Filter and vehicle-mounted equipment

Abstract

The embodiment of the utility model discloses a filter and vehicle-mounted equipment. The filter comprises a noise sensing module used for sensing a noise signal on a power line, and the noise sensing module and the power line are electrically isolated through a magnetic core assembly; and the signal generation module is electrically connected with the noise sensing module and is used for receiving and processing the noise signal, generating a compensation signal opposite to the noise signal in phase and injecting the compensation signal into the power line. Through the above mode, the embodiment of the utility model can effectively reduce electromagnetic interference, reduce the number of common-mode chokes or necessary common-mode chokes, so that the noise reduction performance of the filter is fully exerted, the hardware cost is reduced, and the size of the filter is greatly reduced.

Description

Technical Field

[0001] This utility model relates to the field of electromagnetic interference, and in particular to a filter and vehicle-mounted equipment. Background Technology

[0002] Traditional electromagnetic interference (EMI) filters typically consist of passive components such as X capacitors, Y capacitors, and common-mode (CM) chokes.

[0003] To improve noise reduction performance, the capacitance of the capacitor and the inductance of the choke must be set sufficiently high. This effectively blocks high-frequency noise and maintains the electrical stability of the system. Furthermore, selecting and designing appropriate capacitors and chokes is crucial for effectively controlling EMI noise generated when operating high-speed switching converters. However, the capacitance of Y-capacitors is limited by human safety regulations regarding electric shock. X-capacitors have limited ability to directly reduce common-mode noise, thus restricting the overall noise reduction function. Moreover, blindly increasing the capacitance of X-capacitors may negatively impact the performance of power components and other components in the AC power stage circuit. Utility Model Content

[0004] The main technical problem solved by this utility model embodiment is to provide a filter and vehicle-mounted device that can solve at least some of the defects of existing filters.

[0005] This application provides a filter, including: a noise sensing module for sensing noise signals on a power line, wherein the noise sensing module and the power line are electrically isolated by a magnetic core assembly; and a signal generation module electrically connected to the noise sensing module for receiving and processing the noise signals, generating a compensation signal that is out of phase with the noise signals, and injecting the compensation signal into the power line.

[0006] Optionally, the signal generation module includes: a signal processing unit electrically connected to the noise sensing module, used to receive and process the noise signal and generate the compensation signal; and a signal injection unit electrically connected to the signal processing unit, used to receive the compensation signal and inject the compensation signal into the power line to cancel the noise signal; wherein the noise sensing module and the signal injection unit are electrically separated and are each connected to the power line through their own independent paths.

[0007] Optionally, the noise sensing module includes: multiple magnetic core assemblies, each electrically connected to a phase line in the power line, for collecting electromagnetic interference noise on each phase line; multiple secondary windings, each wound on a magnetic core assembly, for converting the electromagnetic interference noise collected on each phase line into an electrical signal; and a signal aggregation circuit, electrically connected to the multiple secondary windings, for receiving and integrating the electrical signals of each phase line, and outputting a noise signal to the signal generation module.

[0008] Optionally, the noise sensing module includes: multiple magnetic core assemblies, respectively surrounding each phase line in the power line, for sensing electromagnetic interference noise on each phase line; multiple secondary windings, respectively wound on each of the magnetic core assemblies, for converting the electromagnetic interference noise induced on each phase line into electrical signals; and a signal aggregation circuit, electrically connected to the multiple secondary windings, for receiving and integrating the electrical signals of each phase line, and outputting noise signals to the signal generation module.

[0009] Optionally, the noise sensing module includes: a toroidal magnetic core for sensing common-mode noise on multiple phase lines of the power line, wherein the multiple phase lines pass through the toroidal magnetic core simultaneously; and a secondary winding wound on the toroidal magnetic core for converting the sensed common-mode noise into a noise signal and transmitting it to the signal generation module.

[0010] Optionally, the signal processing unit includes: a signal amplifier electrically connected to the noise sensing module for receiving and amplifying the noise signal; a phase inverter electrically connected to the signal amplifier for performing phase inversion processing on the amplified noise signal to generate a compensation signal with the opposite phase to the noise signal; a signal processor electrically connected to the phase inverter for performing digital processing on the noise signal and the compensation signal; and a controller electrically connected to the signal processor and the signal injection unit for adjusting the amplitude and phase parameters of the compensation signal.

[0011] Optionally, the signal generation module further includes: a phase-to-phase balancing unit, electrically connected to the signal processing unit and the signal injection unit, for receiving each phase compensation signal, adjusting the parameters of each phase compensation signal under three-phase load imbalance, and outputting the adjusted phase compensation signals to the signal injection unit.

[0012] Optionally, the signal injection unit includes: an injection transformer electrically connected to the signal processing unit for receiving the compensation signal; and a plurality of injection capacitors, one end of which is electrically connected to the output terminal of the injection transformer and the other end of which is electrically connected to each phase line of the power supply line for coupling the compensation signal to the power supply line.

[0013] Optionally, the injected capacitor is a high-voltage insulating capacitor.

[0014] This application also provides an in-vehicle device including any of the filters described above.

[0015] This invention provides a filter comprising a noise sensing module for sensing noise signals on a power line, wherein the noise sensing module and the power line are electrically isolated by a magnetic core assembly; and a signal generation module electrically connected to the noise sensing module for receiving and processing the noise signals, generating a compensation signal with the opposite phase to the noise signals, and injecting the compensation signal into the power line. This configuration effectively reduces electromagnetic interference, decreases the number of common-mode chokes or the necessary common-mode choke inductance, thereby enabling the filter to fully utilize its noise reduction performance while reducing hardware costs and significantly minimizing the filter's size. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 This is a schematic diagram of the structure of a filter provided by an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of a signal generation module provided in an embodiment of this utility model;

[0019] Figure 3 This is a schematic diagram of another signal generation module provided in this embodiment of the utility model;

[0020] Figure 4 This is a schematic diagram of the structure of a signal processing unit provided in an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the structure of a noise sensing module provided in an embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of another noise sensing module provided in this embodiment of the present invention;

[0023] Figure 7 This is a schematic diagram of the structure of another noise sensing module provided by this utility model embodiment;

[0024] Figure 8 This is a schematic diagram of the structure of a signal injection unit provided in an embodiment of this utility model. Detailed Implementation

[0025] To facilitate understanding of this utility model, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this specification are for illustrative purposes only.

[0026] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0027] Reference Figure 1 , Figure 1 This is a schematic diagram of a filter provided by the present invention. The filter is generally designated as 10. The filter 10 is disposed between the power input terminal 21 and the power output terminal 22, and includes a noise sensing module 100 and a signal generation module 200. The noise sensing module 100 and the signal generation module 200 are electrically connected to form a complete active filtering system.

[0028] The noise sensing module 100 is used to sense noise signals on the power line. According to... Figure 1 As shown, the noise sensing module 100 is electrically isolated from the power line via a magnetic core assembly. Electrical isolation is one of the key features of this filter design, ensuring that the noise sensing circuit is not affected or damaged by high voltage due to direct connection to the power line.

[0029] Electromagnetic isolation refers to the use of specific technologies to block the transmission of electromagnetic energy between different parts of a circuit or system, achieving complete separation of electrical paths. Common methods of electromagnetic isolation include magnetic isolation, optical isolation, and capacitive isolation. In this invention, a magnetic core assembly is used to achieve electromagnetic isolation between the noise sensing module and the power line; this method falls under the category of magnetic isolation technology.

[0030] Magnetic isolation utilizes the transformer principle to transmit signals through electromagnetic induction without establishing a direct electrical connection. In the magnetic core assembly, the primary coil is connected to the power supply line, and the secondary coil is connected to the noise sensing circuit. When the current on the power supply line changes, a changing magnetic field is generated in the magnetic core, which in turn induces a corresponding voltage / current signal in the secondary coil, thus achieving signal transmission without establishing a conductive path.

[0031] The magnetic core assembly serves as the interface between the power line and the noise sensing module 100, enabling it to capture electromagnetic noise on the power line and convert it into a processable electrical signal without creating a conductive path between the power line and the noise sensing circuit.

[0032] The noise sensing module and the signal injection unit are electrically separated and connected to the power line via their respective independent paths, thus preventing the signal processing unit from being directly affected by fluctuations in the electrical environment of the power line. The noise sensing module 100 can sense various electromagnetic interference signals on the power line, including noise from the power grid and electromagnetic interference generated by the device itself. Through the magnetic core assembly, the noise sensing module 100 can accurately capture the amplitude, frequency, and phase information of these interference signals.

[0033] Electromagnetic interference refers to the adverse effects of electromagnetic energy generated by electrical equipment during operation on the surrounding environment or other equipment.

[0034] The signal generation module 200 is electrically connected to the noise sensing module 100 and is used to receive and process noise signals. For example... Figure 1 As shown, the signal generation module 200 receives the noise signal from the noise sensing module 100, performs necessary signal processing, generates a compensation signal that is out of phase with the noise signal, and injects the compensation signal into the power line.

[0035] The core function of the signal generation module 200 is to generate a compensation signal with the same amplitude but opposite phase as the original noise signal. When the compensation signal is injected into the power line, it cancels out the original noise signal, thereby reducing electromagnetic interference.

[0036] The signal generation module 200 needs to have a fast response capability to promptly process the constantly changing noise signals on the power line. At the same time, it also needs to have sufficient accuracy to ensure that the generated compensation signal can accurately cancel the original noise signal.

[0037] The specific working process is as follows: First, AC power enters the filter through the power input terminal 21. Various electromagnetic interference noises exist on the power line. The noise sensing module 100 senses the noise signal on the power line through the magnetic core assembly, thereby monitoring the noise on the power line while maintaining electrical isolation.

[0038] The sensed noise signal is then transmitted to the signal generation module 200 for processing. The signal generation module 200 analyzes the characteristics of the noise signal, including amplitude, frequency, and phase. Based on the analysis results, the signal generation module 200 generates a compensation signal with the same amplitude but opposite phase as the original noise signal.

[0039] Finally, the compensation signal is injected into the power line to cancel out the original noise signal. The power signal, after active filtering, is output from the power output terminal 22, and electromagnetic interference is effectively suppressed.

[0040] Through the aforementioned active filtering process, this filter can significantly reduce the number of common-mode chokes or the necessary common-mode choke inductance, allowing the EMI filter to fully utilize its noise reduction performance, thereby greatly reducing the size of the EMI filter board. This technology is suitable for space-constrained automotive environments, providing a cleaner power environment for automotive electronic devices and reducing the impact of electromagnetic interference on the normal operation of the equipment.

[0041] Reference Figure 2 , Figure 2 The structure of the signal generation module is shown. For example... Figure 2 As shown, the signal generation module 200 includes two main parts: a signal processing unit 210 and a signal injection unit 220.

[0042] The signal processing unit 210 is electrically connected to the noise sensing module 100 and is used to receive and process noise signals to generate compensation signals. The main function of the signal processing unit 210 is to analyze the characteristics of the received noise signal, including information such as amplitude, frequency and phase, and then generate a compensation signal with the same amplitude but opposite phase as the original noise signal.

[0043] The signal injection unit 220 is electrically connected to the signal processing unit 210 and is used to receive the compensation signal and inject the compensation signal into the power line to cancel the noise signal. By injecting a precisely controlled compensation signal into the power line, the original noise signal can be effectively canceled, thereby reducing the level of electromagnetic interference.

[0044] It is worth noting that the noise sensing module 100 and the signal injection unit 220 are electrically separated, each connected to the power line via its own independent path. This separation design prevents the signal processing unit 210 from being directly affected by fluctuations in the electrical environment of the power line, thus improving the stability and reliability of the system. At the same time, the separation design also avoids potential feedback loops, preventing the system from generating self-oscillations.

[0045] The specific working process is as follows: First, the power signal and the noise it carries enter the filter from the power input terminal 21. The noise sensing module 100 senses the noise signal on the power line through the magnetic core assembly, while maintaining electrical isolation from the power line. After the noise signal is converted into a processable electrical signal, it is transmitted to the signal processing unit 210.

[0046] Then, the signal processing unit 210 receives the noise signal and performs necessary signal processing, including signal amplification, spectrum analysis, and phase recognition. Based on the processing results, the signal processing unit 210 generates a compensation signal with the same amplitude but opposite phase as the original noise signal.

[0047] Finally, the generated compensation signal is transmitted to the signal injection unit 220, which injects the compensation signal into the power line to cancel out the original noise signal. The signal injection unit 220 is connected to the power line through its independent path to avoid interference with the noise sensing path. The power signal, after active filtering, is output from the power output terminal 22, and electromagnetic interference is effectively suppressed.

[0048] Reference Figure 3 , Figure 3 Another structure of the signal generation module is shown. For example... Figure 3 As shown, the noise sensing module 100 is disposed on the power line between the power input terminal 21 and the power output terminal 22, and is used to sense noise signals on the power line. The noise sensing module 100 and the power line are electrically isolated by a magnetic core assembly to ensure that the noise sensing circuit is not directly affected by the high voltage of the power line, thereby improving the safety of the system.

[0049] The signal generation module 200 includes three functional units: a signal processing unit 210, a signal injection unit 220, and a phase-to-phase balancing unit 230. The signal processing unit 210 is electrically connected to the noise sensing module 100 and is responsible for receiving and processing noise signals; the signal injection unit 220 is electrically connected to the signal processing unit 210 and is responsible for injecting compensation signals into the power lines; the phase-to-phase balancing unit 230 is electrically connected to the signal processing unit 210 and the signal injection unit 220 and is responsible for adjusting the parameters of the compensation signals of each phase under unbalanced three-phase load conditions.

[0050] The phase-to-phase balancing unit 230 is used to receive the compensation signals of each phase, adjust the parameters of the compensation signals of each phase under the three-phase load imbalance state, and output the adjusted compensation signals of each phase to the signal injection unit 220.

[0051] In a three-phase AC power system, ideally, the three-phase loads should be balanced, meaning the three-phase currents are equal in magnitude and have a phase difference of 120 degrees. However, in practical applications, due to various reasons (such as different power ratings of devices connected to different phases, or the connection of single-phase loads), the three-phase loads are often unbalanced. This imbalance leads to differences in the electromagnetic interference characteristics of each phase line, and if the same compensation strategy is used to treat the noise of each phase, the filtering effect will be limited.

[0052] The phase-to-phase balancing unit 230 monitors the load conditions and noise characteristics of each phase and dynamically adjusts parameters such as the amplitude, frequency, and phase of the compensation signal for each phase to ensure optimal filtering performance even under unbalanced conditions. For example, when the load of a certain phase is detected to be significantly higher than that of other phases, the phase-to-phase balancing unit 230 will adjust the compensation signal parameters of that phase accordingly to adapt to the higher noise level.

[0053] The specific working process is as follows: First, the three-phase AC power signal and its carried noise enter the filter from the power input terminal 21, and pass through the three-phase power lines at the noise sensing module 100. The noise sensing module 100 senses the noise signal on each phase power line through the magnetic core assembly, while maintaining electrical isolation from the power lines. After each phase noise signal is converted into a processable electrical signal, it is transmitted to the signal processing unit 210.

[0054] Subsequently, the signal processing unit 210 receives the noise signals of each phase, performs signal processing, and generates a preliminary compensation signal that is out of phase with the original noise signal of each phase. The preliminary compensation signal is simultaneously transmitted to the inter-phase balancing unit 230 and the signal injection unit 220.

[0055] Then, the phase-to-phase balancing unit 230 receives the compensation signals from each phase and adjusts the parameters of each phase's compensation signal according to the balance of the three-phase load. For example, if a phase has a heavier load, the compensation signal for that phase may require a higher amplitude or more precise phase adjustment. The adjusted compensation signals for each phase are then output from the phase-to-phase balancing unit 230 to the signal injection unit 220.

[0056] Finally, the signal injection unit 220 injects the balanced compensation signals of each phase into the corresponding power lines, which cancel each other out with the original noise signals of each phase. The three-phase power signals, after active filtering, are output from the power output terminal 22, and electromagnetic interference is effectively suppressed.

[0057] Reference Figure 4 , Figure 4 This is a schematic diagram of the signal processing unit provided by this utility model. As shown in the figure, the noise sensing module 100 and the signal injection unit 220 are electrically connected through the signal processing unit 210. The signal processing unit 210 includes a signal amplifier 211, a phase inverter 212, a signal processor 213, and a controller 214.

[0058] As previously described, the filter includes a noise sensing module 100 and a signal generation module. The noise sensing module 100 senses noise signals on the power line and is electrically isolated from the power line via a magnetic core assembly. The signal generation module includes... Figure 4 The signal processing unit 210 and signal injection unit 220 are shown.

[0059] like Figure 4 As shown, the signal processing unit 210 contains four main components, which are arranged in the order of signal processing:

[0060] Signal amplifier 211, electrically connected to noise sensing module 100, is used to receive and amplify noise signals. The main function of signal amplifier 211 is to amplify the weak noise signals received from noise sensing module 100 to a level suitable for subsequent processing. Since noise sensing module 100 is electrically isolated from the power line through a magnetic core assembly, the induced signals are usually weak and require appropriate amplification for effective processing.

[0061] Phase inverter 212, electrically connected to signal amplifier 211, is used to invert the phase of the amplified noise signal, generating a compensation signal with the opposite phase to the noise signal. Phase inverter 212 is the core component for achieving active noise cancellation, ensuring that the generated compensation signal can form destructive interference with the original noise signal.

[0062] Signal processor 213, electrically connected to phase inverter 212, is used for digital processing of noise and compensation signals. Signal processor 213 converts analog signals into digital form, performs digital filtering, spectrum analysis, and other processing to improve the accuracy of the compensation signal and the system's anti-interference capability. Signal processor 213 enables real-time monitoring and dynamic compensation adjustment of electromagnetic interference noise, allowing the compensation signal to adapt to changes in noise characteristics under different operating conditions.

[0063] The controller 214, electrically connected to the signal processor 213 and the signal injection unit 220, is used to adjust the amplitude and phase parameters of the compensation signal. The controller 214 dynamically adjusts the parameters of the compensation signal based on real-time noise characteristics to ensure optimal cancellation effect.

[0064] The signal amplifier 211, phase inverter 212, signal processor 213 and controller 214 together constitute a complete signal processing path, realizing the entire process from noise signal sensing to compensation signal generation.

[0065] The operation of the signal processing unit 210 can be described in detail as follows:

[0066] The noise signal is transmitted from the noise sensing module 100 to the signal amplifier 211. The noise signal usually contains multiple frequency components and has a small amplitude, so it needs to be amplified.

[0067] Signal amplifier 211 amplifies the received noise signal, raising the signal level to a range suitable for subsequent processing. The gain parameter of signal amplifier 211 can be adjusted by controller 214 according to the actual noise level, ensuring that the amplified signal is neither too small to be effectively processed nor too large to cause saturation of subsequent circuits.

[0068] The amplified noise signal is transmitted to the phase inverter 212. The phase inverter 212 performs a 180-degree phase inversion on the signal, generating a compensation signal with the same amplitude but opposite phase as the original noise signal. Phase inversion is the core of active noise cancellation technology, ensuring that the compensation signal can form destructive interference with the original noise signal.

[0069] The phase-inverted signal is transmitted to the signal processor 213. The signal processor 213 first performs analog-to-digital conversion on the signal, converting it into digital form. Then, the signal processor 213 may perform digital filtering, spectrum analysis, and other processing to optimize the characteristics of the compensated signal. For example, it can filter out frequency components that do not need compensation, or employ different compensation strategies for noise in different frequency ranges.

[0070] The processed signal undergoes parameter adjustment by controller 214. Based on the signal processing results and system feedback, controller 214 dynamically adjusts the amplitude and phase parameters of the compensation signal to ensure optimal cancellation. Controller 214 may employ an adaptive algorithm to adjust the compensation parameters in real time according to changes in noise characteristics, improving the filter's adaptability and stability.

[0071] The adjusted compensation signal is finally transmitted to the signal injection unit 220, which injects it into the power line to cancel out the original noise signal.

[0072] Reference Figure 5 , Figure 5 This is a schematic diagram of a noise sensing module provided by this utility model. As shown in the figure, the noise sensing module 100 includes a first magnetic core assembly 111, a first primary winding 112, a second magnetic core assembly 113, a second primary winding 114, a third magnetic core assembly 115, a third primary winding 116, and a signal collection circuit 120. These components are electrically connected to phases A, B, and C of a three-phase power supply line, respectively, for collecting electromagnetic interference noise on each phase line.

[0073] As previously mentioned, the filter includes a noise sensing module 100 and a signal generation module. Figure 5 The internal structure of the noise sensing module 100 is shown in detail. This module is responsible for sensing noise signals on the power line and is electrically isolated from the power line through a magnetic core assembly.

[0074] like Figure 5 As shown, the noise sensing module 100 is designed for a three-phase power system and includes the following main components:

[0075] The first magnetic core assembly 111 is electrically connected to phase A of the power supply line and is used to collect electromagnetic interference noise on phase A. The magnetic core assembly adopts a toroidal or other suitable core structure, which can effectively capture electromagnetic interference signals on the power supply line. The first secondary winding 112 is wound on the first magnetic core assembly 111 and is used to convert the electromagnetic interference noise collected on phase A into an electrical signal. The number of turns and the winding method of the secondary winding are carefully designed to ensure optimal signal conversion efficiency.

[0076] The second magnetic core assembly 113 is electrically connected to the B-phase line in the power supply line and is used to collect electromagnetic interference noise on the B-phase line. The second stage winding 114 is wound on the second magnetic core assembly 113 and is used to convert the electromagnetic interference noise collected on the B-phase line into an electrical signal.

[0077] The third magnetic core assembly 115 is electrically connected to the C-phase line in the power supply line and is used to collect electromagnetic interference noise on the C-phase line. The third stage winding 116 is wound on the third magnetic core assembly 115 and is used to convert the electromagnetic interference noise collected on the C-phase line into an electrical signal.

[0078] The signal aggregation circuit 120 is electrically connected to the primary winding 112, the secondary winding 114, and the tertiary winding 116. It is used to receive and integrate the electrical signals of each phase line and output noise signals to the signal generation module.

[0079] The operation of the noise sensing module 100 can be described in detail below:

[0080] The three-phase power supply enters the filter through the power input terminal 21 and flows through the A-phase, B-phase, and C-phase power lines respectively. When electromagnetic interference noise exists on the power lines, this noise will generate interference current on each phase line.

[0081] The first magnetic core assembly 111 surrounds the A-phase line and senses the interference current on the A-phase line through the principle of electromagnetic induction. Since there is no electrical connection between the magnetic core assembly and the power line, electrical isolation is achieved, ensuring the safety of the filter.

[0082] The interference current on phase A generates a changing magnetic field in the first magnetic core assembly 111. This magnetic field change then induces an electrical signal in the primary winding 112. The intensity and frequency characteristics of this electrical signal reflect the interference situation on phase A.

[0083] Similarly, the second magnetic core assembly 113 and the second stage winding 114 sense and convert the interference on the B-phase line, and the third magnetic core assembly 115 and the third stage winding 116 sense and convert the interference on the C-phase line.

[0084] The electrical signals generated by each secondary winding are transmitted to the signal aggregation circuit 120. The signal aggregation circuit 120 integrates and processes these signals, including but not limited to signal conditioning, preliminary filtering, and signal synthesis, and finally outputs a noise signal that comprehensively reflects the noise status of the three-phase power lines. The integrated noise signal is transmitted to the signal generation module for subsequent compensation signal generation.

[0085] Reference Figure 6 , Figure 6 This is another structural schematic diagram of the noise sensing module provided by this utility model. As shown in the figure, the noise sensing module 100 includes a first magnetic core assembly 111, a first primary winding 112, a second magnetic core assembly 113, a second primary winding 114, a third magnetic core assembly 115, a third primary winding 116, and a signal aggregation circuit 120. Figure 5 The difference is that in this embodiment, each magnetic core assembly surrounds each phase line in the power line, rather than being electrically connected to each phase line.

[0086] As previously mentioned, the filter includes a noise sensing module 100 and a signal generation module. Figure 6 A special structural form of the noise sensing module 100 is shown in detail. This module senses noise signals on the power line through a surrounding magnetic core assembly and achieves electrical isolation.

[0087] like Figure 6 As shown, the noise sensing module 100 adopts a surround design and includes the following main components:

[0088] The first magnetic core assembly 111, surrounding the A-phase line in the power supply line, is used to sense electromagnetic interference noise on the A-phase line. Figure 5 Unlike the direct electrical connection in the first magnetic core assembly, the wraparound design forms a closed loop around the power line, allowing for more comprehensive sensing of electromagnetic field changes on the line. The primary winding 112, wound on the primary magnetic core assembly 111, converts electromagnetic interference noise induced on the A-phase line into an electrical signal. The secondary winding is designed with signal conversion efficiency and frequency response characteristics in mind.

[0089] The second magnetic core assembly 113, which surrounds the B-phase line in the power supply line, is used to sense electromagnetic interference noise on the B-phase line. The second stage winding 114, which is wound on the second magnetic core assembly 113, is used to convert the electromagnetic interference noise induced on the B-phase line into an electrical signal.

[0090] The third magnetic core assembly 115, which surrounds the C-phase line in the power supply line, is used to sense electromagnetic interference noise on the C-phase line. The third stage winding 116, which is wound on the third magnetic core assembly 115, is used to convert the electromagnetic interference noise induced on the C-phase line into an electrical signal.

[0091] The signal aggregation circuit 120, electrically connected to the primary winding 112, the secondary winding 114, and the tertiary winding 116, is used to receive and integrate the electrical signals of each phase line and output noise signals to the signal generation module. The surround design is a key feature of this embodiment, enabling the noise sensing module 100 to more comprehensively sense electromagnetic interference on the power line while maintaining complete electrical isolation.

[0092] The operation of the surround noise sensing module 100 can be described in detail as follows:

[0093] The three-phase power supply enters the filter through the power input terminal 21 and flows through the A-phase, B-phase, and C-phase power lines respectively. When electromagnetic interference noise exists on the power lines, this noise will generate interference current and corresponding electromagnetic fields on each phase line.

[0094] The first magnetic core assembly 111 completely surrounds the A-phase line, forming a closed magnetic circuit. According to Ampere's circuital law, the current flowing in the A-phase line will generate a toroidal magnetic field around it, which is completely captured by the first magnetic core assembly 111. When there is an interfering current on the A-phase line, the changing magnetic field it generates will be induced by the magnetic core assembly.

[0095] The changing magnetic field induces an electrical signal in the primary winding 112. Due to the all-around design, the core assembly can capture the entire magnetic field around the power line, resulting in higher induction efficiency and a more comprehensive reflection of noise on the power line.

[0096] Similarly, the second magnetic core assembly 113 and the second stage winding 114 sense and convert the interference on the B-phase line, and the third magnetic core assembly 115 and the third stage winding 116 sense and convert the interference on the C-phase line.

[0097] The electrical signals generated by each secondary winding are transmitted to the signal aggregation circuit 120. The signal aggregation circuit 120 integrates these signals to generate a signal that comprehensively reflects the noise status of the three-phase power lines. The integrated noise signal is transmitted to the signal generation module for subsequent compensation signal generation.

[0098] Reference Figure 7 , Figure 7 This is another structural schematic diagram of the noise sensing module provided by this utility model. As shown in the figure, the noise sensing module 100 includes a toroidal magnetic core 130 and a secondary winding 140. Unlike the aforementioned embodiments, this embodiment uses a single toroidal magnetic core that passes through three-phase power lines (phase A, phase B, and phase C) simultaneously, specifically for sensing common-mode noise, and has the characteristics of simple structure and strong targeting.

[0099] As previously mentioned, the filter includes a noise sensing module 100 and a signal generation module. Figure 7The paper details the structure of a noise sensing module 100 that focuses on common-mode noise sensing. This module uses a single toroidal magnetic core that passes through multiple phase lines to specifically sense common-mode noise signals while achieving electrical isolation.

[0100] like Figure 7 As shown, the noise sensing module 100 adopts a single toroidal magnetic core design and includes the following main components:

[0101] The toroidal core 130 adopts a closed toroidal structure, through which the three phase lines of the power supply—A, B, and C—pass simultaneously. The toroidal core 130 is made of a high-permeability material, typically ferrite, nanocrystalline, or similar materials, exhibiting excellent high-frequency characteristics and low-loss properties.

[0102] The secondary winding 140, wound on the toroidal core 130, is used to convert induced common-mode noise into an electrical signal and transmit it to the signal generation module. The number of turns, wire diameter, and winding method of the secondary winding 140 are optimized to achieve the best signal conversion efficiency and frequency response characteristics.

[0103] Its most distinctive feature is that the three-phase power lines pass through a single toroidal magnetic core simultaneously, enabling the noise sensing module 100 to specifically sense common-mode noise on the power lines, while having a natural suppression characteristic for differential-mode noise.

[0104] The working process of the toroidal magnetic core noise sensing module 100 can be described in detail as follows:

[0105] The three-phase power supply enters the filter through the power input terminal 21, and the three phase lines, A, B, and C, pass through the toroidal core 130 simultaneously. When common-mode noise exists on the power lines, common-mode currents in the same direction will be generated on the three phase lines. According to the principles of electromagnetism, the magnetic fields generated by the currents in the same direction will be superimposed and enhanced in the toroidal core.

[0106] When differential-mode noise exists on the power line, the current directions on each phase line are different (e.g., current flows into phase A, while current flows out of phases B and C), and the resulting magnetic fields cancel each other out in the toroidal core. This characteristic gives the toroidal core 130 selective induction capability for common-mode noise and natural suppression capability for differential-mode noise. The magnetic field change generated by common-mode noise creates a magnetic flux change in the toroidal core 130.

[0107] According to Faraday's law of electromagnetic induction, the change in magnetic flux induces an electromotive force in the secondary winding 140, generating an electrical signal proportional to the common-mode noise. The induced common-mode noise signal is transmitted through the secondary winding 140 to the signal generation module for subsequent compensation signal generation.

[0108] Reference Figure 8 , Figure 8This is a schematic diagram of the signal injection unit provided by this utility model. As shown in the figure, the filter includes a noise sensing module 100 and a signal generation module 200, wherein the signal generation module includes a signal processing unit 210 and a signal injection unit 220. The signal injection unit 220 includes an injection transformer 221 and multiple injection capacitors (marked as C1, C2, and C3 in the figure) for injecting compensation signals into the three-phase power lines (phase A, phase B, and phase C).

[0109] like Figure 8 As shown, the signal injection unit 220 mainly includes the following components:

[0110] An injection transformer 221, electrically connected to the signal processing unit 210, is used to receive the compensation signal generated by the signal processing unit 210. The injection transformer 221 has a primary side and multiple secondary output terminals. The primary side receives the compensation signal from the signal processing unit 210, and the multiple secondary output terminals are electrically connected to each injection capacitor. The injection transformer 221 may employ a multi-winding design to simultaneously inject compensation signals into multi-phase power lines.

[0111] Multiple injection capacitors (C1, C2, C3) are used. One end of each capacitor is electrically connected to the secondary output terminal of the injection transformer 221, and the other end is electrically connected to each phase line (phase A, phase B, phase C) of the power supply. The injection capacitors are used to couple the compensation signal to the power supply line while blocking the power frequency voltage of the power supply line, thus protecting the signal injection circuit.

[0112] It should be noted that all the injected capacitors are high-voltage insulating capacitors, which have high-frequency signal transmission characteristics and electrical isolation functions, so that the compensation signal can be effectively coupled to the power line without affecting the basic power supply function of the power line; the capacitance value of the injected capacitor is designed according to the operating voltage of the power line and the target noise frequency range to achieve optimized suppression of electromagnetic interference noise in a specific frequency band.

[0113] The operation of the signal injection unit 220 can be described in detail as follows:

[0114] The signal processing unit 210 generates a compensation signal with opposite phase to the noise signal based on the noise signal provided by the noise sensing module 100, and transmits the compensation signal to the primary side of the injection transformer 221. The injection transformer 221 receives the compensation signal and couples the signal from the primary side to each secondary output terminal through the principle of electromagnetic induction. During the coupling process, the injection transformer 221 may adjust the amplitude or phase of the signal as needed to ensure the best compensation effect.

[0115] The compensation signals output from each secondary output terminal of the injection transformer 221 are coupled to phases A, B, and C of the power line through injection capacitors C1, C2, and C3, respectively. As high-frequency coupling elements, the injection capacitors allow the high-frequency compensation signals to pass through while blocking low-frequency power frequency voltage. Since the noise signal on the power line is mainly of high-frequency components, the injection capacitors can effectively couple the high-frequency compensation signals to the power line without affecting normal power transmission. The compensation signals coupled to the power line cancel each other out with the original noise signals, thereby reducing the electromagnetic interference level on the power line.

[0116] Unlike existing technologies, this invention can effectively reduce electromagnetic interference, reduce the number of common-mode chokes or the necessary common-mode choke inductance, thereby reducing hardware costs and significantly shrinking the size of the filter while fully leveraging its noise reduction performance.

[0117] Based on the filters provided in the foregoing embodiments, this application also provides an in-vehicle device that includes the filters provided in the foregoing embodiments.

[0118] It should be noted that while the preferred embodiments of this utility model are provided in the specification and accompanying drawings, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are not intended to impose additional limitations on the content of this utility model; their purpose is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Furthermore, the above-described technical features can be combined with each other to form various embodiments not listed above, all of which are considered to be within the scope of this utility model specification. Moreover, those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A filter, characterized in that, include: A noise sensing module is used to sense noise signals on the power line. The noise sensing module and the power line are electrically isolated through a magnetic core assembly. The signal generation module is electrically connected to the noise sensing module and is used to receive and process the noise signal, generate a compensation signal that is opposite in phase to the noise signal, and inject the compensation signal into the power line.

2. The filter of claim 1, wherein, The signal generation module includes: A signal processing unit, electrically connected to the noise sensing module, is used to receive and process the noise signal and generate the compensation signal; A signal injection unit, electrically connected to the signal processing unit, is used to receive the compensation signal and inject the compensation signal into the power line to cancel the noise signal; The noise sensing module and the signal injection unit are electrically separated and are connected to the power line through their respective independent paths.

3. The filter of claim 1, wherein, The noise sensing module includes: Multiple magnetic core assemblies are electrically connected to each phase line in the power line to collect electromagnetic interference noise on each phase line. Multiple secondary windings are respectively wound on each of the magnetic core assemblies to convert electromagnetic interference noise collected on each phase line into electrical signals; The signal aggregation circuit is electrically connected to the plurality of secondary windings and is used to receive and integrate the electrical signals of each phase line and output noise signals to the signal generation module.

4. The filter of claim 1, wherein, The noise sensing module includes: Multiple magnetic core assemblies are respectively wrapped around each phase line in the power line to sense electromagnetic interference noise on each phase line; Multiple secondary windings are respectively wound on each of the magnetic core assemblies to convert electromagnetic interference noise induced on each phase line into electrical signals; The signal aggregation circuit is electrically connected to the plurality of secondary windings and is used to receive and integrate the electrical signals of each phase line and output noise signals to the signal generation module.

5. The filter according to claim 1, characterized in that, The noise sensing module includes: A toroidal magnetic core is used to sense common-mode noise on multiple phase lines of the power line, which simultaneously pass through the toroidal magnetic core. The secondary winding, wound on the toroidal magnetic core, is used to convert the induced common-mode noise into a noise signal and transmit it to the signal generation module.

6. The filter of claim 2, wherein, The signal processing unit includes: A signal amplifier, electrically connected to the noise sensing module, is used to receive and amplify the noise signal; A phase inverter, electrically connected to the signal amplifier, is used to perform phase inversion processing on the amplified noise signal to generate a compensation signal with the opposite phase to the noise signal. A signal processor, electrically connected to the phase inverter, is used to digitally process the noise signal and the compensation signal; The controller, electrically connected to the signal processor and the signal injection unit, is used to adjust the amplitude and phase parameters of the compensation signal.

7. The filter of claim 2, wherein, The signal generation module further includes: The phase-to-phase balancing unit is electrically connected to the signal processing unit and the signal injection unit. It is used to receive the compensation signals of each phase, adjust the parameters of the compensation signals of each phase under the three-phase load imbalance state, and output the adjusted compensation signals of each phase to the signal injection unit.

8. The filter according to claim 2, characterized in that, The signal injection unit includes: An injection transformer, electrically connected to the signal processing unit, is used to receive the compensation signal; Multiple injection capacitors, one end of which is electrically connected to the output terminal of the injection transformer, and the other end of which is electrically connected to each phase line of the power supply line, are used to couple the compensation signal to the power supply line.

9. The filter according to claim 8, characterized in that, The injected capacitor is a high-voltage insulating capacitor.

10. A vehicle-mounted device, characterized in that, include: The filter as described in any one of claims 1-9.

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