two types： （1） the sampling current detection, which is implemented using a thermal relay with circuit breaker for the thermomagnetic tripping motor protection, and an electronic and solid state relay with circuit breaker and sof~ starter for the thermomagnetic tripping motor protection; （2） the sampling temperature detection, which is to directly detect electromotor winding temperature using bimetallic strip temperature relay, thermal protector, detecting coil, and heat resistance temperature relay. However, the second method is very expensive and difficult to maintain because a motor winding is necessary to directly bury, so it is used only in the cases requiring some frequent operations. Finally, the harmonious cooperation between overload protection device and motor or between overload protection device and short circuit protection device must be considered regardless of the protection device model.
文摘In the process of the continuous development of power electronics technology, motor control gradually toward more optimized, efficient direction. In this paper, the variable frequency asynchronous motor control system as the research object, mainly discusses the design requirements and design content of PLC in the variable frequency asynchronous motor control system, to achieve the control effect of the motor.
基金Supported by the National High Technology Research and Development Program of China(No.2006AA05Z231)the National Natural Science Foundation of China(No.51177025)
文摘A method of feedforward compensation for electromotive force(EMF) in the single-phase permanent magnet linear generation system and a research in the performance of the single-phase PMLG system are presented.A general mathematical model for the single-phase permanet magnet linear generator(PMLG) system is established and the current loop,voltage loop and the feedforward control are studied based on it for the control system.Then this paper analyses the transfer function of the power system,optimizes current loop and voltage loop parameters by engineering algorithm,and calculates the optimal control parameters.An EMF feedforward compensation method is developed to optimize the control system which improves dynamic performance of the power system but does not affect the steady-state performance.The result of this research verifies the correctness and rationality of the design for the control system.
