Filtering design method and device and computer storage medium

Abstract

The invention provides a filtering design method and device and a computer storage medium, and the method comprises the steps: obtaining a capacitance value determined by an original noise spectrum waveform, and obtaining the expected insertion loss of a fast-charging filtering assembly; acquiring first load impedance and second load impedance at two ends of the fast charging line; substituting the capacitance value of the capacitor, the first load impedance and the second load impedance into the insertion loss of the fast-charging filtering assembly to obtain an expected magnetic ring impedance value; selecting a target magnetic ring based on the magnetic ring impedance value; and taking a filter composed of a target capacitor corresponding to the capacitance value of the capacitor and the target magnetic ring as a fast charging filtering assembly of a fast charging port of the controller. By means of the mode, an ingenious calculation mode is used, the development period is shortened while the filtering assembly is accurately designed, the development cost is reduced, and the calculation efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and in particular to a filter design method, device and computer storage medium. Background Art

[0002] In the current technical methods for fast-charging filter component design, at the beginning, designers first design fast-charging filter components based on experience, then simulate the insertion loss of the fast-charging filter components, continuously debug in the simulation, and finally determine the magnetic ring size, capacitor value, and combination of magnetic ring and capacitor of the fast-charging filter component. Finally, after the physical product comes out, based on the actual electromagnetic noise level measured by the whole vehicle in the laboratory, the various parameters of the fast-charging filter component are continuously adjusted and iteratively tested. Finally, a satisfactory insertion loss is obtained, so that the electromagnetic noise level meets the limit after filtering by the fast-charging filter component. The above method wastes resources and is inefficient. Summary of the invention

[0003] The present application provides a filter design method, device and computer storage medium.

[0004] In order to solve the above technical problems, the present application proposes a filter design method, which includes: obtaining the capacitance value determined by the original noise spectrum waveform, and obtaining the expected fast charging filter component insertion loss; obtaining the first load impedance and the second load impedance at both ends of the fast charging line; substituting the capacitance value, the first load impedance and the second load impedance into the fast charging filter component insertion loss to obtain the expected magnetic ring impedance value; selecting the target magnetic ring based on the magnetic ring impedance value; and using the filter composed of the target capacitor corresponding to the capacitance value and the target magnetic ring as the fast charging filter component of the controller fast charging port.

[0005] Wherein, the first end of the target magnetic ring in the filter is connected to the fast charging port of the controller fast charging port, and the second end of the target magnetic ring is connected to the target capacitor.

[0006] Among them, the obtaining of the capacitance value determined by the original noise spectrum waveform includes: collecting the original noise spectrum of the controller fast charging port when no fast charging filter component is added; determining the risk frequency band in the original noise spectrum; and determining the capacitance value based on the risk frequency band.

[0007] The determining of the capacitance value based on the risk frequency band includes: acquiring a risk frequency point in the risk frequency band; and screening the capacitance value of the minimum capacitance that can achieve filtering based on the risk frequency point.

[0008] Among them, obtaining the expected fast charging filter component insertion loss includes: obtaining the voltage source of the risk frequency band based on the original noise spectrum; obtaining the forward transmission coefficient of the fast charging line; and determining the expected fast charging filter component insertion loss based on the forward transmission coefficient and the voltage source.

[0009] Wherein, determining the expected fast-charging filter component insertion loss based on the forward transmission coefficient and the voltage source includes: obtaining a noise limit based on the forward transmission coefficient and the voltage source; determining the expected fast-charging filter component insertion loss based on the difference between the noise limit and the standard conversion limit; wherein the standard conversion limit is the limit after denoising the fast-charging port of the controller.

[0010] Among them, different magnetic ring shapes and / or magnetic ring sizes are traversed to determine the impedance value of each candidate magnetic ring; and the candidate magnetic ring with the smallest difference in impedance value from the magnetic ring is selected as the target magnetic ring.

[0011] In order to solve the above technical problems, the present application proposes a filter design device based on a controller fast charging port, the filter design device comprising an acquisition module, a calculation module and an application module; the acquisition module is used to obtain the capacitance value determined by the original noise spectrum waveform, and obtain the expected insertion loss of the fast charging filter component; obtain the first load impedance and the second load impedance at both ends of the fast charging line; the calculation module is used to substitute the capacitance value, the first load impedance and the second load impedance into the insertion loss of the fast charging filter component to obtain the expected magnetic ring impedance value;

[0012] The application module is used to select a target magnetic ring based on the magnetic ring impedance value; a filter composed of a target capacitor corresponding to the capacitance value and the target magnetic ring is used as a fast charging filter component of the controller fast charging port.

[0013] Different from the prior art, the beneficial effects of the present application are: the filter design device obtains the capacitance value determined by the original noise spectrum waveform, and obtains the expected insertion loss of the fast-charging filter component; obtains the first load impedance and the second load impedance at both ends of the fast-charging line; substitutes the capacitance value, the first load impedance and the second load impedance into the insertion loss of the fast-charging filter component to obtain the expected magnetic ring impedance value; selects the target magnetic ring based on the magnetic ring impedance value; and uses the filter composed of the target capacitor corresponding to the capacitance value and the target magnetic ring as the fast-charging filter component of the fast-charging port of the controller. Through the above method, a clever calculation method is used to accurately design the filter component while reducing the development cycle, reducing development costs, and improving calculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 It is a flowchart of the first embodiment of the filter design method provided by the present application;

[0016] Figure 2 is a flow chart of a second embodiment of the filter design method provided by the present application;

[0017] Figure 3 It is a two-port S-parameter network diagram provided by this application;

[0018] Figure 4 It is a two-port Z parameter network diagram provided by this application;

[0019] Figure 5 It is a two-port network diagram of the filter component of the filter design method provided by the present application;

[0020] Figure 6 It is a structural schematic diagram of an embodiment of a filter design device provided by the present application;

[0021] Figure 7 It is a structural diagram of an embodiment of a computer storage medium provided by the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The filter design method of the present application is applied to a filter design device, wherein the filter design device of the present application can be a server, or a system in which a server and a local terminal cooperate with each other. Accordingly, the various parts included in the filter design device, such as various units, sub-units, modules, and sub-modules, can all be set in the server, or can be set in the server and the local terminal respectively.

[0024] Further, the above-mentioned server can be hardware or software. When the server is hardware, it can be implemented as a distributed server cluster composed of multiple servers, or it can be implemented as a single server. When the server is software, it can be implemented as multiple software or software modules, such as software or software modules for providing distributed servers, or it can be implemented as a single software or software module, which is not specifically limited here. In some possible implementations, the filter design method of the embodiment of the present application can be implemented by a processor calling a computer-readable instruction stored in a memory.

[0025] Fast-charge filter insertion loss refers to the load power loss caused by inserting a fast-charge filter somewhere in the transmission system. It is expressed as the ratio of the power received on the load before the fast-charge filter is inserted to the power received on the same load after insertion, expressed in decibels (dB). Insertion loss is an important indicator for measuring the effect of fast-charge filter components, and is used to evaluate the fast-charge filter component's ability to attenuate noise signals.

[0026] From the above content, it can be seen that since the insertion loss of the fast-charging filter component is the ratio of the power received on the load before the fast-charging filter component is inserted to the power received on the same load after insertion, then this ratio, that is, the insertion loss of the fast-charging filter component, will inevitably change with the impedance of the noise source and the impedance of the load. At present, in the design process of fast-charging filter components, vector network analyzers are generally used to measure their insertion losses, which is also the measurement method recommended by the national standard. The port impedance of the appropriate network analyzer is unified to 50Ω, so the insertion loss of the fast-charging filter component measured by this method represents the insertion loss of the fast-charging filter component when the source impedance and the load impedance are both 50Ω.

[0027] To this end, this application proposes a filter design method, please refer to Figure 1 , Figure 1 It is a flowchart of the first embodiment of the filter design method provided by the present application.

[0028] like Figure 1 As shown, the specific steps are as follows:

[0029] Step S11: Obtain the capacitance value determined by the original noise spectrum waveform, and obtain the expected insertion loss of the fast charging filter component.

[0030] Among them, the original noise spectrum waveform is the noise when no filtering components are added to the controller fast charging port. The original noise spectrum waveform can be obtained by an oscilloscope or simulation, and this application does not make specific limitations.

[0031] In the embodiment of the present application, before designing the fast-charging filter component, first determine its electrical topology as a first-order LC filter with the magnetic ring closer to the fast-charging port. Then determine its key applicable frequency band, and select the filter capacitor (C) based on this frequency band.

[0032] In one embodiment of the present application, the filter design device obtains the capacitance value determined by the original noise spectrum waveform, and determines the capacitance value based on the risk frequency band.

[0033] Specifically, the filter design device obtains risk frequency points in the risk frequency band; and screens the capacitance value of the minimum capacitor that can achieve filtering based on the risk frequency points.

[0034] The risk frequency band is a frequency range data segment in the original noise spectrum waveform whose amplitude value is greater than a preset threshold. For example, if the amplitude corresponding to each frequency point of 20MHz-60MHz is greater than the preset threshold, 20MHz-60MHz is determined to be a risk frequency band. The preset threshold can be set according to an empirical value or can be adaptively adjusted according to actual applications.

[0035] In a specific embodiment of the present application, the noise spectrum waveform can be extracted according to the IGBT double pulse test and the risk frequency band that needs to be filtered can be confirmed.

[0036] The filter design device obtains the noise reduction effect of each capacitor with each capacitance value on the frequencies in the risk frequency band, and selects the capacitor corresponding to the optimal noise reduction effect according to the noise reduction effect.

[0037] The embodiment of the present application determines the corresponding capacitance value according to the risk frequency band, so that the selected capacitance value can be adapted to the corresponding risk frequency band, further paving the way for the filtering effect of the filtering component.

[0038] Furthermore, the present application proposes an embodiment for obtaining the expected insertion loss. For details, please refer to Figure 2-Figure 5 , Figure 2 is a flow chart of a second embodiment of the filter design method provided by the present application; Figure 3 It is a two-port S-parameter network diagram provided by this application; Figure 4 It is a two-port Z parameter network diagram provided by this application; Figure 5 It is a two-port network diagram of the filter component of the filter design method provided by this application.

[0039] like Figure 2 As shown, the specific steps are as follows:

[0040] Step S21: based on the original noise spectrum, obtaining the voltage source of the risk frequency band.

[0041] Specifically, the voltage source is a matrix, and the parameters in the matrix are the amplitudes corresponding to each frequency point in the risk frequency band.

[0042] Step S22: Obtain the forward transmission coefficient of the fast charging line.

[0043] Among them, the forward transmission coefficient is expressed as S in S parameters. 21 1 , also known as gain.

[0044] See also Figure 3-Figure 4 The network analyzer includes a signal source and a receiver. The receiver will detect the change of the output signal passing through the DUT, and then compare it with the source signal input to the DUT to obtain the S parameter. The S parameter is an important parameter in microwave transmission. S12 is the reverse transmission coefficient, S 21 is the forward transfer coefficient, S 11 is the input reflection coefficient, S 22 is the output reflection coefficient. The specific definition is as follows:

[0045] S 11 : Reflection coefficient of port 1 when port 2 is matched;

[0046] S 22 : The reflection coefficient of port 2 when port 1 is matched;

[0047] S 12 : The reverse transmission coefficient from port 2 to port 1 when port 1 is matched;

[0048] S 21 : The forward transmission coefficient from port 1 to port 2 when port 2 is matched;

[0049] When port 1 is the signal source, port 2 is the receiver, and there is only a fast-charge filter component between the ports, S 21 That is the insertion loss of the fast charging filter component when the port impedance is 50Ω.

[0050] The Z parameter is the impedance network parameter, which is defined as:

[0051] Z 11 : Input impedance of port 1 when port 2 is open;

[0052] Z 22 : Output impedance of port 2 when port 1 is open;

[0053] Z 12 : Reverse transfer impedance when port 1 is open circuit;

[0054] Z 21 : Forward transfer impedance when port 2 is open;

[0055] The calculation formula is: [S] = [√Z O ]^-1([Z]-[ZO ])([Z]+[Z O ])^-1[√Z O ].

[0056] Among them, ZO is the impedance of the port, and Z parameters and S parameters can be converted into each other.

[0057] Specifically, in one embodiment of the present application, the filter design device establishes a radiation emission model of the fast charging harness in any simulation software based on the original noise spectrum waveform. The extracted noise spectrum waveform is the voltage source VS, and the digital analog of the fast charging line is established according to the layout of the actual circuit, and the digital analog of the receiving antenna is arranged and established, and the forward transmission coefficient from the noise source radiated outward through the fast charging line to the receiving antenna is determined by simulation.

[0058] In other embodiments of the present application, the forward transmission coefficient can be obtained by actual circuit detection and reception.

[0059] Step S23: Determine the expected fast charge filter component insertion loss based on the forward transmission coefficient and the voltage source.

[0060] Among them, the insertion loss of the fast charging filter component refers to the loss of load power caused by the insertion of components or devices when certain devices or branch circuits are added to a circuit.

[0061] Specifically, the forward transmission coefficient is S 21 1 , the fast charge filter component port impedance is set to the default 50Ω. 21 1 *VS|Compare with the standard transfer limit to determine the expected fast charging filter component insertion loss IL.

[0062] The standard conversion limit is a waveform that is expected to be noise-reduced.

[0063] Step S12: Obtain a first load impedance and a second load impedance at both ends of the fast charging cable.

[0064] Specifically, the filter design device determines the load impedances at both ends of the fast charging harness through measurement or simulation, which are the first load impedance ZR (charging port end) and the second load impedance ZS (controller end).

[0065] Step S13: Substitute the capacitance value, the first load impedance and the second load impedance into the insertion loss of the fast charging filter component to obtain the desired magnetic ring impedance value.

[0066] Capacitors of different capacitance values ​​have fixed frequency characteristics, so the selection of capacitors can be completed under the premise of a clear filtering frequency band. The design of the magnetic ring can be completed under the premise of determining the capacitance. As long as the corresponding impedance at the applicable frequency is accurately grasped, the shape and size of the magnetic ring can be determined. The required impedance size is determined by the required fast charging filter component insertion loss.

[0067] Specifically, the calculation formula for the expected insertion loss can be obtained:

[0068] IL=S21=2*Z21*(ZR*ZS)^1 / 2 / [(Z11+ZS)(Z22+ZR)-Z12*Z21];

[0069] Substituting Z11=jωL-j / ωC;Z12=-j / ωC;Z21=-j / ωC;Z22=-j / ωC;ω=2fΠ, we can get:

[0070] IL=S21=2*(-j / ωC)*(ZR*ZS)^1 / 2 / [(jωL-j / ωC+ZS)(-j / ωC+ZR)+(1 / ωC)^2];

[0071] Then substitute ZL=ωL, ZC=1 / ωC to calculate the expected magnetic ring impedance value:

[0072] ZL=|[-2ZC*(ZS*ZR)^1 / 2 / S21*(-jZC+ZR)]+[j(ZC)^2 / (-jZC+ZR)+jZS+ZC|.

[0073] ZL represents the actual impedance value of the magnetic ring required to meet the insertion loss IL set when the port impedance is 50Ω under the conditions of port impedance ZR and ZS in the actual application of the fast charging filter component.

[0074] Z parameters and S parameters can be converted to each other. Z parameters can be converted to S parameters under different port impedances by using different port impedance values. 12 1 and the port impedance is the actual impedance S 21 2 They can be converted to each other through Z parameters and port impedance.

[0075] Among them, the magnetic ring impedance ZL=ωL. As long as S is fixed 21 The value of remains unchanged, and ZL can be reversed by obtaining the actual values ​​of the first impedance value ZR and the second impedance value ZS.

[0076] Step S14: Select a target magnetic ring based on the magnetic ring impedance value.

[0077] The magnetic ring is a ring-shaped magnetic conductor that has a good inhibitory effect on high-frequency noise. The impedance characteristics of the magnetic ring increase sharply with the increase of signal frequency, thereby preventing high-frequency noise from passing through.

[0078] Specifically, in the embodiment of the present application, the filter design device traverses different magnetic ring shapes and / or magnetic ring sizes to determine the impedance value of each candidate magnetic ring; and selects the candidate magnetic ring with the smallest difference in magnetic ring impedance as the target magnetic ring. The parameters of the target magnetic ring can be accurately determined in the above manner.

[0079] Step S15: A filter composed of a target capacitor and a target magnetic ring corresponding to the capacitance value is used as a fast charging filter component of the controller fast charging port.

[0080] like Figure 5 As shown, Figure 5 It is a two-port network diagram of the filter component of the filter design method provided by this application.

[0081] In one embodiment of the present application, a first end of a target magnetic ring in the filter is connected to a fast charging port of a controller fast charging port, and a second end of the target magnetic ring is connected to a target capacitor.

[0082] The steps in the embodiments of the present application do not require EMC testing in the laboratory, thereby solving the problem that the adjustment of the fast charging filter component under the design method of the prior art depends on iterative EMC testing in the laboratory, resulting in high costs.

[0083] In the embodiment of the present application, according to the principle that any port impedance can be converted to each other between S parameters and Z parameters, the forward transfer coefficient is simulated with a port impedance of 50 ohms, the spectrum data of the noise voltage is extracted, and the expected insertion loss IL is calculated to solve the required magnetic ring impedance. This impedance can achieve the expected insertion loss under the port impedance of the actual working conditions, and the impedance requirement for simulating the expected insertion loss is 50 ohms for each port, eliminating the tediousness of setting the corresponding actual impedance for each frequency point.

[0084] In order to implement the filter design method of the above embodiment, the present application also provides a filter design device, for details, please refer to Figure 6 , Figure 6 It is a structural schematic diagram of an embodiment of a filter design device provided in the present application.

[0085] like Figure 6 As shown, the filter design device 600 of this embodiment includes a processor 61 , a memory 62 , an input / output device 63 , and a bus 64 .

[0086] The processor 61 , the memory 62 , and the input / output device 63 are respectively connected to the bus 64 . The memory 62 stores a computer program, and the processor 61 is used to execute the computer program to implement the filter design method of the above embodiment.

[0087] In this embodiment, the processor 61 may also be referred to as a CPU (Central Processing Unit). The processor 61 may be an integrated circuit chip having the ability to process signals. The processor 61 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The processor 61 may also be a GPU (Graphics Processing Unit), also known as a display core, a visual processor, or a display chip, which is a microprocessor that is specifically used for image computing on computers, workstations, game consoles, and some mobile devices (such as tablet computers, smart phones, etc.). The purpose of the GPU is to convert and drive the display information required by the computer system, and to provide a line scan signal to the display to control the correct display of the display. It is an important component that connects the display and the computer motherboard. As an important component of the computer host, the graphics card is responsible for outputting display graphics. The general-purpose processor may be a microprocessor or the processor 61 may also be any conventional processor, etc.

[0088] The present application also provides a computer storage medium, such as Figure 7 As shown, the computer storage medium 700 is used to store a computer program 71. When the computer program 71 is executed by a processor, it is used to implement the method described in the embodiment of the filter design method of the present application.

[0089] The method involved in the filter design method embodiment of the present application, when implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a device, such as a computer-readable storage medium. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (processor) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0090] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A filter design method based on a controller fast charging port, characterized in that: The filtering design method comprises: Obtain the capacitance value determined by the original noise spectrum waveform, and obtain the expected insertion loss of the fast charging filter component; Obtain a first load impedance and a second load impedance at both ends of the fast charging cable; Substituting the capacitance value, the first load impedance and the second load impedance into the insertion loss of the fast-charging filter component to obtain a desired magnetic ring impedance value; Select the target magnetic ring based on the magnetic ring impedance value; A filter composed of a target capacitor corresponding to the capacitance value and the target magnetic ring is used as a fast charging filter component of the fast charging port of the controller.

2. The filter design method according to claim 1, characterized in that: The first end of the target magnetic ring in the filter is connected to the fast charging port of the controller fast charging port, and the second end of the target magnetic ring is connected to the target capacitor.

3. The filter design method according to claim 1, characterized in that: The obtaining of the capacitance value determined by the original noise spectrum waveform includes: Collecting the original noise spectrum of the fast charging port of the controller when no fast charging filter component is added; determining a risk frequency band in the original noise spectrum; Based on the risk frequency band, the capacitance value of the capacitor is determined.

4. The filter design method according to claim 3, characterized in that: The determining the capacitance value based on the risk frequency band includes: Obtaining risk frequency points in the risk frequency band; The capacitance value of the minimum capacitor that can achieve filtering is screened based on the risk frequency point.

5. The filter design method according to claim 3, characterized in that: The obtaining of the expected insertion loss of the fast charging filter component includes: Based on the original noise spectrum, obtaining the voltage source of the risk frequency band; Obtaining a forward transmission coefficient of the fast charging cable; Based on the forward transmission coefficient and the voltage source, the expected fast charge filter assembly insertion loss is determined.

6. The filter design method according to claim 5, characterized in that: The determining the expected fast charge filter component insertion loss based on the forward transmission coefficient and the voltage source includes: Based on the forward transfer coefficient and the voltage source, obtaining a noise limit value; Determining the expected fast charge filter component insertion loss based on the difference between the noise limit and the standard transfer limit; The standard conversion limit is the limit after the fast charging port of the controller is denoised.

7. The filter design method according to claim 1, characterized in that: The step of selecting a target magnetic ring based on the magnetic ring impedance value includes: Traversing different magnetic ring shapes and / or magnetic ring sizes, and determining the impedance value of each candidate magnetic ring; The candidate magnetic ring with the smallest impedance difference from the magnetic ring is selected as the target magnetic ring.

8. A filter design device based on a controller fast charging port, characterized in that: The filter design device comprises an acquisition module, a calculation module and an application module; The acquisition module is used to obtain the capacitance value determined by the original noise spectrum waveform and to obtain the expected insertion loss of the fast-charging filter component; Obtain a first load impedance and a second load impedance at both ends of the fast charging cable; The calculation module is used to substitute the capacitance value, the first load impedance and the second load impedance into the insertion loss of the fast-charging filter component to obtain a desired magnetic ring impedance value; The application module is used to select a target magnetic ring based on the magnetic ring impedance value; a filter composed of a target capacitor corresponding to the capacitance value and the target magnetic ring is used as a fast charging filter component of the controller fast charging port.

9. A filter design device based on a controller fast charging port, characterized in that: The filter design device includes a memory and a processor coupled to the memory; The memory is used to store program data, and the processor is used to execute the program data to implement the filtering design method according to any one of claims 1 to 7.

10. A computer storage medium, characterized in that: The computer storage medium is used to store program data, and when the program data is executed by a computer, it is used to implement the filter design method according to any one of claims 1 to 7.

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