An automated EMC filter design method

Abstract

The present invention provides an automated EMC filter design method, comprising the following steps: building a power device database to store the switch characteristic parameters of the power device; building a system model library to store the system model to be analyzed of the EMC filter; building a filter component model library to store the filter parameters of the EMC filter; calculating the spectrum results of the analog filter based on the switch characteristic parameters, the system model to be analyzed, and the filter parameters; comparing the spectrum results of the analog filter with an EMC standard library, and determining the parameter design of the EMC filter when the spectrum results meet the design standards of the EMC standard library. After adopting the above technical solution, it is helpful to avoid over-design of the filter structure, and at the same time, it can greatly accelerate the efficiency of research and development and save manpower and testing resources.

Description

Technical Field

[0001] The invention relates to the field of vehicle control, and in particular to an automatic EMC filter design method. Background Art

[0002] At present, as a key component of new energy vehicles, motor controllers generally use power semiconductor devices (such as IGBT, etc.) for pulse width modulation (PWM) control to adjust the three-phase voltage output by the motor controller. The rapid on-off of power semiconductor devices produces a high current change rate di / dt and voltage change rate du / dt, which will produce undesirable electromagnetic noise, which will not only affect the radio receiving equipment inside and outside the vehicle, but also affect other high and low voltage components on the vehicle through the high-voltage power line. In addition, this electromagnetic noise generated by the motor drive system will not only make the equipment itself fail to meet the EMC standard limit requirements, but also cause the entire vehicle to fail to meet the EMC standard limit requirements.

[0003] In order to suppress the electromagnetic interference caused by the switching of the power semiconductor devices of the motor controller, it is an effective method to install an EMC filter on the high-voltage DC power line of the motor controller. At present, the commonly used EMC filter design methods mainly include: engineering test method, circuit model method, etc. However, although the engineering test method is the most widely used method in the current electromagnetic compatibility processing, due to its lack of filter design theory, it requires repeated rounds of tests to determine the filter topology and parameters, and the rectification cycle is long and the cost is high.

[0004] Therefore, a new EMC filter design method is needed that is more accurate than previous trial and error, experience and other methods, and can avoid the waste of time and money caused by over-design and extensive testing. Summary of the invention

[0005] In order to overcome the above technical defects, the purpose of the present invention is to provide an automated EMC filter design method, which helps to avoid over-design of the filter structure, and at the same time can greatly accelerate the efficiency of research and development and save manpower and testing resources.

[0006] The present invention discloses an automated EMC filter design method, comprising the following steps:

[0007] Build a power device database to store the switching characteristic parameters of power devices;

[0008] Build a system model library to store the system models to be analyzed of EMC filters;

[0009] Build a filter component model library to store filter parameters of EMC filters;

[0010] Calculate the spectrum results of the simulated system EMC based on the switch characteristic parameters, the system model to be analyzed, and the filter parameters;

[0011] The spectrum result of the simulated filter in the system is compared with an EMC standard library. When the spectrum result meets the design standard of the EMC standard library, the parameter design of the EMC filter is determined.

[0012] Preferably, the step of building a filter component model library to store filter parameters of the EMC filter includes:

[0013] Collect data of a filter topology library and an LC model library to build a filter component model library;

[0014] The spectrum result of the simulated filter in the system is compared with an EMC standard library. When the spectrum result meets the design standard of the EMC standard library, the steps of determining the parameter design of the EMC filter include:

[0015] When the spectrum result does not meet the design standard of the EMC standard library, the filter parameters are corrected, and the spectrum result of the corrected simulator is compared with the EMC standard library until the spectrum result of the corrected simulator meets the design standard of the EMC standard library.

[0016] Preferably, the automated EMC filter design method further comprises the following steps:

[0017] Extract LC parameters of analog filters that meet design criteria of EMC standard library;

[0018] Design an EMC filter based on LC parameters to form a candidate filter, and compare the LC selection configuration and structural dimensions of the candidate filter with the design model;

[0019] When the LC selection configuration and structural dimensions of the undetermined filter meet the configuration parameters of the design model, the EMC filter is designed;

[0020] When the LC selection configuration and the structural size of the undetermined filter do not meet the configuration parameters of the design model, the LC selection configuration and the structural size are corrected until the configuration parameters of the design model are met.

[0021] Preferably, the design model includes:

[0022] Magnetic material database, capacitor product database, structural dimension database.

[0023] Preferably, the system model library includes a time domain model, a frequency domain model, a time domain and frequency domain hybrid model, at least one system topology and a modulation method;

[0024] The power device database includes power module dynamic parameters, behavioral models, physical models and measured models;

[0025] The filter component model library includes at least one filter topology and an LC nonlinear model, wherein the LC nonlinear model includes a physical model and a measured model.

[0026] Preferably, the step of calculating the spectrum result of the analog filter based on the switch characteristic parameters, the system model to be analyzed, and the filter parameters comprises:

[0027] The spectrum results of the EMC simulation system are calculated by combining the operating conditions to be analyzed, the switch characteristic parameters, the system model to be analyzed, and the filter parameters.

[0028] Compared with the prior art, the above technical solution has the following beneficial effects:

[0029] 1. Reasonably and quickly adjust the filter structure and component parameters to make the filter more compatible with the motor controller requirements;

[0030] 2. Simplifies the filter design process to prevent the reduction of product power density and competitiveness due to over-design. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figure is a flow chart of an automated EMC filter design method according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0032] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0033] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0034] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0035] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0036] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0038] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.

[0039] See also Figure 1 , in order to comply with the schematic diagram of the automated EMC filter design process in a preferred embodiment of the present invention, EMC filters are usually an important component of product optimization solutions. The correct EMC filter topology can save time for product certification and optimization of electromagnetic compatibility performance. In addition, the optimized EMC filter can reduce the cost and volume of the product. The LC components in the EMC filter usually need to handle and withstand considerable reactive current and reactive voltage, that is, they have a sufficiently large reactive power capacity. At the same time, considering that the EMC filter operates in an impedance mismatch state in most cases, their mismatch characteristics need to be considered when selecting the EMC filter to ensure that they are within the range of 0.5 to 30MHz to obtain sufficiently good filtering characteristics, and when the EMC filter suppresses EMI caused by transient noise or high-frequency noise, the LC components used have strict requirements on the control of parasitic parameters.

[0040] In this embodiment, when it is necessary to determine the parameters of the EMC filter, the following steps need to be performed:

[0041] S100: Building a power device database to store switching characteristic parameters of the power devices;

[0042] Power semiconductor devices, also known as power electronic devices, are simply semiconductor devices that process power in EMC filters and have the ability to handle high voltages and high currents. Their switching characteristic parameters refer to the switching loss, switching speed, and oscillation of the EMC filter when it is working. The establishment of this power device database means that the performance of the power devices used will be considered when designing EMC filters.

[0043] S200: Building a system model library to store the system model to be analyzed of the EMC filter;

[0044] For different manufacturers, the system models used are not reusable or regular, that is, when designing each EMC filter, the direction and dimension considered by each technician may be different. In the present invention, the system model database may preferably include a time domain model or a frequency domain model, so as to form the system model to be analyzed when designing the EMC filter, which is used for the system architecture of the EMC filter used in the subsequent steps of analyzing.

[0045] S300: Building a filter component model library to store filter parameters of the EMC filter;

[0046] The filter component model library can store the component types, connection methods, matching methods and circuit parameters of various filter components, so as to help EMC filter designers to know the available design schemes and the advantages and disadvantages of each design scheme as much as possible, so as to store the filter parameters of the EMC filter.

[0047] S400: Calculate the spectrum result of the EMC simulation system based on the switch characteristic parameters, the system model to be analyzed, and the filter parameters;

[0048] S500: Compare the spectrum result of the simulated filter in the system with an EMC standard library, and when the spectrum result meets the design standard of the EMC standard library, determine the parameter design of the EMC filter.

[0049] According to the supporting parameters given under each database, a spectrum result of a simulated filter can be formed. By comparing the result with the EMC standard library, it can be understood that if the requirements are met, the parameter design of the EMC filter can be determined.

[0050] It is understandable that, with the above configuration, firstly, since there are no design standards or design manuals in the industry for all designers of EMC filters, most designers adopt the trial and error method when designing. In the present invention, directional content is given, that is, from the three dimensions of power device database, system model library, and filter component model library, as the main factors to be considered when designing EMC filters. Secondly, even if it has directionality, it is still very difficult for those skilled in the art to determine which factors are used as the main weights in a certain direction. Therefore, when designing, designers can add a large number of known, previous designs to the power device database, system model library, and filter component model library, and combine past design experience to reduce the trial and error cost as much as possible and improve design efficiency.

[0051] In a preferred embodiment, the step S300 of building a filter component model library to store filter parameters of the EMC filter includes:

[0052] S310: Collecting data of a filter topology library and an LC model library to build a filter component model library;

[0053] The filter topology library stores filter topologies for class D power amplifiers: (1) FB-C, ferrite beads and capacitors; (2) LC, inductors and capacitors; and (3) "no filter". These are common filter matching design models. It is also understandable that the LC model library stores LC model matching designs for designers' reference.

[0054] Furthermore, the spectrum result of the simulated filter in the system is compared with an EMC standard library. When the spectrum result meets the design standard of the EMC standard library, the step S500 of determining the parameter design of the EMC filter includes:

[0055] S510: When the spectrum result does not meet the design standard of the EMC standard library, modify the filter parameters, and compare the spectrum result of the modified simulator with the EMC standard library until the spectrum result of the modified simulator meets the design standard of the EMC standard library.

[0056] Through the establishment of the feedback mechanism in step S510, since the motor controllers in different projects, different models and application scenarios have different requirements, the filter parameters can be corrected in the design method of the EMC filter until the spectrum results of the corrected simulator meet the design standards of the EMC filter in a certain motor controller, thereby meeting the basic requirements for the use of the EMC filter.

[0057] In a preferred or optional embodiment, the EMC filter design method further comprises the following steps:

[0058] S600: extracting LC parameters of analog filters that meet design standards of the EMC standard library;

[0059] The analog filter is designed to meet the basic requirements of EMC filter. In order to further optimize it, the LC parameters of the analog filter can be extracted and analyzed.

[0060] S700: Design an EMC filter based on LC parameters to form a candidate filter, and compare the LC selection configuration and structural dimensions of the candidate filter with the design model;

[0061] The undetermined filter formed after the EMC filter is designed based on LC parameters will be tested and considered from other dimensions, that is, the LC selection configuration and structural dimensions of the undetermined filter will be compared with a design model. The actual model is for the actual application scenario, for the EMC filter, such as magnetic materials, capacitor signals, and structural dimensions, whether they meet the magnetic material database, capacitor product database, and structural dimension database. It is understandable that for the structural dimension, even if the electrical requirements are met, the EMC filter that cannot meet the physical conditions is still not applicable.

[0062] S800: When the LC selection configuration and structural dimensions of the filter to be determined meet the configuration parameters of the design model, the EMC filter is designed;

[0063] S800': When the LC selection configuration and structural dimensions of the undetermined filter do not meet the configuration parameters of the design model, correct the LC selection configuration and structural dimensions until they meet the configuration parameters of the design model

[0064] Likewise, a feedback mechanism will be introduced to correct and adjust the filter's LC selection configuration.

[0065] In a preferred embodiment, each database is limited to storing the following models or parameters, which saves the amount of data in the database and provides designers with more targeted and directional information that should be considered when designing EMC filters:

[0066] The system model library includes time domain models, frequency domain models, time domain and frequency domain hybrid models, at least one system topology and modulation method; the power device database includes power module dynamic parameters, behavioral models, physical models and measured models; the filter component model library includes at least one filter topology and LC nonlinear model, wherein the LC nonlinear model includes a physical model and a measured model.

[0067] In another preferred or optional embodiment, the step S400 of calculating the spectrum result of the analog filter based on the switch characteristic parameters, the system model to be analyzed, and the filter parameters includes:

[0068] S410: Calculate the spectrum result of the EMC of the simulation system by combining the working condition to be analyzed and the switch characteristic parameters, the system model to be analyzed, and the filter parameters.

[0069] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An automated EMC filter design method, characterized in that: The following steps are involved: Build a power device database to store the switching characteristic parameters of power devices; Build a system model library to store the system models to be analyzed of EMC filters; Build a filter component model library to store filter parameters of EMC filters; Calculate the EMC spectrum result of the simulation system based on the switch characteristic parameters, the system model to be analyzed, and the filter parameters; The spectrum result of the simulated filter in the system is compared with an EMC standard library. When the spectrum result meets the design standard of the EMC standard library, the parameter design of the EMC filter is determined, wherein The steps of building a filter component model library to store filter parameters of EMC filters include: Collect data of a filter topology library and an LC model library to build a filter component model library; Comparing the spectrum result of the analog filter in the system with an EMC standard library, when the spectrum result meets the design standard of the EMC standard library, the step of determining the parameter design of the EMC filter includes: When the spectrum result does not meet the design standard of the EMC standard library, modify the filter parameters, and compare the spectrum result of the modified simulator with the EMC standard library until the spectrum result of the modified simulator meets the design standard of the EMC standard library; The automated EMC filter design method also includes the following steps: Extract LC parameters of analog filters that meet design criteria of EMC standard library; Designing an EMC filter based on the LC parameters to form a pending filter, and comparing the LC selection configuration and structural dimensions of the pending filter with the design model; When the LC selection configuration and structural dimensions of the undetermined filter meet the configuration parameters of the design model, the EMC filter is designed; When the LC selection configuration and structural dimensions of the undetermined filter do not meet the configuration parameters of the design model, the LC selection configuration and structural dimensions are corrected until the configuration parameters of the design model are met; The system model library includes a time domain model, a frequency domain model, a time domain and frequency domain hybrid model, at least one system topology and a modulation method; The power device database includes power module dynamic parameters, behavior models, physical models and measured models; The filter component model library includes at least one filter topology and an LC nonlinear model, wherein the LC nonlinear model includes a physical model and a measured model.

2. The automated EMC filter design method according to claim 1, characterized in that: The design model includes: Magnetic material database, capacitor product database, structural dimension database.

3. The automated EMC filter design method according to claim 1, characterized in that: The step of calculating the spectrum result of the analog filter based on the switch characteristic parameters, the system model to be analyzed, and the filter parameters includes: The spectrum results of the EMC simulation system are calculated by combining the operating conditions to be analyzed, the switch characteristic parameters, the system model to be analyzed, and the filter parameters.

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