34 results about "Electromagnetic Compatibility Problem" patented technology

The invention discloses a strong electromagnetic protection design method for an electronic warfare unmanned aerial vehicle, and relates to the technical field of electromagnetic protection, electromagnetic interference and electromagnetic compatibility. Establishing an electromagnetic simulation model of the unmanned aerial vehicle and the electronic warfare load, and simulating the electromagnetic environment of the key position; distributing electromagnetic protection indexes of the electronic equipment according to the electromagnetic environment simulation result; front door protection design and rear door protection design are carried out on the equipment level, and comprehensive radio frequency management is carried out on the system level; and carrying out equipment electromagnetic compatibility test verification and full-system electromagnetic compatibility test verification, and finally ensuring compatible work of the unmanned aerial vehicle and the electronic warfare load. The invention provides a top-down strong electromagnetic protection design method for solving the electromagnetic compatibility problem caused by strong electromagnetic interference task loads such as a communication electronic warfare system and a radar electronic warfare system carried by the unmanned aerial vehicle, and the electromagnetic compatibility of the system is improved.

The application discloses a high-density multi-channel Ku-band radio frequency channel integrated micro module, and belongs to the technical field of radio frequency micro systems. The micro module adopts a three-dimensional stacking architecture, and comprises a four-channel transceiving front end IP, a transceiving frequency conversion IP, a local oscillator source IP and a high-density integrated PCB substrate, and the three IPs are silicon-based packages; a received input signal enters the four-channel transceiving front end IP, is subjected to amplitude and phase control, is transmitted to the transceiving frequency conversion IP through the high-density integrated PCB substrate, is subjected to radio frequency frequency gating filtering, is mixed and frequency-converted to an intermediate frequency output. A transmitted input signal enters the transceiving frequency conversion IP, is subjected to frequency mixing and up-conversion, is subjected to radio frequency frequency gating filtering, is transmitted to the four-channel transceiving front end IP through the high-density integrated PCB substrate, is subjected to amplitude and phase control, and is amplified and output through a power amplifier chip. The application adopts a chip preset grounding ring, a silicon substrate independent cavity and an IP shielding cavity, and solves the complex electromagnetic compatibility problem during communication.

The present application relates to a kind of welding methods of stainless steel target assembly, the welding method includes: in the welding surface of wet back plate, first wire and second wire are arranged alternately, then with wet stainless steel target is buckled, then pressure brazing cooling is carried out, obtains stainless steel target assembly;Wherein, the material of first wire and second wire is different;The surface roughness of first wire is greater than the surface roughness of second wire.The welding method provided by the present application realizes the efficient welding of stainless steel target and back plate by using the cooperation between specific wire, the combination rate of target and back plate after welding is significantly improved, can reach 100%, significantly improves the use performance of stainless steel target assembly, is conducive to solving electromagnetic compatibility problem by electromagnetic shielding.

The present application relates to the technical field of environment situation comprehensive perception, and discloses a kind of collaborative work method of comprehensive perception distributed electronic system, using the distributed electronic system including N distributed nodes, any two nodes in N nodes can communicate with each other, and node only works according to a certain single mode at any time;Wherein, N≥2 and N is integer.The present application solves the problems of poor situation awareness capability, obvious electromagnetic compatibility problem and great difficulty in spectrum control when facing environment situation comprehensive perception in prior art.

The utility model relates to the technical field of medical robots, and discloses a mechanical arm with a distributed motion controller and a bronchoscope robot, the mechanical arm with the distributed motion controller comprises a mechanical arm body; the driving unit comprises a plurality of motor modules, and the motor modules are arranged on the mechanical arm body at intervals in the length direction of the mechanical arm body; the control unit comprises a plurality of motion controllers, the motion controllers are arranged on the mechanical arm body and close to the motor modules in a one-to-one correspondence mode, and the motion controllers are electrically connected with the motor modules close to the motion controllers. According to the mechanical arm, the length of the power line adopted by each motor module is shortened, so that the electromagnetic compatibility problem in the mechanical arm body and the transmission delay problem of the motor modules and the motion controller are solved, and the mechanical arm is simple in wiring and easy to produce and assemble.

The invention discloses an electric automobile vehicle-mounted antenna based on radar self-feedback, which comprises a radar sensing module, a self-feedback control module and an intelligent antenna array, and is characterized in that the output end of the radar sensing module is electrically connected with the input end of the self-feedback control module; the control end of the self-feedback control module is in communication connection with the adjusting end of the intelligent antenna array, and the state monitoring end of the intelligent antenna array is in bidirectional communication with the feedback input end of the self-feedback control module. The number of antennas of the whole vehicle is remarkably reduced through integrated design, and the vehicle body layout is simplified; the hardware cost is optimized through modular integration, and the overall system expenditure is reduced. The problem of electromagnetic compatibility of an existing vehicle-mounted antenna system is solved, an intelligent solution integrating environment perception, Internet of Vehicles communication and dynamic adjustment is provided for an electric vehicle through modular design, and the vehicle-mounted antenna system has extremely high engineering application value.

The invention relates to the technical field of filters, in particular to a far-end high-suppression tubular low-pass filter and a control method thereof, and the method comprises the steps: arranging a plurality of sensors in an electromagnetic sensitive region of equipment, and arranging a bypass branch circuit with a far-end high-suppression tubular low-pass filter in an equipment circuit in the electromagnetic sensitive region; calculating an interference source correlation characteristic value, and determining a target interference source correlation characteristic value; calculating a real-time interference source correlation characteristic value, comparing the real-time interference source correlation characteristic value with a target interference source correlation characteristic value, and analyzing and judging whether the equipment has an electromagnetic compatibility problem based on a comparison result Judging whether the equipment has an electromagnetic compatibility problem or starting a far-end high-suppression tubular low-pass filter based on the difference characterization value; and recording a plurality of electromagnetic interference signals corresponding to the same interference source correlation characteristic values, and judging whether the far-end high-suppression tubular low-pass filter is started to reduce the electromagnetic interference or not based on a deviation calculation result. According to the invention, the control accuracy of the far-end high-suppression tubular low-pass filter can be improved.

The invention discloses an automobile wire harness collinear electromagnetic compatibility problem test method, device and equipment and a storage medium, and relates to the technical field of automobile electricities, and the method comprises the steps: determining an interference source and a sensitive source in a vehicle based on an electric appliance list; based on the vehicle wire harness design drawing, risk levels of collinear interference sources and sensitive sources are evaluated; the collinear items with the risk level being the first risk level are sequentially connected to a preset collinear testing device for testing, a testing report is obtained, the first risk level collinear items comprise a first risk level interference source and a first risk level sensitive source, and after risk pre-assessment is conducted based on the electric appliance list and the wiring harness design drawing, the testing report is obtained. The high-risk collinear item is subjected to an empirical test under a real vehicle working condition, and the core problem that the specific wire harness collinear risk cannot be accurately positioned and effectively verified due to the absence of an empirical link and the absence of a real interference mechanism is effectively solved.

The invention discloses an EMI (Electro-Magnetic Interference) power supply filtering device with an anti-reverse-connection module, and relates to the related technical field of power supply filtering. The device comprises a shell; the lower end face of the shell is provided with four groups of circular connectors which are distributed in an array mode, the interior of the shell is divided into a first cavity and a second cavity which are independent through a fixed metal plate, an L-shaped circuit board assembly is arranged in the first cavity through bolts, and a relay is installed in the second cavity; a first split charging opening and a second split charging opening are formed in the two ends of the second cavity respectively, four inductors are arranged in the first cavity, the second cavity, the first split charging opening and the second split charging opening respectively, and five anti-interference magnetic rings which are evenly distributed are fixed to the upper end face of a step part in the second cavity. By using the metal plates, the interior of the shell can be divided into a plurality of independent cavities, and meanwhile, by using the organic film feed-through filters, a plurality of filtering modes can be provided, so that the problems of multiple paths of different signals and mutual electromagnetic compatibility are solved.

A video processor, a video processing method, a display control system and an electronic device. The video processor comprises a receiving module, a preprocessing module, a picture quality processing module, a post-processing module and a video output module, so that the video receiving, video preprocessing, video picture quality processing, video post-processing and video output functions can be integrated in one system. Compared with the distributed system, the integrated video processor reduces the connection and data interaction between the processing cores, improves the system stability, and reduces the influence of power consumption and electromagnetic compatibility problems on the system.

The application relates to the field of antennas, and discloses a small satellite antenna selection and layout method, device and medium. In the design process of the antenna layout, the whole-satellite antenna selection and layout are predicted and designed, electromagnetic compatibility analysis is performed in combination with antenna task requirements, an antenna layout design result is obtained, the antenna layout design result meets the antenna task requirements and can normally operate, the small satellite antenna applicability to specific tasks and electromagnetic compatibility problems can be solved, resource waste caused by subsequent design compensation can be avoided, and task failure can be avoided.

The invention relates to the technical field of radio frequency communication equipment, and discloses a composite system fuze transmitting and receiving assembly based on SIP modules, comprising a transmitting SIP module and a receiving SIP module, the preceding stage of the transmitting SIP module is connected to a phase modulation SIP module, the phase modulation SIP module is connected to a frequency source SIP module and a digital signal processing unit, the frequency source SIP module is connected to the receiving SIP module, and the digital signal processing unit is connected to the receiving SIP module. And the receiving SIP module is also connected to the digital signal processing unit through the intermediate frequency signal module. According to the SIP module, all radio frequency bare chips are integrated into the SIP module, so that electromagnetic shielding design can be carried out on the radio frequency chips in the design process, the problem of electromagnetic compatibility does not need to be considered on a cavity structure, the complexity of the cavity structure is simplified, and the SIP module has the advantages that the space occupancy rate is higher, the integration degree is higher, meanwhile, the wiring distance between devices is shorter, and the reliability of the SIP module is improved. Welding points are fewer; meanwhile, all bare chips are subjected to integrated design, so that the layout area of a printed board is greatly reduced, and the module has the characteristics of miniaturization and integration.

The application discloses a shaft current and radiation emission integrated test method and system for an electric drive system, and belongs to the technical field of testing. Through real road working conditions, the method and system realize the synchronous collection of multiple physical quantities of the electric drive system, and combine a high-fidelity digital twin model to perform dynamic correction and simulation analysis, thereby solving the problems of misalignment of data, missing correlation between internal shaft current and external radiation field, and incapability of quantifying the contribution of the shaft current in the traditional test. Therefore, the specific influence of the shaft current in the total radiation emission of the electric drive system can be accurately identified, a quantitative basis is provided for the diagnosis and optimization of electromagnetic compatibility problems, and the efficiency and accuracy of the EMC test and rectification of the electric drive system of the new energy vehicle are improved.

This application provides an electromagnetic protection structure and an electronic device. The electromagnetic protection structure includes: a first structural component comprising a radio frequency (RF) source; a second structural component coupled to the first structural component with a first current path, the first current path including a nonlinear region, wherein a nonlinear effect occurs in the nonlinear region when the coupled current of the RF source passes through it; and a conductive medium electrically connected to the first and second structural components to form a second current path between the second and first structural components, allowing at least a portion of the coupled current of the RF source to flow from the first structural component, through the second current path, to the second structural component. In this application embodiment, the second current path formed by the conductive medium can shunt the first current path, eliminating or weakening the nonlinear effect on the first current path, thereby solving the electromagnetic compatibility problem of the electronic device caused by nonlinear effects.

The application discloses an EMC forward design method and device for a PCB of a pathological detection equipment and the pathological detection equipment, and comprises the following steps: obtaining the functional module composition of the equipment to be designed; determining the number of PCB stack layers according to the functional module composition of the equipment to be designed; based on the electromagnetic characteristic partition principle, the welding layer for welding components on the PCB is laid out and divided into multiple partitions; according to the electromagnetic compatibility requirement of the equipment to be designed, the wiring path is arranged on each partition, and the interface protection area and / or the shielding filter protection area are set to obtain a pre-designed PCB; the pre-designed PCB is simulated, the wiring path of the pre-designed PCB is adjusted according to the simulation result, and the PCB is manufactured according to the adjusted pre-designed PCB. The EMC test is completed before the formal PCB manufacturing, and the passive design mode of re-arranging, rewiring or replacing components for the designed PCB when electromagnetic compatibility problems occur in the later debugging is completely avoided.

The invention discloses a high-density multichannel Ku wave band radio frequency channel integrated micro module, and belongs to the technical field of radio frequency micro systems. The micro module adopts a three-dimensional stacking framework and comprises a four-channel transceiving front-end IP, a transceiving frequency conversion IP, a local oscillator source IP and a high-density integrated PCB substrate, and the three IPs are all silicon-based packaging; a received input signal enters the four-channel transmit-receive front end IP, is transmitted to the transmit-receive frequency conversion IP through the high-density integrated PCB substrate after amplitude and phase control, is subjected to radio frequency gating filtering, and is subjected to frequency mixing and down-conversion to obtain intermediate frequency output. A transmitting input signal enters the transmitting-receiving frequency conversion IP, is transmitted to the four-channel transmitting-receiving front-end IP through the high-density integrated PCB substrate after being subjected to frequency mixing up-conversion and radio frequency gating filtering, and is amplified and output through the power amplifier chip after being subjected to amplitude phase control. By adopting the chip preset grounding ring, the silicon substrate independent sub-cavity and the IP shielding cavity, the problem of complex electromagnetic compatibility during communication is solved.

The invention discloses an anti-electromagnetic interference filtering device, and relates to the technical field of filtering devices. The filtering device comprises a filtering device body, the filtering device body comprises a shell, the interior of the shell is divided into a first signal bin, a power source bin and a second signal bin, and the top of the shell is fixedly connected with a top cover; a first signal protection plate and a second signal protection plate are installed in the first signal bin and the second signal bin respectively, a power supply protection plate is installed in the power supply bin, a grounding plate is installed at the top of the top cover, and three circular connectors are installed at the bottom of the shell. The top of the top cover is fixedly connected with two fixed seats; different filtering modes are adopted for different types of signals transmitted in the first signal bin, the power source bin and the second signal bin. According to the invention, electromagnetic coupling interference between a power supply loop and a signal loop is effectively avoided by adopting a partition shielding design; different filtering modes are adopted for different transmission signals in the bin bodies, and the electromagnetic compatibility problem in the signal transmission process is solved from the frequency domain.

The application discloses an electromagnetic compatibility evaluation and optimization system based on an intelligent algorithm, and relates to the technical field of electromagnetic compatibility evaluation.The system comprises a data preparation module, a feature extraction and model training module, an evaluation integration module, a parameter optimization module and an optimization adjustment module which are sequentially operated; and the technical key points are as follows: the scheme can not only predict whether the electromagnetic compatibility meets the standard, but also provide specific electromagnetic interference level prediction values through a neural network model, which helps power plant managers to more deeply understand the electromagnetic compatibility status, so that targeted optimization measures can be taken; through improving the accuracy of electromagnetic compatibility evaluation, realizing targeted optimization measures, improving the flexibility and efficiency of system adjustment, and enhancing the decision support of electromagnetic compatibility management, the accurate evaluation and optimization problems in electromagnetic compatibility are solved, and the technical effect of improving the electromagnetic compatibility management level of the power plant control room is achieved.

The utility model discloses a cable-free inductor. The cable-free inductor comprises a PCB (Printed Circuit Board), a first inductor and a second inductor, the power supply module is arranged on the PCB; the power module is arranged on the PCB and is positioned on one side of the power supply module; the magnetic medium is arranged on the PCB, is positioned on one side of the power module and is used for inhibiting an interference signal generated by the power module; and the signal network module is used for connecting the power module with the PCB and communicating the power module with the PCB. According to the utility model, the magnetic medium is integrated and fixed on the PCB of the inductor, and interference signals generated by the power module can be suppressed, so that the electromagnetic compatibility interference phenomenon is suppressed from the source, and the effects of optimizing the electromagnetic compatibility problem and reducing the electromagnetic interference degree are achieved.

The utility model discloses an internet of things driver, which is characterized in that a power supply cavity and a wiring cavity are arranged in an outer shell, a first partition plate is arranged between the power supply cavity and the wiring cavity, and a wire passing hole is arranged on the first partition plate to communicate the power supply cavity with the wiring cavity. A power panel is arranged in the power cavity, a wiring terminal is arranged in the wiring cavity, a connecting wire of the power panel is detachably connected with the wiring terminal through the wire hole, and the wiring terminal is further detachably connected with an input wire and an output wire which are used for being connected with other external components. According to the utility model, the wiring cavity is arranged beside the power supply cavity and the wiring terminal is arranged in the wiring cavity, so that the input wire and the output wire of the power supply do not need to be directly fixed on the power supply board in the power supply cavity, the input wire and the output wire can be detached and replaced as required, and the replacement of any wire length and the replacement of wires with different safety regulations in different countries can be supported. The number of the wiring terminals is multiple, and the input line and the output line of the power supply are respectively connected to different wiring terminals, so that the problem of electromagnetic compatibility is avoided.

The present invention provides a method, apparatus, device, and medium for handling electromagnetic compatibility issues, relating to the field of electromagnetic compatibility technology and intended to improve the efficiency of electromagnetic compatibility problem rectification and reduce labor costs. The method comprises: determining, from an electromagnetic compatibility problem solution database, at least one electromagnetic compatibility problem and at least one solution to the electromagnetic compatibility problem that matches the currently occurring electromagnetic compatibility problem; sequentially executing the solution to each of the at least one electromagnetic compatibility problem until the currently occurring electromagnetic compatibility problem is resolved; and recording the currently occurring electromagnetic compatibility problem and the resolution process of the currently occurring electromagnetic compatibility problem in the electromagnetic compatibility problem solution database, thereby obtaining an updated electromagnetic compatibility problem solution database for use in handling the next occurrence of an electromagnetic compatibility problem.

The present application relates to the technical field of filter, especially to a kind of far-end high rejection tubular low-pass filter and its control method, comprising: setting several sensors in the electromagnetic sensitive area of equipment, and setting the bypass branch circuit with far-end high rejection tubular low-pass filter in the equipment circuit in the electromagnetic sensitive area;Calculate the characteristic value associated with the interference source, determine the characteristic value associated with the target interference source;Calculate the characteristic value associated with the real-time interference source and compare with the characteristic value associated with the target interference source, based on the comparison result analysis to determine whether the equipment appears electromagnetic compatibility problem;Based on the difference characteristic value to determine whether the equipment appears electromagnetic compatibility problem or start far-end high rejection tubular low-pass filter;Record the several electromagnetic interference signals corresponding to the characteristic value associated with the same interference source, based on the deviation calculation result to determine whether the far-end high rejection tubular low-pass filter is started to reduce electromagnetic interference.The present application can improve the accuracy of far-end high rejection tubular low-pass filter control.

The utility model relates to a compressor technical field, especially a kind of compressor control panel, including PCB board, low voltage power supply communication interface, high voltage power supply input interface, compressor drive interface and IGBT chip, further including busbar assembly installed on PCB board, high voltage power supply input interface is installed in the input end of busbar assembly, compressor drive interface is installed in the output end of busbar assembly, low voltage power supply communication interface and IGBT chip are respectively installed on PCB board, so that high voltage current and low voltage current form layered isolation on physical space, this structure fundamentally solves the electromagnetic compatibility problem caused by high and low voltage line sharing PCB board in traditional design, effectively avoids the interference and interference of electromagnetic compatibility on hardware;In addition, high voltage current is placed to busbar assembly, can significantly save the space and layer number of PCB board, reduces material cost.

The invention discloses an electromagnetic compatibility large model reliability retrieval reasoning method and a computer program product. The method comprises the following steps: firstly, automatically extracting a data chart image from a document containing an electromagnetic compatibility test result, forming structured data through a series of technologies, and then forming a series of corresponding retrieval prompt word projects; secondly, constructing a high-quality EMC detection report and a retrieval enhancement generation technology (RAG) database corresponding to the whole suggestion; and finally, similar cases are retrieved in the professional knowledge base and submitted to the large language model, so that the large model generates a comprehensive retrieval reasoning report containing reliability retrieval reasoning based on the current test result, comparative analysis with historical cases, potential electromagnetic compatibility problem diagnosis and optimization suggestions. According to the method, the large model is enabled through an automatic process, intelligent and efficient retrieval reasoning of the electromagnetic compatibility test data is realized, and the reliability and the accuracy of a retrieval reasoning result are improved.

The application relates to the technical field of vehicle-mounted fast-charging chargers, and particularly discloses a vehicle-mounted fast-charging charger circuit detection system and method, which comprises a signal acquisition module, a protocol analysis module used for being connected with a communication interface in a circuit, the protocol analysis module being used for synchronously analyzing communication protocol data between the circuit and external equipment, an electromagnetic compatibility detection module used for being connected with a power input end and a signal output end in the circuit, a chip detection module used for being connected with a chip in the circuit, a data analysis and processing module, and the signal acquisition module, the protocol analysis module, the electromagnetic compatibility detection module, the chip detection module and the data analysis and processing module are cooperatively matched, so that the vehicle-mounted fast-charging charger circuit can be comprehensively and deeply detected, basic performance parameters and a communication protocol can be detected, hidden faults in a chip and complex electromagnetic compatibility problems can be accurately found, and the detection accuracy and reliability are improved.

The application belongs to the technical field of carbon nanomaterials, and particularly relates to a catalytic graphitization method for preparing a magnetic graphene film for electromagnetic shielding. The method is to dope magnetic nanoparticles in graphene oxide dispersion in situ, then spin-coat into a film, and finally perform catalytic graphitization treatment under inert gas protection to obtain a magnetic graphene film. The magnetic nanoparticles play a dual role of catalyst and wave absorber. On the one hand, the graphene oxide film is catalytically graphitized at a temperature lower than the conventional graphitization temperature; on the other hand, the electromagnetic wave can be absorbed by magnetic loss, thereby improving the electromagnetic shielding performance of the graphene film. The method greatly reduces the graphitization temperature of the graphene film, simplifies the requirements for the production equipment, realizes energy saving and cost reduction, and the prepared magnetic graphene film has an absorption-based electromagnetic shielding performance and can be used to solve the electromagnetic compatibility problem of high-integration electronic products.

The invention provides a hydrogen fuel cell power system low-voltage power distribution and control platform electromagnetic compatibility structure, and relates to the technical field of hydrogen fuel cell power systems. The structure comprises a closed double-layer metal shell platform, the closed double-layer metal shell platform comprises an upper cover plate, a lower cover plate and a middle partition plate, and the middle partition plate divides the closed double-layer metal shell platform into an upper layer and a lower layer; the control unit and the power distribution unit are integrated in the closed double-layer metal shell platform, the power distribution unit is fixed on the middle partition plate, and the control unit is fixed on the lower cover plate; at least two sunken grooves are formed in the middle partition plate, and filter circuits are arranged in the sunken grooves. According to the invention, a unified open filtering platform is provided, and electromagnetic compatibility optimization and decoupling generality schemes can be provided for various parts of the hydrogen fuel cell power system. The low-voltage power supply and the control wiring harness are highly modularized, and the problem of coupling interference among parts can be avoided, so that the problem of electromagnetic compatibility of the system is solved, and the electromagnetic compatibility level of the system is improved.

Embodiments of this application provide an electromagnetic protection structure and an electronic device. The electromagnetic protection structure includes: a first structural member, where the first structural member includes a radio frequency source; a second structural member, where a first current path is coupled between the second structural member and the first structural member, the first current path includes a non-linear region, and when a coupling current of the radio frequency source passes through the non-linear region, a non-linear effect is generated in the non-linear region; and a conductive medium, where the conductive medium is electrically connected to the first structural member and the second structural member to form a second current path between the second structural member and the first structural member, so that at least a part of the coupling current of the radio frequency source flows from the first structural member to the second structural member through the second current path. In embodiments of this application, the second current path formed by the conductive medium can shunt the first current path, so as to eliminate or weaken a non-linear effect on the first current path, thereby resolving an electromagnetic compatibility problem of the electronic device caused by the non-linear effect.

The embodiment of the invention provides an electromagnetic protection structure and electronic equipment. The electromagnetic protection structure comprises a first structural member, and the first structural member comprises a radio frequency source; a first current path is coupled between the second structural member and the first structural member, the first current path comprises a non-linear area, and when the coupling current of the radio frequency source passes through the non-linear area, the non-linear area generates a non-linear effect; and the conductive medium is electrically connected with the first structural member and the second structural member to form a second current path between the second structural member and the first structural member, so that at least one part of coupling current of the radio frequency source flows to the second structural member from the first structural member through the second current path. In the embodiment of the invention, the second current path formed by the conducting medium can shunt the first current path, and the non-linear effect on the first current path is eliminated or weakened, so that the electromagnetic compatibility problem of the electronic equipment caused by the non-linear effect is solved.

The invention relates to a real-time variable carrier modulation method and system based on a duty ratio change rate. The method comprises the steps that three-phase duty ratio instructions output by an SVPWM algorithm are obtained, wherein the three-phase duty ratio instructions comprise the first-phase duty ratio instruction, the second-phase duty ratio instruction and the third-phase duty ratio instruction; based on the three-phase duty ratio instruction, in each PWM period, sampling to obtain a current duty ratio instruction, and based on the current duty ratio instruction, calculating a duty ratio change rate; performing filtering processing on the duty ratio change rate to obtain a smooth stable value; and comparing the smooth stable value with a plurality of preset thresholds, and selecting a corresponding carrier frequency according to a comparison result. Based on a real-time customized carrier wave modulation technology, on the premise that the electromagnetic compatibility problem and the harmonic component are not increased as much as possible, the overall switching frequency is effectively reduced by dynamically adjusting the carrier wave frequency, so that the switching loss is reduced, and the system efficiency is improved.