Method and system for monitoring heat loss of silicon carbide power device
By collecting electrical parameters and temperature data and using multi-module collaborative processing, accurate monitoring of the heat loss of silicon carbide power devices was achieved, solving the problems of insufficient accuracy and timeliness in traditional methods and ensuring the safe and stable operation of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG INMARK ELECTRONICS CO
- Filing Date
- 2026-01-21
- Publication Date
- 2026-04-28
AI Technical Summary
Traditional methods for monitoring heat loss in electrical equipment struggle to accurately identify abnormal heat loss states when multiple parameters are coupled, dynamic operating conditions change, and complex fault causes occur. They also lack scientific correction mechanisms and comprehensive analytical dimensions, resulting in insufficient accuracy and timeliness of monitoring.
By collecting electrical parameters and temperature data of key components through preset sensors, and using multi-module collaborative data processing, the system performs anomaly recording, visualization analysis, curve disassembly comparison and comprehensive judgment to accurately identify abnormal heat loss points, quantify loss differences, and generate comprehensive anomaly monitoring results.
It enables precise monitoring of the heat loss of silicon carbide power devices, ensuring real-time control and safety stability of electrical equipment operation status, and improving the accuracy and timeliness of monitoring.
Smart Images
Figure CN121933852A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of heat loss monitoring technology, and more specifically, to a method and system for monitoring the heat loss of silicon carbide power devices. Background Technology
[0002] With the continuous improvement of industrial production intelligence, heat loss, as a key indicator reflecting the operating status of electrical equipment, has become an important means to ensure reliable equipment operation through accurate monitoring and analysis. However, traditional methods for monitoring heat loss in electrical equipment mostly rely on manual inspections to collect data, and the data processing methods are relatively simple, obtaining heat loss data only through simple calculations, lacking scientific correction mechanisms and comprehensive analytical dimensions. Especially when faced with multi-parameter coupling, dynamic operating condition changes, and complex fault causes, traditional monitoring methods often struggle to accurately identify abnormal heat loss states, making it difficult to balance accuracy and timeliness in monitoring.
[0003] Therefore, the existing technology has defects and urgently needs improvement. Summary of the Invention
[0004] In view of the above problems, the purpose of this invention is to provide a method and system for monitoring the heat loss of silicon carbide power devices. The method collects electrical parameters and temperature data of key parts of the device through preset sensors, and completes data processing, anomaly recording, visualization analysis, curve disassembly and comparison and comprehensive judgment through multi-module collaboration. It accurately identifies heat loss anomalies, quantifies loss differences, and generates comprehensive anomaly monitoring results to ensure real-time control of the operating status of electrical equipment and safe and stable operation.
[0005] The first aspect of this invention provides a method for monitoring the heat loss of silicon carbide power devices, comprising: Electrical parameters and temperature data of key components are collected using pre-set sensor devices; The first heat loss data is calculated based on the electrical parameters and the temperature data, and then corrected to obtain the second heat loss data. The second heat loss data is analyzed to determine abnormal states, and corresponding processing is carried out. The abnormal heat loss data F and the duration of the abnormal state M are recorded. A comprehensive analysis score S is calculated based on the duration M of the abnormal state. If the comprehensive analysis score S is greater than a preset score threshold, a score change curve is plotted based on the comprehensive analysis score. A comprehensive analysis of the score change curves is performed to determine the first anomaly point, and one or more sub-heat loss curves are determined based on the first anomaly point. The loss difference score is calculated and summed by combining the sub-heat loss curves with the standard curve to obtain the comprehensive difference score. The comprehensive difference score is analyzed to obtain the final anomaly result.
[0006] In this solution, the acquisition of electrical parameters and temperature data of key components through preset sensor devices includes: Select a preset sensor to detect electrical parameters including real-time voltage V(t) and real-time current I(t); According to the preset principle, at least one temperature acquisition point is determined to collect temperature data T.
[0007] In this solution, the step of calculating the first heat loss data based on the electrical parameters and the temperature data and then correcting it to obtain the second heat loss data includes: Calculate the resistivity R(T) of silicon carbide material based on temperature data: R(T)=R 25 *(1+α*(T-25)); Among them, R 25 α is the DC resistance of the device at a reference temperature of 25°C; α is the temperature coefficient of resistance. The ohmic loss P is calculated using the real-time current and resistance value R(T). o : P o =I(t) 2 *R(T); Calculate conduction loss P using conduction current on : ; Among them, R on This is the DC resistance when the device is turned on; Calculate the turn-off loss P using real-time voltage and real-time current. off ; ; Where a is the turn-off time, which is the time required for the current to drop to 0 from the start of the current cut-off control signal; The ohmic loss P o Conduction loss P on and turn-off loss P off Summing the three values yields the first heat loss data; The first heat loss data is corrected according to the preset correction table to obtain the second heat loss data.
[0008] In this solution, the step of analyzing the second heat loss data, determining abnormal states, processing them accordingly, and recording the abnormal heat loss data F and the duration M of the abnormal state includes: The second heat loss data is compared with the first preset heat loss threshold and the second preset heat loss threshold, respectively. When the second heat loss data exceeds the preset first heat loss threshold, a first warning reminder will be issued; When the second heat loss data is between the preset first preset heat loss threshold and the preset second preset heat loss threshold, it is recorded as abnormal heat loss data F. The duration of the abnormal state is obtained by calculating the cumulative duration of the abnormal heat loss data F; If the duration M of the abnormal state is greater than the preset duration threshold, an early warning will be issued; otherwise, no action will be taken.
[0009] In this scheme, the comprehensive analysis score S is calculated based on the duration M of the abnormal state. If the comprehensive analysis score S is greater than a preset score threshold, a score change curve is plotted based on the comprehensive analysis score, including: Calculate the average value F of all abnormal loss data. b : ; Where n is the number of abnormal loss data F, F i This represents the i-th abnormal loss data; Based on the average value F of all the abnormal loss data b The comprehensive analysis score S is calculated based on the duration M of the abnormal state. ; When the comprehensive analysis score S is greater than the preset score threshold, a score change curve is plotted based on the second heat loss data and the acquisition time after the current operation instruction ends, with time as the horizontal axis and the second heat loss data as the vertical axis.
[0010] In this scheme, the comprehensive analysis of the score change curve to determine the first anomaly point, and the determination of one or more sub-heat loss curves based on the first anomaly point, includes: The coordinate point on the score change curve corresponding to the abnormal heat loss data F is determined as the first abnormal point. Based on the first anomaly point, extract the corresponding score change curves between each adjacent first anomaly point to obtain one or more stator heat loss curves; Set the traversal box according to the preset interception time, and traverse each undetermined sub-heat loss curve forward and backward based on the acquisition time to determine the sub-heat loss curve corresponding to each undetermined sub-heat loss curve.
[0011] In this scheme, the step of setting a traversal frame according to a preset interception time, and traversing each undetermined sub-heat loss curve forward and backward based on the acquisition time to determine the sub-heat loss curve corresponding to each undetermined sub-heat loss curve includes: Each heat loss curve of the undetermined element is analyzed in turn, and the ratio of the difference in heat loss data between two adjacent coordinates in the traversal frame to the corresponding time difference is calculated to determine the corresponding first heat loss change rate. Calculate the ratio of the heat loss data difference between the two coordinates with the largest heat loss data difference within the bounding box to the corresponding time difference, and determine the second heat loss change rate. When there is a first heat loss rate of change greater than the first rate of change threshold or a second heat loss rate of change greater than the second preset rate of change threshold, continue to traverse forward or backward until there is no first heat loss rate of change greater than the first rate of change threshold or a second heat loss rate of change less than or equal to the second preset rate of change threshold. Then, determine the coordinate point corresponding to the minimum heat loss data in the traversal box as the start or end coordinate point of the sub-heat loss curve, and determine the sub-heat loss curve corresponding to each undetermined sub-heat loss curve.
[0012] In this scheme, the loss difference score is calculated and summed by combining the sub-heat loss curve with the standard curve to obtain a comprehensive difference score, including: Obtain the corresponding standard heat loss curve table and the current device's cumulative service life, and determine the standard heat loss curve from the standard heat loss curve table based on the cumulative service life; Based on the start and end times of the sub-heat loss curve, the sub-heat loss curve is compared with the standard heat loss curve to determine the time interval in which the sub-heat loss curve is above the standard heat loss curve as the first time interval. The area enclosed by the sub-heat loss curve and the standard heat loss curve is calculated based on the first time interval, and the loss difference score of the sub-heat loss curve is determined. All loss difference scores are summed to determine the overall difference score.
[0013] In this solution, the analysis of the comprehensive difference score to obtain the final anomaly result includes: Set a threshold for the overall difference score. If the overall difference score is greater than or equal to the threshold, the final abnormal result is determined to be abnormal and an alert is issued immediately. If the overall difference score is less than the threshold, the final abnormal result is determined to be abnormal and no action is taken.
[0014] A second aspect of the present invention provides a monitoring system for the heat loss of silicon carbide power devices, comprising: The data acquisition module is used to collect electrical parameters and temperature data of key parts of the device through preset sensor devices; The data processing module is used to calculate the first heat loss data based on the electrical parameters and the temperature data, and then correct it to obtain the second heat loss data. The first data analysis module is used to analyze the second heat loss data, determine abnormal states, perform corresponding processing, and record the abnormal heat loss data F and the duration of the abnormal state M. The data visualization module is used to calculate a comprehensive analysis score S based on the duration M of the abnormal state. If the comprehensive analysis score S is greater than a preset score threshold, a score change curve is plotted based on the comprehensive analysis score. The second data analysis module is used to comprehensively analyze the score change curve, determine the first anomaly, determine one or more sub-heat loss curves based on the first anomaly, and calculate and sum the loss difference scores by combining the sub-heat loss curves with the standard curve to obtain the comprehensive difference score. The result determination module is used to analyze the comprehensive difference score and obtain the final abnormal result.
[0015] This invention discloses a method and system for monitoring the heat loss of silicon carbide power devices. The method includes: collecting electrical parameters and temperature data of key parts of the device; calculating and correcting first heat loss data to obtain second heat loss data, analyzing the data, identifying abnormal states, handling them accordingly, and recording the abnormal heat loss data F and the duration M of the abnormal state; calculating a comprehensive analysis score S; if the comprehensive analysis score S is greater than a preset score threshold, plotting a score change curve based on the comprehensive analysis score; determining a first abnormal point based on the comprehensive analysis score change curve, and determining one or more sub-heat loss curves based on the first abnormal point; calculating and summing the loss difference score to obtain a comprehensive difference score, analyzing it, and obtaining the final abnormal result. This invention ensures the safety and stability of silicon carbide power device operation by accurately calculating heat loss and analyzing abnormal states, and locating loss difference characteristics. Attached Figure Description
[0016] Figure 1 A flowchart of a method for monitoring the heat loss of a silicon carbide power device provided by the present invention is shown; Figure 2 A block diagram of a monitoring system for thermal loss of silicon carbide power devices provided by the present invention is shown. Detailed Implementation
[0017] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.
[0018] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.
[0019] Figure 1 A flowchart of a method for monitoring the heat loss of a silicon carbide power device provided by the present invention is shown; like Figure 1 As shown, this invention discloses a method for monitoring the heat loss of silicon carbide power devices, comprising: S101 collects electrical parameters and temperature data of key components through preset sensor devices; S102, calculate the first heat loss data based on electrical parameters and temperature data, and then correct it to obtain the second heat loss data; S103, Analyze the second heat loss data, determine the abnormal state, handle it accordingly, and record the abnormal heat loss data F and the duration of the abnormal state M. S104. Calculate the comprehensive analysis score S based on the duration M of the abnormal state. If the comprehensive analysis score S is greater than the preset score threshold, draw a score change curve based on the comprehensive analysis score. S105. Perform a comprehensive analysis of the score change curve to determine the first anomaly point. Based on the first anomaly point, determine one or more sub-heat loss curves. Combine the sub-heat loss curves with the standard curve to calculate the loss difference score and sum them to obtain the comprehensive difference score. S106, analyze the comprehensive difference score to obtain the final abnormal results.
[0020] According to an embodiment of the present invention, a sensor device is used to collect real-time voltage V(t) and real-time current I(t). Following the principle of prioritizing core heat-generating components, at least one temperature acquisition point is selected in the electrical equipment to collect temperature data T from core components with concentrated energy loss and prone to high temperatures. First, the reference DC resistance R of the device at its inherent parameter of 25°C is obtained. 25The system simultaneously acquires the device's real-time temperature data T, real-time on-state current I(t), and real-time terminal voltage V(t) during operation, along with the resistance temperature coefficient α, ensuring consistent timestamps to eliminate timing errors. Ohmic loss, conduction loss, and turn-off loss are calculated from the acquired data and summed to obtain the first heat loss data. Finally, the first heat loss data is corrected against a pre-set correction table, taking into account the device's actual operating conditions and temperature range, resulting in accurate second heat loss data. The second heat loss data is then compared with pre-set first and second heat loss thresholds. If the second heat loss data exceeds the first heat loss threshold, a first warning is triggered. If the second heat loss data falls between the first and second heat loss thresholds, it is marked as abnormal heat loss data F, and the cumulative duration of this abnormal heat loss data is recorded to determine the corresponding abnormal state duration M. It is then determined whether the abnormal state duration exceeds a preset duration threshold. If it does, a corresponding warning is triggered; otherwise, no action is taken. Based on the abnormal heat loss data F and the duration M of the abnormal state, a comprehensive analysis score S is determined. The comprehensive analysis score S is analyzed; if it exceeds a preset score threshold, a score change curve is plotted and further analysis is performed. The coordinate point on the score change curve corresponding to the abnormal heat loss data F is identified as the first abnormal point, and adjacent first abnormal points are connected to determine one or more undetermined sub-heat loss curves. The undetermined heat loss curves are traversed forward and backward to determine their corresponding sub-heat loss curves. The sub-heat loss curve table is compared with the standard heat loss curve table, and the area of the sub-heat loss curve above the standard heat loss curve during the time interval is calculated. The loss difference score of the sub-heat loss curve is determined, and all loss difference scores are accumulated to obtain the comprehensive difference score. A comprehensive difference score threshold is set. If the comprehensive difference score is greater than or equal to the comprehensive difference score threshold, an anomaly is identified, and an immediate warning is issued; otherwise, no action is taken.
[0021] According to an embodiment of the present invention, electrical parameters and temperature data of key components of a device are collected using a preset sensor device, including: Select a preset sensor to detect electrical parameters including real-time voltage V(t) and real-time current I(t); According to the preset principle, at least one temperature acquisition point is determined to collect temperature data T.
[0022] It should be noted that the selection of the preset sensor should be based on the voltage level, current type and switching frequency characteristics of the silicon carbide device. For example, isolated Hall voltage sensors are preferred for voltage detection, and Rogowski coil current sensors are preferred for current detection.
[0023] The preset principles for temperature acquisition points are, for example, prioritizing core heat sources and covering heat conduction paths, and at least one temperature acquisition point needs to be set. When acquiring temperature, the average value of the temperature of all acquired points is taken as the temperature data T.
[0024] Both the preset sensors and preset principles can be set by those skilled in the art according to the actual situation.
[0025] According to an embodiment of the present invention, calculating a first heat loss data based on electrical parameters and temperature data, and then correcting it to obtain a second heat loss data, includes: Calculate the resistivity R(T) of silicon carbide material based on temperature data: R(T)=R 25 *(1+α*(T-25)); Among them, R 25 α is the DC resistance of the device at a reference temperature of 25°C; α is the temperature coefficient of resistance. The ohmic loss P is calculated using real-time current and resistance value R(T). o : P o =I(t) 2 *R(T); Calculate conduction loss P using conduction current on : ; Among them, R on This is the DC resistance when the device is turned on; Calculate the turn-off loss P using real-time voltage and real-time current. off ; ; Where a is the turn-off time, which is the time required for the current to drop to 0 from the start of the current cut-off control signal; The ohmic loss P o Conduction loss P on and turn-off loss P off Summing the three values yields the first heat loss data; The first heat loss data is corrected according to the preset correction table to obtain the second heat loss data.
[0026] It should be noted that 'a' represents the turn-off time, which typically ranges from 50 ns to 150 ns; R 25R(T) represents the DC resistance of the device at a reference temperature of 25°C. This parameter is a basic electrical characteristic of the device at room temperature and can be obtained by consulting the manufacturer's manual or by actual measurement and calibration at room temperature. The accuracy of its value directly determines the baseline accuracy of subsequent loss calculations. α is the temperature coefficient of resistance, which reflects the sensitivity of the resistance of silicon carbide material to temperature changes. It is closely related to the doping concentration and crystal structure of the material. The significance of introducing this coefficient is to eliminate the influence of temperature on the resistance value, so that the calculated R(T) can accurately match the resistance state of the device at the real-time operating temperature.
[0027] Ohmic loss P o It refers to the energy loss caused by the heating of the material due to resistance when current flows through the device in the on state; conduction loss P on Turn-off loss P refers to the power loss that occurs during the transition of a device from the off state to the on state due to the overlap between voltage and current; off This refers to the power loss that occurs during the process of a device switching from the on state to the off state due to the overlap between voltage and current.
[0028] The preset correction table is based on a large amount of measured data from silicon carbide power devices. For example, the operating condition segmentation correction table (engineering quick version) is selected. The significance of introducing the correction table is to eliminate the influence of non-ideal factors on loss calculation, so that the final second heat loss data can truly reflect the actual heat generation level of the device, and provide key technical basis for the reliable operation of silicon carbide power devices.
[0029] The preset correction table can be specifically set by those skilled in the art according to actual needs.
[0030] According to an embodiment of the present invention, the analysis of the second heat loss data, the determination of abnormal states, the corresponding processing, and the recording of abnormal heat loss data F and the duration M of the abnormal state include: The second heat loss data is compared with a first preset heat loss threshold (e.g., 200℃) and a second preset heat loss threshold (e.g., 180℃), respectively. When the second heat loss data exceeds the preset first heat loss threshold, a first warning reminder will be issued; When the second heat loss data is between the preset first preset heat loss threshold and the preset second preset heat loss threshold, it is recorded as abnormal heat loss data F. The duration of the abnormal state is obtained by statistically analyzing the cumulative duration of the abnormal heat loss data F; If the duration M of the abnormal state is greater than the preset duration threshold, an early warning will be issued; otherwise, no action will be taken.
[0031] It should be noted that the preset first heat loss threshold and the preset second heat loss threshold are determined based on the rated operating parameters, extreme tolerance and long-term reliability test data of silicon carbide power devices. The preset first heat loss threshold is the critical value of the device under dangerous operating conditions. Once the heat loss exceeds this threshold, the device will face the risk of thermal breakdown and irreversible performance degradation. The preset second heat loss threshold is the warning value for abnormal operating conditions of the device, which corresponds to the upper limit of heat loss for long-term stable operation of the device. The range that is lower than the preset first heat loss threshold and higher than the preset second heat loss threshold is the potential abnormal operating condition range of the device. Although the device has not reached a dangerous state, long-term operation will accelerate aging and shorten its service life. The setting of the threshold for the duration M of the abnormal state realizes the forward warning of potential device failures.
[0032] The preset first heat loss threshold, the preset second heat loss threshold, and the preset duration threshold can all be set by professionals in the field according to the actual situation, and the preset first heat loss threshold is greater than the preset second heat loss threshold.
[0033] According to an embodiment of the present invention, a comprehensive analysis score S is calculated based on the duration M of the abnormal state. If the comprehensive analysis score S is greater than a preset score threshold, a score change curve is plotted based on the comprehensive analysis score, including: Calculate the average value F of all abnormal loss data. b : ; Where n is the number of abnormal loss data F, F i This represents the i-th abnormal loss data; Based on the average value F of all abnormal loss data b The comprehensive analysis score S is calculated based on the duration M of the abnormal state. ; When the comprehensive analysis score S is greater than the preset score threshold, a score change curve is plotted based on the second heat loss data and the acquisition time after the current operation instruction ends, with time as the horizontal axis and the second heat loss data as the vertical axis.
[0034] It should be noted that the average value F of all abnormal loss data is calculated. b The significance lies in eliminating the evaluation bias caused by single instantaneous fluctuations; the setting of the preset score threshold needs to be determined based on the device accelerated aging test and fault statistics. If the comprehensive analysis shows that the score exceeds the preset score threshold, it indicates that the abnormal situation has significant trend characteristics rather than occasional interference, and further analysis is required.
[0035] The preset score threshold can be set by those skilled in the art according to the actual situation.
[0036] According to an embodiment of the present invention, a comprehensive analysis of the score change curve is performed to determine a first anomaly point, and one or more sub-heat loss curves are determined based on the first anomaly point, including: The coordinate point on the score change curve corresponding to the abnormal heat loss data F is determined as the first abnormal point. Based on the first anomaly point, extract the corresponding score change curves between each adjacent first anomaly point to obtain one or more stator heat loss curves; Set the traversal box according to the preset interception time, and traverse each undetermined sub-heat loss curve forward and backward based on the acquisition time to determine the sub-heat loss curve corresponding to each undetermined sub-heat loss curve.
[0037] It should be noted that the traversal box is set according to the preset intercept time and traversed forward and backward to capture the loss trend before the anomaly occurs and the loss characteristics during the recovery period after the anomaly subsides. The preset intercept time is determined based on the thermal response characteristics and fault evolution cycle of the device, and can be set to 3s for example.
[0038] In addition, when there are two or more adjacent first anomaly points, the score change curve is only truncated from the first anomaly points on both sides (the leftmost and rightmost parts of the adjacent part), and the score change curve between these first anomaly points is determined as a stator heat loss curve to be determined.
[0039] The preset interception time can be set by those skilled in the art according to the actual situation.
[0040] According to an embodiment of the present invention, a traversal frame is set according to a preset interception time, and each undetermined sub-heat loss curve is traversed forward and backward based on the acquisition time to determine the sub-heat loss curve corresponding to each undetermined sub-heat loss curve, including: Each heat loss curve of the undetermined element is analyzed in turn, and the ratio of the difference in heat loss data between two adjacent coordinates in the traversal frame to the corresponding time difference is calculated to determine the corresponding first heat loss change rate. Calculate the ratio of the difference in heat loss data between the two coordinates with the largest difference in heat loss data within the traversal frame to the corresponding time difference, and determine the second rate of change of heat loss. When there is a first heat loss rate of change greater than the first rate of change threshold or a second heat loss rate of change greater than the second preset rate of change threshold, continue to traverse forward or backward until there is no first heat loss rate of change greater than the first rate of change threshold or a second heat loss rate of change less than or equal to the second preset rate of change threshold. Then, determine the coordinate point corresponding to the minimum heat loss data in the traversal box as the start or end coordinate point of the sub-heat loss curve, and determine the sub-heat loss curve corresponding to each undetermined sub-heat loss curve.
[0041] It should be noted that the first heat loss change rate reflects the subtle fluctuation trend of heat loss change at continuous time points, while the second heat loss change rate reflects the overall fluctuation of the sub-heat loss curve; the threshold of the first heat loss change rate can be set to, for example, 0.04w / ms, and the threshold of the second heat loss change rate can be set to 0.038w / ms.
[0042] The first heat loss rate threshold and the second heat loss rate threshold can both be set by those skilled in the art according to the actual situation.
[0043] According to an embodiment of the present invention, by combining the sub-heat loss curve and the standard curve, a loss difference score is calculated and summed to obtain a comprehensive difference score, including: Obtain the corresponding standard heat loss curve table and the current device's cumulative lifespan, and determine the standard heat loss curve from the standard heat loss curve table based on the cumulative lifespan; Based on the start and end times of the sub-heat loss curve, the sub-heat loss curve is compared with the standard heat loss curve to determine the time interval in which the sub-heat loss curve is above the standard heat loss curve as the first time interval. The area enclosed by the sub-heat loss curve and the standard heat loss curve is calculated based on the first time interval, and the loss difference score of the sub-heat loss curve is determined. All loss difference scores are summed to determine the overall difference score.
[0044] It should be noted that the area enclosed by the sub-heat loss curve and the standard heat loss curve can be calculated using methods such as the trapezoidal rule, calculus, or definite integral.
[0045] The steps to obtain the corresponding standard thermal loss curves are as follows: For example, based on the Coffin-Manson model and the Arrhenius model, combined with the parameters and packaging fitting coefficients provided by the manufacturer's silicon carbide device manual, a standard curve table for silicon carbide devices with different lifetimes is obtained. The Coffin-Manson model is an empirical model describing the low-cycle fatigue life of materials, while the Arrhenius model is an empirical model used to correct the lifetime prediction of power devices (such as SiC devices) and quantify the accelerating effect of average temperature on the thermal fatigue failure rate of devices. The cumulative lifetime of the device can be obtained by testing, for example, using the power device reliability testing system of the 45th Research Institute of China Electronics Technology Group Corporation. Based on the cumulative lifetime of the device, the standard thermal loss curve corresponding to the lifetime is selected from the standard curve table for different lifetimes.
[0046] By obtaining the standard curve table and determining the corresponding standard curve based on the cumulative service life, the loss benchmark changes in the device aging process are matched, avoiding the use of a uniform standard to measure the loss status of devices at different life stages, thus ensuring the objectivity and specificity of the comparison benchmark. The area enclosed by the curve within the interval is calculated to obtain the loss difference score, and the two dimensions of abnormal thermal loss data and abnormal state duration are quantified and integrated into a single indicator, which intuitively reflects the severity of abnormal loss.
[0047] According to an embodiment of the present invention, the comprehensive difference score is analyzed to obtain the final anomaly result, including: Set a threshold for the overall difference score. If the overall difference score is greater than or equal to the threshold, the final abnormal result is determined to be abnormal and an alert is issued immediately. If the overall difference score is less than the threshold, the final abnormal result is determined to be abnormal and no action is taken.
[0048] It should be noted that the overall difference score threshold is determined based on the device's full life cycle reliability test data, failure loss assessment, and operation and maintenance cost analysis, for example, it is set to 50.
[0049] By constructing a final quantitative criterion for abnormal thermal loss in silicon carbide power devices, a comprehensive assessment of the impact of abnormal losses throughout the device's entire lifecycle can be achieved. This avoids over-warning of minor and acceptable loss deviations while ensuring accurate identification of serious anomalies that could threaten the safe operation of the device.
[0050] The comprehensive difference score threshold can be set by those skilled in the art according to the actual situation.
[0051] Figure 2 A block diagram of a monitoring system for thermal loss of silicon carbide power devices provided by the present invention is shown.
[0052] like Figure 2 As shown, a second aspect of the present invention provides a monitoring system for the heat loss of silicon carbide power devices, comprising: The data acquisition module is used to collect electrical parameters and temperature data of key parts of the device through preset sensor devices; The data processing module is used to calculate the first heat loss data based on electrical parameters and temperature data, and then correct it to obtain the second heat loss data. The first data analysis module is used to analyze the second heat loss data, determine abnormal states, handle them accordingly, and record the abnormal heat loss data F and the duration of the abnormal state M. The data visualization module is used to calculate the comprehensive analysis score S based on the duration M of the abnormal state. If the comprehensive analysis score S is greater than the preset score threshold, a score change curve is drawn based on the comprehensive analysis score. The second data analysis module is used to comprehensively analyze the score change curve, identify the first outlier, and determine one or more sub-heat loss curves based on the first outlier. Combining the sub-heat loss curves with the standard curve, the loss difference score is calculated and summed to obtain the comprehensive difference score. The results determination module is used to analyze the comprehensive difference score and obtain the final abnormal results.
[0053] All information (including but not limited to user equipment information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.), and signals (including but not limited to signals transmitted between user terminals and other devices) involved in this application have been authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, the "electrical parameters" and "temperature data of key parts of devices" involved in this disclosure were obtained with full authorization.
[0054] This invention discloses a method and system for monitoring the heat loss of silicon carbide power devices. The method includes: collecting electrical parameters and temperature data of key parts of the device; calculating and correcting first heat loss data to obtain second heat loss data, analyzing the data, identifying abnormal states, handling them accordingly, and recording the abnormal heat loss data F and the duration M of the abnormal state; calculating a comprehensive analysis score S; if the comprehensive analysis score S is greater than a preset score threshold, plotting a score change curve based on the comprehensive analysis score; determining a first abnormal point based on the comprehensive analysis score change curve, and determining one or more sub-heat loss curves based on the first abnormal point; calculating and summing the loss difference score to obtain a comprehensive difference score, analyzing it, and obtaining the final abnormal result. This invention ensures the safety and stability of silicon carbide power device operation by accurately calculating heat loss and analyzing abnormal states, and locating loss difference characteristics.
[0055] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.
[0056] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.
[0057] In addition, in the various embodiments of the present invention, each functional unit can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.
[0058] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0059] Alternatively, if the integrated units of this invention are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.
Claims
1. A method for monitoring the heat loss of silicon carbide power devices, characterized in that, include: Electrical parameters and temperature data of key components are collected using pre-set sensor devices; The first heat loss data is calculated based on the electrical parameters and the temperature data, and then corrected to obtain the second heat loss data. The second heat loss data is analyzed to determine abnormal states, and corresponding processing is carried out. The abnormal heat loss data F and the duration of the abnormal state M are recorded. A comprehensive analysis score S is calculated based on the duration M of the abnormal state. If the comprehensive analysis score S is greater than a preset score threshold, a score change curve is plotted based on the comprehensive analysis score. A comprehensive analysis of the score change curves is performed to determine the first anomaly point. Based on the first anomaly point, one or more sub-heat loss curves are determined. Combining the sub-heat loss curves with the standard curve, the loss difference score is calculated and summed to obtain the comprehensive difference score. The comprehensive difference score is analyzed to obtain the final anomaly result.
2. The method for monitoring the heat loss of a silicon carbide power device according to claim 1, characterized in that, The process of collecting electrical parameters and temperature data of key components through a preset sensor device includes: Select a preset sensor to detect electrical parameters including real-time voltage V(t) and real-time current I(t); According to the preset principle, at least one temperature acquisition point is determined to collect temperature data T.
3. The method for monitoring the heat loss of a silicon carbide power device according to claim 2, characterized in that, The step of calculating the first heat loss data based on the electrical parameters and the temperature data, and then correcting it to obtain the second heat loss data, includes: Calculate the resistivity R(T) of silicon carbide material based on temperature data: R(T)=R 25 *(1+α*(T-25)); Among them, R 25 α is the DC resistance of the device at a reference temperature of 25°C; α is the temperature coefficient of resistance. The ohmic loss P is calculated using the real-time current and resistance value R(T). o : P o =I(t) 2 *R(T); Calculate conduction loss P using conduction current on : ； Among them, R on This is the DC resistance when the device is turned on; Calculate the turn-off loss P using real-time voltage and real-time current. off ; ； Where a is the turn-off time, which is the time required for the current to drop to 0 from the start of the current cut-off control signal; The ohmic loss P o Conduction loss P on and turn-off loss P off Summing the three values yields the first heat loss data; The first heat loss data is corrected according to the preset correction table to obtain the second heat loss data.
4. The method for monitoring the heat loss of a silicon carbide power device according to claim 2, characterized in that, The step of analyzing the second heat loss data, determining abnormal states, processing them accordingly, and recording the abnormal heat loss data F and the duration M of the abnormal state includes: The second heat loss data is compared with the first preset heat loss threshold and the second preset heat loss threshold, respectively. When the second heat loss data exceeds the preset first heat loss threshold, a first warning reminder will be issued; When the second heat loss data is between the preset first preset heat loss threshold and the preset second preset heat loss threshold, it is recorded as abnormal heat loss data F. The duration of the abnormal state is obtained by calculating the cumulative duration of the abnormal heat loss data F; If the duration M of the abnormal state is greater than the preset duration threshold, an early warning will be issued; otherwise, no action will be taken.
5. The method for monitoring the heat loss of a silicon carbide power device according to claim 3, characterized in that, The step of calculating a comprehensive analysis score S based on the duration M of the abnormal state, and if the comprehensive analysis score S is greater than a preset score threshold, then plotting a score change curve based on the comprehensive analysis score, including: Calculate the average value F of all abnormal loss data. b : ； Where n is the number of abnormal loss data F, F i This represents the i-th abnormal loss data; Based on the average value F of all the abnormal loss data b The comprehensive analysis score S is calculated based on the duration M of the abnormal state. ； When the comprehensive analysis score S is greater than the preset score threshold, a score change curve is plotted based on the second heat loss data and the acquisition time after the current operation instruction ends, with time as the horizontal axis and the second heat loss data as the vertical axis.
6. The method for monitoring the heat loss of a silicon carbide power device according to claim 1, characterized in that, The process involves comprehensively analyzing the score change curves to determine a first anomaly, and then determining one or more sub-heat loss curves based on this first anomaly, including: The coordinate point on the score change curve corresponding to the abnormal heat loss data F is determined as the first abnormal point. Based on the first anomaly point, extract the corresponding score change curves between each adjacent first anomaly point to obtain one or more stator heat loss curves; Set the traversal box according to the preset interception time, and traverse each undetermined sub-heat loss curve forward and backward based on the acquisition time to determine the sub-heat loss curve corresponding to each undetermined sub-heat loss curve.
7. The method for monitoring the heat loss of a silicon carbide power device according to claim 6, characterized in that, The process of setting a traversal frame according to a preset capture time and traversing each undetermined sub-heat loss curve forward and backward based on the acquisition time to determine the sub-heat loss curve corresponding to each undetermined sub-heat loss curve includes: Each heat loss curve of the undetermined element is analyzed in turn, and the ratio of the difference in heat loss data between two adjacent coordinates in the traversal frame to the corresponding time difference is calculated to determine the corresponding first heat loss change rate. Calculate the ratio of the difference in heat loss data between the two coordinates with the largest difference in heat loss data within the traversal frame to the corresponding time difference, and determine the second rate of change of heat loss. When there is a first heat loss rate of change greater than the first rate of change threshold or a second heat loss rate of change greater than the second preset rate of change threshold, continue to traverse forward or backward until there is no first heat loss rate of change greater than the first rate of change threshold or a second heat loss rate of change less than or equal to the second preset rate of change threshold. Then, determine the coordinate point corresponding to the minimum heat loss data in the traversal box as the start or end coordinate point of the sub-heat loss curve, and determine the sub-heat loss curve corresponding to each undetermined sub-heat loss curve.
8. The method for monitoring the heat loss of a silicon carbide power device according to claim 1, characterized in that, The heat loss curve of the combined sub-combiner is compared with the standard curve. The loss difference score is calculated and summed to obtain a comprehensive difference score, including: Obtain the corresponding standard heat loss curve table and the current device's cumulative service life, and determine the standard heat loss curve from the standard heat loss curve table based on the cumulative service life; Based on the start and end times of the sub-heat loss curve, the sub-heat loss curve is compared with the standard heat loss curve to determine the time interval in which the sub-heat loss curve is above the standard heat loss curve as the first time interval. The area enclosed by the sub-heat loss curve and the standard heat loss curve is calculated based on the first time interval, and the loss difference score of the sub-heat loss curve is determined. All loss difference scores are summed to determine the overall difference score.
9. The method for monitoring the heat loss of a silicon carbide power device according to claim 1, characterized in that, The analysis of the comprehensive difference score yields the final anomaly results, including: Set a threshold for the overall difference score. If the overall difference score is greater than or equal to the threshold, the final abnormal result is determined to be abnormal and an alert is issued immediately. If the overall difference score is less than the threshold, the final abnormal result is determined to be abnormal and no action is taken.
10. A monitoring system for heat loss of silicon carbide power devices, used to implement the monitoring method for heat loss of silicon carbide power devices as described in any one of claims 1-9, characterized in that, include: The data acquisition module is used to collect electrical parameters and temperature data of key parts of the device through preset sensor devices; The data processing module is used to calculate the first heat loss data based on the electrical parameters and the temperature data, and then correct it to obtain the second heat loss data. The first data analysis module is used to analyze the second heat loss data, determine abnormal states, perform corresponding processing, and record the abnormal heat loss data F and the duration of the abnormal state M. The data visualization module is used to calculate a comprehensive analysis score S based on the duration M of the abnormal state. If the comprehensive analysis score S is greater than a preset score threshold, a score change curve is plotted based on the comprehensive analysis score. The second data analysis module is used to comprehensively analyze the score change curve, determine the first anomaly, determine one or more sub-heat loss curves based on the first anomaly, and calculate and sum the loss difference scores by combining the sub-heat loss curves with the standard curve to obtain the comprehensive difference score. The result determination module is used to analyze the comprehensive difference score and obtain the final abnormal result.