658results about How to "Reduce electromagnetic interference" patented technology

The invention provides a method for testing the dynamic strain of the surface of a rotating body in an electromagnetic environment. The method comprises the following steps: constructing a bridge by using strain gauges and acquiring dynamic characteristic data of the rotating part under actual constraint conditions; performing simulation calculation according to the dynamic characteristic data, and determining the optimal pasting position of the strain gauge; pasting a strain gauge and formulating a wiring scheme of a strain gauge wire; the strain gauge is connected with a voltage signal amplifier, the amplified signal is connected with a data acquisition system through a conductive slip ring, and the amplified strain signal is recorded and processed; acquiring strain signals in real time and taking the strain signals as test data, and performing whole-course test in a full-rotating-speed range to complete dynamic strain test on the surface of the rotating body. The system has high sensitivity, the sensitivity and the measurement precision of the system are improved through full-bridge configuration, larger output signals are provided, the full bridge can achieve temperature compensation through symmetrical circuit design, and the system has good linear output characteristics and facilitates signal processing and analysis within the strain range.

The invention relates to the technical field of cables, and provides a low-voltage power supply cable which comprises a plurality of conductive cables, each conductive cable comprises a plurality of stranded conductors, and each stranded conductor is coated with an insulating layer; the plurality of insulating layers are arranged on the inner side of the inner lining layer, the plurality of stranded conductors are all arranged inside the inner lining layer, the space between the inner lining layer and the plurality of insulating layers is filled with a filling layer, the outer part of the inner lining layer is coated with a sheath layer, the end part of each sheath layer is slidably sleeved with the butt-joint cylinder, the stringing assembly is arranged on the butt-joint cylinder, and the heat dissipation assembly is arranged on the inner lining layer. A conductive frame is arranged between every two opposite butt joint cylinders, a conductive assembly is installed on each conductive frame, and a heat dissipation assembly is installed on each conductive assembly. Through the above technical scheme, the problems that in the prior art, due to the fact that high current density is prone to occurring at the butt joint position of two cables, the local temperature of a contact point rises, and the heat dissipation effect is poor are solved. And a gap is generated between the two cables, so that the current transmission performance is influenced.

The invention discloses an electric reactor with internal coil stabilization and auxiliary heat dissipation, and relates to the technical field of coil stabilization, the electric reactor comprises a base, the top surface of the base is fixedly connected with an air-core electric reactor body, the outer surface of the air-core electric reactor body is provided with a coil body, and the top surface of the base is provided with a coil stabilization mechanism for preventing the coil from loosening. An auxiliary heat dissipation mechanism used for assisting heat dissipation of the reactor is arranged on the top face of the base, the coil stabilizing mechanism can clamp a loose coil, pressure can be applied more evenly through clamping and fixing, the coil is more stably fixed, the consistency of the shape and performance of the coil can be kept, and the service life of the reactor is prolonged. The clamping device can avoid direct compression and damage to an insulating layer of the coil, the insulating performance of the coil can be protected, the auxiliary heat dissipation mechanism can scrub the interior of the electric reactor, remove dust and sundries in the electric reactor, reduce heat resistance, improve heat dissipation efficiency and keep the electric reactor to operate within the normal working temperature range.

The invention provides a synchronous zero voltage modulation system and method of a cascade system, a medium and equipment wherein the synchronous zero voltage modulation system of the cascade system comprises a power circuit module and a modulation system; the power circuit module comprises a front-stage four-switch buck-boost converter and a rear-stage LCC-LCC compensated bidirectional wireless charging system; the modulation system comprises a voltage compensation module, a current compensation module, a current comparison module, a synchronization module and a switch driving signal generation module, the output end of the voltage compensation module is connected with the input end of the synchronization module, and the output end of the current compensation module is connected with the input end of the synchronization module. The output end of the current comparison module is connected with the input end of the synchronization module, and the output end of the synchronization module is connected with the driving signal generation module. According to the invention, a plurality of time scales are adopted, the implementation condition of synchronous zero-voltage switch modulation is accurately calculated, the calculation speed is high, the memory occupation amount is small, and the zero-voltage switch synchronous modulation of the cascade system is realized.

The invention relates to the technical field of power supply control, in particular to a power supply control device and a power supply control method and system. The method comprises the following steps: acquiring electromagnetic compatibility parameter data of a power supply device; performing simulation analysis on an electromagnetic environment in the power supply device according to the electromagnetic compatibility parameter data, and predicting high-frequency harmonic waves and electromagnetic interference in a switching process to obtain electromagnetic interference prediction data; performing control design on the soft switch according to the electromagnetic interference prediction data, and generating soft switch control scheme data; switching operation is carried out in the state that the voltage of a switch element is close to zero based on the soft switching control scheme data, current and voltage waveform smooth optimization design is carried out on a resonance circuit, and optimized topological structure data is generated. According to the invention, the overall performance and reliability of the power supply system are significantly improved by improving the electromagnetic compatibility, reducing the switching loss, optimizing the design, monitoring in real time, dynamically adjusting and the like, and the higher requirements of modern electronic equipment on the power supply system are met.

The invention provides an early warning method in construction temporary warehouse electric power material supply, which comprises the following steps: establishing a three-dimensional electromagnetic field distribution model based on actual environment influence according to a relative position relationship between a highway construction temporary warehouse and a high-voltage transmission line, and obtaining electromagnetic environment theoretical distribution of each warehouse; in the temporary warehouse, electromagnetic sensors are arranged according to materials, highly sensitive to electromagnetic interference, of electronic components, and large-dynamic-range electromagnetic sensors are arranged according to materials, high in electromagnetic field induction, of metal materials; monitoring data collected by various electromagnetic sensors of the warehouse are transmitted back to a power grid dispatching center in real time through the low-power-consumption wide-area Internet of Things and are associated with warehouse material structure parameters, and a database is constructed; historical data of a power grid load and an electromagnetic environment are mined, an association rule of an electromagnetic interference characteristic and a power transmission line operation condition is extracted, and a collaborative prediction model of a multi-warehouse electromagnetic safety situation is established.

The invention provides a brake device and a motor, the brake device comprises a first rotating assembly and a second rotating assembly, the first rotating assembly is fixed on a rotating shaft, and the second rotating assembly is connected with the first rotating assembly in an extrusion manner under the action of a first elastic piece; the first rotating assembly can rotate relative to the second rotating assembly; the rotation stopping assembly can be switched between a first working position and a second working position, when the rotation stopping assembly is switched to the first working position, the rotation stopping assembly is connected with the second rotating assembly in a clamped mode, and when the rotation stopping assembly is switched to the second working position, the rotation stopping assembly is separated from the second rotating assembly; and the electromagnetic driving assembly is fixed on the bracket, and the rotation stopping assembly can be switched between the first working position and the second working position under the action of the electromagnetic driving assembly, so that the technical problems of overlarge size and overweight of the electromagnetic driving assembly of the motor in the prior art can be solved.

The invention discloses a stacked structure of a SiC module and a manufacturing process of the stacked structure. The module forms a full-bridge circuit topology through four SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) chips. A stacked structure is adopted, four SiC MOSFET chips are divided into two groups to form an upper layer and a lower layer, namely an upper bridge arm and a lower bridge arm of a circuit, the upper layer chip and the lower layer chip are connected through a welding ball and are welded to an upper lining plate and a lower lining plate respectively, a direct-current bus terminal is led out from the upper layer to be connected with an external direct-current power source positive electrode, and a direct-current bus terminal is led out from the lower layer to be connected with an external direct-current power source negative electrode. A direct-current bus terminal is led out from the lower layer to be connected with a negative electrode of an external direct-current power supply, two alternating-current output terminals are led out from a solder ball joint, and a laminated structure reduces a commutation path to obtain low parasitic inductance; the upper lining plate and the lower lining plate of the stacked structure are both connected to the radiator to form a double-face heat dissipation structure, in addition, the upper lining plate and the lower lining plate are connected through the copper columns, low heat resistance is obtained, and the heat reliability problem of the module is solved.

The invention provides an anti-interference transformer with a cooling structure, and belongs to the technical field of transformers, the anti-interference transformer comprises a transformer main body, the transformer main body is connected with a reinforcing assembly, the reinforcing assembly comprises a transition box, one end of the transition box is provided with a heat dissipation cylinder, the lower end of the reinforcing assembly is provided with a backflow assembly, and the backflow assembly comprises a backflow box and a drain pipe. The transformer body is connected with a filter, the reinforcing assembly further comprises an extension cylinder, an ejector rod and a sealing baffle, and a telescopic spring is arranged in the extension cylinder; a swinging assembly and a position measuring assembly. The transformer cooling device has the beneficial effects that impurities can be removed and precipitated in the flowing cooling process of insulating oil so as to reduce damage to a transformer, the fan can be triggered to rotate along with temperature rise so as to improve the heat dissipation efficiency, meanwhile, dust can be removed so as to reduce accumulation of charges in the dust, and the service life of the transformer is prolonged. And electromagnetic interference and corona discharge are effectively reduced, so that the anti-interference effect of the transformer main body is improved.

The invention discloses a multi-cable parallel connection anti-bias cable structure, and relates to the technical field of cables, the cable structure comprises a cable body, the cable body is provided with a mounting mechanism, the mounting mechanism comprises a circular ring groove, two circular pipes, a three-way pipe, a sealing plug and a clamping groove, and a rectangular block is fixed in the circular ring groove; according to the invention, the installation mechanism is arranged, so that the multi-cable parallel-connection anti-bias-current cable and the suspension wire can be conveniently installed in an overhead manner in the long-distance overhead laying process, that is, when the multi-cable parallel-connection anti-bias-current cable is subjected to long-distance overhead laying, a constructor can distribute and install the suspension wire and the cable at equal intervals; therefore, the situation that the service life of the cable is affected due to uneven stress of the cable is avoided, the using effect of the multi-cable parallel connection anti-bias-current cable is improved, and meanwhile the using efficiency of the multi-cable parallel connection anti-bias-current cable is improved.

The invention discloses a three-phase LLC resonant converter parameter design method and system based on a time domain model, and belongs to the field of power electronic resonant converter parameter design, and the method comprises the following steps: determining a design demand and working condition distribution; according to the time domain model of the three-phase LLC resonant converter, respectively selecting feasible working modes for different working conditions; according to the selection result of the working modes, the transformation ratio n of the transformer is designed, and the maximum gain Mmax and the minimum gain Mmin are calculated; establishing a relationship between the effective value of the resonance current and the parameters of the resonance converter, and deducing an optimal parameter design constraint condition of the effective value of the resonance current under all working conditions; and solving the parameters of the three-phase LLC resonant converter with the optimal effective value of the resonance current under all working conditions by adopting an optimization method on the premise of meeting all parameter design constraint conditions. The method can optimize the effective value of the full-working-condition resonance current and improve the efficiency of the converter.

The invention relates to a QSFP-DD packaging 400G optical module structure, and belongs to the technical field of optical modules. Comprising a module upper cover, a module base and a pull ring, the module upper cover and the module base form a containing cavity, an MPO optical fiber adapter and a module circuit board assembly are arranged in the containing cavity, and first cooling fins and second cooling fins are arranged on the module upper cover and the module base respectively; the module circuit board assembly comprises a PCB, a heat dissipation block is arranged on the PCB, and a heat dissipation table is arranged on the module upper cover. A module upper cover and a rubber coating area are arranged on the inner side of the pull ring, a pull ring handle is arranged at one end of the pull ring, and the pull ring handle is flush with the bottom of the module base. According to the QSFP-DD packaging 400G optical module structure provided by the invention, the heat dissipation efficiency is remarkably improved, the MPO jumper wire insertion space is optimized, more internal space of the PCB is provided, the signal loss is reduced, the connection stability of the light-transmitting assembly and the silicon optical assembly is enhanced, and the optical signal loss is reduced.

The invention aims to provide a new energy high-frequency wire harness design method based on electromagnetic compatibility optimization, and relates to the technical field of new energy, and the method comprises the steps: 1, building a new energy high-frequency wire harness type electromagnetic source model, and obtaining the electromagnetic source intensity; calculating a spatial electromagnetic field intensity based on the electromagnetic source intensity; step 2, calculating equivalent transmission line parameters based on the space electromagnetic field intensity; based on the equivalent transmission line parameters, frequency-dependent characteristic impedance is calculated; step 3, calculating crosstalk voltage according to the frequency-variable characteristic impedance; calculating a radiation field of the new energy high-frequency wire harness; calculating the shielding effectiveness of the new energy high-frequency wire harness according to the radiation field; 4, according to the step 1, the step 2 and the step 3, constraint conditions are set, an objective function under the constraint conditions is established, and the objective function is solved through iteration to find the corresponding optimal design parameter vector of the new energy high-frequency wire harness. According to the invention, the transmission stability and the anti-interference capability of the new energy high-frequency wire harness are significantly improved.

The invention relates to the field of wireless charging, and discloses an electric field coupling unmanned aerial vehicle wireless charging system with low electromagnetic interference and a control method, and the system comprises a primary side energy transmission unit which comprises a DC power supply, a high-frequency inverter and a primary side compensation sub-circuit which are connected in sequence; the secondary side energy transmission unit comprises an energy storage device, a rectifier and a secondary side compensation sub-circuit which are connected in sequence; the intermediate unit is respectively connected with the primary side compensation sub-circuit and the secondary side compensation sub-circuit and comprises a coupling mechanism and a switch module connected with the coupling mechanism; the transmitting end of the coupling mechanism is based on a four-pole-plate coupling mechanism, transmitting pole plates and dielectric layers are arranged on the inner walls of the four side walls of the unmanned aerial vehicle centering device, and the receiving end of the coupling mechanism still adopts a cylindrical receiving pole plate nested on the outer side of a cylinder at the bottom of an undercarriage; and after the unmanned aerial vehicle is centered, the wireless power supply requirement can be met by controlling the on-off of the corresponding transmitting polar plates no matter the receiving polar plates are longitudinally distributed or transversely distributed.

The invention relates to a vibration signal detection system for motor state diagnosis and a method thereof, the system comprises a piezoelectric acceleration sensor, a charge transfer module, a range selection module, an amplification module, an oscilloscope acquisition module and a data analysis module which are connected in sequence, and the piezoelectric acceleration sensor is used for acquiring charges generated by vibration; the charge transfer module is used for determining charge change in the vibration process; the range selection module is used for adjusting the gain of the amplification module; the amplification module is used for amplifying the charge change signal; the oscilloscope acquisition module is used for acquiring the amplified charge change signal; and the data analysis module performs fast Fourier transform and frequency sweep sampling calculation processing on the signals acquired by the oscilloscope acquisition module to obtain a vibration frequency value. Compared with the prior art, the method detects the dynamic process of vibration, is rich in perceivable characteristic parameters, effectively improves the measurement precision of motor vibration signals, and is suitable for motor state diagnosis application based on technologies such as deep learning.

The embodiment of the invention provides a data processing method of a display device and the display device, for each backlight driver, if the dimming data of the current frame of the backlight driver is different from the dimming data of the previous frame, a backlight controller sends the dimming data of the current frame to the backlight driver; the backlight driver drives the light emitting unit to emit light according to the dimming data of the current frame, if the dimming data of the current frame of the backlight driver is the same as the dimming data of the previous frame, the backlight controller does not send the dimming data of the current frame to the backlight driver, and the backlight driver drives the light emitting unit to emit light according to the dimming data of the previous frame. Compared with sending the dimming data of all the backlight drivers, the dimming data of the current frame is only sent to the backlight drivers with changed data, so that the data transmission quantity, the electromagnetic interference, the power loss and the data transmission time can be reduced, and the response rate of the display equipment is improved.

The invention discloses a multi-channel symmetrical CLLC topological structure and a power balance control method thereof, and the structure comprises a multi-channel symmetrical CLLC converter main circuit loop, a high-precision sampling module, a phase shift angle controller module, an input capacitor, an output capacitor and an equivalent load. And more efficient electric energy conversion and power management control are realized. According to the power balance control method, phase shift control is carried out on a secondary side switching tube control signal of a power loop through a fundamental wave analysis method, a forward gain formula under the control method is derived, and output gain regulation and control are carried out on converters with power errors in the multi-path symmetrical CLLC converters. And thus, the power balance control among the multi-path symmetrical CLLC converters is realized.

The present invention discloses an electromagnetic composite nondestructive testing sensor, system and method, belonging to the field of nondestructive testing technology, including an excitation component and a receiving component; the excitation component includes a first excitation coil for receiving an extremely low frequency excitation signal, a low frequency excitation signal or a medium-high frequency excitation signal, and a second excitation coil for receiving a medium-low frequency excitation signal or a high frequency excitation signal. The excitation component and the receiving component working based on excitation signals of different frequencies are integrated into the same sensor, and different excitation signals are introduced into the first excitation coil and the second excitation coil at different times to achieve different nondestructive tests, including eddy current detection, AC electromagnetic field detection, magnetic Barkhausen noise detection, incremental magnetic permeability detection and other nondestructive tests, so as to obtain stress changes caused by microstructures, the influence of incremental magnetic permeability on stress, and the influence of electrical conductivity and magnetic permeability on stress, so as to accurately judge the stress size of components, and provide an experimental verification basis for the study of complex stress theory.

The invention relates to a transformer substation electromagnetic environment testing method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: determining a test site of an electromagnetic environment of a transformer substation; steady-state background testing is carried out at the testing site, and steady-state background testing data are obtained; acquiring the environment humidity of the test site; under the condition that the environment humidity is greater than a first preset humidity threshold value, the horizontal rotation rate of the electromagnetic probe is adjusted according to the environment humidity; according to the adjusted horizontal rotation rate of the electromagnetic probe, performing a transient background test at the test site to obtain transient background test data; according to the steady state background test data and the transient state background test data, training to obtain an electromagnetic environment simulation model; and obtaining electromagnetic environment test data of the transformer substation by using the electromagnetic environment simulation model. By adopting the method, the electromagnetic environment of the transformer substation can be evaluated more comprehensively, and the test accuracy can be improved in an environment with relatively high humidity.

The utility model discloses a novel armored cable, and belongs to the technical field of armored cables. Comprising a plurality of semi-conductive conductor shielding sleeves, a plurality of conductor cores are arranged in the semi-conductive conductor shielding sleeves, the peripheries of the semi-conductive conductor shielding sleeves are fixedly sleeved with an electromagnetic shielding sleeve, the outer wall of the electromagnetic shielding sleeve is sleeved with a fireproof layer, the outer wall of the fireproof layer is sleeved with a non-metal armor layer, and the outer wall of the non-metal armor layer is sleeved with a fireproof layer. A plurality of supporting strips are arranged in the non-metal armor layer and are annularly and uniformly distributed, and the supporting strips in the non-metal armor layer are made of carbon fiber reinforced plastic materials, so that the non-metal composite materials have excellent mechanical strength and light weight characteristics, the mechanical protection performance of the cable can be ensured, and the service life of the cable is prolonged. The weight of the cable is remarkably reduced, laying and installation are facilitated, the elastic bands are installed between the adjacent supporting strips, the multiple supporting strips can be evenly distributed on the outer wall of the fireproof layer through installation of the elastic bands, and meanwhile the multiple supporting strips can be conveniently fixed.

The embodiment of the invention provides a high-side switch driving circuit and a high-side driving chip. The circuit comprises a current generation module and a current control module, the current generation module provides the sum of a first pull-up current and a second pull-up current when a logic signal is a first level signal, and provides the sum of a first pull-down current and a second pull-down current when the logic signal is a second level signal; when the logic signal jumps into a first level signal, the current control module adjusts the inverted voltage of the inverted input end of the high-side switch according to the output voltage of the high-side switch, and generates the positive phase voltage at the positive input end of the high-side switch according to the sum of the first pull-up current and the second pull-up current so as to drive the high-side switch to be switched on. And when the logic signal jumps to the second level signal, the reverse phase voltage is adjusted according to the output voltage and the sum of the first pull-down current and the second pull-down current so as to drive the high-side switch to be turned off. The circuit can reduce the electromagnetic interference of the switching action of the high-side switch on the peripheral current, and also can reduce the pulse offset.

The invention discloses a circuit, a system and a PCB structure for improving electric leakage performance of a PCB based on an FR-4 board, the circuit and the system are suitable for current measurement of a semiconductor lower than picoampere level, the circuit and the system comprise an equipotential protection layer, the equipotential protection layer is connected with a signal line and is arranged close to a signal end, the equipotential protection layer is used for ensuring that the potential of the equipotential protection layer is the same as that of the signal end, and the equipotential protection layer is connected with the signal line and is arranged close to the signal end; the two ends of the to-be-protected signal line have no voltage difference so as to reduce an electric leakage state; the constant-temperature protection module is connected with the equipotential protection layer and comprises a heating resistance wire, a temperature detection chip, a temperature control unit, an isolation buffer unit and an isolation power supply, under the condition of not increasing too much cost, a common pcb plate FR-4 can be used for realizing a picoampere-level electric leakage test, a dual-guarantee effect is provided, and the cost is reduced. Comprising equipotential protection and heating dehumidification to increase dielectric impedance.

The utility model discloses an ultrasonic gas meter binding post assembly which comprises a binding post body, a needle-shaped terminal, a waterproof connector needle-shaped male end, a circuit board, a valve signal female end and a metering module signal female end, the circuit board is arranged in the binding post body, the needle-shaped terminal and the waterproof connector needle-shaped male end are both arranged on the circuit board, and the valve signal female end is connected with the metering module signal female end. The number of the waterproof connector needle-shaped male ends is two, the two waterproof connector needle-shaped male ends are arranged on the lower surface of the circuit board, and the valve signal female end and the metering module signal female end are detachably connected with any waterproof connector needle-shaped male end to achieve function transmission. According to the ultrasonic gas meter binding post assembly, connection of an external signal line can be omitted, electromagnetic interference is reduced, and the anti-interference performance of an ultrasonic gas meter is improved; the binding post is simple in structure, the binding post body and the circuit board are injection-molded, and connection is stable; meanwhile, a plurality of sealing grooves are formed and used for sealing the binding posts, the controller and the gas meter shell, and the connection reliability is high.

The invention provides a low-power-consumption control method and system for a power chip, and relates to the technical field of power device control, and the method comprises the steps: collecting the load power, the temperature of a power device and the response duration of the power chip through a multi-mode detection module; the information is input to the control module; estimating a real-time parasitic parameter disturbance term through an adaptive disturbance observer according to the response duration of the power device; determining a first constraint about the duty ratio of the PWM signal of the internal voltage source by taking reduction of the heat loss of the power device as a target; determining a second constraint about the output voltage of the driving voltage source by taking reduction of the response duration of the power device as a target; the target PWM signal duty ratio of the output voltage source and the target output voltage of the driving voltage source are determined under the first constraint and the second constraint in combination with the real-time parasitic parameter disturbance term; and controlling the power chip according to the target PWM signal duty ratio and the target output voltage. Control power consumption is reduced, and control efficiency is improved.

The invention provides a tandem type high-voltage pulse power supply and a method for reducing electromagnetic interference through a control switch transient trajectory thereof, and belongs to the technical field of power electronic conversion. A tandem type high-voltage pulse power supply is commonly used in the field of industrial manufacturing and is high-power power electronic equipment. According to the invention, by controlling the switch conduction time of the series power device group, the function fitting of the switch transient trajectory is realized, and the traditional single-slope rising transient trajectory is fitted into the S-shaped transient trajectory, so that the amplitude spectrum of the switch waveform under high frequency is effectively reduced, and the electromagnetic anti-interference capability of the series high-voltage pulse power supply is improved. According to the invention, the electromagnetic interference of the tandem high-voltage pulse power supply is reduced through a low-cost switch transient trajectory control method, and the high-quality high-voltage pulse waveform with adjustable width can be output.

The invention relates to a three-phase-to-single-phase alternating-current transformer, a transformation device and a railway power transmission system. A first primary winding in the transformer comprises an A-phase primary winding, a B-phase primary winding and a C-phase primary winding, the first end of each phase of primary winding is correspondingly connected with single-phase alternating current, and the first ends of the phase of primary windings are mutually connected to form a neutral point; the first secondary winding comprises an A-phase secondary winding, a B-phase secondary winding and a C-phase secondary winding, the A-phase secondary winding is connected with the second primary winding, the first end of the B-phase secondary winding is connected with the first end of the C-phase secondary winding to form a neutral point, and the second end of the B-phase secondary winding and the second end of the C-phase secondary winding are jointly connected to the third primary winding; the first end of each phase of secondary winding and the first end of the corresponding phase of primary winding are dotted terminals; the second secondary winding is coupled with the second primary winding and the third primary winding. By adopting the transformer, the conversion from three-phase alternating current to single-phase alternating current can be efficiently realized.

The invention provides an electromagnetic noise prediction control method for a vehicle silicon carbide controller, and the method comprises the steps: receiving parameters, such as d-axis current, q-axis current, rated torque and actual rotating speed, so as to calculate a rotating speed error signal; a discrete anti-integral saturation speed PI controller is used to calculate a reference torque according to the error signal, and the modulation wave frequency, the electrical angle frequency and the stator flux linkage are further deduced. D-axis voltage and q-axis voltage at the next moment are predicted through a current prediction control algorithm, compensation is carried out to obtain predicted values of torque and electromagnetic noise, and meanwhile a carrier wave ratio predicted value at the next moment is calculated. Calculating a cost function under different switching states, wherein the function comprehensively considers the weight factors of the carrier ratio and the common-mode voltage EMI suppression value; and digital filtering is carried out by selecting a value which minimizes the cost function, and the value is output to a silicon carbide controller so as to drive the permanent magnet synchronous motor to operate. The invention aims to effectively reduce electromagnetic interference generated in high-frequency switching operation and improve the output performance of a motor at the same time.

The invention discloses a PCB layout design method and system based on heat dissipation optimization, and the method comprises the steps: carrying out the logic design and electrical performance analysis of a to-be-optimized PCB, and obtaining a preliminarily optimized PCB; performing simulation analysis on the preliminarily optimized PCB to obtain an optimization analysis result of the PCB; performing wiring optimization and multilayer board optimization on the preliminarily optimized PCB according to an optimization analysis result of the PCB to obtain an optimized PCB; and performing verification analysis on the optimized PCB according to an electrical design rule to obtain a final optimized PCB. According to the embodiment of the invention, the electromagnetic interference can be reduced, the electromagnetic compatibility and the heat dissipation capability of the circuit are improved, and the stable transmission of signals is realized. The method can be widely applied to the technical field of electronic circuit layout design.

The invention discloses an optical fiber direct connection atomic spectrum frequency locking device. The device comprises an atomic gas chamber, an error signal acquisition device, a locking device and a coupling light generation and modulation device which are connected through an optical fiber. The coupled light generation and modulation device generates coupled laser which contains a radio frequency modulation signal and has a wavelength of 509 nm. The atomic gas chamber receives the coupling laser and the detection laser with the wavelength of 852 nm, in the atomic gas chamber, the detection laser is divided into reference light and signal light, and the signal light and the coupling light are oppositely transmitted through the atomic gas chamber to generate a Rydberg atomic spectrum. The error signal acquisition device detects the signal light and the reference light and generates an error signal. And the locking device generates a radio frequency modulation signal and locks the coupling light output frequency according to the error signal. The invention also comprises a method for using the device. According to the device and the method, the problems that an all-fiber laser light source frequency locking device for Rydberg atom preparation is complex and poor in effect are solved.

The utility model discloses a magnetism gathering type linear motor, comprising a stator comprising a stator yoke portion extending along the X-axis direction and a plurality of stator tooth portions arranged on the stator yoke portion at intervals along the X-axis direction; the mover is arranged opposite to the stator in the Y-axis direction, and the mover comprises a mover yoke part and an iron core monomer connected with the mover yoke part; each single iron core comprises an iron core end part and first permanent magnets and second permanent magnets which are arranged on the iron core end part, the magnetizing directions of the first permanent magnets and the second permanent magnets are not parallel, the first permanent magnets and the second permanent magnets are alternately arranged along the X-axis direction, the number of the first permanent magnets is N, the number of the second permanent magnets is N-1, and N is greater than or equal to 2; the stator tooth part comprises a stator top wall adjacent to the iron core single body and two first stator side walls connected to the two sides of the stator top wall in the X-axis direction, and a chamfer structure is formed between the stator top wall and the first stator side walls. By adopting the structure, the magnetic gathering effect is obvious, and the cogging force of the motor is effectively reduced.