4164 results about "Magneto" patented technology

The invention relates to the technical field of motor control, in particular to a permanent magnet motor current control system based on predictive compensation, which comprises a thermal field identification module, a response offset identification module, a correction track generation module, an amplitude limiting interval decision module and a compensation instruction output module. According to the method, a dynamic prediction correction mechanism is established based on thermal field characteristics and a response error trend, real-time adjustment of a current track of the permanent magnet motor is realized, a three-dimensional space thermal load curved surface is constructed by means of a stator temperature rise curve, a permanent magnet temperature change rate and driving torque fluctuation, and transient influence of thermal working condition change on magnetic performance of the motor is reflected. A multi-dimensional prediction compensation path is integrally constructed through interaction among multiple thermal field parameters, electromagnetic response variables and time sequence feature points, the response precision and control stability of the permanent magnet motor under the dynamic working condition are improved, the magnetic performance attenuation influence caused by thermal drift is reduced, and meanwhile the tracking consistency under current track disturbance is improved.

The invention provides a high-temperature chemical pipeline defect detection system and method based on magnetostrictive ultrasonic guided waves, and relates to the technical field of high-temperature chemical pipeline defect detection.The method comprises the steps that magnetostrictive excitation signals are applied, the propagation process of the guided waves in a pipeline is calculated through numerical simulation, and the amplitude and phase information of guided wave signals is obtained; performing time-frequency domain analysis on the guided wave signal, extracting group velocities and phase velocities of guided waves in different modes, determining frequency dispersion characteristics of the guided waves, and evaluating the influence of a high-temperature environment on guided wave propagation; processing the received guided wave signal by adopting a modal decomposition and reconstruction algorithm to obtain a corrected guided wave signal; and carrying out feature extraction and parameter estimation on the corrected guided wave signal to obtain the position, size and type information of the pipeline defect. According to the invention, the problem of multilayer heterogeneous pipeline guided wave detection in a high-temperature environment is solved, the accuracy and reliability of defect detection are improved, and an effective method is provided for pipeline health monitoring and safety assessment.

The invention provides a permanent magnet motor and a variable-frequency scroll compressor, and relates to the technical field of scroll compressor design and manufacturing, and the permanent magnet motor comprises a stator iron core and a rotor iron core; the stator iron core comprises stator slots which are uniformly distributed along the circumference, copper windings are embedded in the slots, stator yokes which are uniformly distributed are arranged outside the bottom of each slot, each stator yoke is provided with an arc-shaped long slot, stator teeth are arranged between every two adjacent stator slots, and the tops of the stator teeth are sunken to form through-flow slots; the rotor core is internally provided with magnetic steel grooves which are uniformly distributed, two same first magnetic isolation grooves are arranged between two adjacent magnetic steel grooves, magnetic steel is arranged in the magnetic steel grooves, and the top of each magnetic steel is provided with two second magnetic isolation grooves which are symmetrically distributed. The outer side radius Rs1 of the stator core, the inner side radius Rs2 of the stator core and the axial length Lis of the stator core meet the following conditions: 1.282 < = Lis / (Rs1-Rs2) < = 2.778, and 34 < = Rs1-Rs2 < = 39 mm. The power density of the motor can be increased, the cost is reduced, the efficiency is improved, and the harmonic content is reduced so as to suppress torque ripple.

The invention discloses a permanent magnet motor demagnetization fault diagnosis method based on deep learning, and relates to the technical field of permanent magnet motor fault diagnosis, and the method comprises the steps: collecting the operation state data of a permanent magnet synchronous motor and a fan in real time through a sensor network, and generating a basic variable; multi-modal features in the basic variables are extracted, a health index sequence is constructed, and a demagnetization risk score is generated; setting a self-adaptive diagnosis opportunity control strategy, and determining the opportunity of next diagnosis detection according to the current demagnetization risk score; establishing a demagnetization risk prediction model, predicting a demagnetization risk score at the next diagnosis time, generating a dynamic risk threshold value, and judging whether a demagnetization early warning decision is triggered or not; allocating a maintenance task priority according to the current demagnetization risk score and the historical mode; comprehensively calculating the overall health index of the fan system, and predicting the residual life of the fan permanent magnet motor. According to the method, the problem of resource waste caused by unreasonable diagnosis time in the demagnetization fault diagnosis of the permanent magnet motor is solved.

The invention provides a permanent magnet motor and a scroll inverter compressor, and relates to the technical field of scroll compressor design and manufacturing, and the permanent magnet motor comprises a stator iron core and a rotor iron core; the stator core comprises stator teeth and a stator yoke which are uniformly distributed along the circumference, fluid through grooves are formed in the outer side of the stator yoke at the tops of the stator teeth, stator grooves are formed in two adjacent stator teeth and the stator yoke between the two stator teeth, and a plurality of strands of conductive circular enameled wires are embedded in each stator groove; the outer side of the rotor core is composed of linear segments and arcs, air grooves which are evenly distributed are formed in the rotor core, non-uniform magnetic isolation bridges are formed between the air grooves and the linear segments on the outer side of the rotor core, a certain distance is formed between every two adjacent air grooves, parallel magnetic conductive ribs are formed, and permanent magnets with the magnetic field directions changing alternately are embedded in the air grooves. A rivet hole, a lightening hole and a shaft hole are arranged close to the inner side of the rotor core. Therefore, the defined proportionality coefficient Ks is kept in a reasonable range, the power density of the motor can be increased, the cost is reduced, and the efficiency is improved.

The invention discloses a variable air gap domain-based permanent magnet motor topology hierarchy optimization design method and a motor, and the method comprises the steps: firstly determining an electromagnetic performance layer optimization target, constructing a geometric parameter model, carrying out the dimensionality reduction of a high-dimensional parameter, and constructing a first hierarchy optimization sub-model I; performing geometric parameter optimization on the stator and rotor basic domain by combining a multi-objective optimization algorithm to obtain an optimized motor I; analyzing and optimizing the characteristic electromagnetic force of the motor I under different working conditions to serve as a second-level optimization target, constructing a second-level optimization sub-model II, performing small-scale online topological optimization in combination with a multi-target genetic algorithm, performing secondary design on a motor air gap design domain, obtaining a sample data set, constructing a parallel agent model, and constructing a second-level optimization sub-model II; then large-scale off-line topological optimization is carried out, and remodeling of a motor air gap design domain is achieved; and performing simulation evaluation on the final optimized motor. According to the method, on the premise that the vehicle permanent magnet driving electromagnetic performance is kept, electromagnetic vibration noise under multiple working conditions is suppressed, and meanwhile optimization efficiency is remarkably improved.

There is provided an intravascular blood pump for insertion into a patient's heart. The blood pump comprises a slotless permanent magnet motor contained within a housing, the motor having p magnet pole pairs and n phases, where p is an integer greater than zero, and n is an integer ≥3. The motor comprises a stator extending along a longitudinal axis of the housing and having 2np coils wound to form two coils per phase per magnet pole pair. The stator comprises inner and outer windings each comprising np coils electrically connected such that the current flowing through the coils is in the same direction, the coils of the outer winding arranged on an outer surface of the coils of the inner winding.

The invention discloses a dual three-phase permanent magnet motor current control method and system under high speed and low carrier wave ratio, and belongs to the technical field of permanent magnet motor control. The method mainly comprises the following steps: reconstructing a motor mathematical model by adopting VSD conversion and Park conversion; designing a linear expansion state observer; a reference value of an output voltage vector is obtained in combination with deadbeat predictive current control; and performing time delay compensation and angle delay compensation on the output voltage vector to obtain a reference value of a final output voltage vector, sending the reference value to an SVPWM module for modulation, and outputting a PWM pulse signal for driving a motor. No motor parameter is used in the current loop design process, system errors caused by mismatching of the motor parameters can be avoided, and the system robustness is improved; meanwhile, only one control parameter needs to be determined, the parameter setting difficulty is greatly reduced, and stable operation of the high-speed permanent magnet motor under the low carrier wave ratio is achieved.

The invention provides a rotor iron core, a permanent magnet motor and an inverter compressor, and relates to the technical field of motor and compressor design and manufacture, the rotor iron core comprises uniformly distributed permanent magnet grooves, a groove is arranged between two adjacent permanent magnet grooves, each groove extends inwards along the radial direction of the rotor iron core, parallel magnetic bridges are arranged between the grooves and the permanent magnet grooves, and the permanent magnet grooves are connected with the parallel magnetic bridges. A first magnetic barrier groove, a second magnetic barrier groove and a third magnetic barrier groove which are symmetrically distributed are formed in the two sides of the top of each permanent magnet groove respectively, a first arc and a second arc are arranged on the outer side of the rotor core above the magnetic barrier grooves, the second arc intersects with the side edge of the groove, and permanent magnets with alternating magnetism are embedded in the permanent magnet grooves. The radius Rr of the outer side of the rotor iron core, the distance ho from the middle point of the bottom of the permanent magnet groove to the center point of the rotor iron core and the thickness hm of the permanent magnet meet the condition that (Rr-ho) / hm is larger than 2 and smaller than or equal to 3.4. By reasonably arranging the position and the size of the magnetic barrier groove, magnetic circuit distribution can be changed, magnetic flux leakage can be reduced, the power density of the motor can be increased, and electromagnetic vibration noise of the motor and the compressor can be reduced.

The invention discloses a design method of a coreless stator axial magnetic flux permanent magnet motor. The method specifically comprises the following steps: firstly, determining a basic structure, a permanent magnet structure and performance demand parameters of the coreless stator axial magnetic flux permanent magnet motor; determining stator and rotor structure parameters of the motor according to the performance requirement parameters of the motor; establishing a simplified model of an internal magnetic circuit of the motor, determining excitation magnetic potential of the motor, and establishing a finite element dynamic simulation model of the coreless stator axial flux permanent magnet motor based on a Maxwell equation; and finally, comparing the finite element dynamic simulation result with the motor performance demand parameter, if the finite element dynamic simulation result does not meet the requirement, correcting the motor design structure parameter and the electromagnetic parameter, and re-determining the stator and rotor structure parameter of the motor until the finite element dynamic simulation result of the motor meets the motor performance demand parameter. The design cost of the coreless stator axial magnetic flux permanent magnet motor is reduced, the design period is shortened, and the design efficiency and the design precision are improved.

The invention relates to the technical field of permanent magnet motor speed regulation, in particular to a speed regulation control system of a permanent magnet motor, which realizes high-dimensional accurate description of the running state of the motor by identifying the magnetic performance change of a permanent magnet under different thermal state conditions and combining the structural change characteristics of a motor winding. Response consistency and error convergence performance of control gain adjustment are remarkably improved, a proportional integral factor value group is obtained by adjusting an interval gain sequence, ordered switching path planning between operation states is achieved, abnormal states are found in advance, an excitation fluctuation source is accurately positioned, and by constructing a voltage excitation adjustment set, the control gain adjustment accuracy is improved. The method effectively improves the flexible adjustment capability and the abnormity response rate of a control strategy, achieves the multi-time-domain, multi-segment, quick response and stable speed regulation of the permanent magnet motor under a complex working condition, remarkably improves the dynamic adaptive capability and the output control precision, and reduces the energy consumption and response lag.

The invention discloses a crane steel wire rope flaw detection device and a flaw detection method, and belongs to the technical field of nondestructive flaw detection. The device comprises a magnetic memory flaw detection module and a wheel type rope climbing robot device for driving the magnetic memory flaw detection module to move along a crane steel wire rope, the magnetic memory flaw detection module comprises a hollow flaw detection shell, the flaw detection shell is longitudinally provided with a central through hole for a crane steel wire rope to penetrate through, and a plurality of giant magneto-impedance effect magnetic sensors are evenly arranged in the flaw detection shell in the circumferential direction of the central through hole. Therefore, a sensor array used for detecting the leakage magnetic field intensity of the crane steel wire rope is formed, and the giant magneto-impedance effect magnetic sensors are arranged in a coplanar mode. The device is mainly based on the giant magneto-impedance effect magnetic sensor and the metal magnetic memory principle, extremely weak magnetic nondestructive testing is conducted on the crane steel wire rope, and the device is convenient to use, high in detection precision, simple in structure and suitable for various steel wire rope detection environments.

The invention belongs to the technical field of permanent magnet synchronous generator demagnetization fault detection, and particularly discloses a permanent magnet motor fault early warning system based on big data, which comprises a high-frequency injection and grid-connected control module, a fault early warning module and a fault early warning module, actively injecting a high-frequency disturbance signal of which the frequency is higher than the fundamental frequency into a control loop of the permanent magnet synchronous generator; the multi-source synchronous acquisition module is used for synchronously acquiring multi-dimensional operation parameters of the permanent magnet synchronous generator and performing time domain alignment and frequency domain separation on the multi-dimensional operation parameters to obtain synchronous acquisition signals; the composite feature extraction module is used for extracting a multi-dimensional demagnetization criterion of the permanent magnet synchronous generator based on the synchronous acquisition signal; the self-adaptive threshold regression prediction module is used for performing fusion evaluation on the multi-dimensional demagnetization criteria by using the demagnetization health index model to generate a demagnetization judgment result of the demagnetization degree of the permanent magnet synchronous generator; the method has the advantages that the demagnetization recognition accuracy is improved, and early warning is achieved.

The invention provides a double-squirrel-cage permanent magnet motor with a fractional slot concentrated winding and a pole-changing switching method, the motor comprises a stator and a rotor, the stator comprises a stator winding design and a winding pole-changing switching method, and two groups of conducting bars are arranged on the outer circumferential side of the rotor. The two groups of conducting bars are respectively connected with the two end rings to form two independent double-squirrel-cage structures, and each conducting bar corresponds to a permanent magnet steel magnetic pole distributed in the circumferential direction of the rotor. Two groups of conducting bars are arranged on the outer side of the rotor, and the two groups of conducting bars are respectively connected with the two end rings to form two independent double-squirrel-cage structures. The independent double-squirrel-cage structure not only can filter specific-order magnetomotive force harmonics generated by a stator winding, but also greatly reduces the magnetic leakage phenomenon due to the position relation between the conducting bars and the magnetic poles of the permanent magnets, so that the blocking effect of the conducting bars on a permanent magnetic circuit is reduced to the minimum, the utilization rate of the permanent magnets is improved, and the cost is reduced.

The invention provides a permanent magnet motor based on permanent magnet included angle optimization and a cogging torque suppression method thereof.The permanent magnet motor comprises a stator iron core, an armature winding, rotor iron cores and permanent magnets, and each pole of rotor iron core is provided with two sets of first V-shaped permanent magnet grooves and second V-shaped permanent magnet grooves which are symmetrical about the center line of the rotor iron core and are different in size; the permanent magnets are arranged in the first V-shaped permanent magnet grooves and the second V-shaped permanent magnet grooves respectively, the permanent magnets in the first V-shaped permanent magnet grooves and the second V-shaped permanent magnet grooves are arranged in a V-V shape, the included angle between the permanent magnets in the first V-shaped permanent magnet grooves is alpha, the included angle between the permanent magnets in the second V-shaped permanent magnet grooves is beta, and the permanent magnets in the first V-shaped permanent magnet grooves and the permanent magnets in the second V-shaped permanent magnet grooves are separated by the aid of an NSGA-II algorithm under the condition that the distance of the magnetic isolation bridge is unchanged. By adjusting the angle between the permanent magnets in the first V-shaped permanent magnet grooves and the second V-shaped permanent magnet grooves, the best matching combination of the small permanent magnet included angle alpha and the large permanent magnet included angle beta is optimized, and the arc-shaped auxiliary grooves are formed in the surface of the rotor iron core, so that the cogging torque of the permanent magnet motor is optimized.

The invention discloses a magnetorheological damper durability test device, and particularly relates to the field of magnetorheological dampers, the magnetorheological damper durability test device comprises a box body and a to-be-tested magnetorheological damper, the rear end of the box body is provided with a test cavity with a triangular cross section, and the interiors of the left and right inclined side walls of the test cavity are respectively provided with a liquid storage cavity and an equipment cavity. According to the durability test device for the magneto-rheological damper, the material spraying assembly is arranged, water or powder can be sprayed to the magneto-rheological damper, the device is used for simulating a rainy day environment or simulating a dust and gravel road surface, and the complex environment encountered by the magneto-rheological damper in actual use is truly restored; meanwhile, the amplitude adjusting assembly allows the amplitude of vibration applied to the shock absorber to be accurately and continuously adjusted, and road surfaces with different jolting degrees are simulated. According to the invention, environmental factors such as water, dust, temperature, amplitude, inclination angle and the like can be independently controlled, so that test results can more accurately reflect the durability of the magnetorheological damper under specific working conditions, and data one-sidedness is avoided.

The invention belongs to the field of magnetic refrigeration materials, and particularly discloses a gadolinium-based molybdate magnetic refrigeration material and a preparation method and application thereof. The gadolinium-based molybdate magnetic refrigeration material comprises GdXMoO4, wherein X is F, Cl, Br or I; the magnetic phase change temperature of the gadolinium-based molybdate magnetic refrigeration material is less than 2K, and the maximum magnetic entropy change of the gadolinium-based molybdate magnetic refrigeration material is greater than or equal to 12J. Kg <-1 >. K <-1 > when the magnetic field change is 0-50kOe. The gadolinium-based molybdate magnetic refrigeration material disclosed by the invention has extremely low magnetic phase transition temperature, has relatively high magnetocaloric efficiency in a low magnetic field, is an extremely low temperature region magnetic refrigeration material with excellent performance, and has a wide application prospect in the field of extremely low temperature magnetic refrigeration.

The invention relates to a permanent magnet synchronous motor current control method of an adjustable switching frequency FCS-MPC. Compared with the prior art, the defect that the switching frequency of an inverter is not fixed in current control of an existing FCS-MPC permanent magnet synchronous motor system is overcome. The method comprises the following steps: acquiring data of a driving system; constructing a discrete current prediction control model; determining a cost function and a delay compensation strategy; calculating a current error control band degree; selecting an optimal voltage vector; and outputting the voltage vector. According to the invention, the unique advantages of the FCS-MPC are reserved, and the defect that the inherent switching frequency is not fixed is overcome, so that the FCS-MPC can operate under the specified switching frequency in a wide speed regulation range; by introducing the PI type switching frequency controller, the zero-static-error tracking of the switching frequency reference value can be realized, and the control method realizes the effective regulation and control of the switching frequency on the basis of ensuring the current control performance of the permanent magnet motor.

The invention discloses a cross coupling calculation method and device based on an unequal-width magnetic circuit model, and the method comprises the steps: adding a permanent magnet equivalent magnetomotive force source into a large-pole magnetic circuit and a small-pole magnetic circuit of a d-axis in a permanent magnet motor through employing a normalization method, and obtaining a normalized large-pole magnetic circuit and a normalized small-pole magnetic circuit, the magnetic circuit model is a d-axis-permanent magnet cross coupling magnetic circuit model based on a normalized large and small pole magnetic circuit method; a magnetic isolation bridge part in the magnetic circuit model is adjusted, a permanent magnet is added, and before the magnetic circuit model is adjusted, a large-pole magnetic circuit triangular area and a small-pole magnetic circuit triangular area are not communicated with the magnetic isolation bridge; in a large and small pole magnetic circuit with permanent magnet magnetomotive force, connecting a triangular area between permanent magnets and a magnetic isolation bridge to obtain a corrected magnetic circuit model after the magnetic isolation bridge channel is corrected; and calculating the total magnetic flux and inductance of the loop by combining the corrected magnetic circuit model and the corresponding equivalent magnetic circuit.

The invention discloses a multi-turn memory optomagnetic encoder hybrid system, belongs to the technical field of position and angle measurement encoders, and aims at solving the problems that an existing optomagnetic hybrid encoder is complex in signal processing, long in axial length, insufficient in precision stability and prone to losing the number of turns and the position. The system comprises an optical encoder, a gallium arsenide magnetic signal acquisition sensor, a multi-antipode unequal magnetic ring, a processor, a hardware circuit, an ultra-low power consumption circuit, a signal acquisition module, a signal processing module and the like, integrates self-developed magnetic angle analysis, turn number memory correction and other algorithms, and adopts dual-redundancy design and intelligent signal mode switching. The method simplifies the signal processing flow, shortens the axial length, improves the measurement precision and stability, enhances the environmental adaptability and fault-tolerant capability, prolongs the endurance, and is suitable for the position angle measurement in a high-precision and severe environment.

The invention relates to the technical field of permanent magnet motors, in particular to a salient pole rate reversible degree enhanced permanent magnet motor and a design method thereof. The salient pole rate reversible degree enhanced permanent magnet motor comprises a rotating shaft, a rotor sleeving the rotating shaft, and a stator coaxially sleeving the rotor; eight trapezoidal magnetic barriers with centers on a q axis and eight bread-type permanent magnets with centers on a d axis are embedded in the rotor along the circumferential direction in a staggered manner; the bread-type permanent magnets are magnetized along the inner and outer thickness directions, and the magnetizing directions are opposite; and two sides of each bread-shaped permanent magnet are respectively provided with a bulb-shaped magnetic barrier contacted with the bread-shaped permanent magnet. According to the invention, a plurality of variable magnetic resistances instead of a single magnetic resistance can be innovatively introduced into the rotor by ingeniously changing the armature current under different working conditions, so that the leakage magnetic flux and the effective magnetic flux of the motor are changed, meanwhile, the target of enhancing the reversible degree of the salient pole rate under all working conditions is achieved, and the diversified performance requirements under different working conditions can be met.

The invention discloses a motor, a compressor and refrigeration equipment, and relates to the technical field of permanent magnet motors, stator teeth and stator slots on the inner circumference of a stator core are alternately distributed, windings are arranged in the stator slots, the number of the stator slots is Q, the diameter of the maximum outer circle contour of the stator core is D1, the diameter of the maximum circle contour defined by the slot bottoms of the plurality of stator slots is D2, the diameter of the minimum inner circle outline of the stator core is D3, the rotor is rotatably mounted in the stator, the number of pole pairs of the rotor is P, and GCD (Q, P) * (D1-D2) / 2) / ((D1-D3) / 2) is greater than or equal to 1.4 and less than or equal to 2.6, and ((D2-D3) / 2) / (D3 / 2) is greater than or equal to 0.3 and less than or equal to 0.42, and GCD (Q, P) is the largest common divisor of Q and P. The technical scheme provided by the invention aims at balancing the rigidity and temperature of the stator, and ensuring the low-noise operation of the motor and the operation reliability of the motor at the same time.

The invention discloses a permanent magnet motor turn-to-turn short circuit fault diagnosis method considering complex working condition influence, belongs to the technical field of permanent magnet motor fault diagnosis, and aims to solve the problems that a turn-to-turn short circuit diagnosis result of a permanent magnet synchronous motor for an electric vehicle is easily influenced by working conditions and slight faults are difficult to diagnose under complex operation working conditions. The method comprises the following steps: step 1, high-frequency signal injection and information acquisition; injecting the high-frequency rotating voltage signal into a motor control system under a natural coordinate system, and collecting each phase of high-frequency current and each phase of high-frequency voltage of the motor through a band-pass filter; 2, subtracting the high-frequency voltage from the healthy voltage under the condition that the high-frequency signal is injected, and calculating to obtain a high-frequency voltage residual error of each phase; 3, according to the high-frequency voltage residual error of each phase, obtaining two fault characteristic quantities, namely the standard deviation of the high-frequency voltage residual error and the absolute average value of the high-frequency voltage residual error of each phase; and 4, judging whether a turn-to-turn short circuit fault occurs or not according to the fault characteristic quantity, and judging a fault phase.

The invention discloses a fault detection method suitable for a permanent magnet motor sewage pump, and particularly relates to the technical field of motor equipment operation fault detection.The fault detection method comprises the following steps that stage division is conducted on the operation process of the permanent magnet motor sewage pump, and staged dynamic baselines corresponding to all operation stages are established; extracting transient abrupt change of the operating parameters under the dynamic baseline constraint and forming a transient abnormal event sequence; the method comprises the following steps: judging the damage degree grade of a transient abnormal event, continuously accumulating risk integrals, outputting early warning information when a risk reaches a trigger condition, and generating an operation disposal instruction; according to the invention, by constructing a staged dynamic baseline and extracting a transient abnormal event, accurate identification of abnormal behaviors in different operation stages is realized; and in combination with a continuous accumulation mechanism of the damage degree grade and the risk integral, when the risk reaches a triggering condition, an early warning is output, and an operation disposal instruction is generated, so that the accuracy, timeliness and operation safety of fault detection of the permanent magnet motor sewage pump are improved.

The invention discloses a magnetic induction intensity detection device based on laser self-mixing interference, which is characterized in that laser emitted by a laser is divided into two light paths after being split by an optical splitter; wherein a polarizing film, a magneto-optical crystal and a transducer are sequentially arranged on one optical path; the transducer is electrically connected with the control module, and the control module generates a continuous sine wave signal to continuously control the transducer; a detector is arranged on the other light path; the detector is electrically connected with the Fourier transform module, and the Fourier transform module analyzes a laser self-mixing interference signal acquired by the detector; the magneto-optical crystal is located in the magnetic field; laser emitted by the laser device is reflected for multiple times between the laser device and the transducer, and laser self-mixing interference is formed under the action of the polaroid. The laser is reflected for multiple times between the laser and the transducer, the Faraday optical rotation effect can be enhanced, the polaroid serves as the polarizer and the polarization analyzer, and the advantages that an external polarization analyzer is not needed, the measurement cost is reduced, and the sensitivity is improved are achieved.

The invention discloses a low-vibration permanent magnet motor for harmonic directional suppression rotor modification and a design method thereof. The structure and size of the permanent magnet motor are determined; analyzing the electromagnetic performance of the motor, and determining the harmonic order and phase of the radial permanent magnetic flux density; analyzing the vibration characteristics of the motor, and determining the main vibration frequency of the motor and the radial force order of dominant vibration so as to determine the order of the radial permanent magnetic flux density needing to be reduced; analyzing the relationship between the air gap magnetic conductance and the magnetic flux density, and determining the order and phase to which the air gap magnetic conductance needs to be added according to the distribution of the radial permanent magnet magnetic flux density to be reduced; a compensation function is established by adding air gap magnetic conductance which is opposite to the radial permanent magnetic flux density needing to be reduced, and the shaping position and shape are determined according to the period and shape of the compensation function; and considering the torque performance and stress of the motor, and determining the shaping depth. By adopting the method provided by the invention, the specific radial permanent magnetic flux density harmonic wave can be directly reduced, the vibration response can be effectively inhibited, and the torque performance of the motor can be ensured to be unchanged.

The invention belongs to the related technical field of motor control, and discloses a permanent magnet synchronous motor field weakening control method and device fusing current feedforward and model prediction control, and the method comprises the steps: (1) building a multi-objective optimization function based on a torque tracking error, current fluctuation and voltage limitation of a permanent magnet synchronous motor, solving the multi-objective optimization function through an interior point penalty function and a Newton iteration method based on a feedforward instruction torque and a model prediction control instruction torque to obtain an optimal current pair of the permanent magnet synchronous motor; (2) constructing a field weakening control fusion model based on the obtained optimal current pair, the feed-forward instruction torque and the model prediction control instruction torque; and (3) fusing the feedforward instruction torque and the model prediction control instruction torque through the dynamic weight factor of the flux-weakening control fusion model, and obtaining a flux-weakening control instruction of the permanent magnet synchronous motor in combination with the optimal current pair, thereby realizing flux-weakening control of the synchronous permanent magnet motor. The method has a multi-target cooperation capability.

The present invention belongs to the technical field of permanent magnet motors, and specifically is an axial flow fan blade permanent magnet motor rotor, comprising a motor shaft rotatably connected inside a motor housing, an iron core fixed to the outside of the motor shaft, the iron core arranged inside the motor housing, a slot body provided on the outside of the iron core, a permanent magnet fixed inside the slot body, a first fan blade fixed to one end of the motor shaft, the first fan blade arranged inside the motor housing, a plurality of heat dissipation channels provided at equal intervals inside the iron core, a plurality of circulation channels provided at equal intervals on one side of the heat dissipation channel, the circulation channel being arranged between two adjacent permanent magnets, and a plurality of air outlets provided at one end of the motor housing away from the first fan blade; the on-off of the end of the heat dissipation channel can be switched by rotating a first baffle inside the heat dissipation channel, and at the same time, the first baffle drives a second baffle to rotate to control the on-off of the circulation channel, and the internal air can be circulated by controlling the on-off during the preheating process of the motor, so as to achieve faster preheating.

The invention relates to the technical field of vibration isolation and reduction engineering, and discloses a modular multi-mechanism vibration isolation, energy consumption and vibration absorption integrated device and a control method thereof.The modular multi-mechanism vibration isolation, energy consumption and vibration absorption integrated device comprises a support, a plurality of corrugated plates are fixedly connected to the interior of the support, and magnetorheological dampers are fixedly connected to the bottoms of the inner walls of the corrugated plates; a magneto-rheological damper is fixedly connected to the top of the support, a dynamic vibration absorber is fixedly connected to the top of the magneto-rheological damper, a particle damper is fixedly connected to the top of the dynamic vibration absorber, a control unit is arranged on the outer side of the support, the magneto-rheological damper comprises a first shell, and a piston rod is fixedly connected to the inner wall of the first shell. By integrating multiple mechanisms such as corrugated plate vibration isolation, particle damping energy consumption, dynamic vibration absorber vibration absorption and magneto-rheological damper intelligent control, all-directional vibration suppression is achieved, under different frequencies and vibration working conditions, all modules work cooperatively, the vibration reduction effect is greatly improved, and the vibration isolation efficiency gt within the broadband of 20-2000 Hz is ensured; 85%.

The invention relates to an efficient magneto-rheological chemical machining device and method for the inner face of a pipe fitting and relates to the technical field of machining, the efficient magneto-rheological chemical machining device comprises a base, the upper surface of the base is fixedly connected with a fixing rack, and a chuck is rotationally arranged on the right side of the fixing rack and used for clamping and rotating the pipe fitting; the right side of the fixed rack is rotationally connected with a guide lead screw. The composite grinding technology of magnetorheological machining and chemical liquid polishing is introduced, the spraying assembly and the magnetic grinding assembly are installed on the surface of the machining rod at the same time, the magnetic grinding assembly is adjacent to the spraying assembly, and synchronous operation of chemical polishing liquid spraying and magnetic grinding is achieved; the inner wall of the pipe fitting can be ground after the spraying assembly is used for spraying, the polishing effect and efficiency of the inner surface of the pipe fitting are improved, the problems of low precision, microcracks and the like of current magnetic grinding machining of the pipe fitting are solved, and the time and cost of high-precision machining are effectively reduced.