Overload fault protection method and system for frequency converter and medium

Abstract

The invention discloses an overload fault protection method and system for a frequency converter and a medium, and relates to the technical field of overload protection. The method comprises the following steps: positioning a connection structure of the frequency converter, setting a first TVS circuit at the input end of the frequency converter, and setting a second TVS circuit at the output end of the frequency converter; acquiring real-time operation parameters of the frequency converter; constructing an adjacent element tolerance parameter library of the frequency converter; and determining an overload fault type and an overload fault rate, and adaptively triggering the logic controller to execute the grading protection of the first TVS circuit and the second TVS circuit according to the overload fault type and the overload fault rate. The technical problem that in the prior art, a frequency converter lacks differential protection for overload faults under different operation conditions, and consequently protection is insufficient is solved, self-adaptive recognition of overload fault types and rates is achieved on the basis of real-time operation parameters and an adjacent element tolerance parameter library, and the reliability of the frequency converter is improved. And the grading protection is triggered to improve the operation safety of the frequency converter.

Description

Technical Field

[0001] This invention relates to the field of overload protection technology, and specifically to overload fault protection methods, systems and media for frequency converters. Background Technology

[0002] Inverters, as core equipment for motor drive and energy efficiency control, are widely used in industrial production, power systems, and automation control. However, inverters are susceptible to factors such as current surges, voltage distortion, rapid temperature rise, and harmonic interference during operation, which can lead to overload faults. When an overload fault occurs, if it is not identified and effective protective measures are not taken in time, it will not only damage the inverter itself but may also have a cascading effect on its connected adjacent components, causing system shutdown or even equipment failure. Existing overload protection technologies are mostly based on single threshold triggering, lacking differentiated consideration of different operating conditions and the tolerance characteristics of different adjacent components, often resulting in insufficient or excessive protection, failing to balance timeliness and accuracy of protection. Summary of the Invention

[0003] This application provides a method, system, and medium for overload fault protection of frequency converters, which solves the technical problem in the prior art that frequency converters lack differentiated protection for overload faults under different operating conditions, resulting in insufficient protection.

[0004] A first aspect of this application provides an overload fault protection method for a frequency converter, the method comprising: The connection structure of the frequency converter is defined, and a first TVS circuit is set at the input end of the frequency converter and a second TVS circuit is set at the output end of the frequency converter according to the connection structure. The first TVS circuit and the second TVS circuit are controlled by a logic controller. Real-time operating parameters of the frequency converter are collected, including current amplitude, voltage distortion rate, temperature rise rate and harmonic component ratio. A tolerance parameter library for adjacent components of the frequency converter is constructed, including the adjacent component types of the frequency converter and the corresponding overload tolerance parameters. Based on the real-time operating parameters and the adjacent component tolerance parameter library, the overload fault type and overload fault rate are determined, and the logic controller is adaptively triggered to execute the graded protection of the first TVS circuit and the second TVS circuit according to the overload fault type and overload fault rate.

[0005] A second aspect of this application provides an overload fault protection system for a frequency converter, the system comprising: Circuit Setting Module: Locates the connection structure of the frequency converter, sets a first TVS circuit at the input end of the frequency converter according to the connection structure, and sets a second TVS circuit at the output end of the frequency converter. The first TVS circuit and the second TVS circuit are controlled by a logic controller. Parameter Acquisition Module: Acquires the real-time operating parameters of the frequency converter, including current amplitude, voltage distortion rate, temperature rise rate, and harmonic component ratio. Parameter Library Construction Module: Constructs a library of adjacent element tolerance parameters for the frequency converter, including the adjacent element types and corresponding overload tolerance parameters. Protection Trigger Module: Determines the overload fault type and overload fault rate based on the real-time operating parameters and the adjacent element tolerance parameter library, and adaptively triggers the logic controller to execute graded protection of the first TVS circuit and the second TVS circuit according to the overload fault type and overload fault rate.

[0006] A third aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the overload fault protection method for frequency converters provided in this application.

[0007] One or more technical solutions provided in this application have at least the following technical effects or advantages: First, the connection structure of the frequency converter is located. Based on this structure, a first TVS circuit is installed at the input terminal of the frequency converter, and a second TVS circuit is installed at the output terminal. The first and second TVS circuits are controlled by a logic controller. Next, real-time operating parameters of the frequency converter are collected, including current amplitude, voltage distortion rate, temperature rise rate, and harmonic component ratio. Then, a tolerance parameter library for adjacent components of the frequency converter is constructed, including the types of adjacent components and their corresponding overload tolerance parameters. Finally, based on the real-time operating parameters and the adjacent component tolerance parameter library, the overload fault type and overload fault rate are determined. The logic controller is then adaptively triggered to execute graded protection of the first and second TVS circuits according to the overload fault type and rate. This solves the technical problem in existing technologies where frequency converters lack differentiated protection for overload faults under different operating conditions, leading to insufficient protection. It achieves the technical effect of adaptively identifying overload fault types and rates based on real-time operating parameters and the adjacent component tolerance parameter library, and triggering graded protection to improve the operational safety of the frequency converter. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic flowchart of an overload fault protection method for a frequency converter provided in an embodiment of this application. Figure 2 This is a schematic diagram of the overload fault protection system for a frequency converter provided in an embodiment of this application.

[0010] Figure labeling: Circuit setting module 11, parameter acquisition module 12, parameter library construction module 13, protection trigger module 14. Detailed Implementation

[0011] This application solves the technical problem in the prior art that frequency converters lack differentiated protection against overload faults under different operating conditions by providing an overload fault protection method, system and medium for frequency converters.

[0012] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0013] It should be noted that the terms "comprising" and "having" are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to these processes, methods, products, or devices.

[0014] Example 1, as Figure 1 As shown, this application provides an overload fault protection method for frequency converters, wherein the method includes: The connection structure of the frequency converter is defined, and a first TVS circuit is set at the input end of the frequency converter and a second TVS circuit is set at the output end of the frequency converter according to the connection structure. The first TVS circuit and the second TVS circuit are controlled by a logic controller.

[0015] In this embodiment, the connection structure of the frequency converter is positioned, including an input terminal adjacent element, the frequency converter body, and an output terminal adjacent element. According to the connection structure, a first transient voltage suppression (TVS) circuit is provided at the input terminal of the frequency converter, and a second transient voltage suppression circuit is provided at the output terminal of the frequency converter. The input terminal of the first TVS circuit is connected to the output terminal of the input terminal adjacent element, and the output terminal of the first TVS circuit is connected to the input terminal of the frequency converter, used for transient suppression protection of the input current and voltage entering the frequency converter. The input terminal of the second TVS circuit is connected to the output terminal of the frequency converter, and the output terminal of the second TVS circuit is connected to the input terminal of the output terminal adjacent element, used for transient suppression protection of the voltage and current signals output by the frequency converter.

[0016] Both the first TVS circuit and the second TVS circuit are electrically connected to the logic controller. The logic controller can control the on / off state and operating mode of the first TVS circuit and the second TVS circuit based on real-time operating parameters and overload fault judgment results, thereby adaptively triggering graded protection under different operating conditions to achieve differentiated overload protection for input and output signals.

[0017] Furthermore, according to the connection structure, a first TVS circuit is provided at the input terminal of the frequency converter, and a second TVS circuit is provided at the output terminal of the frequency converter. The method includes: Based on the connection structure, the input terminal adjacent element and the output terminal adjacent element of the frequency converter are determined; the output terminal of the input terminal adjacent element is connected to the input terminal of the first TVS circuit, the output terminal of the first TVS circuit is connected to the input terminal of the frequency converter, the output terminal of the frequency converter is connected to the input terminal of the second TVS circuit, and the output terminal of the second TVS circuit is connected to the input terminal of the output terminal adjacent element.

[0018] Preferably, the input and output adjacent elements of the frequency converter are determined, wherein the input adjacent element is a power supply-side device that provides power to the frequency converter, and the output adjacent element is an execution-side device connected to the load of the frequency converter. The output of the input adjacent element is electrically connected to the input of a first TVS circuit, and then the output of the first TVS circuit is electrically connected to the input of the frequency converter. This allows the first TVS circuit to suppress and clamp abnormal signals under the control of the logic controller when surge voltage or overload current occurs at the input, thereby preventing them from directly affecting the frequency converter itself. The output of the frequency converter is electrically connected to the input of a second TVS circuit, and then the output of the second TVS circuit is electrically connected to the input of the output adjacent element. This allows the second TVS circuit to act promptly under the trigger of the logic controller when overload impact or transient interference occurs at the output when the frequency converter outputs power, ensuring the operational stability of the output adjacent element. Through the configuration of TVS circuits at the input and output ends, a bidirectional protection mechanism for the frequency converter and its adjacent elements is achieved.

[0019] Furthermore, if the input terminal adjacent element or the output terminal adjacent element includes multiple adjacent elements, the input terminal adjacent element or the output terminal adjacent element is connected to the first TVS circuit and the second TVS circuit respectively according to the series connection relationship or parallel connection relationship of the multiple adjacent elements.

[0020] When there is more than one input or output adjacent element, but it is composed of multiple adjacent elements, the corresponding circuit configuration needs to be made according to the connection method between these adjacent elements. Specifically, if multiple input or output adjacent elements are connected in series, the output terminal of the last adjacent element in the series connection is electrically connected to the input terminal of the first or second TVS circuit, so that the TVS circuit can suppress and protect the voltage and current transmitted to the inverter or load side at the end of the series link; if multiple input or output adjacent elements are connected in parallel, the common connection point of all parallel branches is electrically connected to the input terminal of the first or second TVS circuit, so that the TVS circuit can suppress and protect the overall electrical signal of the parallel circuit.

[0021] The real-time operating parameters of the frequency converter are collected, including current amplitude, voltage distortion rate, temperature rise rate, and harmonic component ratio.

[0022] In this embodiment, a current sensor collects current signals from the input or output of the frequency converter and extracts the current amplitude to determine the current load level. A voltage detection module samples the input and output voltage waveforms of the frequency converter and calculates the voltage distortion rate using fast Fourier transform or other spectral analysis methods to characterize the degree of voltage waveform distortion and harmonic interference level. A temperature sensor collects temperature data from the frequency converter's power module or heat dissipation element and calculates the temperature rise rate based on the time series to reflect the heat accumulation caused by overload conditions. Simultaneously, a harmonic analysis module decomposes the collected current and voltage signals, extracts harmonic components, and calculates the proportion of harmonic components to evaluate the power quality characteristics under overload operating conditions.

[0023] Construct a library of adjacent element tolerance parameters for the frequency converter, wherein the adjacent element tolerance parameters include the type of adjacent element of the frequency converter and the corresponding overload tolerance parameters.

[0024] Specifically, for different adjacent components connected to the inverter's input and output terminals, a database of adjacent component types is established, which includes power modules, filter capacitors, power switching devices, cables, load motors, and other key peripheral components. Subsequently, for each type of adjacent component, overload tolerance parameters are collected and defined, including allowable current thresholds, allowable voltage thresholds, allowable temperature rise thresholds, allowable harmonic distortion rate thresholds, and corresponding response time thresholds. These tolerance parameters are obtained through a comprehensive analysis of historical operating data, experimental test data, and device specification information, and are written into the database in a structured data format. Finally, based on the correspondence between the unique ID of the adjacent component, the adjacent component type, and the overload tolerance parameters, a callable adjacent component tolerance parameter library is formed. This allows the logic controller to quickly retrieve the tolerance capabilities of the corresponding adjacent components based on the inverter's real-time operating parameters during operation, providing a reliable basis for the dynamic determination of overload fault types and fault rates.

[0025] Furthermore, the method for constructing a library of adjacent element tolerance parameters for the frequency converter includes: Collect fault condition datasets corresponding to historical overload fault events of the frequency converter. The fault condition datasets include a first-stage fault condition dataset and a second-stage fault condition dataset. The first-stage fault condition dataset consists of the instantaneous operating condition dataset of the frequency converter under the overload fault event and the operating condition impact dataset of adjacent components. The second-stage fault condition dataset consists of the recovery operating condition dataset of the frequency converter after the execution of fault protection under the overload fault event and the operating condition impact dataset of adjacent components. Analyze the influence range of adjacent components according to the fault condition datasets corresponding to the historical overload fault events. Identify the range of adjacent components with an influence greater than a preset value as a constraint condition, and identify adjacent components that constitute the adjacent component tolerance parameter library.

[0026] First, operational data of the frequency converter under historical overload fault events is collected to form a fault condition dataset. This dataset includes operating condition information from two stages: the first stage dataset contains the frequency converter operating parameters (including current amplitude, voltage distortion rate, temperature rise rate, and harmonic component ratio) at the instant the overload fault occurs, as well as the transient impact data on adjacent input and output components caused by the overload shock; the second stage dataset contains data on the degree of impact on the frequency converter operating parameters and adjacent components during the recovery process after the implementation of fault protection measures (such as limiting, reducing load, or shutting down). Then, correlation analysis is performed on the first and second stage fault condition datasets. Based on the changes in electrical parameters, temperature rise rate, and harmonic distortion of adjacent components, the influence degree of each adjacent component in the overload event is calculated. The influence degree is then compared with a preset threshold to identify the range of adjacent components with an influence degree greater than the threshold, and this range is used as a constraint condition for constructing the tolerance parameter library. Finally, the identified adjacent components are classified according to their type (such as power modules, power devices, filter units, output motors, etc.) to establish corresponding overload tolerance parameter entries. The parameters are then calibrated by combining experimental verification data and device specification data, thereby forming a complete adjacent component tolerance parameter library for the logic controller to call during operation.

[0027] Furthermore, the overload tolerance parameters include allowable current threshold, allowable voltage threshold, allowable temperature rise threshold, and response time threshold; after encoding the adjacent elements, they are stored in the database according to the defined parameter library data structure in sequence according to the adjacent element code ID, adjacent element type, and overload tolerance parameters to obtain the adjacent element tolerance parameter library.

[0028] Overload tolerance parameters characterize the safe withstand capability of different adjacent components under overload conditions. Specifically, these include allowable current threshold, allowable voltage threshold, allowable temperature rise threshold, and response time threshold. The allowable current threshold limits the maximum current amplitude that an adjacent component can withstand under overload conditions; the allowable voltage threshold limits the upper limit of voltage and distortion amplitude that an adjacent component can withstand; the allowable temperature rise threshold limits the temperature rise of an adjacent component per unit time to prevent performance degradation due to heat accumulation; and the response time threshold limits the duration that an adjacent component can sustain under overload conditions, thereby ensuring its reliability under extreme conditions.

[0029] Preferably, each adjacent element is uniquely coded, and a parameter database data structure is established. This data structure includes the adjacent element's code ID, the adjacent element type, and the corresponding overload tolerance parameter entry. The database management module stores and indexes this data to construct the adjacent element tolerance parameter database.

[0030] Based on the real-time operating parameters and the adjacent element tolerance parameter library, the overload fault type and overload fault rate are determined, and the adaptive trigger logic controller is executed to perform graded protection of the first TVS circuit and the second TVS circuit according to the overload fault type and overload fault rate.

[0031] In this embodiment, the logic controller compares and calculates real-time operating parameters with the tolerance parameter library of adjacent components to determine the overload fault type and overload fault rate. Specifically, the logic controller calls the corresponding allowable current threshold, allowable voltage threshold, allowable temperature rise threshold, and response time threshold from the adjacent component tolerance parameter library and compares them with the real-time acquired current amplitude, voltage distortion rate, temperature rise rate, and harmonic component ratio. When any real-time operating parameter exceeds the corresponding tolerance threshold, it is determined as an overload fault. The overload fault type is identified according to the type of parameter exceeding the limit, and the overload fault rate is determined by calculating the over-limit amplitude and duration.

[0032] The logic controller performs adaptive triggering of graded protection based on the judgment result: if the overload fault is of a minor level, it controls the first TVS circuit and the second TVS circuit to perform amplitude limiting protection to suppress abnormal current or voltage fluctuations; if the overload fault is of a moderate level, in addition to controlling the TVS circuit to disconnect from the frequency converter, it also controls the frequency converter to perform load reduction operation; if the overload fault is of a severe level, it controls the TVS circuit to disconnect and further triggers the frequency converter to perform emergency shutdown to prevent the fault from spreading and damage to adjacent components.

[0033] Furthermore, the method for determining the overload fault type and overload fault rate based on the real-time operating parameters and the adjacent element tolerance parameter library includes: The process involves identifying the input and output adjacent components of the frequency converter; retrieving the overload tolerance parameters of the input and output adjacent components from the adjacent component tolerance parameter library; calculating the input overload index based on the real-time operating parameters and the overload tolerance parameters of the input adjacent components; calculating the output overload index based on the real-time operating parameters and the overload tolerance parameters of the output adjacent components; and identifying the overload fault type and overload fault rate by analyzing the input and output overload indices.

[0034] Preferably, the connection structure of the frequency converter is identified, and the adjacent elements at the input end and the adjacent elements at the output end are determined respectively; the overload tolerance parameters of the adjacent elements at the input end and the overload tolerance parameters of the adjacent elements at the output end are obtained by calling the adjacent element tolerance parameter library. The overload tolerance parameters include allowable current threshold, allowable voltage threshold, allowable temperature rise threshold and response time threshold, etc.

[0035] The logic controller compares the real-time operating parameters with the tolerance parameters of the adjacent components at the input end, and generates an input end overload index by calculating the deviation of the over-limit amplitude from the threshold. This index can reflect the risk level of the input end under overload conditions. Similarly, the real-time operating parameters are compared with the tolerance parameters of the adjacent components at the output end to calculate the output end overload index.

[0036] Specifically, the real-time current amplitude is compared with the allowable current threshold of adjacent components to calculate the current over-limit ratio; the real-time voltage distortion rate is compared with the allowable voltage threshold to calculate the voltage over-limit ratio; the real-time temperature rise rate is compared with the allowable temperature rise threshold to calculate the temperature rise over-limit ratio; and the real-time harmonic component ratio is compared with the allowable harmonic threshold to calculate the harmonic over-limit ratio. Based on preset weighting coefficients, the above over-limit ratios are weighted and synthesized to obtain the input overload index and the output overload index, which are used to characterize the overload degree of adjacent components at the input and output ends.

[0037] By comparing the magnitudes of the input and output overload indicators and combining them with the duration of the overload condition, the type of overload fault can be identified. At the same time, the overload fault rate can be calculated based on the ratio of the magnitude of the overload indicator exceeding the threshold to the duration.

[0038] Furthermore, the method of adaptively triggering the logic controller to perform graded protection of the first TVS circuit and the second TVS circuit according to the overload fault type and overload fault rate includes: Protection level analysis is performed according to the overload fault type and overload fault rate to obtain the protection level; a first-level protection level range, a second-level protection level range, and a third-level protection level range are set, and the protection level is analyzed based on the first-level protection level range, the second-level protection level range, and the third-level protection level range; wherein, if the protection level is first-level protection, the first TVS circuit and the second TVS circuit are controlled to perform amplitude limiting protection; if the protection level is second-level protection, the first TVS circuit and the second TVS circuit are controlled to disconnect from the inverter, and the inverter is controlled to reduce the load based on the inverter controller; if the protection level is third-level protection, the first TVS circuit and the second TVS circuit are controlled to disconnect from the inverter, and the inverter is controlled to stop based on the inverter controller.

[0039] Preferably, the logic controller is adaptively triggered according to the overload fault type and overload fault rate to execute graded protection for the first TVS circuit and the second TVS circuit. Specifically, the logic controller performs a comprehensive analysis based on the overload fault type and overload fault rate to generate a corresponding protection level determination result; the system presets a first-level protection level range, a second-level protection level range, and a third-level protection level range, which correspond to mild, moderate, and severe overload conditions, respectively; the logic controller maps the actually calculated overload index to the corresponding protection range, thereby determining the final protection level.

[0040] The protection level is determined by comprehensively analyzing the overload fault type and overload fault rate. Specifically, the overload fault type is used to determine the manifestation of the fault, such as current overload, voltage distortion overload, temperature rise overload, or harmonic overload; the overload fault rate is used to characterize the fault development trend, reflecting the growth rate and duration of the real-time operating parameters exceeding the limit. As shown in Table 1, when the overload fault type is a mild current or voltage overload and the fault rate is in the low-speed growth range, the logic controller triggers level one protection, controlling the first TVS circuit and the second TVS circuit to perform amplitude limiting protection; when the overload fault type is a composite overload or temperature rise overload and the fault rate is in the medium-speed growth range, the logic controller triggers level two protection, controlling the first TVS circuit and the second TVS circuit to disconnect from the inverter, and performing load reduction operation on the inverter through the inverter controller; when the overload fault type is a severe overload or multi-parameter coupled overload and the fault rate is in the high-speed growth range, the logic controller triggers level three protection, controlling the first TVS circuit and the second TVS circuit to disconnect from the inverter, and further performing emergency shutdown through the inverter controller.

[0041] Table 1 Overload fault types Monitoring parameters Rate / Amplitude Threshold Conditions Determine the protection level Control measures Current-type overload Current amplitude Exceeding the allowable current threshold by 5% and with a rise rate <2% / s Level 1 protection TVS Limiting Protection Current-type overload Current amplitude Exceeding the allowable current threshold by 10% and with a rise rate of 2%~5% / s Level 2 protection TVS disconnected + inverter load reduced Current-type overload Current amplitude Exceeding the allowable current threshold by 20% and with a rise rate ≥ 5% / s Level 3 protection TVS disconnected + inverter stopped Voltage distortion type overload Voltage distortion rate (THD) Exceeding the allowable threshold by 5% and with a rate <1% / s Level 1 protection TVS Limiting Protection Voltage distortion type overload Voltage distortion rate (THD) Exceeding the allowable threshold by 10% and with a rate of 1%~3% / s Level 2 protection TVS disconnected + inverter load reduced Voltage distortion type overload Voltage distortion rate (THD) Exceeding the allowable threshold by 15% and with a rate ≥ 3% / s Level 3 protection TVS disconnected + inverter stopped Temperature rise type overload Temperature rise rate Exceeding the allowable temperature rise threshold by 10% and at a rate <1℃ / min Level 1 protection TVS Limiting Protection Temperature rise type overload Temperature rise rate Exceeding the allowable temperature rise threshold by 20% and at a rate of 1~3℃ / min Level 2 protection TVS disconnected + inverter load reduced Temperature rise type overload Temperature rise rate Exceeding the allowable temperature rise threshold by 30% and at a rate ≥ 3℃ / min Level 3 protection TVS disconnected + inverter stopped Harmonic overload Harmonic component ratio Exceeding the allowable percentage by 5% and with a rate <1% / s Level 1 protection TVS Limiting Protection Harmonic overload Harmonic component ratio Exceeding the allowable percentage by 10% and with a rate of 1%~3% / s Level 2 protection TVS disconnected + inverter load reduced Harmonic overload Harmonic component ratio Exceeding the allowable percentage by 15% and with a rate ≥ 3% / s Level 3 protection TVS disconnected + inverter stopped If the determination result is Level 1 protection, the logic controller controls the first and second TVS circuits to maintain electrical connection with the inverter and suppresses current and voltage signals according to the limiting protection strategy template to mitigate transient impacts. If the determination result is Level 2 protection, the logic controller controls the first and second TVS circuits to disconnect from the inverter and issues a load reduction command through the inverter controller to allow the inverter to continue operating under a lower load to prevent the fault from escalating. If the determination result is Level 3 protection, the logic controller controls the first and second TVS circuits to disconnect from the inverter and further issues a shutdown command through the inverter controller to ensure timely shutdown under severe overload conditions, thereby preventing damage to the inverter body and adjacent components.

[0042] Furthermore, if the protection level is Level 1 protection, the method for controlling the first TVS circuit and the second TVS circuit to perform amplitude limiting protection includes: Define a limiting strategy template, which includes identifying the mapping relationship between overload fault types and limiting protection parameters. The limiting protection parameters include current limiting protection parameters, voltage limiting protection parameters, and current and voltage limiting protection parameters. If the protection level is Level 1 protection, identify the matching limiting protection parameters for the overload fault type according to the limiting strategy template. Control the first TVS circuit and the second TVS circuit to perform limiting protection according to the matching limiting protection parameters.

[0043] If the protection level is determined to be Level 1 protection, the logic controller will perform amplitude limiting protection on the first and second TVS circuits to prevent transient overloads from impacting the inverter and its adjacent components. Specifically, the system predefines an amplitude limiting strategy template, which establishes a mapping relationship between overload fault types and amplitude limiting protection parameters. These parameters include at least current amplitude limiting protection parameters, voltage amplitude limiting protection parameters, and combined current and voltage amplitude limiting protection parameters.

[0044] When the protection level is determined to be Level 1 protection, the logic controller retrieves the corresponding limiting protection parameter item from the limiting strategy template based on the overload fault type identified in real time. The logic controller then controls the first and second TVS circuits according to the matched limiting protection parameter item, putting them into a limiting operating state. By dynamically clamping the current or voltage amplitude at the input and output terminals, the logic controller keeps the current or voltage within the corresponding threshold range, thereby effectively suppressing transient overload impacts while ensuring the inverter continues to operate.

[0045] In summary, the embodiments of this application have at least the following technical effects: First, the connection structure of the frequency converter is located. Based on this structure, a first TVS circuit is installed at the input terminal of the frequency converter, and a second TVS circuit is installed at the output terminal. The first and second TVS circuits are controlled by a logic controller. Next, real-time operating parameters of the frequency converter are collected, including current amplitude, voltage distortion rate, temperature rise rate, and harmonic component ratio. Then, a tolerance parameter library for adjacent components of the frequency converter is constructed, including the types of adjacent components and their corresponding overload tolerance parameters. Finally, based on the real-time operating parameters and the adjacent component tolerance parameter library, the overload fault type and overload fault rate are determined. The logic controller is then adaptively triggered to execute graded protection of the first and second TVS circuits according to the overload fault type and rate. This solves the technical problem in existing technologies where frequency converters lack differentiated protection for overload faults under different operating conditions, leading to insufficient protection. It achieves the technical effect of adaptively identifying overload fault types and rates based on real-time operating parameters and the adjacent component tolerance parameter library, and triggering graded protection to improve the operational safety of the frequency converter.

[0046] Example 2, based on the same inventive concept as the overload fault protection method for frequency converters in the foregoing examples, such as... Figure 2 As shown, this application provides an overload fault protection system for a frequency converter, wherein the system includes: Circuit setting module 11: Locates the connection structure of the frequency converter, sets a first TVS circuit at the input end of the frequency converter according to the connection structure, and sets a second TVS circuit at the output end of the frequency converter. The first TVS circuit and the second TVS circuit are controlled by a logic controller. Parameter acquisition module 12: Acquires the real-time operating parameters of the frequency converter, including current amplitude, voltage distortion rate, temperature rise rate, and harmonic component ratio. Parameter library construction module 13: Constructs a neighboring element tolerance parameter library for the frequency converter, including the neighboring element type of the frequency converter and the corresponding overload tolerance parameter. Protection triggering module 14: Determines the overload fault type and overload fault rate based on the real-time operating parameters and the neighboring element tolerance parameter library, and adaptively triggers the logic controller to execute graded protection of the first TVS circuit and the second TVS circuit according to the overload fault type and overload fault rate.

[0047] Furthermore, the circuit setting module 11 is used to perform the following method: Based on the connection structure, the input terminal adjacent element and the output terminal adjacent element of the frequency converter are determined; the output terminal of the input terminal adjacent element is connected to the input terminal of the first TVS circuit, the output terminal of the first TVS circuit is connected to the input terminal of the frequency converter, the output terminal of the frequency converter is connected to the input terminal of the second TVS circuit, and the output terminal of the second TVS circuit is connected to the input terminal of the output terminal adjacent element.

[0048] Furthermore, the circuit setting module 11 is used to perform the following method: If the input terminal adjacent element or the output terminal adjacent element includes multiple adjacent elements, the input terminal adjacent element or the output terminal adjacent element is connected to the first TVS circuit and the second TVS circuit respectively according to the series connection relationship or parallel connection relationship of the multiple adjacent elements.

[0049] Furthermore, the parameter library construction module 13 is used to perform the following methods: Collect fault condition datasets corresponding to historical overload fault events of the frequency converter. The fault condition datasets include a first-stage fault condition dataset and a second-stage fault condition dataset. The first-stage fault condition dataset consists of the instantaneous operating condition dataset of the frequency converter under the overload fault event and the operating condition impact dataset of adjacent components. The second-stage fault condition dataset consists of the recovery operating condition dataset of the frequency converter after the execution of fault protection under the overload fault event and the operating condition impact dataset of adjacent components. Analyze the influence range of adjacent components according to the fault condition datasets corresponding to the historical overload fault events. Identify the range of adjacent components with an influence greater than a preset value as a constraint condition, and identify adjacent components that constitute the adjacent component tolerance parameter library.

[0050] Furthermore, the protection trigger module 14 is used to perform the following method: The process involves identifying the input and output adjacent components of the frequency converter; retrieving the overload tolerance parameters of the input and output adjacent components from the adjacent component tolerance parameter library; calculating the input overload index based on the real-time operating parameters and the overload tolerance parameters of the input adjacent components; calculating the output overload index based on the real-time operating parameters and the overload tolerance parameters of the output adjacent components; and identifying the overload fault type and overload fault rate by analyzing the input and output overload indices.

[0051] Furthermore, the protection trigger module 14 is used to perform the following method: Protection level analysis is performed according to the overload fault type and overload fault rate to obtain the protection level; a first-level protection level range, a second-level protection level range, and a third-level protection level range are set, and the protection level is analyzed based on the first-level protection level range, the second-level protection level range, and the third-level protection level range; wherein, if the protection level is first-level protection, the first TVS circuit and the second TVS circuit are controlled to perform amplitude limiting protection; if the protection level is second-level protection, the first TVS circuit and the second TVS circuit are controlled to disconnect from the inverter, and the inverter is controlled to reduce the load based on the inverter controller; if the protection level is third-level protection, the first TVS circuit and the second TVS circuit are controlled to disconnect from the inverter, and the inverter is controlled to stop based on the inverter controller.

[0052] Furthermore, the protection trigger module 14 is used to perform the following method: Define a limiting strategy template, which includes identifying the mapping relationship between overload fault types and limiting protection parameters. The limiting protection parameters include current limiting protection parameters, voltage limiting protection parameters, and current and voltage limiting protection parameters. If the protection level is Level 1 protection, identify the matching limiting protection parameters for the overload fault type according to the limiting strategy template. Control the first TVS circuit and the second TVS circuit to perform limiting protection according to the matching limiting protection parameters.

[0053] Furthermore, the parameter library construction module 13 is used to perform the following methods: The overload tolerance parameters include allowable current threshold, allowable voltage threshold, allowable temperature rise threshold, and response time threshold. After encoding the adjacent elements, the parameters are stored in the database according to the defined parameter library data structure, in that order: adjacent element code ID, adjacent element type, and overload tolerance parameter, to obtain the adjacent element tolerance parameter library.

[0054] Example 3: Based on the same inventive concept as the overload fault protection method for frequency converters in the preceding examples, this example provides a computer-readable storage medium for storing software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the overload fault protection method for frequency converters in this application. The processor executes various functional applications and data processing of the computer device by running the software programs, instructions, and modules stored in the memory, thereby implementing the aforementioned overload fault protection method for frequency converters.

[0055] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, the above description focuses on specific embodiments of this specification. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0056] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0057] This specification and accompanying drawings are merely illustrative examples of this application and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Therefore, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. An overload fault protection method for frequency converters, characterized in that, The method includes: The connection structure of the inverter is defined, and a first TVS circuit is set at the input end of the inverter according to the connection structure, and a second TVS circuit is set at the output end of the inverter. The first TVS circuit and the second TVS circuit are controlled by a logic controller. The real-time operating parameters of the frequency converter are collected, including current amplitude, voltage distortion rate, temperature rise rate, and harmonic component ratio. Construct a library of adjacent element tolerance parameters for the inverter, wherein the adjacent element tolerance parameters include the type of adjacent element of the inverter and the corresponding overload tolerance parameters; Based on the real-time operating parameters and the adjacent element tolerance parameter library, the overload fault type and overload fault rate are determined, and the adaptive trigger logic controller is executed to perform graded protection of the first TVS circuit and the second TVS circuit according to the overload fault type and overload fault rate.

2. The method as described in claim 1, characterized in that, A first TVS circuit is provided at the input terminal of the frequency converter according to the connection structure, and a second TVS circuit is provided at the output terminal of the frequency converter. The method includes: Based on the connection structure, determine the input terminal adjacent element and the output terminal adjacent element of the frequency converter; The output terminal of the input terminal adjacent element is connected to the input terminal of the first TVS circuit, the output terminal of the first TVS circuit is connected to the input terminal of the frequency converter, the output terminal of the frequency converter is connected to the input terminal of the second TVS circuit, and the output terminal of the second TVS circuit is connected to the input terminal of the output terminal adjacent element.

3. The method as described in claim 2, characterized in that, If the input terminal adjacent element or the output terminal adjacent element includes multiple adjacent elements; According to the series or parallel connection relationship of the plurality of adjacent elements, the input terminal adjacent element or the output terminal adjacent element is connected to the first TVS circuit and the second TVS circuit respectively.

4. The method as described in claim 1, characterized in that, The method for constructing the adjacent element tolerance parameter library of the frequency converter includes: Collect the fault condition dataset corresponding to the historical overload fault events of the frequency converter. The fault condition dataset includes a first-stage fault condition dataset and a second-stage fault condition dataset. The first stage fault condition dataset consists of the instantaneous operating condition dataset of the inverter under an overload fault event and the operating condition impact dataset of adjacent components. The second stage fault condition dataset consists of the recovery operating condition dataset of the inverter after the fault protection is executed under an overload fault event and the operating condition impact dataset of adjacent components. The influence range of adjacent elements is analyzed based on the fault condition dataset corresponding to the historical overload fault events. The range of adjacent elements with an influence greater than the preset value is identified as a constraint condition, and adjacent elements that constitute the adjacent element tolerance parameter library are identified.

5. The method as described in claim 2, characterized in that, The method for determining the overload fault type and overload fault rate based on the real-time operating parameters and the adjacent element tolerance parameter library includes: Determine the adjacent elements at the input and output ends of the frequency converter; The overload tolerance parameters of the input terminal adjacent element and the overload tolerance parameters of the output terminal adjacent element are obtained by calling the adjacent element tolerance parameter library. The overload index is calculated based on the real-time operating parameters and the overload tolerance parameters of the adjacent components at the input end, thus obtaining the input end overload index. The overload index is calculated based on the real-time operating parameters and the overload tolerance parameters of the adjacent components at the output end, and the output end overload index is obtained. By identifying the overload fault type of the input overload index and the output overload index, the overload fault type and overload fault rate are determined.

6. The method as described in claim 1, characterized in that, The method includes: An adaptive triggering logic controller executes graded protection for the first TVS circuit and the second TVS circuit according to the overload fault type and overload fault rate. The protection level is obtained by analyzing the overload fault type and overload fault rate. Set up a first-level protection level range, a second-level protection level range, and a third-level protection level range, and analyze the protection level based on the first-level protection level range, the second-level protection level range, and the third-level protection level range; Wherein, if the protection level is Level 1 protection, the first TVS circuit and the second TVS circuit are controlled to perform amplitude limiting protection; If the protection level is level two protection, the first TVS circuit and the second TVS circuit are disconnected from the inverter, and the inverter is reduced in load based on the inverter controller. If the protection level is level three, the first TVS circuit and the second TVS circuit are disconnected from the inverter, and the inverter is stopped based on the inverter controller.

7. The method as described in claim 6, characterized in that, If the protection level is Level 1 protection, controlling the first TVS circuit and the second TVS circuit to perform amplitude limiting protection includes the following methods: Define a limiting strategy template, which includes identifying the mapping relationship between overload fault types and limiting protection parameters, wherein the limiting protection parameters include current limiting protection parameters, voltage limiting protection parameters, and current and voltage limiting protection parameters. If the protection level is Level 1 protection, the matching limiting protection parameter item for the overload fault type is identified according to the limiting strategy template; The first TVS circuit and the second TVS circuit are controlled to perform amplitude limiting protection according to the matching amplitude limiting protection parameters.

8. The method as described in claim 1, characterized in that, The overload tolerance parameters include the allowable current threshold, the allowable voltage threshold, the allowable temperature rise threshold, and the response time threshold; After encoding the adjacent elements, the adjacent elements are stored in the database according to the defined parameter library data structure, in that order: adjacent element code ID, adjacent element type, and overload tolerance parameter, thus obtaining the adjacent element tolerance parameter library.

9. An overload fault protection system for frequency converters, characterized in that, For implementing the overload fault protection method for a frequency converter according to any one of claims 1-8, the system comprises: Circuit setting module: Locates the connection structure of the frequency converter, sets a first TVS circuit at the input end of the frequency converter according to the connection structure, sets a second TVS circuit at the output end of the frequency converter, and controls the first TVS circuit and the second TVS circuit through a logic controller; Parameter acquisition module: Acquires the real-time operating parameters of the frequency converter, including current amplitude, voltage distortion rate, temperature rise rate, and harmonic component ratio; Parameter library construction module: Constructs a parameter library for the adjacent elements of the frequency converter, wherein the adjacent element tolerance parameters include the types of adjacent elements of the frequency converter and the corresponding overload tolerance parameters; Protection triggering module: Based on the real-time operating parameters and the adjacent element tolerance parameter library, determine the overload fault type and overload fault rate, and adaptively trigger the logic controller to execute the graded protection of the first TVS circuit and the second TVS circuit according to the overload fault type and overload fault rate.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by the processor, the program implements the overload fault protection method for frequency converters as described in any one of claims 1-8.

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