An online monitoring method and system for power module health status

Abstract

The application provides an online monitoring method and system for the health state of a power module, and relates to the technical field of power module life monitoring, and comprises the following steps: acquiring the output current and output voltage of a first power module at different temperatures in an initial state, drawing an initial output characteristic curve graph, determining the intersection of the curves of the output current and output voltage in the output characteristic curve graph at different temperatures, and obtaining an initial state label; controlling the first power module to work until failure; synchronously obtaining a failure state label and / or at least one intermediate state label; collecting the real-time output current, real-time output voltage and real-time temperature of a second power module in a running state, drawing a real-time output characteristic curve graph, and obtaining a real-time state label; and obtaining a target result of the health state of the power module in the running state according to the real-time state label, so as to solve the problem that there is no method for monitoring the health state of a power module.

Description

Technical Field

[0001] This invention relates to the field of power module lifespan monitoring technology, and in particular to an online monitoring method and system for the health status of power modules. Background Technology

[0002] With the increasing prevalence of vehicle electrification, various automotive power conversion devices, such as drive motor controllers, on-board bidirectional chargers, and automotive DC-DC converters, have become standard equipment in electric vehicles. The core components of these devices—power modules—primarily Insulated Gate Bipolar Transistors (IGBTs) and Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs)—are crucial to reliability in this market. Existing vehicle manufacturers have invested heavily in diagnostics and prognostics, such as real-time diagnostic systems running on vehicles to determine when components fail. These systems warn drivers before failures occur, allowing for vehicle repairs and enabling component replacement without causing inconvenience to the driver.

[0003] However, thermal capacitance and thermal resistance are considered constant throughout the entire lifespan of a power module, making it impossible to monitor the health status of the power module, such as when it must be replaced. Existing methods use thermal resistance residuals to determine the lifespan of a power module, but this method can only be used to predict power module aging caused by the aging of the heat sink substrate under the power chip. It cannot achieve online monitoring of the impact of the power supply status of the bonding wires on the power chip on the lifespan of the power module. Therefore, a method is needed to monitor the health status of the power module online by considering the status of the bonding wires on the power chip. Summary of the Invention

[0004] To overcome the above-mentioned technical deficiencies, the present invention aims to provide an online monitoring method and system for the health status of power modules, which solves the problem that existing methods lack consideration of the aging of bonding wires on the power chips of power modules and perform real-time online monitoring of the health status of power modules.

[0005] This invention discloses an online monitoring method for the health status of a power module, comprising:

[0006] Obtain multiple output currents and output voltages of the first power module under different temperatures in its initial state;

[0007] According to the output current and the output voltage at different temperatures, an initial output characteristic curve diagram is drawn, an intersection of the curves of the output current and the output voltage at different temperatures in the output characteristic curve diagram is determined, and an initial state label is obtained;

[0008] The first power module is controlled to work until failure;

[0009] The output current and the output voltage of the first power module at different temperatures in a failure state and / or in a plurality of intermediate states are synchronously acquired to draw a failure output characteristic curve diagram and an intermediate output characteristic curve diagram, and a failure state label and / or at least one intermediate state label are obtained;

[0010] The real-time output current, the real-time output voltage and the real-time temperature of the second power module in a running state are collected, and a real-time output characteristic curve diagram is drawn, so that a real-time state label is obtained according to the intersection of the curves generated by the real-time output current and the real-time output voltage at different temperatures; wherein the initial state of the second power module is consistent with the initial state of the first power module;

[0011] According to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label on a preset coordinate axis, a target result of the health state of the power module in the running state is obtained.

[0012] Preferably, the target result of the health state of the power module in the running state is obtained according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label, including:

[0013] The offset of the real-time state label relative to any two of the initial state label, the failure state label or the intermediate state label is calculated in the current dimension and / or the voltage dimension;

[0014] The proportion of the offset in the total amount of change in the current dimension of the two labels is calculated to obtain an offset degree;

[0015] The offset degree is converted into a percentage to obtain the target result of the health state of the power module in the running state.

[0016] Preferably, the target result of the health state of the power module in the running state is obtained according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label, including:

[0017] The curve slope at the corresponding intersection of the initial state label, the failure state label or the intermediate state label is calculated as a first slope, a second slope or a third slope, respectively;

[0018] obtaining a curve slope at the intersection point corresponding to the real-time state label as a fourth slope;

[0019] According to the change of the fourth slope relative to any two of the first slope, the second slope, or the third slope;

[0020] Calculate the proportion of the change of the fourth slope in the change of the two slopes, and convert it to percentage to obtain the target result of the health status of the power module under the running state.

[0021] Preferably, the target result of the health status of the power module under the running state according to the position distribution of the real-time state label relative to the initial state label, the failure state label, or the intermediate state label comprises:

[0022] Determine a plurality of intermediate state labels, generate a state change curve diagram according to the initial state label, the failure state label, and each intermediate state label, and store it in a preset address;

[0023] Match the label consistent with the position of the real-time state label from the state change curve diagram at the preset address to obtain the target result of the health status of the power module under the running state.

[0024] Preferably, the target result of the health status of the power module under the running state according to the position distribution of the real-time state label relative to the initial state label, the failure state label, or the intermediate state label comprises:

[0025] According to a preset standard, divide the initial state label and the failure state label into a plurality of regions;

[0026] Calculate the distance between the real-time state label and the initial state label or the failure state label, and the ratio of the distance between the initial state label and the failure state label;

[0027] According to the region where the real-time state label is located, the ratio is weighted and converted to percentage to obtain the target result of the health status of the power module under the running state.

[0028] Preferably, the real-time temperature is controlled by self-heating and heat dissipation of the second power module under the running state.

[0029] Preferably, a real-time output characteristic curve diagram is drawn to obtain a real-time state label at the intersection of the curve generated according to the real-time output current, real-time output voltage at different temperatures, comprising:

[0030] Set the real-time output current, real-time output voltage, and real-time temperature collected in any state as a mark;

[0031] Each mark falls into a preset current and voltage change graph, and a real-time output characteristic curve graph is drawn;

[0032] According to the shadow area formed by each mark, the part with the minimum shadow area is determined as the intersection point, and a real-time state label is obtained.

[0033] The application also provides a power module health state monitoring system, comprising a preprocessing unit and a real-time processing unit.

[0034] The preprocessing unit comprises the following:

[0035] An acquisition module is configured to acquire a plurality of output currents and output voltages of the first power module at different temperatures in an initial state.

[0036] A first state determination module is configured to draw an initial output characteristic curve graph according to the output currents and output voltages at different temperatures, determine the intersection points of the curves of the output currents and output voltages at different temperatures in the output characteristic curve graph, and obtain an initial state label.

[0037] An operation module is configured to control the first power module to work until failure.

[0038] A second state determination module is configured to acquire a plurality of output currents and output voltages of the first power module at different temperatures in a failure state and / or a plurality of intermediate states synchronously when the operation module is executed, draw a failure output characteristic curve graph and / or an intermediate output characteristic curve graph, and obtain a failure state label and / or at least one intermediate state label.

[0039] The real-time processing unit comprises the following:

[0040] An acquisition module is configured to acquire a plurality of output currents and output voltages of the first power module at different temperatures in an initial state.

[0041] A processing module is configured to obtain a target result of the health state of the power module in the running state according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label on a preset coordinate axis.

[0042] After the above technical scheme is adopted, the following beneficial effects are achieved compared with the prior art:

[0043] The application provides an online monitoring method and system for the health state of a power module, which acquires a first power module in an initial state, determines an initial state label according to the intersection of an output characteristic curve, and then operates the first power module in a test environment to synchronously acquire a failure state label and / or at least one intermediate state label. The output current and output voltage of a second power module in a real-time working scene are collected, the second power module generates heat during operation and dissipates heat through a heat sink, at this time, temperature changes occur, the intersection of the output current and voltage curves formed at different temperatures, i.e., a real-time state label, is collected, and based on the distribution of the real-time state label relative to the initial state label, the failure state label and / or the at least one intermediate state label, a target result of the health state of the power module in a running state is acquired, the influence of the aging of a binding wire (even including a conductive part or a chip) on the service life is considered in the calculation of the health state of the power module, and the problem that there is no method for real-time online monitoring of the health state of a power module is solved. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 A flowchart of the online monitoring method for the health state of a power module according to the first embodiment of the application;

[0045] Figure 2 An output characteristic curve of the first power module or the second power module in the initial state in the online monitoring method for the health state of a power module according to the first embodiment of the application;

[0046] Figure 3 An intermediate output characteristic curve of the first power module in the online monitoring method for the health state of a power module according to the first embodiment of the application;

[0047] Figure 4 An output characteristic curve of the first power module in multiple intermediate states in the online monitoring method for the health state of a power module according to the first embodiment of the application;

[0048] Figure 5 A flowchart for acquiring a real-time state label in the online monitoring method for the health state of a power module according to the first embodiment of the application;

[0049] Figure 6 A real-time output characteristic curve in the online monitoring method for the health state of a power module according to the first embodiment of the application;

[0050] Figure 7 A module schematic diagram of the monitoring system for the health state of a power module according to the application.

[0051] FIGURE LABELS:

[0052] 7 - Monitoring system of the health status of the power module; 71 - Pre-processing unit; 72 - Real-time processing unit; 711 - Acquisition module; 712 - First status determination module; 713 - Operation module; 714 - Second status determination module; 721 - Acquisition module; 722 - Processing module. DETAILED DESCRIPTION

[0053] The advantages of the present application are further set forth in the description that follows, and will be appreciated by persons skilled in the art upon reading and understanding the attached figures and detailed description.

[0054] Exemplary embodiments are described herein below with reference to the accompanying drawings. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It can be evident, however, that the present application can be practiced without these specific details. In other instances, well-known structures and functions have not been described in detail in order to avoid obscuring the description of the one or more embodiments.

[0055] The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in the description of the present application and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It also will be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0056] It is to be understood that the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It is to be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0057] In the description of the present application, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are terms of convenience and are not to be construed as limiting on the present application unless otherwise indicated by context. Accordingly, the application is not limited to the precise arrangements and instrumentalities shown in the drawings.

[0058] In the description of the present application, unless otherwise specified and limited, it is necessary to explain that the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be mechanical connection or electrical connection, it can be the communication inside two elements, it can be direct connection or indirect connection through intermediate medium, and the specific meaning of the above terms can be understood by the person skilled in the art according to the specific circumstances.

[0059] In the subsequent description, the suffix such as "module", "component" or "unit" used to represent the element is only for the convenience of the description of the present application, and has no specific meaning in itself. Therefore, "module" and "component" can be used mixedly.

[0060] Embodiment one: the present embodiment discloses a kind of online monitoring method of power module health state, the output characteristic curve (i.e. the change curve of output voltage and output current) of power module is considered in different temperatures Form an intersection point (see Figure 2 Wherein I ce Real-time current, U ce Real-time voltage), The intersection point will gradually shift with the aging process of the binding line (and / or conductive part, chip, conductive part includes but is not limited to binding line, wire, etc.) of power module. Therefore, by monitoring the trend of the intersection point, the real-time online health status of the power module can be evaluated, see Figure 1 , including the following steps:

[0061] S100: obtain a plurality of output currents and output voltages of a first power module at different temperatures in initial state;

[0062] In the above steps, the initial state is 100% healthy state, i.e. the best health state, it should be noted that in this method, the initial state of each power module obtained from the same preparation process is consistent, as described above, in order to obtain the intersection point in initial state, the output current and voltage at different temperatures need to be obtained, here the different temperatures can be achieved by placing the first power module in an external auxiliary device environment with controlled temperature, it should be noted that in this method, the different temperatures refer to a plurality of temperature points (or ranges), and there is a temperature difference between each temperature point, the temperature difference between each temperature can be set to be consistent or inconsistent, which is used to obtain the intersection point generated according to different temperatures.

[0063] S200: draw an initial output characteristic curve according to the output current and output voltage at different temperatures, determine the intersection point of the output current and output voltage curve at different temperatures in the output characteristic curve, and obtain an initial state label;

[0064] Specifically, after obtaining the output current and output voltage, the output characteristic curves at different temperatures can be drawn (see Figure 2 ), the horizontal axis of which is the output voltage and the vertical axis is the output current. At each temperature, a current / voltage change curve can be obtained, wherein, according to the output characteristic curve of Figure 2 , the change function of Vce and Ice can be obtained, wherein, T j is the junction temperature (the junction temperature is the highest temperature of the actual semiconductor chip (wafer, die) in the electronic device), V0 is the on-state voltage drop at T j0 , R0 is the power chip resistance at T j0 , a and b are temperature coefficients. The intersection point of each current / voltage change curve corresponds to the data (including but not limited to XY axis position (i.e. corresponding U, I value), slope of the intersection point, health status 100%) in the initial state label in this method. As an illustration, the state label in this embodiment includes but is not limited to the information corresponding to the intersection point in the XY axis position (i.e. corresponding U, I value), the slope of the intersection point, the health status, etc.

[0065] S300: Control the first power module to work until failure;

[0066] Specifically, obtaining any power module (i.e. the first power module described above) under a certain preparation process can control its work to failure in a test environment (power cycle test) (specifically, the judgment standard of failure can be set according to the specific implementation scene, including but not limited to that the output current reaching the preset value is failure). The intersection points of the output characteristic curves of the power module at different temperatures under the initial state, the failure state and / or multiple intermediate states are obtained, so as to subsequently monitor the real-time health status of other power modules in the actual application environment.

[0067] S400: Synchronously obtain multiple output currents and output voltages of the first power module at different temperatures under the failure state and / or multiple intermediate states to draw failure output characteristic curve graph and / or intermediate output characteristic curve graph, and obtain failure state label and / or at least one intermediate state label;

[0068] Specifically, during the operation process of the above step S300, multiple intersection points in the working process can be synchronously obtained while controlling the first power module to work (see Figure 3 and Figure 4 , Figure 3 is the output characteristic curve graph (i.e. intermediate output characteristic curve graph) under an intermediate state (10 km cycle), wherein Figure 4For the local enlarged view of the intersection of the curves, the flower-shaped mark can be more clearly seen, which is the intersection point in different states (junction temperature 80K, 10km, 20km, 40km, 80km cycle). It can be seen that the overall intersection point moves to the right and down with the decrease of the life of the power module. According to the data corresponding to the intersection points, a plurality of state labels can be generated, which are used to represent the health status of the first power module in different states, so as to obtain the real-time health status according to the measured intersection point in the real-time environment. The intermediate state can be set to one or more.

[0069] S500: Collecting real-time output current, real-time output voltage and real-time temperature of the second power module in running state, and drawing real-time output characteristic curve diagram, to obtain real-time state label according to the intersection of the curves generated by the real-time output current and real-time output voltage at different temperatures; wherein the initial state of the second power module is consistent with the initial state of the first power module;

[0070] It should be noted that the real-time temperature is controlled by self-heating and heat dissipation of the second power module in running state, that is, when the second power module is used in a certain automobile system, the second power module will generate self-heating or use heat dissipation elements to dissipate heat when the automobile running state changes (such as braking or instantaneous acceleration). At this time, the temperature will change, so that different output voltages and output currents under multiple real-time temperatures can be obtained. Since the automobile state change time trigger is short, it is not necessary to wait for the temperature change time as in the existing method of controlling the temperature to monitor the life of the power module. Based on the real-time output current, real-time output voltage and real-time temperature in running state, the real-time health status of the second power module (which can include one or more) can be monitored online.

[0071] It should be noted that in actual operation, each time the automobile running state changes, a current and voltage at multiple temperatures can be obtained, which is recorded as a point in the output characteristic curve diagram. When the automobile running state changes multiple times, multiple currents and resistances can be obtained, that is, multiple points are recorded in the output characteristic curve diagram, and multiple points can form multiple curves to form intersection points. Specifically, the real-time output characteristic curve diagram is drawn to obtain the real-time state label according to the intersection of the curves generated by the real-time output current and real-time output voltage at different temperatures, as shown in Figure 5 , including:

[0072] S510: Setting the real-time output current, real-time output voltage and real-time temperature collected in any state as a mark;

[0073] That is, as mentioned above, during the use of the second power module, the temperature change cannot be directly controlled. Therefore, it relies on the self-heating and heat dissipation caused by changes in the vehicle's state to achieve online health status monitoring. Thus, the output voltage, output current and corresponding real-time temperature are collected in real time. When the tags obtained from several collections are integrated into different output voltages and output currents at the same temperature, they can be integrated into different output voltages and output currents.

[0074] S520: Each mark falls into a preset current and voltage change graph, and a real-time output characteristic curve is plotted.

[0075] Specifically, each marker is displayed as a point on the terminal of a preset current and voltage change graph, where the horizontal axis represents voltage and the vertical axis represents current. Points at the same temperature can be connected to form a curve (e.g., ...). Figure 6 in the I / U diagram).

[0076] S530: Based on the shadow area formed by each marker, determine the part with the smallest shadow area as the intersection point, and obtain the real-time status label.

[0077] Specifically, in this method, in order to determine the health status of the power module, the final intersection point formed within the output characteristic curve is used as the basis for judgment. Since the curves of different currents and voltages of the power module under the same health status at different temperatures have only one intersection point, the display points corresponding to the above-mentioned markers will converge into two shadows connected by the intersection point. Thus, the information of the intersection point can be clearly shown from the preset current and voltage change graph, including but not limited to the XY axis position, the slope of the position, etc. The collection of various information generates a real-time status label.

[0078] S600: Based on the positional distribution of the real-time status tag relative to the initial status tag, failure status tag, or intermediate status tag on a preset coordinate axis, obtain the target result of the health status of the power module under the operating state.

[0079] Specifically, preferably, to facilitate a clear display of the location distribution, initial state labels, failure state labels, or intermediate state labels can be written into a preset coordinate axis (i.e., as shown in the image). Figure 6 As shown in the figure, U is the X-axis and I is the Y-axis, and the real-time status labels are also written into it for comparison and visualization. The location distribution of the real-time status labels can be determined in various ways, including but not limited to the following four methods proposed in this embodiment. It is preferable to use any one of these methods for calculation, or to use a combination of several methods for calculation. Here, the following four methods are described in detail.

[0080] Method 1: Calculate the location distribution of real-time status tags in the current and / or voltage dimensions to determine the target result.

[0081] Specifically, the target result of the health status of the power module in the running state is obtained according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label in the preset coordinate axis, including the following:

[0082] S611: Calculate the offset of the real-time state label relative to any two of the initial state label, the failure state label or the intermediate state label in the current dimension and / or the voltage dimension;

[0083] Specifically, the offset is the offset in the current dimension or the voltage dimension, which can be, for example, the offset of the real-time state label (point A) relative to the initial state label (point B) and the failure state label (point C) in the X axis or the Y axis, or the offset in both axes. Since the health status of the power module is nonlinear, considering the offset in both axes is more accurate, but only considering any one of the offsets can also be used for calculating the offset degree below.

[0084] S612: Calculate the proportion of the offset in the total amount of current dimension change of the two labels to obtain the offset degree;

[0085] Specifically, the offset degree is the offset proportion of (point A) relative to the initial state label (point B) and the failure state label (point C) in the X axis or the Y axis.

[0086] S613: Convert the offset degree to percentage to obtain the target result of the health status of the power module in the running state.

[0087] Specifically, after obtaining the offset degree in the above steps, since the health status in the initial state is 100%, if the initial state label and the aging state label are used as the reference, it can be directly multiplied by 100%. If the intermediate state label is used as the reference, it needs to be converted according to the health status difference of the two labels.

[0088] Method two: calculate the position distribution according to the slope of the position of the real-time state label to determine the target result:

[0089] Specifically, the target result of the health status of the power module in the running state is obtained according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label in the preset coordinate axis, including the following:

[0090] S621: Calculate the curve slope of the intersection point corresponding to the initial state label, the failure state label or the intermediate state label, as the first slope, the second slope or the third slope, respectively;

[0091] It should be noted that the slope of the curve can be the slope of the curve at the same temperature corresponding to the initial state label, the failure state label or the intermediate state label, or the slope of the straight line formed by the intersection and the origin, but the calculation method of each slope remains consistent, that is, the slope of the curve at a certain temperature or the slope formed with the origin is used.

[0092] S622: Obtain the slope of the curve at the intersection corresponding to the real-time state label as a fourth slope;

[0093] Specifically, the slope of the curve at the intersection corresponding to the real-time state label is consistent with the calculation method of the first, second or third slope.

[0094] S623: According to the change of the fourth slope relative to any two of the first, second or third slopes;

[0095] As an illustration, the change of the fourth slope relative to any two slopes can be the change ratio or the change value (i.e., the change value can be obtained by four-section weighting in combination with the following method)

[0096] S624: Calculate the proportion of the change of the fourth slope in the change of the two slopes, and perform percentage conversion to obtain the target result of the health state of the power module under the running state.

[0097] Specifically, similar to method one, the percentage conversion is directly multiplied by 100% when the first and second slopes are used as references, and the difference between the relative two labels is used as a reference for conversion when the third slope and the other are used as references.

[0098] Method three: Calculate a plurality of intermediate state labels and generate a state change curve graph to determine the health state corresponding to the real-time state label to obtain the target result:

[0099] Specifically, the target result of the health state of the power module under the running state is obtained according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label on the preset coordinate axis, including the following:

[0100] S631: Determine a plurality of intermediate state labels, generate a state change curve graph according to the initial state label, the failure state label and each intermediate state label, and store it in a preset address;

[0101] Specifically, a plurality of intermediate state labels are determined, that is, in the process of steps S300-S400, the more intermediate state labels obtained by the method, the higher the accuracy. As a further preferred embodiment, after generating the state change curve, a change function can be calculated according to each label. The change function is a target result obtained directly from the values of the corresponding points of the labels in the preset coordinate axis. The change function can also be generated with the aid of a model and autonomously calculated.

[0102] S632: Matching the label consistent with the real-time state label position from the state change curve at a preset address to obtain a target result with the health status of the power module in the running state.

[0103] In the above steps, the label consistent with the real-time state label position is matched to directly obtain the corresponding health status, which is convenient and fast.

[0104] Method four: According to the health status change trend of the power module, the area where the real-time state label is located is determined, and a target result is obtained by weighted calculation according to the position distribution of the state label.

[0105] Specifically, the target result with the health status of the power module in the running state is obtained according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label in the preset coordinate axis, including the following:

[0106] S641: Dividing the initial state label and the failure state label into a plurality of areas according to a preset standard;

[0107] Specifically, the aging speed of the power module presents a trend of fast-slow-fast, so the initial state label and the failure state label can be divided into at least three areas, and the change speed of each area is different

[0108] S642: Calculating the distance between the real-time state label and the initial state label or the failure state label, and the ratio of the distance between the initial state label and the failure state label;

[0109] In this embodiment, the total change function between the initial state label and the failure state label (or a preset basic change function, a general function, etc.) can be used as a basis, that is, the distance change between the real-time state label and the initial state label is weighted in each area. It should be noted that the calculation of the above distance can use the distance calculation in the coordinate axis or use common distance calculation algorithms (including but not limited to Euclidean distance, etc., which can be selected according to actual use scenarios).

[0110] S643: According to the area where the real-time state label is located, the ratio is weighted and percentage converted to obtain a target result of the health status of the power module in the running state.

[0111] Specifically, as an example, the area where the real-time state label is located can be determined according to the range in which the numerical value corresponding to XY under the coordinate axis falls. At the same time, the percentage conversion in the fourth method is different from the operation in the first method and the second method. The percentage conversion here is to multiply the numerical value obtained in the above step by 100% for percentage conversion, because the initial state label and the aging state label are used as references in the above step.

[0112] It should be noted that the above four methods are used to determine the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label, and the target result is obtained based on this. The above four methods can be combined with each other, such as the first method and the fourth method, which are weighted in the current dimension and the current dimension; or the first method and the third method, which are used to fill the numerical value in the state change curve by using the first method. This method does not limit this. Other methods for determining the position distribution in the coordinate system can also be used.

[0113] The online monitoring method of the health status of the power module provided in the embodiment uses the characteristic that the output characteristic curve will form an intersection point at different temperatures, which will gradually shift with the aging process of the binding line (conductive member or chip) of the power module. The position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label is calculated, so as to determine the health status of the current power module in real time. Since the output current and the output voltage are collected, the impact of the aging of the binding line, the conductive member (including but not limited to the binding line, the wire and the like) or the chip on the service life can be considered. This is different from the existing method of calculating the aging of the power module due to the aging of the heat dissipation substrate under the power chip by using the thermal capacity or the thermal resistance, which solves the problem that there is no method for monitoring the health status of the power module.

[0114] Embodiment Two: The embodiment provides an online monitoring system 7 of the health status of a power module, which is shown in Figure 7 , comprising a preprocessing unit 71 and a real-time processing unit 72.

[0115] The preprocessing unit 71 comprises the following:

[0116] The acquisition module 711 is configured to acquire a plurality of output currents and output voltages of the first power module at different temperatures in an initial state; the initial state is a state with a health status of 100%, i.e., an optimal state, and the initial states of the power modules obtained by the same preparation process are consistent. The different temperatures refer to a plurality of temperature points (or ranges), and there is a temperature difference between each temperature point. The temperature difference between each temperature can be set to be consistent or inconsistent.

[0117] The first state determination module 712 is configured to draw an initial output characteristic curve according to the output currents and the output voltages at different temperatures, determine an intersection of a curve of the output current and the output voltage at different temperatures in the output characteristic curve, and obtain an initial state label.

[0118] Specifically, the initial state label includes, but is not limited to, XY axis positions, a slope of a position of the intersection, a health status of 100%, and the like.

[0119] The operation module 713 is configured to control the first power module to work until failure.

[0120] Specifically, the first power module can be controlled to work until failure in a test environment. The judgment standard for failure can be set according to a specific implementation scenario, including but not limited to that the output current reaching a preset value is failure.

[0121] The second state determination module 714 is configured to acquire a plurality of output currents and output voltages of the first power module at different temperatures in a failure state and / or a plurality of intermediate states, draw a failure output characteristic curve and / or an intermediate output characteristic curve, and obtain a failure state label and / or at least one intermediate state label, when the operation module is executed.

[0122] The real-time processing unit 72 includes the following:

[0123] The acquisition module 721 is configured to acquire real-time output currents, real-time output voltages, and real-time temperatures of the second power module in a running state, draw a real-time output characteristic curve, and obtain a real-time state label according to an intersection of a curve generated by the real-time output currents and the real-time output voltages at different temperatures; the initial state of the second power module is consistent with the initial state of the first power module.

[0124] It should be noted that the real-time temperature is controlled by the second power module in the running state, that is, when the second power module is used in a certain automobile system, when the automobile running state changes (such as braking or instantaneous acceleration), the second power module will generate self-heating or use the heat dissipation element to dissipate heat, at this time the temperature will change. In actual operation, each time the automobile running state changes, a current and voltage at multiple temperatures can be obtained, which is recorded as a point in the output characteristic curve diagram, and multiple currents and resistances can be obtained when the automobile running state changes multiple times, that is, multiple points are recorded in the output characteristic curve diagram, and multiple points can form multiple curves to form an intersection, that is, a real-time state label.

[0125] The processing module 722 is configured to obtain a target result of the health state of the power module in the running state according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label on the preset coordinate axis.

[0126] Specifically, the position distribution of the real-time state label can be determined in various ways, including but not limited to the four methods proposed in the present embodiment: calculating the position distribution of the real-time state label in the current dimension or the voltage dimension, calculating the position distribution according to the slope of the position where the real-time state label is located, calculating multiple intermediate state labels and generating a state change curve diagram to determine the health state corresponding to the real-time state label, and obtaining the target result by partitioning and weighting calculation according to the health state change trend of the power module. The foregoing four methods can be selected in any one or a combination of multiple methods to obtain the target result.

[0127] In the embodiment, the initial state label, the failure state label and / or the intermediate state label are acquired in the preprocessing unit 71, the real-time state label is determined by the real-time processing unit 72, and the health state of the power module is determined based on the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label, so that real-time monitoring is realized. Specifically, in the real-time processing unit 72, the output voltage and current of the first power module in the initial state are acquired by the acquisition module 711, and the initial state label is determined by the first state determination module 712 according to the intersection of the output characteristic curve diagram, and then the first power module is operated in the test environment by the operation module 713, and the failure state label and / or at least one intermediate state label are synchronously obtained by the second state determination module 714 during the execution of the operation module 713. In the real-time processing unit 72, the output current and output voltage of the second power module in the real-time working scene are acquired by the acquisition module 721. Since the second power module will generate self-heating or use the heat dissipation of the heat dissipation element when the automobile running state changes (such as braking or instantaneous acceleration), temperature changes will occur at this time, and the intersection formed by the output current and voltage curve at different temperatures, i.e. the real-time state label, can be acquired. The target result of the real-time health state of the power module in the running state for online monitoring is obtained by the processing module 722 using one or more calculation methods of the current dimension or the voltage dimension, the slope, multiple intermediate state labels or partition weighted calculation. In the calculation of the health state of the power module, the influence of the binding wire, the conductive part or the chip aging on the service life is considered, so that the problem that there is no method for monitoring the health state of the power module binding wire or the conductive part is solved.

[0128] It should be noted that the embodiments of the present application have better implementation, and do not limit the present application in any form. Any skilled person in the art can change or modify the above-mentioned disclosed technical content into equivalent effective embodiments, as long as the content of the technical scheme of the present application is not deviated, and any modification or equivalent change and modification of the above-mentioned embodiments according to the technical essence of the present application are still within the scope of the technical scheme of the present application.

Claims

1. An online monitoring method of the health state of a power module, characterized in that, The method comprises the following steps: acquiring a plurality of output currents and output voltages of a first power module at different temperatures in an initial state; drawing an initial output characteristic curve according to the output currents and output voltages at different temperatures, determining the intersection of the curves of the output currents and output voltages at different temperatures in the output characteristic curve, and obtaining an initial state label; the state label comprises the position of the intersection on a preset coordinate axis, the slope of the position where the intersection is located, and a health state, wherein the initial health state is 100%, the X-axis of the preset coordinate axis is voltage, and the Y-axis is current; controlling the first power module to work until failure; synchronously acquiring a plurality of output currents and output voltages of the first power module at different temperatures in a failure state and / or a plurality of intermediate states, drawing a failure output characteristic curve and / or an intermediate output characteristic curve, determining the intersection of the curves of the output currents and output voltages at different temperatures in the output characteristic curve, and obtaining a failure state label and / or at least one intermediate state label; acquiring real-time output currents, real-time output voltages and real-time temperatures of a second power module in a running state, and drawing a real-time output characteristic curve to obtain a real-time state label according to the intersection of the curves generated by the real-time output currents and real-time output voltages at different temperatures; wherein the initial state of the second power module is consistent with the initial state of the first power module; obtaining a target result according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label on the preset coordinate axis.

2. The on-line monitoring method according to claim 1, characterized in that, The method of obtaining a target result according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label comprises the following steps: calculating the offset of the real-time state label relative to any two of the initial state label, the failure state label or the intermediate state label in the current dimension and / or the voltage dimension; calculating the proportion of the offset in the total change of the current dimension of the two labels to obtain an offset degree; performing percentage conversion on the offset degree to obtain a target result.

3. The on-line monitoring method according to claim 1, characterized in that, The method of obtaining a target result according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label comprises the following steps: calculating the curve slope at the intersection corresponding to the initial state label, the failure state label or the intermediate state label as a first slope, a second slope or a third slope respectively; obtaining the curve slope at the intersection corresponding to the real-time state label as a fourth slope; obtaining the change of the fourth slope relative to any two of the first slope, the second slope or the third slope; calculating the proportion of the change of the fourth slope in the change of the two slopes, and performing percentage conversion to obtain a target result.

4. The on-line monitoring method according to claim 1, characterized in that, The method of obtaining a target result according to the position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label comprises the following steps: determining a plurality of intermediate state labels, generating a state change curve according to the initial state label, the failure state label and each intermediate state label, and storing in a preset address. Matching the tag consistent with the real-time state tag position from the state change graph at a preset address, a target result is obtained.

5. The on-line monitoring method according to claim 1, characterized in that, The target result is obtained according to the position distribution of the real-time state tag relative to the initial state tag, the failure state tag or the intermediate state tag, including: According to a preset standard, the initial state tag and the failure state tag are divided into multiple regions; The distance between the real-time state tag and the initial state tag or the failure state tag is calculated, and the ratio of the distance between the initial state tag and the failure state tag is calculated. According to the region where the real-time state tag is located, the ratio is weighted and percentage converted to obtain a target result.

6. The online monitoring method of claim 1, wherein: The real-time temperature is controlled by self-heating and heat dissipation of the second power module in the running state.

7. The on-line monitoring method of claim 1, wherein: A real-time output characteristic curve graph is drawn to obtain a real-time state tag from the intersection of curves generated by the real-time output current and the real-time output voltage at different temperatures, including: Setting the real-time output current, real-time output voltage and real-time temperature collected in any state as a mark; Each mark falls into a preset current and voltage change graph, and a real-time output characteristic curve graph is drawn; According to the shadow area formed by each mark, the part with the smallest shadow area is determined as the intersection to obtain the real-time state tag.

8. An online monitoring system for the health status of a power module, comprising a preprocessing unit and a real-time processing unit, wherein: The preprocessing unit comprises: An acquisition module for acquiring multiple output currents and output voltages of a first power module at different temperatures in an initial state; A first state determination module for drawing an initial output characteristic curve graph according to the output currents and output voltages at different temperatures, determining the intersection of the curves of the output currents and output voltages in the output characteristic curve graph at different temperatures, and obtaining an initial state tag; the state tag includes the position of the intersection on a preset coordinate axis, the slope of the position of the intersection and the health status, wherein the initial health status is 100%, the X-axis of the preset coordinate axis is the voltage, and the Y-axis is the current; An operation module for controlling the first power module to work until failure; A second state determination module for synchronously acquiring multiple output currents and output voltages of the first power module at different temperatures in a failure state and / or multiple intermediate states while the operation module is executing, drawing a failure output characteristic curve graph and / or an intermediate output characteristic curve graph, determining the intersection of the curves of the output currents and output voltages in the output characteristic curve graph at different temperatures, and obtaining a failure state tag and / or at least one intermediate state tag; The real-time processing unit comprises: An acquisition module for acquiring real-time output currents, real-time output voltages and real-time temperatures of a second power module in a running state, and drawing a real-time output characteristic curve graph to obtain a real-time state tag from the intersection of curves generated by the real-time output current and the real-time output voltage at different temperatures; wherein the initial state of the second power module is consistent with the initial state of the first power module. ​ ​ The processing module is configured to obtain a target result of a health state of the power module in the running state according to a position distribution of the real-time state label relative to the initial state label, the failure state label or the intermediate state label on a preset coordinate axis.

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