14 results about "Linear induction motor" patented technology

The invention relates to a joining tool (10) for connecting at least two elements (36, 38) by driving in a connecting element in the form of a self-piercing rivet (34), comprising a drive (14) which is designed to generate an axial force in order to drive the self-piercing rivet (34) into the elements (36, 38) to be connected; and an actuator (22) which is designed to apply the force generated by the drive (14) to the self-piercing rivet (34); wherein the joining tool (10) comprises a linear induction motor (14) as a drive (14). The invention also relates to a method for connecting at least two elements (36, 38) by driving in a self-piercing rivet (34), wherein the self-piercing rivet (34) is driven into the elements (36, 38) to be connected by applying an axial force to the self-piercing rivet (34), wherein the axial force is generated by a linear induction motor (14).

A conveyor system for transporting goods within a warehouse facility. The system includes an array of guide tracks and carriages moveable along the guide tracks for transporting goods within the warehouse facility. A drive system includes drivers spaced along the guide tracks. The drivers may utilize linear induction motors, propels the carriages along the guide tracks. The linear induction motors utilize stepper motors, and optionally microstepping motors. A warehouse management system controls the linear drive system to transport goods throughout warehouse facility for storage and order fulfilment. The linear driver conveyor system includes perpendicular transfers at which carriages can be transferred from one conveyor line to another, without the need for mechanical processes, such as lift or buffers, to move the carriage between conveyor lines.

A polyphase linear induction motor including a movable primary member (100), the primary member (100) including a magnetic material (110), a polyphase winding (120) arranged around the magnetic material, and a stationary longitudinally-extending secondary member (150) separated from the primary member (100) by a gap, the secondary member (150) including an electrically-conductive reaction plate (200) and a backing magnetic material (300), wherein the secondary member includes a middle section (205) and two outer sections (210.1, 210.2), the middle section (205) and the two outer sections (210.1, 210.2) arranged next to each other in parallel to an axis of longitudinal extension of the reaction plate (200).

The application provides an electromagnetic quasi-zero stiffness vibration isolation device and method based on a composite nested structure, and belongs to the technical field of vibration isolation. The device comprises a supporting base, two linear induction motor assemblies symmetrically arranged on the base and provided with a preset gap, and a suspension support frame composed of a vertical conductive support plate and a horizontal magnetic conductive support plate. The vertical conductive support plate can float up and down in the gap and forms a positive stiffness module with the motor assembly to provide a main supporting force and positive stiffness. Two pairs of symmetrical electric eddy current stator pairs are distributed on the left and right sides of the horizontal magnetic conductive support plate and form a negative stiffness module with the horizontal magnetic conductive support plate to provide negative stiffness. Each pair of electric eddy current stator pairs comprises an upper electric eddy current stator assembly and a lower electric eddy current stator assembly which are mutually repulsive and float up and down on the left and right sides of the horizontal magnetic conductive support plate. The positive and negative stiffness modules are coaxially arranged and are connected in parallel through a composite nested structure to realize the quasi-zero stiffness characteristic. The application can realize dynamic stiffness adjustment, improve the vibration isolation effect and reliability.

This invention discloses a method for obtaining parameters of a stationary linear induction motor based on the finite element method. The motor's rotor is stationary, and the method can account for the magnetic saturation of the primary core and secondary yoke. It is applicable to both short-primary and long-primary linear induction motors. First, the induction plate of the secondary winding is removed from the calculation model. Under current source excitation mode, an AC current with a preset current and frequency is applied to the input terminal of the primary winding. The current magnitude is varied, and the total equivalent resistance, reactance, and maximum air gap normal magnetic flux density of the motor are obtained under different current inputs. Then, the induction plate of the secondary winding is restored to the calculation model. Under current source excitation mode, an AC current with a preset current and frequency is applied to the input terminal of the primary winding, and the total equivalent resistance, reactance, and maximum air gap normal magnetic flux density of the motor are obtained. Finally, based on the above calculated values, the parameters in the T-type equivalent circuit of the induction motor are calculated.

The application discloses a kind of excitation inductance identification method, current control method and system of linear induction motor, belong to linear motor control technical field;In each control cycle, with back electromotive force as observation, the reference model based on sliding mode observer is constructed to calculate back electromotive force observation value, and adjustable model containing excitation inductance is used to calculate back electromotive force, and the adaptive rate of excitation inductance and back emf error is calculated to calculate the corresponding excitation inductance, to realize the identification of excitation inductance.The application constructs reference model irrelevant to the change of excitation inductance, and uses sliding mode instead of current differential term, eliminates the noise caused by current differential term in existing reference model, avoids the interference of current noise on back emf observation result, improves the accuracy of excitation inductance identification;On this basis, the inherent chattering problem of sliding mode observer is further eliminated by using cascaded low-pass filter, and the accuracy of excitation inductance identification is further improved.

This invention discloses a flat-type moving primary linear induction motor, comprising a motor base, a motor stator assembly, a mover assembly, a power supply device, and a guiding device. The motor stator assembly is vertically fixed within the hollow frame of the motor base. Multiple vertically arranged guide rails are fixedly arranged on the left and right sides of the motor stator assembly. Multiple sliding contact line structures are arranged on the vertical inner wall of the motor stator assembly frame. The mover assembly includes a mover frame sleeved around the outer periphery of the motor stator assembly and a mover winding fixedly mounted in the middle of the mover frame. A sliding groove is provided on the mover frame. The guide rails are inserted into the sliding grooves, allowing the mover frame to move axially along the guide rail direction due to the constraint of the sliding grooves. Collectors are installed on the left and right sides of the mover frame, and the mover winding is powered by sliding contact through the collectors and the sliding contact line structures. This invention features high thrust density, compact structure, low cost, reliable operation, and convenient maintenance, and can be applied to high-thrust acceleration fields.

This invention provides a sensorless control method for a piecewise linear induction motor based on an extended state observer phase-locked loop (PLL), belonging to the field of motor control technology. The method includes: constructing an equivalent mathematical model of the piecewise linear induction motor without coupling coefficient terms; constructing a sliding mode observer based on an integral sliding surface combined with an exponential reaching law to obtain the back electromotive force (EMF) observation value required by the PLL; inputting the back EMF observation value into the PLL based on the extended state observer to extract the synchronous angular velocity and synchronous electrical angle, and calculating the secondary velocity estimate and secondary displacement estimate; feeding back the synchronous angular velocity, secondary velocity estimate, and secondary displacement estimate to the closed-loop control system to achieve sensorless operation of the piecewise linear induction motor. This invention can improve the speed and position estimation accuracy of the system under high dynamic conditions, and enhance the system's robustness and dynamic response performance.

The invention discloses a multi-motor cooperative minimum loss control method and system for linear induction motors, and belongs to the technical field of linear motor control. The method comprises the following steps: deducing a function relationship between thrust and total loss of a plurality of motors under the control of minimum loss according to a relationship between a primary flux linkage and loss of a single motor; defining a thrust distribution coefficient, and establishing a multi-motor thrust-total loss optimization model comprising a total thrust constraint, a thrust constraint of each motor, a voltage constraint and a normal force difference constraint of adjacent motors; taking the thrust distribution coefficient as an optimization variable, and adopting a sequential quadratic programming method to carry out optimization distribution on each motor thrust instruction; and finally, according to the optimized thrust instruction of each motor, realizing thrust tracking and loss regulation and control of each motor in combination with a single-motor minimum loss control strategy. According to the invention, cooperative minimum loss control from a single-machine system to a multi-machine system is realized, and the overall operation efficiency of the multi-motor system is effectively improved.

The invention discloses a bifurcation chaos stability analysis method for a high-speed linear induction motor. The bifurcation chaos stability analysis method comprises the following steps: S1, establishing a complex vector mathematical model of the high-speed linear induction motor under PI control; s2, exporting a state-space equation of the system based on the complex vector mathematical model; s3, solving the state-space equation to obtain a balance point of the system; s4, judging the local stability of the balance point obtained in the step S3; s5, identifying global bifurcation characteristics and chaotic dynamics behaviors of the system; s6, determining a stability domain boundary of the proportional-integral control parameters; and S7, analyzing the stability of the high-speed linear induction motor based on bifurcation chaos. According to the method, dynamic behaviors of the system are analyzed through numerical solution, the defect that a traditional transfer function method is insufficient in non-linear and time-varying parameter sensitivity problem analysis capacity is overcome, and a more accurate theoretical basis is provided for stable control of the motor under the ultra-high-speed working condition.

The application provides a kind of maglev train non-contact linear drive device, relating to the technical field of suspended train, including rotor, rotor is suitable for rotationally connected with car body, rotor includes permanent magnet;Stator is suitable for fixedly connected with car body, stator is set to the side of rotor away from car body and forms first air gap with rotor, stator includes energized coil, the projection of stator in vertical direction overlaps at least a part of rotor;Conductor plate is laid along the track extension direction and forms second air gap with rotor, the projection of conductor plate in vertical direction overlaps at least another part of rotor.The application realizes force transmission by magnetic field effect, without physical contact, reduces wear and failure rate, and its permanent magnet excitation, compared with linear induction motor, significantly improves the power factor of driving device, reduces energy consumption, compared with linear synchronous motor, it only needs to lay passive conductor plate on the track, reduces the construction cost.

The invention discloses an unequal-length segmented power supply linear induction motor modeling method and system, and belongs to the technical field of electric vehicle control, and the method comprises the steps: constructing a multi-segment coupling electromagnetic model, and according to the length difference of each stator segment; a dynamic weight factor is designed, and the magnetic field weight of each stator segment is adjusted through a smooth function according to the overlapping length of the rotor position and the segment boundary; learning edge force in real time based on a neural network, and outputting a compensation force coefficient to the mechanical dynamics model; the mechanical resonant frequency is monitored through a vibration sensor, and the equivalent stiffness is dynamically corrected. By means of the mode, the mechanical resonance frequency is monitored on line through the vibration sensor, the equivalent stiffness and the damping ratio of the system are dynamically adjusted in a closed-loop mode according to the mechanical resonance frequency, harmful resonance conditions can be effectively broken, the mechanical vibration amplitude is restrained at the low level, the mechanical structure is protected, and the stability margin of the control system is improved.

The invention discloses a linear induction motor full-speed-domain optimization control method based on an active flux linkage, and belongs to the technical field of linear motor control, and the method comprises the steps: sampling the state quantity of a motor system in real time, and determining a thrust reference value according to the sampling speed; reconstructing a primary voltage, and calculating an active flux linkage at the current moment according to the sampling current and the reconstructed voltage; according to the thrust reference value, motor active flux linkage amplitudes, phase voltages and efficacy under the three working conditions of the maximum thrust current ratio, the maximum power factor and the maximum thrust flux linkage ratio are calculated, and a reference active flux linkage amplitude used for motor control is determined; and determining a dq-axis current reference value according to the active flux linkage amplitude reference value, the actual value and the thrust reference value, and completing motor closed-loop control according to the current reference value and the actual value. According to the method, the parameter robustness of the observed flux linkage can be enhanced by defining the active flux linkage, and key indexes such as motor thrust and efficacy in full-speed-domain operation can be effectively improved by optimizing the value of the active flux linkage.

The linear actuator comprises a driving structure, the outer wall of the driving structure is fixedly connected with a guiding structure, the outer wall of the side, away from the driving structure, of the guiding structure is fixedly connected with a tensioning structure, and the inner wall of the guiding structure is slidably connected with a sliding structure and a synchronous belt; the two ends of the synchronous belt are fixedly connected with the sliding structures, and the inner wall of the synchronous belt is meshed with the outer walls of the driving structure and the tensioning structure; the utility model relates to the technical field of linear actuators, according to the guide structure and the sliding structure, through the matching design of the V-shaped guide rail and the idler wheel, the V-shaped inclined plane limits transverse deviation through bidirectional constraint, the motion resistance can be effectively reduced, meanwhile, the linear motion of the sliding seat can be ensured, and the magnetic strip at the top of the sliding rail tightly adsorbs a steel belt through magnetic force; a totally-closed protection structure is formed, impurities such as dust, water vapor and oil dirt can be effectively prevented from entering the sliding rail, and abrasion or clamping stagnation of core components such as the V-shaped guide rail and the synchronous belt caused by pollution is avoided.