CN111931329A

CN111931329A - Interference processing device, electrical equipment and interference processing method thereof

Info

Publication number: CN111931329A
Application number: CN202010565312.2A
Authority: CN
Inventors: 王习文; 高小丽; 许敏; 张纪东; 朱永强; 李卓翰
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-06-19
Filing date: 2020-06-19
Publication date: 2020-11-13
Also published as: WO2021253816A1

Abstract

The invention discloses an interference processing device, electrical equipment and an interference processing method thereof, wherein the device comprises the following components: the device comprises a determining unit, a processing unit and a processing unit, wherein the determining unit is used for determining an interference source and an interference propagation path of electrical equipment; the modeling unit is used for constructing a conducted interference equivalent circuit model of the electrical equipment based on an interference source of the electrical equipment; the verification unit is used for verifying the conducted interference equivalent circuit model of the electrical equipment in a time domain or a frequency domain based on the interference propagation path of the electrical equipment to obtain a verification result; and the determining unit is also used for positioning and/or quantizing the interference source of the electrical equipment according to the verification result to obtain the position of the interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment. The scheme of the invention can solve the problem that the interference source risk point is difficult to locate when the electrical equipment is designed, and achieves the effect of conveniently locating the interference source risk point when the electrical equipment is designed.

Description

Interference processing device, electrical equipment and interference processing method thereof

Technical Field

The invention belongs to the technical field of electronic circuits, and particularly relates to an interference processing device, electrical equipment and an interference processing method thereof, in particular to a method for predicting, modeling and positioning conducted EMI (electro-magnetic interference) of a variable frequency air conditioner, the electrical equipment and the interference processing method thereof.

Background

In the early stage of design of the variable frequency air conditioner, the Interference source risk is difficult to predict and identify, and the Interference source strength cannot be quantized, so that when the test result of conducted EMI (electromagnetic Interference) exceeds the standard, EMC (electromagnetic compatibility) is difficult to modify from a mechanism layer.

The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.

Disclosure of Invention

The present invention aims to solve the above-mentioned drawbacks, and provide an interference processing apparatus, an electrical device, and an interference processing method thereof, so as to solve the problem that it is difficult to locate an interference source risk point during design of the electrical device, and achieve an effect of conveniently locating the interference source risk point during design of the electrical device.

The invention provides an interference processing device, comprising: the device comprises a determining unit, a modeling unit and a verifying unit; the device comprises a determining unit, a processing unit and a processing unit, wherein the determining unit is used for determining an interference source and an interference propagation path of electrical equipment; the modeling unit is used for constructing a conducted interference equivalent circuit model of the electrical equipment based on an interference source of the electrical equipment; the verification unit is used for verifying the conducted interference equivalent circuit model of the electrical equipment in a time domain or a frequency domain based on the interference propagation path of the electrical equipment to obtain a verification result; and the determining unit is also used for positioning and/or quantizing the interference source of the electrical equipment according to the verification result to obtain the position of the interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment.

Optionally, the determining unit determines an interference source and an interference propagation path of the electrical device, including: acquiring components, PCB layout and/or loads of the electrical equipment, and acquiring an electric conduction path of a circuit formed by the components, the PCB layout and/or the loads of the electrical equipment; determining an interference source of the electrical equipment according to components, PCB layout and/or load of the electrical equipment; and determining an interference propagation path of the interference source of the electrical equipment according to the interference source of the electrical equipment and an electric conduction path of a circuit formed by components, PCB layout and/or loads of the electrical equipment.

Optionally, the constructing unit constructs a conducted interference equivalent circuit model of the electrical device, including: dividing components in the electrical equipment according to the types of the components to obtain passive components, active components and/or loads; constructing a high-frequency equivalent circuit model of a passive device and a load; constructing a high-frequency dynamic model of the active device; constructing parasitic parameter models of the passive device and the active device to the ground, and extracting a PCB parasitic parameter model; and according to the interference propagation path of the electrical equipment, connecting a high-frequency equivalent circuit model, a high-frequency dynamic model, a device parasitic parameter model and a PCB parasitic parameter model corresponding to an interference source of the electrical equipment in a circuit mode to obtain a conducted interference equivalent circuit model containing differential mode interference and common mode interference in the electrical equipment.

Optionally, wherein the passive device comprises: capacitive and/or inductive devices; the building unit builds a high-frequency equivalent circuit model of the passive device and the load, and comprises the following steps: for a capacitor device, measuring the impedance of the capacitor device in a required frequency band, and constructing an RLC equivalent circuit containing a set frequency parasitic parameter according to the amplitude-frequency characteristic and the phase-frequency characteristic of the impedance of the capacitor device, wherein the RLC equivalent circuit is used as a high-frequency equivalent circuit model of the capacitor device; and/or determining the resonance points and the number of the resonance points of the inductive device and/or the load in a given test frequency range for the inductive device and/or the load; establishing a set of RLC models at each resonance point for each resonance point; fitting the RLC models at all the resonance points to obtain an RLC composite model of the inductance device and/or the load, wherein the RLC composite model is used as a high-frequency equivalent circuit model of the inductance device and/or the load; and/or the construction unit constructs a high-frequency dynamic model of the active device, and comprises: determining static characteristic parameters and dynamic characteristic parameters of the active device, and constructing a behavior model of the active device according to the static characteristic parameters and the dynamic characteristic parameters of the active device; verifying the behavior model of the active device, and determining the behavior model of the active device with the verification result conforming to the set result as a high-frequency dynamic model of the active device; and/or the construction unit constructs device parasitic parameter models of the passive device and the active device to the ground, and comprises the following steps: establishing a model of a device-to-ground high-frequency equivalent circuit model of a common-mode interference device capable of generating common-mode interference in the passive device and the active device by utilizing a mode of constructing the high-frequency equivalent circuit models of the passive device and the load, wherein the model is used as a device parasitic parameter model of the passive device and the active device to the ground; and/or the construction unit extracts a PCB parasitic parameter model, and comprises the following steps: the method comprises the steps of extracting RLCG parameters of line layout including via holes from a PCB of the electrical equipment, and accessing a packaging model of the RLCG parameters of the line layout including the via holes in the PCB to a circuit model of the electrical equipment to serve as a PCB parasitic parameter model.

Optionally, the method further comprises: the determining unit is further used for optimizing design parameters of the electrical equipment according to the position of the interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment so as to optimize the anti-interference performance of the electrical equipment in the design stage of the electrical equipment; wherein, the design parameter of electrical equipment includes: PCB layout of the electrical equipment and/or device type selection of the electrical equipment.

In accordance with another aspect of the present invention, there is provided an electrical apparatus, including: the interference processing apparatus described above.

In another aspect, the present invention provides an interference processing method for an electrical device, including: determining an interference source and an interference propagation path of the electrical equipment; constructing a conducted interference equivalent circuit model of the electrical equipment based on an interference source of the electrical equipment; verifying a conducted interference equivalent circuit model of the electrical equipment in a time domain or a frequency domain based on an interference propagation path of the electrical equipment to obtain a verification result; and according to the verification result, positioning and/or quantifying the interference source of the electrical equipment to obtain the position of the interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment.

Optionally, determining an interference source and an interference propagation path of the electrical device includes: acquiring components, PCB layout and/or loads of the electrical equipment, and acquiring an electric conduction path of a circuit formed by the components, the PCB layout and/or the loads of the electrical equipment; determining an interference source of the electrical equipment according to components, PCB layout and/or load of the electrical equipment; and determining an interference propagation path of the interference source of the electrical equipment according to the interference source of the electrical equipment and an electric conduction path of a circuit formed by components, PCB layout and/or loads of the electrical equipment.

Optionally, constructing a conducted interference equivalent circuit model of the electrical device includes: dividing components in the electrical equipment according to the types of the components to obtain passive components, active components and/or loads; constructing a high-frequency equivalent circuit model of a passive device and a load; constructing a high-frequency dynamic model of the active device; constructing parasitic parameter models of the passive device and the active device to the ground, and extracting a PCB parasitic parameter model; and according to the interference propagation path of the electrical equipment, connecting a high-frequency equivalent circuit model, a high-frequency dynamic model, a device parasitic parameter model and a PCB parasitic parameter model corresponding to an interference source of the electrical equipment in a circuit mode to obtain a conducted interference equivalent circuit model containing differential mode interference and common mode interference in the electrical equipment.

Optionally, wherein the passive device comprises: capacitive and/or inductive devices; constructing a high-frequency equivalent circuit model of a passive device and a load, comprising the following steps of: for a capacitor device, measuring the impedance of the capacitor device in a required frequency band, and constructing an RLC equivalent circuit containing a set frequency parasitic parameter according to the amplitude-frequency characteristic and the phase-frequency characteristic of the impedance of the capacitor device, wherein the RLC equivalent circuit is used as a high-frequency equivalent circuit model of the capacitor device; and/or determining the resonance points and the number of the resonance points of the inductive device and/or the load in a given test frequency range for the inductive device and/or the load; establishing a set of RLC models at each resonance point for each resonance point; fitting the RLC models at all the resonance points to obtain an RLC composite model of the inductance device and/or the load, wherein the RLC composite model is used as a high-frequency equivalent circuit model of the inductance device and/or the load; and/or, constructing a high-frequency dynamic model of the active device, comprising: determining static characteristic parameters and dynamic characteristic parameters of the active device, and constructing a behavior model of the active device according to the static characteristic parameters and the dynamic characteristic parameters of the active device; verifying the behavior model of the active device, and determining the behavior model of the active device with the verification result conforming to the set result as a high-frequency dynamic model of the active device; and/or constructing a device parasitic parameter model of the passive device and the active device to the ground, wherein the device parasitic parameter model comprises the following steps: establishing a model of a device-to-ground high-frequency equivalent circuit model of a common-mode interference device capable of generating common-mode interference in the passive device and the active device by utilizing a mode of constructing the high-frequency equivalent circuit models of the passive device and the load, wherein the model is used as a device parasitic parameter model of the passive device and the active device to the ground; and/or, extracting a PCB parasitic parameter model, comprising: the method comprises the steps of extracting RLCG parameters of line layout including via holes from a PCB of the electrical equipment, and accessing a packaging model of the RLCG parameters of the line layout including the via holes in the PCB to a circuit model of the electrical equipment to serve as a PCB parasitic parameter model.

Optionally, the method further comprises: optimizing design parameters of the electrical equipment according to the position of an interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment so as to optimize the anti-interference performance of the electrical equipment in the design stage of the electrical equipment; wherein, the design parameter of electrical equipment includes: PCB layout of the electrical equipment and/or device type selection of the electrical equipment.

According to the scheme, the interference source and the interference propagation path of the electrical equipment are determined, the interference equivalent circuit model of the electrical equipment is constructed based on the interference source, the interference equivalent circuit model is tested according to a circuit connection mode to determine the frequency point with larger interference component and is positioned, so that the quantization and the positioning of the interference source are realized, the EMC optimization and rectification are traceable based on the quantization and the positioning of the interference source, the EMC risk positioning is enhanced, and the accurate positioning of the risk point during the design of the controller and the system is facilitated.

Furthermore, according to the scheme of the invention, by determining the conducted EMI interference source and the interference path of the variable frequency air conditioner, modeling is carried out on the interference source, time domain simulation analysis is carried out on an equivalent model of the variable frequency air conditioner in a circuit connection mode, Fast Fourier Transform (FFT) is carried out on a time domain waveform to a frequency domain waveform, and finally, a frequency point with a large interference component in a frequency spectrum is positioned; the conducted interference risk point can be determined in advance, and the PCB design and the device type selection are optimized.

Furthermore, according to the scheme of the invention, after the interference device and the interference propagation path are determined, the passive device in the device generating the interference source is modeled, then the active device, mainly a switch tube working under a high-speed switch, is extracted, the PCB and the equivalent circuit model of the device to the ground are extracted, and finally the equivalent circuit model of the conducted interference of the variable frequency air conditioner containing the differential mode interference and the common mode interference is established, so that the system interference source can be accurately identified, and the interference frequency point can be positioned.

Therefore, according to the scheme provided by the invention, the interference source and the interference propagation path of the electrical equipment are determined, the interference equivalent circuit model of the electrical equipment is constructed based on the interference source, the interference equivalent circuit model is tested according to a circuit connection mode to determine the frequency point with larger interference component and position the frequency point, so that the quantization and positioning of the interference source are realized, the problem that the risk point of the interference source is difficult to position during the design of the electrical equipment is solved, and the effect of conveniently positioning the risk point of the interference source during the design of the electrical equipment is achieved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic structural diagram of an interference processing apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a basic propagation path of conducted interference in an embodiment of the inverter air conditioner;

FIG. 3 is a schematic flow chart illustrating a positioning process of a conducted interference source according to an embodiment of the inverter air conditioner;

FIG. 4 is a schematic structural diagram of an embodiment of a capacitive high-frequency equivalent circuit model;

FIG. 5 is a schematic diagram of an embodiment of an equivalent circuit model of an inductor;

FIG. 6 is a schematic flow chart diagram of one embodiment of a switch tube characterization modeling step;

FIG. 7 is a schematic structural diagram of a system conducted interference lumped model layout of an embodiment of the inverter air conditioner;

fig. 8 is a flowchart illustrating an interference processing method according to an embodiment of the present invention;

FIG. 9 is a flowchart illustrating an embodiment of determining an interference source and an interference propagation path of an electrical device according to the method of the present invention;

fig. 10 is a schematic flow chart of an embodiment of constructing a conducted interference equivalent circuit model of an electrical device in the method of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

According to an embodiment of the present invention, there is provided an interference processing apparatus. Referring to fig. 1, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The interference processing device can be mainly applied to the interference processing scheme of electrical equipment, and the interference processing device of the electrical equipment such as frequency conversion equipment such as a frequency conversion air conditioner and the like can comprise: the device comprises a determining unit, a modeling unit and a verifying unit. Wherein:

in an alternative example, the determining unit may be configured to determine an interference source and an interference propagation path of the electrical device.

Optionally, the determining unit determines an interference source and an interference propagation path of the electrical device, and may include:

the determining unit may be further configured to obtain components, a PCB layout, and/or a load of the electrical equipment, and obtain an electrical conduction path of a circuit formed by the components, the PCB layout, and/or the load of the electrical equipment.

The determining unit may be further configured to determine an interference source of the electrical device according to components, a PCB layout, and/or a load of the electrical device. And the number of the first and second groups,

the determining unit may be further specifically configured to determine an interference propagation path of the interference source of the electrical equipment according to the interference source of the electrical equipment and an electrical conduction path of a circuit formed by components, a PCB layout, and/or a load of the electrical equipment.

For example: and determining system interference factors and a propagation path according to the circuit characteristics, components, PCB layout, load and the like of the variable frequency air conditioner. The parasitic capacitance and parasitic inductance existing in the device and layout in the controller generate dv or dt and di or dt under the high-frequency switch to generate interference components in the circuit, and finally the interference components are represented as disturbance voltage on each frequency point through FFT.

Therefore, by determining the interference source and the interference propagation path of the electrical equipment, a basis can be provided for modeling, and the accuracy of modeling is also favorably ensured.

In an alternative example, the modeling unit may be configured to construct a conducted interference equivalent circuit model of the electrical device based on the interference source of the electrical device.

Optionally, the constructing unit constructs the conducted interference equivalent circuit model of the electrical equipment based on the interference source of the electrical equipment, and may include:

the building unit can be specifically used for dividing the components in the electrical equipment according to the types of the components to obtain the passive components, the active components and/or the load.

For example: and performing characteristic modeling on the interference source according to the variable frequency air conditioner control system for accurately determining the interference source. The elements are classified into passive elements and active elements. For passive devices, in order to reduce interference characteristics, the devices cannot be regarded as simple and ideal linear devices, and a high-frequency equivalent circuit model of the devices needs to be constructed. The scheme of the invention provides the equivalent modeling rule of the passive device aiming at the variable frequency air conditioner controller component, and the modeling model ensures that the component has strong consistency. Since the elements included in the circuit model are all composed of R (i.e. resistance) or L (i.e. inductance) or C (i.e. capacitance) or D (i.e. diode) or IGBT (i.e. insulated gate bipolar transistor) or MOSFET (i.e. MOSFET), the former RLC passive elements occupy the main body, and the latter D or IGBT or MOSFET is an active switching device.

The building unit can be specifically used for building a high-frequency equivalent circuit model of the passive device and the load, such as building a high-frequency equivalent circuit of the passive device, the load such as a compressor and a fan; constructing a high-frequency dynamic model of an active device, such as constructing high-frequency dynamic models of active devices such as MOSFET (metal oxide semiconductor field effect transistor) or IGBT (insulated gate bipolar transistor); and constructing device parasitic parameter models of the passive device and the active device to the ground and extracting a PCB parasitic parameter model, such as constructing the device parasitic parameter model to the ground and extracting the PCB parasitic parameter model.

The passive device may include: capacitive type devices and/or inductive type devices.

More optionally, the building unit builds the high-frequency equivalent circuit model of the passive device and the load, and may include at least one of the following building processes.

The first construction process: the construction unit can be specifically used for measuring the impedance of the capacitor device in a required frequency band for the capacitor device, and an RLC equivalent circuit containing the set frequency parasitic parameters is built according to the amplitude-frequency characteristic and the phase-frequency characteristic of the impedance of the capacitor device and serves as a high-frequency equivalent circuit model of the capacitor device.

For example: a capacitance-type device: and measuring the impedance of the radio frequency unit in a required frequency band by using an impedance analyzer, and constructing an RLC equivalent circuit containing high-frequency parasitic parameters according to the amplitude-frequency characteristic and the phase-frequency characteristic of the impedance. The accuracy and the validity of the model can be verified through the Z parameter in the circuit. Within a given test frequency range (10khz to 30Mhz), a specific RLC circuit model is described by the number of resonance points of the impedance curve and the specific characteristics of the curve. Because the capacitance impedance characteristic curve is in capacitance characteristic before the resonance point, the output capacitance becomes inductive after passing through the resonance frequency point. Because the high-frequency characteristic is simpler, the high-frequency characteristic is expressed by a group of RLC circuit models which are connected in series:

an equivalent model of which can be seen in fig. 4. In turn, the remaining capacitive devices may be RLC equivalent in the same manner. According to circuit theory, where ESR (i.e., equivalent series resistance), ESL (equivalent series inductance), and C are determined by the resonance point of the device frequency response curve (amplitude). The frequency of the resonance point may satisfy the following expression according to circuit theory:

and a second construction process: the building unit can be specifically used for determining the resonance points and the number of the resonance points of the inductive device and/or the load in a given test frequency range for the inductive device and/or the load. For each resonance point, a set of RLC models is established at each resonance point. And fitting the RLC models at all the resonance points to obtain an RLC composite model of the inductive device and/or the load, wherein the RLC composite model is used as a high-frequency equivalent circuit model of the inductive device and/or the load.

The method can be used for fitting the resonance point and constructing the RLC model by impedance amplitude-frequency and phase-frequency curve characteristics no matter whether the device is a capacitor device or an inductor device.

For example: inductance type device: because the high-frequency distributed capacitance of the inductance device is more complex, the more RLC groups are used, the more accurate the high-frequency equivalent model is. An inductance model is used as an example for the following description.

In a given test frequency range (150 KHz-30 MHz), the inductor is formed by connecting two groups of RLC circuits in parallel in series. Before and after the first resonance point, the inductor is inductive firstly and then capacitive. Before and after the second resonance point, the inductor is capacitive first and then inductive. Wherein the first resonance point corresponds mainly to the first group R₁、L₁And C₁The second resonance point mainly corresponds to R₂、L₂And C₂Thus, the effect of the two sets of parameters in the composite is considered. Its equivalent model can be described by the following expression:

the inductance high frequency equivalent model is shown in fig. 5. Fig. 5 shows two sets of RLC fits, where the higher the number of sets of fits, the more accurate the high frequency equivalent model is in the case of more resonance points.

Loads of other devices such as a motor, a compressor and the like are inductive devices, the frequency response curve of the inductive devices at high frequency is complex, the inductive devices have multiple resonance points, and equivalent treatment can be carried out according to specific conditions.

Therefore, an integral conducted interference source modeling method and a positioning strategy are provided aiming at the types and the spatial layout of electrical equipment such as variable frequency air-conditioning devices; the method not only carries out qualitative analysis (such as potential jump points in a conduction path, positioning of an interference emission source and the like) on the conduction interference source of the variable frequency air conditioner, but also carries out accurate modeling by using a high-frequency equivalent circuit fitting mode on the basis, and finally transforms time domain signals into frequency domain signals through FFT to carry out interference frequency point analysis, thereby theoretically predicting and positioning the generation of the interference source.

More optionally, the constructing unit constructs a high-frequency dynamic model of the active device, which may include: the construction unit can be specifically used for determining the static characteristic parameters and the dynamic characteristic parameters of the active device and constructing a behavior model of the active device according to the static characteristic parameters and the dynamic characteristic parameters of the active device; and verifying the behavior model of the active device, and determining the behavior model of the active device with the verification result conforming to the set result as the high-frequency dynamic model of the active device.

For example: active devices relate to switching devices such as a MOSFET, an IGBT and an IPM module (namely, an intelligent power module), and the like, and the devices can generate serious interference signals when being switched on and off rapidly. The scheme of the invention relates to semiconductor switching devices, an IGBT behavior model is constructed according to static characteristic and dynamic characteristic parameters of the IGBT, and a relation curve of collector current Ic and gate electrode-emitter voltage Vge is obtained. For the dynamic characteristics, the IGBT is frequently turned on and off, the internal junction capacitance is repeatedly charged and discharged, and resonance is generated with the internal parasitic inductance, thereby causing electromagnetic interference, and thus the internal parasitic capacitance and inductance parameters need to be obtained. The model can be set and completed in Simplorer, and finally the accuracy of the model can be verified through the voltage current waveform and the actual measurement goodness of fit of power-on and power-off of a switch tube in a double-pulse test. The Simplorer is multi-domain electromechanical system design and simulation analysis software with strong functions, and can be used for modeling, designing, simulation analysis and optimization of electromechanical integrated systems such as electrical, electromagnetic, power electronics and control.

For example: taking the IGBT as an example, the relevant parameters in the IGBT equivalent model are finally determined by utilizing the characteristic modeling steps of the IGBT. The characteristic modeling step of the switching tube can comprise the following steps: and inquiring a data manual according to the selected power device, extracting relevant characteristic parameters through a Simplorer extraction tool, establishing an output characteristic Ic-Vce and transfer characteristic Ic-Vge relation curve, constructing an equivalent circuit model of internal parasitic parameters of the device, simulating, testing and comparing, and optimizing the parameters of the device until the parameters are substantially consistent with the actually measured parameters.

Therefore, the high-frequency dynamic model of the active device can be obtained accurately by constructing the high-frequency dynamic model of the active device according to the static characteristic parameters and the dynamic characteristic parameters of the active device.

More optionally, the constructing unit constructs a device parasitic parameter model of the passive device and the active device to ground, and may include: the building unit may be further configured to perform model building of a device-to-ground high-frequency equivalent circuit model on a common-mode interference device capable of generating common-mode interference in the passive device and the active device in a manner of building a high-frequency equivalent circuit model of the passive device and the load, and use the model building as a device parasitic parameter model of the passive device and the active device to the ground.

For example: and a device-to-ground distribution parameter and PCB parasitic parameter model. According to the method for establishing the equivalent model of the passive device, the high-frequency equivalent circuit model of the device to the ground is mainly established for devices which are easy to generate common-mode interference, such as a motor, a radiator, a machine shell and the like from three phases to the ground, and all the devices are equivalently replaced by RLC elements. And (3) testing the impedance characteristic curve of the device to the ground through an impedance analyzer, and fitting the amplitude curve and the phase curve to obtain a plurality of groups of RLC values (the values are consistent with a passive device modeling method).

Therefore, model establishment of a device-to-ground high-frequency equivalent circuit model is performed on the common-mode interference device capable of generating common-mode interference in the passive device and the active device, accuracy and reliability of modeling of the interference source can be improved, and accuracy of positioning and quantification of the interference source is further improved.

More optionally, the extracting, by the building unit, the PCB parasitic parameter model may include: the building unit may be further configured to extract an RLCG parameter of a line layout that may include a via hole from a PCB of the electrical device, and access a package model of the RLCG parameter of the line layout that may include the via hole in the PCB to a circuit model of the electrical device, as a parasitic parameter model of the PCB.

For example: the PCB parasitic parameters can be obtained by extracting RLCG parameters of the line layout including via holes from the PCB and inserting a packaging model of the RLCG parameters into a system circuit model, wherein the RLCG model of the PCB comprises a matrix-form packaging model of resistance, inductance, capacitance and conductance generated by the PCB layout when the frequency changes.

For example: the method is characterized in that the variable frequency air conditioner is taken as an object, a conducted interference propagation path and a structure of the variable frequency air conditioner are analyzed in detail, and the propagation path and the interference source of the interference of the whole system are analyzed and modeled based on the system level analysis of the variable frequency air conditioner. The method comprises the steps of modeling interference source devices generated by the variable frequency air conditioner by active devices and passive devices, considering the acquisition of parasitic parameters of the devices such as a PCB (printed Circuit Board) and the devices to the ground on the basis of independent analysis of the devices, and providing an acquisition method aiming at RLCG parameters on the PCB and carrying out modular overlapping on all interference sources. Therefore, on the aspect of system-level modeling and interference source positioning, the scheme of the invention has more involved interference components, more complex models and more sufficient consideration factors, and emphasizes the influence on the generation and propagation of the interference.

Therefore, different modeling modes are adopted for different interference source types of the conducted interference, and finally the circuit model considers ground and coupling to build an equivalent circuit model of the conducted interference of the variable frequency air conditioner, which contains differential mode interference and common mode interference, so that the system interference source can be accurately identified, and the interference frequency point can be accurately positioned.

The building unit may be further configured to connect a high-frequency equivalent circuit model, a high-frequency dynamic model, a device parasitic parameter model, and a PCB parasitic parameter model corresponding to an interference source of the electrical equipment in a circuit manner according to an interference propagation path of the electrical equipment, so as to obtain a conducted interference equivalent circuit model including differential mode interference and common mode interference in the electrical equipment.

For example: the method includes the steps of constructing a high-frequency equivalent model of the conducted interference lumped model of the variable-frequency air conditioner, completing the establishment of high-frequency equivalent circuits and high-frequency dynamic models of the passive devices and the active devices, and constructing the conducted interference lumped model of the variable-frequency air conditioner system according to the types of the components and the equivalent circuits of the individual components included in each unit according to the example shown in fig. 7.

The conducted interference lumped model layout shown in fig. 7 is an initiative for conducted EMI modeling analysis of the variable frequency air conditioner, each unit module in the lumped model is formed by passive modeling and active device modeling, for example, the filtering and rectifying unit includes an equivalent circuit model formed by a choke coil (a passive inductive device) and an X capacitor Y capacitor (a passive capacitive device), and the switching power supply includes an equivalent circuit model formed by a high frequency transformer (a passive inductive device) and a switching tube (an active device).

In the example shown in fig. 7, the neutral line N, the live line L, and the ground GND are considered, and the parasitic parameters of the unit modules to the ground are mainly considered. As shown in fig. 7, the parameters include a distribution parameter of the rectifying and smoothing unit to the ground, a distribution parameter of the radiator to the ground, a distribution parameter of the compressor to the third phase, and the like. Therefore, the considered model comprises a differential mode interference path (L-N) and a common mode interference path (L-GND, N-GND), and a large part of interference propagates through a loop formed by coupling with the ground, so that an equivalent circuit model formed by the distribution parameters of each unit module to the ground is very important. This has a significant effect on the authenticity and integrity of the interference band prediction.

Therefore, the system-level conducted interference model adopts the method of modularizing interference, finally, the module is connected with a combined lap joint circuit in a module connection mode according to a conduction path, and the whole conducted interference source model is connected with a 220V 50Hz alternating current power supply. And performing time domain simulation of the circuit and performing FFT (fast Fourier transform) for spectrum analysis. For the variable frequency air conditioner, the conducted interference test frequency band is 150 Khz-30 MHz, the frequency point location is carried out on the conducted interference spectrum to the interference source, and the interference frequency point and the interference intensity are determined.

Therefore, after the interference device and the interference propagation path are determined, firstly, a passive device in the interference source generating device is modeled, then, an equivalent circuit model of the active device, which is mainly a switch tube working under a high-speed switch, is extracted, then, a PCB (printed Circuit Board) and a device to the ground is extracted, and finally, a frequency conversion air conditioner conducted interference equivalent circuit model containing differential mode interference and common mode interference is built; the system interference source can be accurately identified, and the interference frequency point can be positioned.

In an optional example, the verification unit may be configured to verify the conducted interference equivalent circuit model of the electrical device in a time domain or a frequency domain based on the interference propagation path of the electrical device, so as to obtain a verification result. For example: and constructing a frequency conversion air conditioner conducted interference lumped high-frequency equivalent circuit model, and carrying out model verification in a time domain or a frequency domain.

In an optional example, the determining unit may be further configured to locate and/or quantify the interference source of the electrical device according to the verification result, so as to obtain a location of the interference source of the electrical device and/or an interference amount of the interference source of the electrical device. For example: and positioning the frequency spectrum of the interference source and determining the interference amplitude.

For example: determining an interference source and an interference propagation path aiming at the working principle, a controller and a structural layout of the variable frequency air conditioner, providing a characteristic modeling method for magnetic components and switching elements which mainly generate the interference source, and constructing a lumped interference equivalent circuit model of the variable frequency air conditioner system; the interference frequency band and the limit value are preliminarily determined according to the simulation result of the equivalent circuit model of the interference source, so that the interference source of the system is positioned and quantified.

For example: aiming at the conducted EMI prediction and analysis of electrical equipment such as a variable frequency air conditioner, a variable frequency household electrical appliance product, a vehicle-mounted air conditioner and the like, an interference source propagation model can be established from a circuit angle, and according to the problem points positioned by an equivalent circuit model, the EMC is optimized, rectified and actively traceable, the EMC risk positioning is strengthened, and the risk points are accurately positioned in the design process of a controller and a system.

Therefore, by determining an EMI (electro-magnetic interference) interference source and an interference path conducted by electrical equipment such as a variable frequency air conditioner, modeling the interference source, performing time domain simulation analysis on an equivalent model of the interference source in a circuit connection mode, performing Fast Fourier Transform (FFT) on a time domain waveform to a frequency domain waveform, and finally positioning a frequency point with a large interference component in a frequency spectrum; the problem that the conducted EMI is difficult to predict and position during device model selection and layout design in the design early period of the variable frequency air conditioner can be solved, so that the positioning and quantification processing of interference sources of electrical equipment such as the variable frequency air conditioner are convenient and accurate.

In an optional embodiment, after locating and/or quantifying the interference source of the electrical device, the method may further include: the process of optimizing the design parameters of the electrical equipment may specifically include: the determining unit may be further configured to optimize design parameters of the electrical equipment according to a position of an interference source of the electrical equipment and/or an interference amount of the interference source of the electrical equipment, so as to optimize anti-interference performance of the electrical equipment at a design stage of the electrical equipment.

The design parameters of the electrical equipment can include: PCB layout of the electrical equipment and/or device type selection of the electrical equipment.

For example: the interference source propagation model can be established from a circuit angle, and according to the problem points of the equivalent circuit model positioning, EMC optimization, rectification, active traceability, EMC risk positioning reinforcement and accurate risk point positioning during controller and system design are facilitated.

Therefore, by positioning and quantifying the interference source of the electrical equipment, the conducted interference risk point can be determined in advance to optimize the PCB design and device model selection, and if the device model selection and PCB layout of the variable frequency air conditioner hardware design can be optimized, the method is favorable for shortening the development period of novel products and providing reliable basis for the EMC stability of the variable frequency air conditioner.

Through a large number of tests, the technical scheme of the invention is adopted, the interference source and the interference propagation path of the electrical equipment are determined, the interference equivalent circuit model of the electrical equipment is constructed based on the interference source, the interference equivalent circuit model is tested according to a circuit connection mode to determine the frequency point with larger interference component and position the frequency point, so that the quantization and positioning of the interference source are realized, the EMC optimization and rectification are traceable based on the quantization and positioning of the interference source, the EMC risk positioning is strengthened, and the accurate positioning of the risk point during the design of the controller and the system is facilitated.

According to the embodiment of the invention, the electric equipment corresponding to the interference processing device is also provided. The electric device may include: the interference processing apparatus described above.

Considering that on the conduction path of the interference source, the EMI problem risk is strongly related to the device layout, the routing is dense and the path is complex, and meanwhile, there are multiple path coupling influences overlapping, so it is difficult to distinguish the main interference path. Therefore, the interference source of the system needs to be positioned and quantified, an interference source propagation model is established from the circuit angle, and problem points are positioned according to an equivalent circuit model, so that EMC optimization, rectification and active traceability are realized, EMC risk positioning is strengthened, and accurate positioning of risk points in the design of a controller and the system is facilitated.

In an optional embodiment, the scheme of the invention provides a scheme for predicting, modeling and positioning conducted EMI (electro magnetic interference) of a variable frequency air conditioner, mainly relates to the technical field of electronic circuits such as power electronics and electromagnetic compatibility, and realizes positioning and quantification of an interference source of a system by primarily determining an interference frequency band and a limit value according to an interference source equivalent circuit model simulation result, so that the selection of hardware design devices and the PCB layout of the variable frequency air conditioner can be optimized, the development cycle of a novel product can be shortened, and a reliable basis is provided for the EMC stability of the variable frequency air conditioner.

Specifically, an interference source propagation model can be established from a circuit angle, and according to the problem points of the equivalent circuit model, EMC optimization, rectification and active traceability are realized, EMC risk positioning is strengthened, and accurate positioning of the risk points during design of a controller and a system is facilitated.

The interference source modeling scheme provided by the scheme of the invention can be popularized to the prediction and analysis of conducted EMI (electro-magnetic interference) of other frequency conversion household appliances, vehicle-mounted air conditioners and the like.

In an optional example, the scheme of the invention determines an interference source and an interference propagation path according to the working principle, the controller and the structural layout of the variable frequency air conditioner, provides a characteristic modeling method for magnetic components and switching elements which mainly generate the interference source, and constructs a lumped interference equivalent circuit model and a block diagram of the variable frequency air conditioner system. The method for extracting the device-to-ground parasitic parameters and the RLCG (resistance inductance capacitance conductance) parameters in the PCB is provided, and the model accuracy is improved.

Specifically, according to the scheme of the invention, a frequency conversion air conditioner conducted EMI interference source and an interference path are determined, modeling is carried out on the interference source, time domain simulation analysis is carried out on an equivalent model of the frequency conversion air conditioner in a circuit connection mode, Fast Fourier Transform (FFT) is carried out on a time domain waveform to a frequency domain waveform, and finally a frequency point with a large interference component in a frequency spectrum is positioned; the problem that the conducted EMI is difficult to predict and position during device model selection and layout design in the design early period of the variable frequency air conditioner can be solved, so that the conducted interference risk point can be determined in advance through the scheme of the invention, and the PCB design and the device model selection are optimized.

Furthermore, according to the scheme of the invention, after the interference device and the interference propagation path are determined, the passive device in the interference source generating device is modeled, then the active device, mainly a switch tube working under a high-speed switch, is extracted, the PCB and the equivalent circuit model of the device to the ground are extracted, and finally the equivalent circuit model of the conducted interference of the variable frequency air conditioner containing the differential mode interference and the common mode interference is established. The problem that the common-mode interference path coupled to the ground is not fully considered because the module does not model the system as a whole can be solved, and the technical effects of accurately identifying the system interference source, positioning the interference frequency point and verifying the model by the rectification scheme are achieved.

For example: it is generally considered that the interference finally reflected between L and N lines is called differential mode interference, and the interference propagated between L line to earth and N line to earth becomes common mode interference, and the common mode interference is generally the main interference. The common mode interference propagation to the ground of the line is in the same direction and the differential mode interference is in the opposite direction. The differential mode interference is mainly generated by high-frequency parameters of an active device MOSFET, an IGBT, a passive device electrolytic capacitor and an inductor between the bus and the ground after rectification and is transmitted in a loop formed by the bus and the ground, and the differential mode interference is mainly reflected on a transmission path for realizing the function and mainly concentrated on a low-frequency section; therefore, accurate modeling of the device has great influence on accurate reduction of the differential mode interference source; the common mode interference is mainly generated by propagation paths of L to ground and N to ground, and because a plurality of positions of the PCB and the load are grounded, the common mode interference sources are more and complicated, so that the extraction of parasitic parameters of the PCB and the accurate reduction of the parasitic parameters of the device to the ground have great influence on the common mode interference sources.

In an alternative embodiment, a specific implementation process of the scheme of the present invention can be exemplarily described with reference to the examples shown in fig. 2 to fig. 7.

Fig. 2 is a schematic diagram of a conducted interference propagation path of a typical inverter air conditioner, in which a Linear Impedance Stabilization Network (LISN) is connected to shield power noise when the system is connected to an external power source. The impedance stabilization network (LISN) can simulate a laboratory test environment and avoid power grid harmonic interference. A power supply, a communication line and a condenser pipe are connected between the indoor unit and the outdoor unit, the indoor unit is provided with a fan, the outdoor unit is provided with a compressor, a fan and the like, an equivalent circuit model is complex, inductive loads are provided, and a strong interference source can be generated and coupled on a cable.

The controller includes a filter unit (such as an X capacitor and a choke coil), a switching power supply (including a switching tube and a high-frequency transformer), a PFC unit (a PFC inductor and a switching tube), an inverter unit (an IPM module), and a radiator; the interference source is coupled to the cable through an electric field and a magnetic field to form a loop with the ground, and the disturbance voltage is finally detected by the receiver. The internal parasitic capacitance of the switch tube, the distributed capacitance of the switch tube and the radiator, the PCB parasitic parameters, the joint of the cable and the electrical box and the like can generate strong interference.

Fig. 2 illustrates the transmission of EMI from the indoor unit to the outdoor unit of the inverter air conditioner, wherein the conducted interference generated by the indoor unit control part is coupled to the outdoor unit via the power line, the communication line and the pipeline, and the outdoor unit includes the filter, the switch power supply, the driver, and the like, and is finally coupled to the compressor and the blower. These units contain an equivalent circuit model of passive RLC (i.e., resistance, inductance, and capacitance) and noise sources of active switching transistors. The structure shown in fig. 2 can provide a basis for subsequent conducted interference modeling. The RLC in fig. 2 illustrates the equivalent circuit model where interference can occur, and the noise source generated by the switching tube, propagating along the path in fig. 2.

Fig. 3 is a schematic flow chart of a positioning process of a conducted interference source of the inverter air conditioner. As shown in fig. 3, the process for locating the conducted interference source of the inverter air conditioner may include:

and 11, determining system interference factors and a propagation path according to the circuit characteristics, components, PCB layout, loads and the like of the variable frequency air conditioner.

For example: circuit features, which may include: the internal circuit structure of the variable frequency air conditioner controller PCB and the controller peripheral circuit (including communication between an internal machine and an external machine, a load, a sensor, a WIFI module and the like) are mainly determined according to functions realized on the PCB, and the circuit structure comprises a filter rectifier, a switching power supply, a PFC unit, an inverter unit, a main control unit and the like. Wherein each cell contains both passive and active devices requiring equivalence.

For example: according to the circuit characteristics, components and parts, PCB layout, load and the like of the variable frequency air conditioner, system interference elements and propagation paths are determined, and the method can comprise the following steps: dv/dt and di/dt generated by high-speed switching device in controller are passed through junction capacitance in switching device and leakage inductance L generated by transformer and inductance_leakAnd distributed capacitance C of device and PCB_sAre produced together. According to the formula, in the circuit system, the interference current is as follows:

the interference voltage is:

which generates a disturbing current and a disturbing voltage appearing in the conduction path, which generates a conduction disturbance. If the interference occurs between L, N, the interference is differential mode interference, and if the interference is L to earth or N to earth, the interference is common mode interference, and in the inverter air conditioning control system, the differential mode interference and the common mode interference exist at the same time.

The parasitic capacitance and parasitic inductance existing in the device and layout in the controller generate dv or dt and di or dt under the high-frequency switch to generate interference components in the circuit, and finally the interference components are represented as disturbance voltage on each frequency point through FFT.

And step 12, constructing passive devices and load high-frequency equivalent circuits such as compressors and fans.

Specifically, for accurately determining the interference source, the interference source characteristic modeling is carried out according to the variable frequency air conditioner control system. The elements are classified into passive elements and active elements.

For passive devices, in order to reduce interference characteristics, the devices cannot be regarded as simple and ideal linear devices, and a high-frequency equivalent circuit model of the devices needs to be constructed. The scheme of the invention provides the equivalent modeling rule of the passive device aiming at the variable frequency air conditioner controller component, and the modeling model ensures that the component has strong consistency.

Since the elements included in the circuit model are all composed of R (i.e. resistance) or L (i.e. inductance) or C (i.e. capacitance) or D (i.e. diode) or IGBT (i.e. insulated gate bipolar transistor) or MOSFET (i.e. MOSFET), the former RLC passive elements occupy the main body, and the latter D or IGBT or MOSFET is an active switching device.

For passive devices, capacitive and inductive devices are involved. The passive device model is equivalent to a circuit model built by three components of a resistor R, an inductor L and a capacitor C, and a component complex impedance form with frequency-variable characteristics is used.

Optionally, the capacitive type device: and measuring the impedance of the radio frequency unit in a required frequency band by using an impedance analyzer, and constructing an RLC equivalent circuit containing high-frequency parasitic parameters according to the amplitude-frequency characteristic and the phase-frequency characteristic of the impedance. The accuracy and the validity of the model can be verified through the Z parameter in the circuit. Within a given test frequency range (10khz to 30Mhz), a specific RLC circuit model is described by the number of resonance points of the impedance curve and the specific characteristics of the curve. Because the capacitance impedance characteristic curve is in capacitance characteristic before the resonance point, the output capacitance becomes inductive after passing through the resonance frequency point. Because the high-frequency characteristic is simpler, the high-frequency characteristic is expressed by a group of RLC circuit models which are connected in series:

an equivalent model of which can be seen in fig. 4.

In turn, the remaining capacitive devices may be RLC equivalent in the same manner. According to circuit theory, where ESR (i.e., equivalent series resistance), ESL (equivalent series inductance), and C are determined by the resonance point of the device frequency response curve (amplitude). The frequency of the resonance point may satisfy the following expression according to circuit theory:

the ESR, which is equivalent to R in the expression of Zc, does not have frequency conversion characteristics, and L and C affect impedance. When there is a frequency point f and satisfies

Where ω is 2 pi f. The impedance is R, and this point is the resonant frequency point.

Optionally, the inductive type device: because the high-frequency distributed capacitance of the inductance device is more complex, the more RLC groups are used, the more accurate the high-frequency equivalent model is. An inductance model is used as an example for the following description.

Multiple actual measurement and experience show that the frequency response curve of loads such as a compressor, a fan and the like is complex and generally reaches more than 7 and 8 resonance points, so that the difficulty in constructing RLC models of all the resonance points in a test frequency band is high, the actual measurement has uncertainty, and therefore a good effect can be obtained by generally selecting 4-5 resonance points for fitting, and the fitting method refers to impedance frequency response curve fitting of an inductance device.

And step 13, constructing high-frequency dynamic models of active devices such as MOSFET or IGBT.

Active devices relate to switching devices such as a MOSFET, an IGBT and an IPM module (namely, an intelligent power module), and the like, and the devices can generate serious interference signals when being switched on and off rapidly. The scheme of the invention relates to semiconductor switching devices, an IGBT behavior model is constructed according to static characteristic and dynamic characteristic parameters of the IGBT, and a relation curve of collector current Ic and gate electrode-emitter voltage Vge is obtained. For the dynamic characteristics, the IGBT is frequently turned on and off, the internal junction capacitance is repeatedly charged and discharged, and resonance is generated with the internal parasitic inductance, thereby causing electromagnetic interference, and thus the internal parasitic capacitance and inductance parameters need to be obtained. The model can be set and completed in Simplorer, and finally the accuracy of the model can be verified through the voltage current waveform and the actual measurement goodness of fit of power-on and power-off of a switch tube in a double-pulse test. The Simplorer is multi-domain electromechanical system design and simulation analysis software with strong functions, and can be used for modeling, designing, simulation analysis and optimization of electromechanical integrated systems such as electrical, electromagnetic, power electronics and control.

Taking an IGBT as an example, the characterization modeling step may be as shown in fig. 6, and finally determine relevant parameters in the IGBT equivalent model. As shown in fig. 6, the switching tube characterization modeling step may include:

and step 21, inquiring a data manual according to the model selection power device.

And 22, extracting the related characteristic parameters by using a Simplorer extraction tool.

And step 23, establishing an output characteristic Ic-Vce and a transfer characteristic Ic-Vge relation curve.

And 24, constructing an equivalent circuit model of the parasitic parameters in the device.

And step 25, simulating and testing comparison, and optimizing device parameters until the parameters are substantially consistent with the actual measurement.

And 14, constructing a parasitic parameter model of the device to the ground and extracting a PCB parasitic parameter model.

And a device-to-ground distribution parameter and PCB parasitic parameter model. According to the method for establishing the equivalent model of the passive device, the high-frequency equivalent circuit model of the device to the ground is mainly established for devices which are easy to generate common-mode interference, such as a motor, a radiator, a machine shell and the like from three phases to the ground, and all the devices are equivalently replaced by RLC elements. And (3) testing the impedance characteristic curve of the device to the ground through an impedance analyzer, and fitting the amplitude curve and the phase curve to obtain a plurality of groups of RLC values (the values are consistent with a passive device modeling method).

The PCB parasitic parameters can be obtained by extracting RLCG parameters of the line layout including via holes from the PCB and inserting a packaging model of the RLCG parameters into a system circuit model, wherein the RLCG model of the PCB comprises a matrix-form packaging model of resistance, inductance, capacitance and conductance generated by the PCB layout when the frequency changes.

And step 15, building a frequency conversion air conditioner conducted interference lumped high-frequency equivalent circuit model, and carrying out model verification in a time domain or a frequency domain.

Fig. 7 is a schematic structural diagram of a layout of a conducted interference lumped model of the inverter air conditioning system. As shown in fig. 7, in the lumped model of conducted interference of the variable frequency air conditioning system, the input end of the filtering and rectifying unit is connected to the live line L and the zero line N of the power supply, and the output end of the filtering and rectifying unit is connected to the compressor after passing through the PFC unit, the PCB module, the inverter unit, the cable and the pipeline in sequence. And the ground end of the filtering and rectifying unit is connected with the back ground GND through the parameter setting of the ground. The PFC unit is grounded GND through a switching power supply. The inversion unit is grounded GND after being set by the distribution parameters of the radiator. The cable and the pipeline are grounded GND after being set with ground distribution parameters. The compressor is set to the back ground GND through three phase-to-ground distribution parameters.

The frequency conversion air conditioner conducted interference lumped high-frequency equivalent model is built, the establishment of the high-frequency equivalent circuit and the high-frequency dynamic model of the passive device and the active device is completed, and the frequency conversion air conditioner system conducted interference lumped model can be built according to the type of the components and the independent equivalent circuit of the components contained in each unit according to the example shown in fig. 7.

The system level conducted interference model adopts the method of modularizing interference, finally, the module is connected with a combined lap joint circuit in a module connection mode according to a conduction path, and the whole conducted interference source model is connected with a 220V 50Hz alternating current power supply. And performing time domain simulation of the circuit and performing FFT (fast Fourier transform) for spectrum analysis. For the variable frequency air conditioner, the conducted interference test frequency band is 150 Khz-30 MHz, the frequency point location is carried out on the conducted interference spectrum to the interference source, and the interference frequency point and the interference intensity are determined.

And step 16, positioning the frequency point of the interference source on the frequency spectrum and determining the interference amplitude.

In the embodiment, the inverter air conditioner is taken as an object, the conducted interference propagation path and structure of the inverter air conditioner are analyzed in detail, and the propagation path and the interference source of the interference of the whole system are analyzed and modeled based on the system level analysis of the inverter air conditioner.

Specifically, different modeling ways are adopted for different interference source types of the conducted interference, and finally the circuit model considers ground and coupling. The device for generating the interference source of the variable frequency air conditioner is divided into an active device and a passive device for modeling, the acquisition of the parasitic parameters of the device to the PCB, the device to the ground and the like is considered on the basis of the independent analysis of the device, in addition, an acquisition method is provided for the RLCG parameters on the PCB, and all the interference sources are subjected to a modular overlapping mode. Therefore, on the aspect of system-level modeling and interference source positioning, the scheme of the invention has more involved interference components, more complex models and more sufficient consideration factors, and emphasizes the influence on the generation and propagation of the interference.

Therefore, the scheme of the invention provides an integral conducted interference source modeling method and a positioning strategy aiming at the type and the spatial layout of the variable frequency air conditioner; the method not only carries out qualitative analysis (such as potential jump points in a conduction path, positioning of an interference emission source and the like) on the conduction interference source of the variable frequency air conditioner, but also carries out accurate modeling by using a high-frequency equivalent circuit fitting mode on the basis, and finally transforms time domain signals into frequency domain signals through FFT to carry out interference frequency point analysis, thereby theoretically predicting and positioning the generation of the interference source.

Since the processes and functions implemented by the electrical apparatus of this embodiment substantially correspond to the embodiments, principles, and examples of the apparatus shown in fig. 1, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment.

After a large number of tests, by adopting the technical scheme of the invention, the EMI interference source and the interference path conducted by the variable frequency air conditioner are determined, the interference source is modeled, the equivalent model of the interference source is subjected to time domain simulation analysis in a circuit connection mode, then Fast Fourier Transform (FFT) is carried out on the time domain waveform to a frequency domain waveform, and finally the frequency point with larger interference component in the frequency spectrum is positioned; the conducted interference risk point can be determined in advance, and the PCB design and the device type selection are optimized.

According to an embodiment of the present invention, there is also provided an interference processing method for an electrical device, which corresponds to the electrical device, as shown in fig. 8, which is a schematic flow chart of an embodiment of the method of the present invention. The interference processing method of the electrical equipment can be mainly applied to the interference processing scheme of the electrical equipment, and the interference processing method of the electrical equipment, such as frequency conversion equipment such as a frequency conversion air conditioner and the like, can comprise the following steps: step S110 to step S140.

Step S110, determining an interference source and an interference propagation path of the electrical device.

Optionally, with reference to the schematic flow chart of an embodiment of determining the interference source and the interference propagation path of the electrical device in the method of the present invention shown in fig. 9, a specific process of determining the interference source and the interference propagation path of the electrical device in step S110 is further described, which may include: step S210 to step S230.

Step S210, obtaining components, PCB layout and/or loads of the electrical equipment, and obtaining an electrical conduction path of a circuit formed by the components, the PCB layout and/or the loads of the electrical equipment.

Step S220, determining an interference source of the electrical equipment according to components, PCB layout and/or load of the electrical equipment. And the number of the first and second groups,

step S230, determining an interference propagation path of the interference source of the electrical equipment according to the interference source of the electrical equipment and an electrical conduction path of a circuit formed by components, PCB layout and/or loads of the electrical equipment.

And step S120, constructing a conducted interference equivalent circuit model of the electrical equipment based on the interference source of the electrical equipment.

Optionally, the specific process of constructing the equivalent circuit model of the conducted interference of the electrical equipment in step S120 may be further described with reference to a schematic flow chart of an embodiment of constructing the equivalent circuit model of the conducted interference of the electrical equipment in the method of the present invention shown in fig. 10, where the specific process may include: step S310 to step S330.

And S310, dividing the components in the electrical equipment according to the types of the components to obtain passive components, active components and/or loads.

Step S320, constructing a high-frequency equivalent circuit model of the passive device and the load, such as constructing the passive device and the high-frequency equivalent circuit of the load such as a compressor, a fan and the like; constructing a high-frequency dynamic model of an active device, such as constructing high-frequency dynamic models of active devices such as MOSFET (metal oxide semiconductor field effect transistor) or IGBT (insulated gate bipolar transistor); and constructing device parasitic parameter models of the passive device and the active device to the ground and extracting a PCB parasitic parameter model, such as constructing the device parasitic parameter model to the ground and extracting the PCB parasitic parameter model.

More optionally, the constructing the high-frequency equivalent circuit model of the passive device and the load in step S330 may include at least one of the following construction processes:

the first construction process: for a capacitor device, measuring the impedance of the capacitor device in a required frequency band, and constructing an RLC equivalent circuit containing a set frequency parasitic parameter according to the amplitude-frequency characteristic and the phase-frequency characteristic of the impedance of the capacitor device, wherein the RLC equivalent circuit is used as a high-frequency equivalent circuit model of the capacitor device.

an equivalent model of which can be seen in fig. 4. In turn, the remaining capacitive devices may be RLC equivalent in the same manner. According to circuit theory, where ESR (i.e., equivalent series resistance), ESL (equivalent series inductance), and C are determined by the resonance point of the device frequency response curve (amplitude).The frequency of the resonance point may satisfy the following expression according to circuit theory:

and a second construction process: for the inductive devices and/or the loads, determining resonance points and the number of the resonance points of the inductive devices and/or the loads in a given test frequency range; establishing a set of RLC models at each resonance point for each resonance point; and fitting the RLC models at all the resonance points to obtain an RLC composite model of the inductive device and/or the load, wherein the RLC composite model is used as a high-frequency equivalent circuit model of the inductive device and/or the load.

More optionally, the step S330 of constructing a high-frequency dynamic model of the active device may include: determining static characteristic parameters and dynamic characteristic parameters of the active device, and constructing a behavior model of the active device according to the static characteristic parameters and the dynamic characteristic parameters of the active device; and verifying the behavior model of the active device, and determining the behavior model of the active device with the verification result conforming to the set result as the high-frequency dynamic model of the active device.

More optionally, constructing a device parasitic parameter model of the passive device and the active device to the ground in step S330 may include: by means of constructing high-frequency equivalent circuit models of the passive device and the load, model building of a device-to-ground high-frequency equivalent circuit model is conducted on a common-mode interference device capable of generating common-mode interference in the passive device and the active device, and the common-mode interference device is used as a device parasitic parameter model of the passive device and the active device to the ground.

More optionally, the extracting the PCB parasitic parameter model in step S330 may include: the method comprises the steps of extracting RLCG parameters of line layout including via holes from a PCB of the electrical equipment, and accessing a packaging model of the RLCG parameters of the line layout including the via holes in the PCB to a circuit model of the electrical equipment to serve as a PCB parasitic parameter model.

Step S330, according to the interference propagation path of the electrical equipment, connecting the high-frequency equivalent circuit model, the high-frequency dynamic model, the device parasitic parameter model and the PCB parasitic parameter model corresponding to the interference source of the electrical equipment according to a circuit mode to obtain a conducted interference equivalent circuit model containing differential mode interference and common mode interference in the electrical equipment.

Step S130, based on the interference propagation path of the electrical equipment, verifying the conducted interference equivalent circuit model of the electrical equipment in a time domain or a frequency domain to obtain a verification result. For example: and constructing a frequency conversion air conditioner conducted interference lumped high-frequency equivalent circuit model, and carrying out model verification in a time domain or a frequency domain.

And step S140, positioning and/or quantifying the interference source of the electrical equipment according to the verification result to obtain the position of the interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment. For example: and positioning the frequency spectrum of the interference source and determining the interference amplitude.

In an optional embodiment, after locating and/or quantifying the interference source of the electrical device, the method may further include: the process of optimizing the design parameters of the electrical equipment may specifically include: and optimizing the design parameters of the electrical equipment according to the position of the interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment so as to optimize the anti-interference performance of the electrical equipment in the design stage of the electrical equipment.

Since the processes and functions implemented by the method of the present embodiment substantially correspond to the embodiments, principles, and examples of the electrical apparatus, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of the present embodiment.

After a large number of tests verify that by adopting the technical scheme of the embodiment, after the interference device and the interference propagation path are determined, firstly, a passive device in the device generating the interference source is modeled, then, an equivalent circuit model of the active device, mainly a switch tube working under a high-speed switch, PCB and the device to the ground is extracted, and finally, a frequency conversion air conditioner conducted interference equivalent circuit model containing differential mode interference and common mode interference is built, so that the system interference source can be accurately identified, and the interference frequency point can be positioned.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. An interference processing apparatus, comprising: the device comprises a determining unit, a modeling unit and a verifying unit; wherein the content of the first and second substances,

the device comprises a determining unit, a processing unit and a processing unit, wherein the determining unit is used for determining an interference source and an interference propagation path of electrical equipment;

the modeling unit is used for constructing a conducted interference equivalent circuit model of the electrical equipment based on an interference source of the electrical equipment;

the verification unit is used for verifying the conducted interference equivalent circuit model of the electrical equipment in a time domain or a frequency domain based on the interference propagation path of the electrical equipment to obtain a verification result;

and the determining unit is also used for positioning and/or quantizing the interference source of the electrical equipment according to the verification result to obtain the position of the interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment.

2. The interference processing apparatus according to claim 1, wherein the determining unit determines the interference source and the interference propagation path of the electrical device, and includes:

acquiring components, PCB layout and/or loads of the electrical equipment, and acquiring an electric conduction path of a circuit formed by the components, the PCB layout and/or the loads of the electrical equipment;

determining an interference source of the electrical equipment according to components, PCB layout and/or load of the electrical equipment; and the number of the first and second groups,

and determining an interference propagation path of the interference source of the electrical equipment according to the interference source of the electrical equipment and an electric conduction path of a circuit formed by components, PCB layout and/or loads of the electrical equipment.

3. The interference processing apparatus according to claim 1, wherein the constructing unit constructs a conducted interference equivalent circuit model of the electrical device, including:

dividing components in the electrical equipment according to the types of the components to obtain passive components, active components and/or loads;

constructing a high-frequency equivalent circuit model of a passive device and a load; constructing a high-frequency dynamic model of the active device; constructing parasitic parameter models of the passive device and the active device to the ground, and extracting a PCB parasitic parameter model;

and according to the interference propagation path of the electrical equipment, connecting a high-frequency equivalent circuit model, a high-frequency dynamic model, a device parasitic parameter model and a PCB parasitic parameter model corresponding to an interference source of the electrical equipment in a circuit mode to obtain a conducted interference equivalent circuit model containing differential mode interference and common mode interference in the electrical equipment.

4. The interference processing apparatus of claim 3, wherein,

a passive device, comprising: capacitive and/or inductive devices;

the building unit builds a high-frequency equivalent circuit model of the passive device and the load, and comprises the following steps:

for a capacitor device, measuring the impedance of the capacitor device in a required frequency band, and constructing an RLC equivalent circuit containing a set frequency parasitic parameter according to the amplitude-frequency characteristic and the phase-frequency characteristic of the impedance of the capacitor device, wherein the RLC equivalent circuit is used as a high-frequency equivalent circuit model of the capacitor device; and/or the presence of a gas in the gas,

for the inductive devices and/or the loads, determining resonance points and the number of the resonance points of the inductive devices and/or the loads in a given test frequency range; establishing a set of RLC models at each resonance point for each resonance point; fitting the RLC models at all the resonance points to obtain an RLC composite model of the inductance device and/or the load, wherein the RLC composite model is used as a high-frequency equivalent circuit model of the inductance device and/or the load;

and/or the presence of a gas in the gas,

the construction unit constructs a high-frequency dynamic model of the active device, and comprises the following steps:

determining static characteristic parameters and dynamic characteristic parameters of the active device, and constructing a behavior model of the active device according to the static characteristic parameters and the dynamic characteristic parameters of the active device; verifying the behavior model of the active device, and determining the behavior model of the active device with the verification result conforming to the set result as a high-frequency dynamic model of the active device;

and/or the presence of a gas in the gas,

the constructing unit constructs a parasitic parameter model of the passive device and the active device to the ground, and comprises the following steps:

establishing a model of a device-to-ground high-frequency equivalent circuit model of a common-mode interference device capable of generating common-mode interference in the passive device and the active device by utilizing a mode of constructing the high-frequency equivalent circuit models of the passive device and the load, wherein the model is used as a device parasitic parameter model of the passive device and the active device to the ground;

and/or the presence of a gas in the gas,

the construction unit extracts a PCB parasitic parameter model, and comprises the following steps:

the method comprises the steps of extracting RLCG parameters of line layout including via holes from a PCB of the electrical equipment, and accessing a packaging model of the RLCG parameters of the line layout including the via holes in the PCB to a circuit model of the electrical equipment to serve as a PCB parasitic parameter model.

5. The interference processing apparatus according to any one of claims 1 to 4, further comprising:

the determining unit is further used for optimizing design parameters of the electrical equipment according to the position of the interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment so as to optimize the anti-interference performance of the electrical equipment in the design stage of the electrical equipment;

wherein, the design parameter of electrical equipment includes: PCB layout of the electrical equipment and/or device type selection of the electrical equipment.

6. An electrical device, comprising: the interference processing apparatus of any one of claims 1 to 5.

7. An interference processing method for an electrical device, comprising:

determining an interference source and an interference propagation path of the electrical equipment;

constructing a conducted interference equivalent circuit model of the electrical equipment based on an interference source of the electrical equipment;

verifying a conducted interference equivalent circuit model of the electrical equipment in a time domain or a frequency domain based on an interference propagation path of the electrical equipment to obtain a verification result;

and according to the verification result, positioning and/or quantifying the interference source of the electrical equipment to obtain the position of the interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment.

8. The interference processing method of claim 7, wherein determining the interference source and the interference propagation path of the electrical device comprises:

9. The interference processing method according to claim 7, wherein constructing a conducted interference equivalent circuit model of an electrical device comprises:

10. The interference processing method according to claim 9, wherein,

a passive device, comprising: capacitive and/or inductive devices;

constructing a high-frequency equivalent circuit model of a passive device and a load, comprising the following steps of:

and/or the presence of a gas in the gas,

constructing a high-frequency dynamic model of an active device, comprising:

and/or the presence of a gas in the gas,

constructing a parasitic parameter model of the passive device and the active device to the ground, which comprises the following steps:

and/or the presence of a gas in the gas,

extracting a PCB parasitic parameter model, comprising:

11. The interference processing method according to any one of claims 7 to 10, further comprising:

optimizing design parameters of the electrical equipment according to the position of an interference source of the electrical equipment and/or the interference amount of the interference source of the electrical equipment so as to optimize the anti-interference performance of the electrical equipment in the design stage of the electrical equipment;