Permanent magnet linear motor and control device

Abstract

This invention provides a permanent magnet linear motor and its control device, belonging to the field of motor technology. The permanent magnet linear motor includes a stator module and a mover module. The stator module includes a stator winding and a stator core. After winding, the stator winding is embedded and fixed in the winding slots of the stator core. The upper and lower sets of stator modules are arranged in parallel and symmetrically, and the stator module has a segmented structure. The mover module includes a mover core and permanent magnets. The permanent magnets are symmetrically arranged, and permanent magnets are fixed on the upper and lower sides of the mover core. The mover module has a double-sided short secondary permanent magnet structure. The mover module is placed in the air gap area between the upper and lower sets of stator modules. This invention reduces the difficulty of motor installation, prevents deformation of the steel structure, and reduces thrust fluctuations by using a segmented stator with adjustable mounting slots. The fractional-slot winding and optimized neodymium iron boron permanent magnets improve motor efficiency and reduce motor energy consumption. The dual-controller alternating drive and closed-loop control achieve smooth switching of stator segments and stable operation of the mover.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a permanent magnet linear motor and its control device. Background Technology

[0002] Permanent magnet linear motors are widely used in rail transportation, precision manufacturing, and logistics transportation due to their advantages such as eliminating the need for intermediate transmission mechanisms, fast response speed, and high thrust density.

[0003] In existing technologies, stators are mostly designed as a single integrated section. When applied to long stroke scenarios of 10m or more, the weight of a single stator section can reach hundreds of kilograms. Not only does transportation require specialized heavy equipment, but the hoisting and positioning accuracy during on-site installation is also difficult to control. Furthermore, it is susceptible to the influence of micro-deformation of the site's steel structure due to temperature changes or loads, resulting in large air gap deviations between the stator and mover, affecting operational stability. Stator windings generally use integer slot distribution windings with a large amount of overlapping copper wires at the ends. At the same time, ferrite permanent magnets are selected, leading to insufficient residual magnetism. Alternatively, the pole arc coefficient and magnetization direction length may not be optimized according to the pole pitch and air gap length, further increasing the range of air gap magnetic flux density fluctuations and reducing the motor's thrust density and energy efficiency. The control devices are mostly based on a single controller driving multiple stator windings. The single controller needs to handle the current regulation of multiple windings simultaneously, which is prone to synchronization delay. When the mover moves at high speed, the stator segment switching is prone to jamming, and the current control accuracy is insufficient, resulting in an increased deviation between the actual running trajectory and the predetermined trajectory of the mover, which cannot meet the precision requirements of precision manufacturing. The installation structure design is not perfect. Most schemes do not set the vertical limit and lateral guide mechanism of the mover. The mover is prone to lateral deviation during operation, and no isolation measures are taken. The slight deformation of the site steel structure will be directly transmitted to the stator, which will further deteriorate the air gap and even cause the stator core and the mover permanent magnet to scrape, reducing the reliability and service life of the motor.

[0004] Therefore, there is an urgent need for a systematic, high-precision permanent magnet linear motor and its matching control device that balances performance and economy. Summary of the Invention

[0005] The purpose of this invention is to provide a permanent magnet linear motor and control device to solve the above problems.

[0006] In a first aspect, embodiments of the present invention provide a permanent magnet linear motor, the permanent magnet linear motor comprising: Stator module, mover module; The stator module includes a stator winding and a stator core. After the stator winding is wound, it is embedded and fixed in the winding slot of the stator core. The upper and lower sets of stator modules are arranged in parallel and symmetrically. The stator module has a segmented structure. The moving module includes a moving core and permanent magnets. The permanent magnets are symmetrically arranged, and permanent magnets are fixed on the upper and lower sides of the moving core. The moving module is a double-sided short secondary permanent magnet structure. The moving submodule is placed in the air gap area between the upper and lower sets of stator modules.

[0007] Furthermore, the stator module consists of 30 segments, with each segment having a length of 0.5m and a total length of 15m. Each stator segment uses a 12-slot, 10-pole fractional-slot concentrated winding.

[0008] Furthermore, the width of the stator core is:

[0009] in, p For extreme logarithms, L a For the core width, The leakage coefficient is... F For rated thrust, For the fundamental winding coefficient, For air gap magnetic flux density, A For electrical load, The rated efficiency of the motor, The power factor.

[0010] Furthermore, the stator winding adopts a fractional-slot concentrated winding, and the wiring adopts a star connection. The calculation formula for the winding coefficient is:

[0011]

[0012] in, This is the fundamental short-range coefficient. The fundamental wave distribution coefficient, ω is the short-pitch angle of the winding, and c is the number of coil groups.

[0013] Furthermore, the permanent magnet is made of neodymium iron boron material, and the lateral length L of the permanent magnet is... p With motor width L a Consistent; the longitudinal width of the permanent magnet is (0.6-0.9)τ; the length in the magnetization direction... h m Calculate using the following formula:

[0014] Where τ is the polar moment. This is the polar arc coefficient. g B is the length of the air gap on one side of the motor. r The remanence of a permanent magnet.

[0015] Furthermore, the permanent magnet linear motor also includes a mounting assembly; The mounting assembly includes a mover upper guide rail, a stator mounting bracket, and a stator mounting slot. The mover upper guide rail provides vertical and lateral constraints for the mover module. The stator mounting bracket is used to fix the stator windings. The stator mounting slot is used to isolate the site steel structure to prevent deformation of the steel structure from affecting the permanent magnet linear motor.

[0016] Furthermore, one end of the stator mounting bracket is provided with a mover upper guide rail, and the other end is provided with a stator fixing part. The stator fixing part is used to fix the stator coil, and the stator mounting bracket can withstand the rated load impact without deformation. The stator mounting slot is located below the stator mounting bracket; The length of the stator mounting bracket is set to 1 meter, and 2 stator modules are placed on each stator mounting bracket; Two adjacent stator mounting brackets share a mounting slot, and adjusting screws are provided on the left, right, and bottom sides of the site steel structure where it mates with the mounting slot.

[0017] Secondly, embodiments of the present invention also provide a permanent magnet linear motor control device, the device comprising: Dual motor controller, multi-section switch, speed closed-loop control module and two sets of current closed-loop control modules; The dual-motor controller is connected to the odd-numbered and even-numbered stator windings of the permanent magnet linear motor via multiple sets of switches, forming a synchronous drive power supply structure for the dual-motor controller. It alternately supplies power to adjacent stator windings, with each set of motor controllers driving only one stator winding. The speed closed-loop control module adopts... I d The vector control strategy with =0 has its output connected to the input of two sets of current closed-loop control modules. The output of the speed closed-loop control module is used as the common q-axis given current for the two sets of current closed-loop control modules. The two sets of current closed-loop control modules are respectively connected to the dual-motor controller. The current closed-loop control modules cooperate with multiple sets of segment switches to control the current of each stator segment winding, driving the linear motor to move along a predetermined trajectory.

[0018] Furthermore, all of the multiple segment switches are semiconductor switches, and each segment switch corresponds to a stator segment winding. The dual-motor controller has a built-in independent current regulation module, and the two current regulation modules respectively control the current of the odd-numbered stator segment winding and the even-numbered stator segment winding.

[0019] Furthermore, the speed closed-loop control module includes a speed detector and a PI regulator. The speed detector is used to collect the real-time operating speed of the linear motor mover, and the PI regulator outputs a q-axis given current based on the deviation between the real-time operating speed and the predetermined trajectory speed. Both sets of current closed-loop control modules have built-in current detectors and current regulators. The current detector collects the real-time current of the corresponding stator winding, and the current regulator adjusts the output current based on the deviation between the common q-axis given current and the real-time current.

[0020] As can be seen from the above technical solutions, the present invention has the following advantages: In this invention, a permanent magnet linear motor and control device are disclosed. The stator module adopts a segmented structure, combined with a stator mounting slot with adjusting screws. This reduces the difficulty of transporting and installing long-stroke stators, isolates the influence of site steel structure deformation, avoids uneven air gap, and reduces thrust fluctuations. The stator uses a fractional-slot concentrated winding, combined with neodymium iron boron permanent magnets, to improve the fundamental winding coefficient, reduce leakage flux loss, make the air gap magnetic flux density more stable, and reduce energy consumption. The control device uses a dual-motor controller to alternately drive odd and even stator segments, combined with a speed closed loop of Id=0 vector control and an independent current closed loop, to achieve smooth switching between adjacent stator segments, solve the synchronization difference and stuttering problems of single controllers, improve current control accuracy, and ensure that the mover runs smoothly along the predetermined trajectory. The upper guide rail of the mover provides vertical and lateral constraints, and the stator mounting bracket can withstand the rated load without deformation, enhancing the moving stability and device structural durability, and improving overall operational reliability. Attached Figure Description To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the permanent magnet linear motor of the present invention.

[0022] Figure 2 This is a schematic diagram of the permanent magnet linear motor control device of the present invention.

[0023] Figure 3 This is a schematic diagram of the power supply circuit topology for the dual-motor controller in the permanent magnet linear motor control device of the present invention.

[0024] Figure 4 This is a schematic diagram of the operating trajectory control principle in the permanent magnet linear motor control device of the present invention. Detailed Implementation

[0025] In the detailed description below of a permanent magnet linear motor and control device, various embodiments of the invention will be described more fully. The invention may have various embodiments, and adjustments and changes may be made therein. However, it should be understood that there is no intention to limit the various embodiments of the invention to the specific embodiments disclosed herein, but rather the invention should be understood to cover all adjustments, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of the invention.

[0026] It should be understood that, when used in this specification, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0027] The terms "one embodiment" or "some embodiments" used in this invention mean that one or more embodiments of the invention include the specific features, structures, or characteristics described in that embodiment. Therefore, the terms "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of the invention do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0028] To make the objectives, features, and advantages of this invention more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solutions protected by this invention. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] Please see Figure 1 The diagram shown is of a permanent magnet linear motor, which includes: Stator module, mover module; The stator module includes a stator winding and a stator core. After the stator winding is wound, it is embedded and fixed in the winding slot of the stator core. The upper and lower sets of stator modules are arranged in parallel and symmetrically. The stator module has a segmented structure. The moving module includes a moving core and permanent magnets. The permanent magnets are symmetrically arranged, and permanent magnets are fixed on the upper and lower sides of the moving core. The moving module is a double-sided short secondary permanent magnet structure. The moving submodule is placed in the air gap area between the upper and lower sets of stator modules.

[0030] It should be noted that in this embodiment, the stator module adopts a segmented design, avoiding the problems of difficult transportation and installation and easy deformation of the whole structure. The symmetrical arrangement of the upper and lower parts optimizes the distribution of the air gap magnetic field, reduces unilateral magnetic pull, and improves operational stability. The mover is a double-sided short secondary permanent magnet structure, with permanent magnets symmetrically fixed on the upper and lower sides of the mover core. This not only increases the thrust density but also reduces leakage magnetic loss. At the same time, the short secondary design reduces the weight of the mover and enhances dynamic response capability. The mover is placed in the air gap between the upper and lower stator modules. With the symmetrical layout of the stator, the uniformity of the air gap can be ensured, further reducing thrust fluctuation and improving the overall operating performance of the motor.

[0031] As a refinement and extension of the specific implementation methods described above, and to fully illustrate the specific implementation process in this embodiment, another permanent magnet linear motor is provided, including: Stator module, mover module; The stator module includes a stator winding and a stator core. After the stator winding is wound, it is embedded and fixed in the winding slot of the stator core. The upper and lower sets of stator modules are arranged in parallel and symmetrically. The stator module has a segmented structure. The moving module includes a moving core and permanent magnets. The permanent magnets are symmetrically arranged, and permanent magnets are fixed on the upper and lower sides of the moving core. The moving module is a double-sided short secondary permanent magnet structure. The moving submodule is placed in the air gap area between the upper and lower sets of stator modules.

[0032] For example, based on the actual site and requirements, a linear motor is designed for use in an electromagnetic launch demonstration system, which needs to meet the following design requirements: the linear motor has an acceleration length of 10.5 meters, a braking distance of 4.5 meters, and an overall length of 15 meters; the linear motor's final speed is ≥3.5 meters / second, and the load weight is 48 kg; it adopts a dual-sided short secondary structure; it adopts segmented power supply control; the linear motor is installed on a steel structure; and it is capable of relatively precise trajectory control.

[0033] The stator module consists of 30 segments, with each segment being 0.5m long and the total length being 15m. Each stator segment uses a 12-slot, 10-pole fractional-slot concentrated winding.

[0034] It should be noted that the primary length is determined based on the site length and the number of segments; the polar distance is then calculated. The formula is:

[0035] in, v s This is the maximum operating speed of the motor. f The power supply frequency is 40Hz; if the power supply frequency is set to 40Hz, then the pole spacing will be 0.05 meters.

[0036] The width of the stator core is:

[0037] in, p For extreme logarithms, L a For the core width, The leakage coefficient is... F For rated thrust, For the fundamental winding coefficient, For air gap magnetic flux density, A For electrical load, The rated efficiency of the motor, The power factor.

[0038] It should be noted that the air gap affects parameters such as the motor's power factor, efficiency, and thermal load. The power factor and thermal load are directly proportional to the air gap length, while efficiency is inversely proportional. The air gap also directly affects the thrust; under the same conditions, a smaller air gap results in greater thrust, but also greater magnetic reluctance and normal attraction, requiring higher processing standards and making motor installation more difficult. In this embodiment, the motor needs to be mounted on a steel structure. To allow for a certain amount of deformation, the air gap cannot be too small; it is initially set at 3mm.

[0039] The stator winding adopts a fractional slot concentrated winding, and the wiring adopts a star connection. The calculation formula for the winding coefficient is:

[0040]

[0041] in, This is the fundamental short-range coefficient. The fundamental wave distribution coefficient, ω is the short-pitch angle of the winding, and c is the number of coil groups.

[0042] It should be noted that for permanent magnet linear motors, due to the large number of poles, fractional slot concentrated windings are often used. Compared to integer slot windings, fractional slot windings greatly reduce tooth harmonic electromotive force, improve the sinusoidal nature of the back EMF waveform, enhance motor performance, and significantly reduce copper usage.

[0043] For fractional-slot concentrated windings, to obtain a higher winding coefficient, the electromotive force difference between the two element sides of the coil is close to 180°. Using α = p0·360° / Z0≈180°, we can obtain Z0≈2p0. Referring to the fractional-slot concentrated winding slot pole matching table (Table 1), Z0 can be 9 or 12. Based on the dimensions and segmented matching requirements, Z0=12 is selected, i.e., a 12-slot, 10-pole motor is used. Because single-layer windings have a large inductance and poor load-carrying capacity, double-layer windings are often used.

[0044] Table 1. Slot Pole Matching Table for Fractional Slot Concentrated Windings

[0045] The permanent magnet is made of neodymium iron boron material, and the lateral length L of the permanent magnet is... p With motor width L a Consistent; the longitudinal width of the permanent magnet is (0.6-0.9)τ; the length in the magnetization direction... h m Calculate using the following formula:

[0046] Where τ is the polar moment. This is the polar arc coefficient. g B is the length of the air gap on one side of the motor. r The remanence of a permanent magnet.

[0047] For example, currently, permanent magnets mainly use neodymium iron boron (NdFeB) materials; this embodiment uses a 35UH grade permanent magnet. Its remanence B... r =1.2T, coercivity H c =880kA / m.

[0048] It should be noted that increasing the electromagnetic load can effectively reduce the size of the motor, but due to limitations in heat dissipation and permanent magnet materials, the electrical and magnetic loads cannot be too large, and iterative calculations based on experience are mainly required.

[0049] The permanent magnet linear motor also includes a mounting assembly; The mounting assembly includes a mover upper guide rail, a stator mounting bracket, and a stator mounting slot. The mover upper guide rail provides vertical and lateral constraints for the mover module. The stator mounting bracket is used to fix the stator windings. The stator mounting slot is used to isolate the site steel structure to prevent deformation of the steel structure from affecting the permanent magnet linear motor.

[0050] One end of the stator mounting bracket is provided with a mover upper guide rail, and the other end is provided with a stator fixing part. The stator fixing part is used to fix the stator coil, and the stator mounting bracket can withstand the rated load impact without deformation. The stator mounting slot is located below the stator mounting bracket; The length of the stator mounting bracket is set to 1 meter, and 2 stator modules are placed on each stator mounting bracket; Two adjacent stator mounting brackets share a mounting slot, and adjusting screws are provided on the left, right, and bottom sides of the site steel structure where it mates with the mounting slot.

[0051] To verify the performance of the permanent magnet linear motor, a 3D model of the motor was built using Maxwell software. Rated operating conditions were set: current I = 8A, frequency f = 40Hz, and motion boundary conditions (speed 4m / s) were applied for simulation. Copper losses were calculated from the winding resistance and current. Iron losses were obtained by extracting the core flux density waveform from the unloaded magnetic field and substituting it into the Steinmetz formula. The total loss was calculated as the sum of copper and iron losses. The losses of the permanent magnet linear motor were analyzed and calculated. Since the linear motor needs to be installed on a steel structure platform, excessive weight would make it difficult to guarantee installation accuracy. Furthermore, the deformation of the steel structure would severely affect the accuracy of the mechanical air gap. Therefore, further optimization of the overall weight of the linear motor was necessary. The optimized permanent magnet linear motor had a total weight reduced to 815kg. A genetic algorithm can be used to optimize the overall weight of the permanent magnet linear motor. Finite element analysis was used to calculate the no-load magnetic field, current source, and voltage source. A Maxwell model of the motor was established, and a no-load condition (mover stationary, stator unpowered) was set. The simulation showed that the no-load air gap magnetic flux density distribution exhibited a sinusoidal pattern with a peak value of 0.85T and an effective back electromotive force of 380V. In the current source mode, using maximum torque-to-current ratio control, the minimum current was 7.8A at a rated thrust of 400N, corresponding to an input voltage of 360V. With a voltage source set to a 360V input voltage and a 30° phase difference between the current and voltage, the simulation showed an electromagnetic thrust of 402N under rated load, with thrust fluctuation ≤5% and iron loss of 82W, verifying that the motor performance met the standards.

[0052] Please see Figure 2 The diagram shows a control device for a permanent magnet linear motor, which includes: Dual motor controller, multi-section switch, speed closed-loop control module and two sets of current closed-loop control modules; The dual-motor controller is connected to the odd-numbered and even-numbered stator windings of the permanent magnet linear motor through multiple sets of segment switches, forming a synchronous drive power supply structure for the dual-motor controller. It alternately supplies power to two adjacent stator windings, and each set of motor controllers drives only one stator winding. The speed closed-loop control module adopts a vector control strategy with Id=0. Its output is connected to the input of two sets of current closed-loop control modules, and the output of the speed closed-loop control module is used as the common q-axis given current for the two sets of current closed-loop control modules. The two sets of current closed-loop control modules are respectively connected to the dual-motor controller. The current closed-loop control module cooperates with multiple sets of segment switches to control the current of each stator segment winding, driving the linear motor to move along a predetermined trajectory.

[0053] It should be noted that the dual-motor controller uses segment switches to connect odd and even stator segments, forming an alternating power supply structure. Each group drives only one stator segment, avoiding the synchronization lag and switching stuttering of a single controller driving multiple segments, thus adapting to the segmented control requirements of long-stroke stators; the speed closed loop adopts... I d =0 vector control reduces excitation losses while outputting a common q-axis current, ensuring that the two sets of current closed-loop control references are consistent; the two sets of current closed loops work together with the segment switch to precisely regulate the current of each stator segment, correct current deviations in real time, effectively suppress thrust fluctuations, ensure that the mover runs smoothly along the predetermined trajectory, and improve the overall motor control accuracy and running stability.

[0054] As a refinement and extension of the specific implementation of the above embodiments, in order to fully illustrate the specific implementation process of this embodiment, another permanent magnet linear motor control device is provided, including: Dual motor controller, multi-section switch, speed closed-loop control module and two sets of current closed-loop control modules; like Figure 3 As shown, the dual-motor controller is connected to the odd-numbered stator windings and even-numbered stator windings of the permanent magnet linear motor through multiple sets of segment switches, forming a dual-motor controller synchronous drive power supply structure, which alternately supplies power to two adjacent stator windings, and each set of motor controllers drives only one stator winding. It should be noted that, Figure 3 It mainly consists of two inverters, multiple primary windings, and a switching circuit unit. Inverter I (odd-numbered segments) connects to odd-numbered primary winding segments 1, 3, n-1, etc., while inverter II (even-numbered segments) connects to even-numbered primary winding segments 2, 4, 6, etc. The switching circuit unit (including IGBTs and other switching elements) switches the power supply to each winding segment through the IGBT circuit switching drive signal control bus. The overall architecture adopts an odd-even segmented, independent inverter architecture, which can realize segmented and efficient power supply and thrust control of permanent magnet linear motors.

[0055] For example, the DC bus voltage Udc is simultaneously connected to the DC side of both inverter I (odd-segment drive) and inverter II (even-segment drive), providing a shared DC power supply for both. The AC output terminal of inverter I is connected to the input terminal of the switching circuit unit matched with each odd-numbered primary winding segment, and the AC output terminal of inverter II is connected to the input terminal of the switching switch matched with each even-numbered primary winding segment. The three-phase terminals of each odd-numbered primary winding segment are connected to the output terminal of its corresponding switching circuit unit, and the three-phase terminals of each even-numbered primary winding segment are connected to the output terminal of its corresponding switching switch. The drive signal terminals of all switching circuit units and switching switches are connected in parallel to the IGBT circuit switching drive signal control bus. The output terminal of the speed closed-loop control module is simultaneously connected to the input terminals of two sets of current closed-loop control modules. The output terminals of the two sets of current closed-loop control modules are respectively connected to the control ports of inverter I and inverter II to independently regulate the output current of the two inverters.

[0056] All of the multiple segment switches are semiconductor switches, and each segment switch corresponds to a stator segment winding. The dual-motor controller has an independent built-in current regulation module, and the two current regulation modules respectively control the current of the odd-numbered stator segment winding and the even-numbered stator segment winding.

[0057] like Figure 4 As shown, the speed closed-loop control module adopts I d The vector control strategy with =0 has its output connected to the input of two sets of current closed-loop control modules. The output of the speed closed-loop control module is used as the common q-axis given current for the two sets of current closed-loop control modules. The two sets of current closed-loop control modules are respectively connected to the dual-motor controller. The current closed-loop control modules cooperate with multiple sets of segment switches to control the current of each stator segment winding, driving the linear motor to move along a predetermined trajectory.

[0058] It should be noted that the speed closed-loop control module includes a speed detector and a PI regulator. The speed detector is used to collect the real-time running speed of the linear motor mover, and the PI regulator outputs a q-axis given current based on the deviation between the real-time running speed and the predetermined trajectory speed. Both sets of current closed-loop control modules have built-in current detectors and current regulators. The current detector collects the real-time current of the corresponding stator winding, and the current regulator adjusts the output current based on the deviation between the common q-axis given current and the real-time current.

[0059] For example, the given velocity v of the velocity closed loop m The deviation from the actual operating speed v of the motor is connected to a speed PI controller, the output of which serves as the q-axis reference current. i qd-axis given current i d1 and i d2 Take 0, i d1 The actual d-axis current of the odd-numbered windings of the motor i d1 deviation, i d2 The actual d-axis current of the even-numbered winding segments i d2 The deviation corresponds to the connection of two sets of d-axis current PI regulators, and the output is... u sd1 , u sd2 ; i q The actual q-axis current of the odd-numbered windings of the motor i q1 Deviation, actual q-axis current of even-numbered winding segments i q2 The deviation corresponds to two sets of q-axis current PI regulators, and the output is... u sq1 and u sq2 .

[0060] The input to the 2r / 2s coordinate transformation module 1 is: u sd1 , u sq1 The electrical angle obtained by converting the motor position using a grating ruler to an angle is also shown. θ The odd-numbered segment winding three-phase given current of its output is connected to the SVPWM1 module, and the SVPWM1 module outputs the PWM1 signal connected to inverter 1; the input of the 2r / 2s coordinate transformation 2 module is... u sd2 , u sq2 and electrical angle θ The even-numbered segment winding three-phase given current is output and connected to the SVPWM2 module, whose output PWM signal 2 is connected to inverter 2; The input to the 3s / 2r coordinate transformation module 1 is the actual three-phase current and electrical angle output from inverter 1 to the odd-numbered winding segments. θ Output i d1 , i q1And feed it back to the corresponding current deviation terminal; the input of the 3s / 2r coordinate transformation module 2 is the actual three-phase current and electrical angle output from inverter 2 to the even-numbered winding segments. θ Output i d2 , i q2 And feed it back to the corresponding current deviation terminal; DC bus voltage U dc The inverters are connected to the DC side of inverter 1 and inverter 2 respectively, and both inverter 1 and inverter 2 are connected to the stator winding of the permanent magnet linear motor.

[0061] It should be noted that this embodiment employs a dual-motor controller and odd-even segmented drive, along with a switching circuit controlled by semiconductor segment switches and IGBT bus control. This allows the stator windings to be connected to corresponding inverters in odd and even segments, enabling alternating power supply to adjacent segments and a single controller driving only one segment of the winding. This avoids redundant energy consumption from supplying power to the entire segment, significantly improving the efficiency of long-stroke power supply. Furthermore, by using bus synchronous control, it shortens the segment switching response time, solving the stuttering problem of traditional single-controller multi-segment drive and ensuring smooth high-speed movement of the rotor.

[0062] The dual controllers have built-in independent current regulation modules, coupled with two sets of independent current closed loops, which can separately regulate the odd and even segment currents; combined with I d =0 vector control strategy, using the speed closed-loop output as the common q-axis command current, thus borrowing... I d =0 characteristics improve power factor and energy efficiency, and through independent closed-loop adaptation to different winding operating conditions, significantly improve current control accuracy and reduce thrust fluctuations.

[0063] The coordinate transformation module, SVPWM module, and grating ruler feedback form a precise adjustment link: the 2r / 2s transformation converts the current command into a three-phase signal, and the SVPWM outputs a stable PWM wave; the 3s / 2r transformation provides closed-loop feedback of the actual current, which, together with real-time position and angle feedback, improves signal conversion accuracy and trajectory tracking accuracy, making it suitable for high-precision scenarios such as precision manufacturing. The control device balances long-stroke efficiency, smooth operation, and control precision, providing reliable control support for the large-scale long-stroke application of permanent magnet linear motors.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A permanent magnet linear motor, characterized in that, The permanent magnet linear motor includes: Stator module, mover module; The stator module includes a stator winding and a stator core. After the stator winding is wound, it is embedded and fixed in the winding slot of the stator core. The upper and lower sets of stator modules are arranged in parallel and symmetrically. The stator module has a segmented structure. The moving module includes a moving core and permanent magnets. The permanent magnets are symmetrically arranged, and permanent magnets are fixed on the upper and lower sides of the moving core. The moving module is a double-sided short secondary permanent magnet structure. The moving submodule is placed in the air gap area between the upper and lower sets of stator modules.

2. The permanent magnet linear motor according to claim 1, characterized in that, The stator module consists of 30 segments, with each segment being 0.5m long and the total length being 15m. Each stator segment uses a 12-slot, 10-pole fractional-slot concentrated winding.

3. The permanent magnet linear motor according to claim 1, characterized in that, The width of the stator core is: in, p For extreme logarithms, L a For the core width, The leakage coefficient is... F For rated thrust, For the fundamental winding coefficient, For air gap magnetic flux density, A For electrical load, The rated efficiency of the motor, The power factor.

4. The permanent magnet linear motor according to claim 1, characterized in that, The stator winding adopts a fractional slot concentrated winding, and the wiring adopts a star connection. The calculation formula for the winding coefficient is: in, This is the fundamental short-range coefficient. The fundamental wave distribution coefficient, ω is the short-pitch angle of the winding, and c is the number of coil groups.

5. The permanent magnet linear motor according to claim 1, characterized in that, The permanent magnet is made of neodymium iron boron material, and the lateral length L of the permanent magnet is... p With motor width L a Consistent; the longitudinal width of the permanent magnet is (0.6-0.9)τ; the length in the magnetization direction... h m Calculate using the following formula: Where τ is the polar moment. This is the polar arc coefficient. g B is the length of the air gap on one side of the motor. r This refers to the remanence of a permanent magnet.

6. The permanent magnet linear motor according to claim 1, characterized in that, The permanent magnet linear motor also includes a mounting assembly; The mounting assembly includes a mover upper guide rail, a stator mounting bracket, and a stator mounting slot. The mover upper guide rail provides vertical and lateral constraints for the mover module. The stator mounting bracket is used to fix the stator windings. The stator mounting slot is used to isolate the site steel structure to prevent deformation of the steel structure from affecting the permanent magnet linear motor.

7. The permanent magnet linear motor according to claim 6, characterized in that, One end of the stator mounting bracket is provided with a mover upper guide rail, and the other end is provided with a stator fixing part. The stator fixing part is used to fix the stator coil, and the stator mounting bracket can withstand the rated load impact without deformation. The stator mounting slot is located below the stator mounting bracket; The length of the stator mounting bracket is set to 1 meter, and 2 stator modules are placed on each stator mounting bracket; Two adjacent stator mounting brackets share a mounting slot, and adjusting screws are provided on the left, right, and bottom sides of the site steel structure where it mates with the mounting slot.

8. A control device for a permanent magnet linear motor, wherein the control device is applied to the permanent magnet linear motor according to any one of claims 1-7, characterized in that, The device includes: a dual-motor controller, a multi-segment switch, a speed closed-loop control module, and two sets of current closed-loop control modules; The dual-motor controller is connected to the odd-numbered and even-numbered stator windings of the permanent magnet linear motor through multiple sets of segment switches, forming a synchronous drive power supply structure for the dual-motor controller. It alternately supplies power to two adjacent stator windings, and each set of motor controllers drives only one stator winding. The speed closed-loop control module adopts I d =0 vector control strategy, the output terminal is connected to the input terminal of two sets of current closed loop control modules respectively, and the output of the speed closed loop control module is used as the common q-axis given current of the two sets of current closed loop control modules. The two sets of current closed-loop control modules are respectively connected to the dual-motor controller. The current closed-loop control module works with multiple sets of segment switches to control the current of each stator segment winding and drive the linear motor to move along a predetermined trajectory.

9. The permanent magnet linear motor control device according to claim 8, characterized in that, All of the multiple segment switches are semiconductor switches, and each segment switch corresponds to a stator segment winding. The dual-motor controller has an independent built-in current regulation module, and the two current regulation modules respectively control the current of the odd-numbered stator segment winding and the even-numbered stator segment winding.

10. The permanent magnet linear motor control device according to claim 8, characterized in that, The speed closed-loop control module includes a speed detector and a PI regulator. The speed detector is used to collect the real-time running speed of the linear motor mover, and the PI regulator outputs a q-axis given current based on the deviation between the real-time running speed and the predetermined trajectory speed. Both sets of current closed-loop control modules have built-in current detectors and current regulators. The current detector collects the real-time current of the corresponding stator winding, and the current regulator adjusts the output current based on the deviation between the common q-axis given current and the real-time current.

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