Methods and related equipment for monitoring the health status of electric drive power control switches

Abstract

This application discloses a method and related equipment for monitoring the health status of an electric drive power control switch. The method includes: acquiring operating state parameters of the electric drive power control switch; if the operating state parameters meet the event triggering conditions set for a desaturation event, determining the junction temperature rise of the electric drive power control switch in the current desaturation event based on the operating state parameters using a junction temperature estimation algorithm; determining the health loss value of the electric drive power control switch in the current desaturation event based on the junction temperature rise using a pre-constructed health model for the electric drive power control switch; and calculating the health status value of the electric drive power control switch based on the health loss values ​​of the electric drive power control switch in the current desaturation event and historical desaturation events, wherein the health status value is used to characterize the health degree of the electric drive power control switch. The technical solution provided by this application can improve the accuracy of monitoring the health status of electric drive power control switches.

Description

Technical Field

[0001] This application belongs to the field of vehicle drive motor monitoring technology, and in particular relates to a method and related equipment for monitoring the health status of an electric drive power control switch. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the electric drive system, as the core power unit of the vehicle, directly determines the vehicle's driving safety, range, and service life. The electric drive power control switch, as the core power device of the electric drive system, plays a crucial role in turning the current on and off, and its health status is closely related to the stable operation of the electric drive system.

[0003] During actual vehicle operation, complex road conditions and sudden acceleration can easily trigger desaturation events, causing the electric drive power control switch to be subjected to a huge short-circuit current instantaneously. This leads to a sharp rise in chip junction temperature, causing irreversible damage to the internal structure of the device. This not only shortens its lifespan but may also cause instantaneous failure, seriously threatening driving safety. However, traditional vehicle maintenance methods are based on fixed mileage or time periods, which cannot capture the dynamic damage process of the electric drive power control switch in real time. Fixed derating strategies lack accurate assessment of the device's internal health status, failing to quantify the damage caused by each desaturation event or adjust operating parameters according to the actual health level of the device, resulting in insufficient accuracy in health status monitoring results. This may not only lead to premature replacement of spare parts, increasing maintenance costs, but may also cause system failures due to the failure to identify weakened devices in a timely manner.

[0004] Therefore, improving the accuracy of health status monitoring of electric drive power control switches has become an urgent technical problem to be solved. Summary of the Invention

[0005] The embodiments of this application provide a method, apparatus, computer program product, computer-readable storage medium, and vehicle for monitoring the health status of an electric drive power control switch, thereby improving the accuracy of monitoring the health status of the electric drive power control switch at least to a certain extent.

[0006] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0007] According to a first aspect of the present application, a method for monitoring the health status of an electric drive power control switch is provided. The method includes: acquiring operating state parameters of the electric drive power control switch; if the operating state parameters satisfy an event triggering condition set for a desaturation event, determining the junction temperature rise of the electric drive power control switch in the current desaturation event based on the operating state parameters using a junction temperature estimation algorithm; determining the health loss value of the electric drive power control switch in the current desaturation event based on the junction temperature rise using a health model pre-constructed for the electric drive power control switch; and calculating a health status value of the electric drive power control switch based on the health loss values ​​of the electric drive power control switch in the current desaturation event and historical desaturation events, wherein the health status value is used to characterize the health level of the electric drive power control switch.

[0008] In some embodiments of this application, based on the foregoing scheme, the operating state parameters include the current value of the electric drive power control switch and the duration of each current value; the event triggering conditions include: any current value is greater than or equal to the desaturation current threshold, and the duration of any current value is greater than or equal to the set duration threshold.

[0009] In some embodiments of this application, based on the foregoing scheme, the operating state parameters include the saturation voltage drop, voltage, and switching frequency of the electric drive power control switch; the step of determining the junction temperature rise of the electric drive power control switch in the current desaturation event based on the operating state parameters using a junction temperature estimation algorithm includes: calculating the minimum and maximum junction temperatures of the electric drive power control switch in the current desaturation event based on the operating state parameters using a junction temperature estimation algorithm; and determining the difference between the maximum and minimum junction temperatures as the junction temperature rise of the electric drive power control switch in the current desaturation event.

[0010] In some embodiments of this application, based on the foregoing scheme, the health model includes a power cycling capability curve characterizing the relationship between junction temperature rise and rated cycle count, wherein the rated cycle count is the maximum number of cycles that the electric drive power control switch can withstand for the corresponding junction temperature rise; the step of determining the health loss value of the electric drive power control switch in the current desaturation event based on the junction temperature rise and through a health model pre-constructed for the electric drive power control switch includes: finding the corresponding rated cycle count in the power cycling capability curve based on the junction temperature rise; and determining the reciprocal of the rated cycle count as the health loss value of the electric drive power control switch in the current desaturation event.

[0011] In some embodiments of this application, based on the foregoing scheme, calculating the health status value of the electric drive power control switch based on the health loss values ​​of the electric drive power control switch in the current desaturation event and historical desaturation events includes: calculating the health status value of the electric drive power control switch using the following formula:

[0012] in, This indicates the health status value of the electric drive power control switch; Indicates that the electric drive power control switch is in the first... Health loss value in the sub-desaturation event.

[0013] In some embodiments of this application, based on the foregoing scheme, after calculating the health status value of the electric drive power control switch, the method further includes: determining the current health level of the electric drive power control switch based on the health status value, wherein the health level is positively correlated with the health status value; if the current health level is lower than the previously determined health level, then the desaturation current threshold is lowered according to the derating factor corresponding to the current health level.

[0014] In some embodiments of this application, based on the foregoing scheme, the method further includes: determining a warning strategy that matches the health level; and issuing a warning to the electric drive power control switch according to the warning strategy.

[0015] According to a second aspect of the present application, a device for monitoring the health status of an electric drive power control switch is provided. The device includes: an acquisition unit for acquiring operating state parameters of the electric drive power control switch; a first determination unit for determining, based on the operating state parameters and using a junction temperature estimation algorithm, the junction temperature rise of the electric drive power control switch in the current desaturation event if the operating state parameters meet an event triggering condition set for a desaturation event; a second determination unit for determining, based on the junction temperature rise and using a health model pre-constructed for the electric drive power control switch, a health loss value of the electric drive power control switch in the current desaturation event; and a calculation unit for calculating a health status value of the electric drive power control switch based on the health loss values ​​of the electric drive power control switch in the current desaturation event and historical desaturation events, wherein the health status value characterizes the health level of the electric drive power control switch.

[0016] According to a third aspect of the embodiments of this application, a computer program product is provided, the computer program product including computer instructions stored in a computer-readable storage medium and adapted to be read and executed by a processor to cause a computer device having the processor to perform an operation as described in any of the first aspects above.

[0017] According to a fourth aspect of the embodiments of this application, a computer-readable storage medium is provided, the computer-readable storage medium storing at least one computer program instruction, the at least one computer program instruction being loaded and executed by a processor to perform the operation as described in any of the first aspects above.

[0018] According to a fifth aspect of the present application, a vehicle is provided, the vehicle including one or more processors and one or more memories, the one or more memories storing at least one computer program instruction, the at least one computer program instruction being loaded and executed by the one or more processors to perform the operation as described in any of the first aspects above.

[0019] Based on the technical solution proposed in this application, a complete process of acquiring parameters, determining events, calculating junction temperature rise, quantifying health losses, and calculating health status values ​​can be achieved to realize real-time monitoring and accurate evaluation of the health status of electric drive power control switches. This breaks through the limitations of traditional fixed maintenance cycles and fixed derating strategies, transforming invisible device damage into quantifiable health indicators. It can not only accurately reflect the actual health status of devices, but also provide reliable data support for subsequent dynamic derating and predictive maintenance. It can effectively avoid system failures caused by premature replacement of spare parts or device failure due to inaccurate monitoring, thereby ensuring the reliability of the electric drive system while reducing the total life cycle maintenance cost. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 A flowchart of a method for monitoring the health status of an electric drive power control switch according to an embodiment of this application is shown; Figure 2 A schematic diagram of the power cycling capability curve in an embodiment of this application is shown; Figure 3 A block diagram of a device for monitoring the health status of an electric drive power control switch according to an embodiment of this application is shown; Figure 4 A schematic diagram of the vehicle structure in an embodiment of this application is shown. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0023] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices. It should also be noted that, for the sake of simplicity, certain components in the drawings that do not affect the interpretation of the technical solution of this application have been appropriately omitted.

[0024] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined. Therefore, the actual execution order may change depending on the actual situation.

[0025] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0026] This application proposes a monitoring scheme for the health status of an electric drive power control switch, aiming to improve the accuracy of monitoring the health status of the electric drive power control switch, thereby achieving precise quantification of device damage and real-time assessment of its health status.

[0027] Next, this application will elaborate on the proposed monitoring scheme for the health status of the electric drive power control switch. (Refer to...) Figure 1 The flowchart illustrates a method for monitoring the health status of an electric drive power control switch according to an embodiment of this application. This method can be executed by a device with computational processing capabilities, such as... Figure 1 As shown, the method includes at least steps 110 to 140, which are described in detail below: In step 110, the operating status parameters of the electric drive power control switch are obtained.

[0028] In this application, the electric drive power control switch can be an Insulated Gate Bipolar Transistor (IGBT) module. As the core power switching device of the drive motor controller of new energy vehicles, its health status directly affects the lifespan, performance, driving reliability and safety of the vehicle's electric drive system.

[0029] In this application, the operating state parameters of the electric drive power control switch are the basis for subsequent judgment of desaturation events, calculation of junction temperature rise and health loss.

[0030] It should be noted that the desaturation event refers to a damaging operating condition in which the electric drive power control switch experiences an abnormal surge in current during operation due to complex road conditions, sudden acceleration, or other scenarios, exceeding the normal control range of the device and causing a sharp increase in the junction temperature of the electric drive power control switch. When a desaturation event occurs, the electric drive power control switch will be subjected to a huge short-circuit current instantaneously, and its saturation voltage drop, voltage, and other operating parameters will simultaneously show abnormal changes.

[0031] Continue to refer to Figure 1 In step 120, if the operating state parameters meet the event triggering conditions set for the desaturation event, then based on the operating state parameters, the junction temperature rise of the electric drive power control switch in the current desaturation event is determined by the junction temperature estimation algorithm.

[0032] In this application, the operating state parameters may include the current value of the electric drive power control switch and the duration of each current value.

[0033] In this application, true desaturation events can be filtered out by pre-set event triggering conditions, avoiding misjudging normal current fluctuations as damaging desaturation events. Specifically, the event triggering conditions may include: any current value is greater than or equal to a desaturation current threshold, and the duration of the maintenance of any current value is greater than or equal to a set duration threshold.

[0034] In this application, the current value in the operating status parameters is the core data for determining whether an overcurrent has occurred, while the duration of the current value is used to distinguish between instantaneous peak current and a true desaturation event. This is because factors such as circuit interference may cause the current to momentarily exceed the threshold, but such instantaneous fluctuations will not cause substantial damage to the electric drive power control switch. Only when the over-threshold current lasts for a certain period of time will it cause a sharp increase in junction temperature and form desaturation damage.

[0035] In this application, the desaturation current threshold can be set by combining the rated current of the electric drive power control switch and the initial maximum operating current. The desaturation current threshold can be a preset multiple of the initial maximum operating current. It should be noted that the initial maximum operating current can be calculated based on the most severe normal operating conditions (such as the highest ambient temperature, the maximum heat sink thermal resistance, etc.) to ensure the safety of the desaturation current threshold setting.

[0036] In this application, the set duration threshold can be used to filter transient interference. For example, the set duration can be set to 1~10μs, and the specific value can be adjusted according to the circuit characteristics and device performance of the electric drive system.

[0037] For example, in a specific embodiment, assuming the rated current of the electric drive power control switch is 100A, the initial maximum operating current determined based on the most severe normal operating conditions is 80A, the desaturation current threshold is set to 1.125 times the initial maximum operating current, i.e., 90A, and the duration threshold is set to 5μs. During vehicle operation, the monitoring system can collect the current value and corresponding duration of the electric drive power control switch in real time. When the monitored current value is 92A and the duration is 3μs, although the current value exceeds the desaturation current threshold of 90A, the duration does not reach the set duration threshold of 5μs, so it is determined that no desaturation event has occurred. When the monitored current value is 95A and the duration is 6μs, both the current value ≥ 90A and the duration ≥ 5μs are satisfied, so it is determined that the electric drive power control switch has experienced a desaturation event.

[0038] In this application, after a desaturation event is triggered, the junction temperature rise caused by the desaturation event can be accurately calculated based on the operating state parameters and the junction temperature estimation algorithm. The junction temperature rise is a key indicator reflecting the degree of device damage, because the sharp increase in junction temperature during a desaturation event can cause irreversible damage to the internal structure of the device.

[0039] Based on the above scheme, by clearly defining the current value and duration of the operating status parameters, as well as the corresponding event triggering conditions, it is possible to accurately distinguish between genuine desaturation events and instantaneous current fluctuations or circuit interference, avoid misjudgment and omission of desaturation events, ensure the accuracy of subsequent junction temperature rise and health loss value calculations, and provide a reliable event identification basis for monitoring the health status of electric drive power control switches, thereby further improving the reliability and practicality of the entire monitoring scheme.

[0040] In this application, the operating state parameters may further include the saturation voltage drop, voltage, and switching frequency of the electric drive power control switch.

[0041] In this application, the saturation voltage drop, voltage, and switching frequency are important parameters affecting the switching losses of the electric drive power control switch. The losses of the electric drive power control switch include conduction losses and switching losses, which are directly converted into heat, causing the junction temperature to rise. Therefore, these parameters need to be combined in the junction temperature estimation process to ensure the accuracy of the estimation results.

[0042] Furthermore, in such Figure 1 In step 120 shown, determining the junction temperature rise of the electric drive power control switch during the current desaturation event based on the operating state parameters using a junction temperature estimation algorithm can be performed according to steps 121 to 122 as follows: Step 121: Based on the operating state parameters, calculate the minimum and maximum junction temperatures of the electric drive power control switch in the current desaturation event using a junction temperature estimation algorithm.

[0043] Step 122: The difference between the maximum junction temperature and the minimum junction temperature is determined as the junction temperature rise of the electric drive power control switch in the current desaturation event.

[0044] In this application, the junction temperature estimation algorithm refers to a class of algorithms that calculate the junction temperature of an electric drive power control switch chip based on the operating state parameters of the switch (such as current value, saturation voltage drop, voltage, switching frequency, etc.), combined with the device characteristics, heat loss principle, and heat conduction law of the switch, through mathematical modeling or data mapping. Its core purpose is to accurately obtain junction temperature data without directly contacting the chip junction region (in scenarios where direct temperature measurement is not possible), providing core input for junction temperature rise calculation, health loss quantification, and health status assessment.

[0045] In this application, the junction temperature estimation algorithm may include the semiconductor loss model method. Its core principle is that the junction temperature rise of the electric drive power control switch originates from its own losses (electrical energy converted into heat energy). These losses mainly include conduction losses and switching losses (turn-on losses and turn-off losses), and in some scenarios, parasitic losses also need to be considered. The algorithm first calculates the total losses based on the operating state parameters, and then, combined with the device's thermal resistance model, estimates the junction temperature change using the heat conduction formula.

[0046] In this application, the junction temperature estimation algorithm may also include the thermal impedance model method. Its core principle is: based on the thermal impedance curve of the electric drive power control switch (which can be provided by the manufacturer to characterize the response relationship between junction temperature and time and loss), the loss change curve over time is convolved with the thermal impedance curve to obtain the change law of junction temperature over time.

[0047] In this application, the junction temperature estimation algorithm may also include the voltage-temperature characteristic method (Vce-Tj curve method), neural network prediction method, etc., and this application does not make specific limitations on it.

[0048] In this application, the core application scenario of the junction temperature estimation algorithm can be that when a desaturation event occurs, based on the collected operating state parameters such as current value, saturation voltage drop, voltage, and switching frequency, the minimum junction temperature before the event and the maximum junction temperature during the event can be calculated, and then the junction temperature rise can be obtained by the difference between the two, laying the foundation for the application of subsequent health models.

[0049] In this application, the minimum junction temperature may refer to the normal operating junction temperature of the electric drive power control switch before the desaturation event occurs, at which time the device is in a stable operating state and the junction temperature is relatively stable.

[0050] In this application, the maximum junction temperature can be the peak junction temperature during the desaturation event. As the current increases sharply during the desaturation event, the loss spikes instantly, and the junction temperature rises rapidly to the peak value.

[0051] In this application, the junction temperature rise is the difference between the maximum and minimum junction temperature, which can directly reflect the impact of desaturation events on the junction temperature of the device and is the core basis for quantifying health loss.

[0052] For example, in a specific embodiment, assuming a desaturation event occurs in the electric drive power control switch, the monitoring system collects operating status parameters including a saturation voltage drop of 1.5V, a DC bus voltage of 350V, a switching frequency of 10kHz, a current value of 60A before the event, and a peak current of 105A during the event. Using a semiconductor loss model as the junction temperature estimation algorithm, the system first calculates the conduction loss based on the saturation voltage drop and current value, then calculates the switching loss based on the voltage and switching frequency, and finally combines parameters such as the heatsink thermal resistance to calculate that the normal operating junction temperature (minimum junction temperature) of the electric drive power control switch before the desaturation event is 90℃, and the peak junction temperature (maximum junction temperature) during the desaturation event is 152℃. Therefore, the junction temperature rise is 152℃ - 90℃ = 62℃.

[0053] Based on the above scheme, by supplementing operating state parameters such as saturation voltage drop, voltage, and switching frequency, and clarifying the method for calculating the junction temperature rise of the minimum and maximum junction temperatures, the calculation of the junction temperature rise becomes more comprehensive and accurate. This avoids the junction temperature estimation error caused by relying solely on current parameters, and provides accurate input data for subsequent quantification of health loss values ​​through health models. This further improves the accuracy of health status monitoring and ensures that the degree of damage caused by desaturation events to the electric drive power control switch can be truly reflected.

[0054] Continue to refer to Figure 1 In step 130, based on the junction temperature rise, the health loss value of the electric drive power control switch in the current desaturation event is determined by using a health model pre-built for the electric drive power control switch.

[0055] In this application, the health model may include a power cycling capability curve characterizing the relationship between junction temperature rise and rated cycle number, wherein the rated cycle number is the maximum number of cycles that the electric drive power control switch can withstand for the corresponding junction temperature rise.

[0056] Furthermore, the determination of the health loss value of the electric drive power control switch in the current desaturation event based on the junction temperature rise and through a pre-constructed health model for the electric drive power control switch can be performed according to the following steps 131 to 132: Step 131: Based on the junction temperature rise, find the corresponding rated number of cycles in the power cycle capability curve.

[0057] Step 132: Determine the reciprocal of the rated number of cycles as the health loss value of the electric drive power control switch in the current desaturation event.

[0058] In this application, the power cycle capability curve can be a core technical chart provided by the electric drive power control switch manufacturer, and is an inherent attribute of the electric drive power control switch. Reference Figure 2 The diagram shows a power cycle capability curve in an embodiment of this application. Figure 2 As shown, the horizontal axis of the electric drive power control switch can be the junction temperature fluctuation amplitude (i.e., the junction temperature rise in this scheme), and the vertical axis is the rated number of cycles. Its core can reflect the maximum number of cycles that the electric drive power control switch can withstand under different junction temperature fluctuation conditions. If the number of cycles is exceeded, the device will experience performance degradation (such as saturation voltage rise, thermal resistance increase) until failure.

[0059] In this application, the health loss value can be calculated by the reciprocal of the rated number of cycles. This logic is based on Miner's linear cumulative damage theory, which assumes that the damage to the device under different stress levels is linearly cumulative. When the cumulative damage reaches 1, the device fails. Therefore, the damage caused by each desaturation event can be quantified as the reciprocal of the rated number of cycles corresponding to the event, thereby achieving accurate quantification of device damage.

[0060] For example, in a specific embodiment, assuming that in the power cycle capability curve provided by the electric drive power control switch manufacturer, a junction temperature rise of 50°C corresponds to a rated cycle count of 2 × 10⁻⁶. 5 The rated number of cycles corresponding to a junction temperature rise of 60℃ is 1×10⁻⁶. 5 The rated number of cycles corresponding to a junction temperature rise of 70℃ is 3×10⁻⁶. 4 If the junction temperature rise of the electric drive power control switch during a desaturation event is 60°C, the corresponding rated cycle count can be determined by referring to the power cycle capability curve as 1×10⁻⁶. 5 Then, the health loss value of this desaturation event is 1 / (1×10^2). 5 ) = 1 × 10 -5 If another desaturation event with a junction temperature rise of 70°C occurs subsequently, the corresponding rated cycle count is 3 × 10⁻⁶. 4 Then the health loss value for this event is 1 / (3×10). 4 )≈3.33×10 -5 .

[0061] Based on the above scheme, using the power cycle capability curve provided by the manufacturer as the health model ensures the authority and accuracy of the health model, conforming to the actual loss characteristics of the electric drive power control switch. Furthermore, using the reciprocal of the rated cycle count as the health loss value, based on the mature Miner linear cumulative damage theory, allows for the precise quantification of device damage caused by desaturation events. This transforms abstract damage into concrete numerical values, providing a scientific basis for subsequent health status calculations. This solves the technical problem of traditional methods being unable to quantify device damage, improving the scientific rigor and reliability of health status monitoring.

[0062] Continue to refer to Figure 1 In step 140, based on the health loss values ​​of the electric drive power control switch in the current desaturation event and historical desaturation events, the health status value of the electric drive power control switch is calculated, and the health status value is used to characterize the health level of the electric drive power control switch.

[0063] In this application, the health status value of the electric drive power control switch is calculated based on the health loss value of the electric drive power control switch in the current desaturation event and historical desaturation events. The health status value of the electric drive power control switch can be calculated by the following formula (1):

[0064] in, This indicates the health status value of the electric drive power control switch; Indicates that the electric drive power control switch is in the first... Health loss value in the sub-desaturation event.

[0065] In this application, as shown in formula (1), the health status value (SOH) can range from 0 to 1. When the electric drive power control switch is in a brand new state, no desaturation event has occurred, and the sum of the health loss values ​​is 0. At this time, the health status value is 1 (i.e., 100%). As desaturation events occur, the health loss values ​​continue to accumulate, and the health status value gradually decreases. When the health status value drops to 0, it indicates that the cumulative damage of the device has reached its limit and failure is imminent.

[0066] In this application, the above formula (1) can intuitively reflect the inverse relationship between health loss value and health status value. By accumulating the health loss values ​​of all historical desaturation events and the current desaturation event, it can comprehensively reflect the damage accumulation of the device throughout its entire life cycle and provide users with a clear and quantitative reference for the device health status.

[0067] For example, in a specific embodiment, suppose that the electric drive power control switch has experienced 5 desaturation events since it was put into use, and the health loss value of each event is 8×10. -6 1×10 -5 9×10 -6 1.2×10 -5 1.1×10 -5 According to the above formula (1), the sum of health loss values ​​is first calculated to be 5 × 10. -5 Therefore, the health status value SOH of the electric drive power control switch is 1 - 5 × 10⁻⁵. -5=0.99995, or 99.995%, indicates that the device is currently in good health with minimal cumulative damage. If multiple desaturation events subsequently occur, and the cumulative health loss value reaches 0.05, the health status value will be 0.95 (95%), still in a good condition. When the cumulative health loss value reaches 0.5, the health status value is 0.5 (50%), indicating that the device has suffered significant cumulative damage and requires close monitoring and preparation for maintenance and replacement.

[0068] Based on the above scheme, calculating the health status value through a clear formula makes the assessment of health status more intuitive and quantitative. Users can clearly know the remaining lifespan and health status of the electric drive power control switch, avoiding the vague judgment of health status in traditional methods. The above formula (1) is based on the cumulative damage theory and comprehensively considers the impact of all desaturation events on the device, which can ensure the accuracy and comprehensiveness of the health status value, providing direct data support for subsequent dynamic derating, early warning and maintenance decisions, and realizing the transformation from preventive maintenance to predictive maintenance.

[0069] In this application, after calculating the health status value of the electric drive power control switch, the following steps 151 to 152 may also be performed: Step 151: Based on the health status value, determine the current health level of the electric drive power control switch, wherein the health level is positively correlated with the health status value.

[0070] Step 152: If the current health level is lower than the health level determined in the last time, then the desaturation current threshold is lowered according to the dereasing coefficient corresponding to the current health level.

[0071] In this application, the health level can be a range based on health status values, used to more intuitively reflect the health status of the electric drive power control switch. The higher the health status value, the higher the health level, and the longer the reliability and remaining life of the device. The lower the health status value, the lower the health level, and the higher the risk of device failure.

[0072] In this application, the setting of the derating factor needs to comprehensively consider the device's performance potential and safety redundancy. Different health levels correspond to different derating factors. The higher the health level, the closer the derating factor is to 1, allowing the device to perform at its full potential. The lower the health level, the smaller the derating factor, and the stricter the limitation on the device's operating current, in order to reduce the probability of subsequent desaturation events and delay damage accumulation. If the current health level is lower than the previously determined health level, it indicates that the device's health status is declining. At this time, lowering the desaturation current threshold can reduce the current stress on the device, avoid accelerated damage caused by continuing to bear high current after the health status has declined, and extend the device's service life.

[0073] For example, in a specific embodiment, the following table can be preset: Table 1. Mapping Relationship between Health Status and Deduction Coefficient

[0074] As shown in Table 1, in this embodiment, the health level classification criteria can be preset: A health status value of ≥90% is classified as Level 4, corresponding to a reduction coefficient of 1.0; A health status value of 70% to 90% is classified as Level 3, corresponding to a reduction coefficient of 0.95. A health status value of 50% to 70% is classified as Level 2, corresponding to a reduction coefficient of 0.85. A health status value of <50% is classified as Level 1, corresponding to a reduction coefficient of 0.70.

[0075] Assuming the initial desaturation current threshold of the electric drive power control switch is 90A, and the previously determined health status value was 92%, corresponding to a healthy level, then the calculated health status value is 85%, corresponding to a caution level. Since the current health level is lower than the previous one, the desaturation current threshold is lowered to 90A × 0.95 = 85.5A using a derating factor of 0.95. If the health status value subsequently drops to 65%, corresponding to a declining health level, which is lower than the previous caution level, then the desaturation current threshold is further lowered to 85.5A × 0.85 ≈ 72.68A using a derating factor of 0.85.

[0076] Based on the above scheme, by determining the health level and dynamically adjusting the derating, the operating parameters of the electric drive power control switch can be adaptively optimized. When the device is in good health, its performance potential can be fully released, improving the efficiency of the electric drive system and the driving experience. When the device's health deteriorates, lowering the desaturation current threshold reduces current stress, delaying damage accumulation, reducing the risk of failure, and ensuring the stable operation of the electric drive system. In this way, this dynamic adjustment mechanism avoids the performance waste or insufficient derating problems caused by traditional fixed derating strategies, achieving a balance between reliability, performance, and cost, thereby further improving the usability and economy of the entire monitoring scheme.

[0077] In this application, steps 161 to 162 may also be performed: Step 161: Determine an early warning strategy that matches the health level.

[0078] Step 162: Issue an early warning to the electric drive power control switch according to the aforementioned early warning strategy.

[0079] In this application, the early warning strategy is a targeted alert mechanism based on health levels. Different health levels correspond to different early warning methods and intensities, allowing users to be promptly aware of changes in the health status of the electric drive power control switch and take appropriate maintenance measures. The early warning information can be delivered to vehicle owners, vehicle manufacturer after-sales systems, repair stations, etc., and through methods such as vehicle dashboard alerts, mobile app push notifications, and after-sales system notifications, ensuring that relevant personnel receive the early warning information in a timely manner. For higher health levels, the early warning intensity is lower, requiring only routine alerts. For lower health levels, the early warning intensity is higher, requiring explicit reminders for maintenance or replacement, and even limiting vehicle power output to compel user attention.

[0080] For example, in a specific implementation, the following early warning strategy can be formulated based on health level: When the health level (i.e., level 4) (SOH≥90%) is reached, no warning prompt may be issued, and the health status data may only be recorded in the vehicle diagnostic system. When the level of care is 3 (70%≤SOH<90%), a level 1 warning can be triggered. A yellow warning icon and the text message "Slight wear on the electric drive power control switch, it is recommended to check it during the next maintenance" will be displayed on the vehicle's instrument panel. At the same time, the warning information will be synchronized to the car manufacturer's after-sales system, which will mark the vehicle and focus on checking it during the user's next maintenance. When the level drops (i.e., Level 2) (50%≤SOH<70%), a Level 2 warning can be triggered. An orange warning icon and the text message "Electric drive power control switch is severely worn and requires maintenance within 1 month" will be displayed on the vehicle's instrument panel. At the same time, a maintenance reminder will be pushed to the user's mobile APP, and the after-sales system will proactively contact the user to schedule a repair and push the address of the nearest repair station. When the danger level (i.e., Level 1) (SOH < 50%) is reached, a Level 3 warning can be triggered. A red warning icon and the text message "Electric drive power control switch is about to fail, stop immediately and replace" will be displayed on the vehicle's instrument panel. At the same time, the vehicle's electronic control unit will limit power output, with the maximum speed not exceeding 60 km / h. After receiving the rescue request, the service station will synchronize the vehicle's location and component health data and arrange emergency rescue.

[0081] Based on the above solution, by formulating early warning strategies that match health levels, graded early warnings for health status can be achieved. This allows users to take appropriate measures based on the intensity of the warning, avoiding maintenance delays or over-maintenance due to unclear information. Multi-channel delivery of early warning information ensures effective reach, especially for high-intensity warnings for low health levels, which compels users to pay attention to device status and prevent driving safety accidents caused by device failure. Simultaneously, the linkage between early warning information and after-sales systems and service stations enables closed-loop management from early warning to maintenance, improving maintenance efficiency, reducing maintenance costs, and further ensuring the reliability of the electric drive system and driving safety.

[0082] In this application, based on the above-mentioned inventive concept, data storage, fault tolerance mechanism, multi-scenario adaptation and other optimized designs can be integrated to further improve the reliability and applicability of this solution.

[0083] Specifically, in terms of data storage, non-volatile memory can be used to store key data and health status information related to desaturation events, forming a desaturation log. This memory has the characteristics of not losing data when power is off, having a high number of erase / write cycles, and fast read / write speeds, ensuring the continuity and security of data storage. At the same time, the desaturation log is stored locally and backed up in the cloud. When stored locally, the complete data of the most recent 1,000 events is retained, and after that, it is overwritten according to the first-in-first-out principle. Cloud backup avoids data loss due to local storage failure, ensuring the traceability of data throughout its entire lifecycle.

[0084] In terms of fault tolerance mechanisms, the monitoring system adopts a dual-sensor redundancy design, with two sensors configured for each monitoring parameter. When the data deviation between the two sensors is ≤3%, the average value is taken as the monitoring result. When the deviation is >3%, a sensor fault alarm is triggered, and the average value of historical data is temporarily used to replace it, ensuring that damage calculation and health status assessment are not interrupted. At the same time, a dual-MCU design is adopted. When the main MCU fails, the backup MCU takes over the work within 10ms, ensuring the normal issuance of derating instructions and early warning prompts, thus improving the stability of the system.

[0085] In terms of multi-scenario adaptation, this solution can also be adapted to various scenarios that use electric drive power control switches, such as electric drive systems for new energy vehicles, energy storage power stations, traction converters for rail transit, and industrial frequency converters. By simply adjusting parameters such as the desaturation current threshold, setting time threshold, and derating factor according to the operating conditions of different scenarios, accurate monitoring of the health status of electric drive power control switches under different scenarios can be achieved, which has broad promotional value.

[0086] Overall, based on the technical solution proposed in this application, by completing the entire process of acquiring parameters, determining events, calculating junction temperature rise, quantifying health losses, and calculating health status values, real-time monitoring and accurate assessment of the health status of electric drive power control switches can be achieved. This breaks through the limitations of traditional fixed maintenance cycles and fixed derating strategies, transforming invisible device damage into quantifiable health indicators. It not only accurately reflects the actual health level of the devices but also provides reliable data support for subsequent dynamic derating and predictive maintenance. This can effectively avoid system failures caused by premature replacement of spare parts or device failure due to inaccurate monitoring, thereby ensuring the reliability of the electric drive system while reducing the total life cycle maintenance cost.

[0087] The following describes an embodiment of the apparatus described in this application, which can be used to execute the method for monitoring the health status of the electric drive power control switch in the above embodiments of this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method for monitoring the health status of the electric drive power control switch described above in this application.

[0088] See Figure 3 The diagram shows a block diagram of a device for monitoring the health status of an electric drive power control switch according to an embodiment of this application.

[0089] like Figure 3 As shown, the monitoring device 300 for the health status of the electric drive power control switch according to an embodiment of this application includes: an acquisition unit 301, a first determination unit 302, a second determination unit 303, and a calculation unit 304.

[0090] The system includes: an acquisition unit 301 for acquiring operating state parameters of the electric drive power control switch; a first determination unit 302 for determining, based on the operating state parameters and using a junction temperature estimation algorithm, the junction temperature rise of the electric drive power control switch in the current desaturation event if the operating state parameters meet the event triggering conditions set for the desaturation event; a second determination unit 303 for determining, based on the junction temperature rise and using a pre-built health model for the electric drive power control switch, the health loss value of the electric drive power control switch in the current desaturation event; and a calculation unit 304 for calculating the health status value of the electric drive power control switch based on the health loss values ​​of the electric drive power control switch in the current desaturation event and historical desaturation events, wherein the health status value characterizes the health level of the electric drive power control switch.

[0091] In some embodiments of this application, based on the foregoing scheme, the operating state parameters include the current value of the electric drive power control switch and the duration of each current value; the event triggering conditions include: any current value is greater than or equal to the desaturation current threshold, and the duration of any current value is greater than or equal to the set duration threshold.

[0092] In some embodiments of this application, based on the foregoing scheme, the operating state parameters include the saturation voltage drop, voltage, and switching frequency of the electric drive power control switch; the first determining unit 302 is configured to: calculate the minimum and maximum junction temperatures of the electric drive power control switch in the current desaturation event based on the operating state parameters using a junction temperature estimation algorithm; and determine the difference between the maximum and minimum junction temperatures as the junction temperature rise of the electric drive power control switch in the current desaturation event.

[0093] In some embodiments of this application, based on the foregoing scheme, the health model includes a power cycling capability curve characterizing the relationship between junction temperature rise and rated cycle count, wherein the rated cycle count is the maximum number of cycles that the electric drive power control switch can withstand for the corresponding junction temperature rise; the second determining unit 303 is configured to: find the corresponding rated cycle count in the power cycling capability curve based on the junction temperature rise; and determine the reciprocal of the rated cycle count as the health loss value of the electric drive power control switch in the current desaturation event.

[0094] In some embodiments of this application, based on the foregoing scheme, the calculation unit 304 is configured to calculate the health status value of the electric drive power control switch using the following formula:

[0095] in, This indicates the health status value of the electric drive power control switch; Indicates that the electric drive power control switch is in the first... Health loss value in the sub-desaturation event.

[0096] In some embodiments of this application, based on the foregoing scheme, the device further includes: an adjustment unit, configured to, after calculating the health status value of the electric drive power control switch, determine the current health level of the electric drive power control switch based on the health status value, wherein the health level is positively correlated with the health status value; if the current health level is lower than the previously determined health level, then the desaturation current threshold is lowered according to the derating coefficient corresponding to the current health level.

[0097] In some embodiments of this application, based on the foregoing scheme, the device further includes: an early warning unit, configured to determine an early warning strategy matching the health level; and to issue an early warning to the electric drive power control switch according to the early warning strategy.

[0098] Based on the same inventive concept, embodiments of this application provide a computer program product, the computer program product including computer instructions stored in a computer-readable storage medium and adapted to be read and executed by a processor so as to cause a computer device having the processor to perform operations performed by the method for monitoring the health status of the electric drive power control switch as described above.

[0099] Based on the same inventive concept, embodiments of this application provide a computer-readable storage medium storing at least one computer program instruction, which is loaded and executed by a processor to implement the operation performed by the method for monitoring the health status of the electric drive power control switch as described above.

[0100] Based on the same inventive concept, this application also provides a vehicle, see reference. Figure 4 The diagram shows a structural schematic of a vehicle according to an embodiment of this application. The vehicle includes one or more memories 404, one or more processors 402, and at least one computer program (computer program instruction) stored in the memory 404 and executable on the processor 402. When the processor 402 executes the computer program, it implements the method for monitoring the health status of the electric drive power control switch as described above.

[0101] Among them, Figure 4 In this document, a bus architecture (represented by bus 400) is used. Bus 400 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 402 and memory represented by memory 404. Bus 400 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 405 provides an interface between bus 400 and receiver 401 and transmitter 403. Receiver 401 and transmitter 403 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 402 is responsible for managing bus 400 and general processing, while memory 404 can be used to store data used by processor 402 during operation.

[0102] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. When implemented in software executed by a processor, the functions can be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this application and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units can be integrated into a single processing unit, or each unit can exist physically separately, or two or more units can be integrated into a single unit.

[0103] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0104] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0105] When the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, 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 steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing computer program instructions, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0106] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for monitoring the health status of an electric drive power control switch, characterized in that, The method includes: Obtain the operating status parameters of the electric drive power control switch; If the operating state parameters meet the event triggering conditions set for the desaturation event, then based on the operating state parameters, the junction temperature rise of the electric drive power control switch in the current desaturation event is determined by the junction temperature estimation algorithm. Based on the junction temperature rise, the health loss value of the electric drive power control switch in the current desaturation event is determined by using a health model pre-built for the electric drive power control switch. Based on the health loss values ​​of the electric drive power control switch in the current desaturation event and historical desaturation events, the health status value of the electric drive power control switch is calculated, and the health status value is used to characterize the health level of the electric drive power control switch.

2. The method according to claim 1, characterized in that, The operating status parameters include the current value of the electric drive power control switch and the duration of each current value. The event triggering conditions include: any current value is greater than or equal to the desaturation current threshold, and the duration of the maintenance of any current value is greater than or equal to the set duration threshold.

3. The method according to claim 2, characterized in that, The operating status parameters include the saturation voltage drop, voltage, and switching frequency of the electric drive power control switch; The step of determining the junction temperature rise of the electric drive power control switch during the current desaturation event based on the operating state parameters using a junction temperature estimation algorithm includes: Based on the operating state parameters, the minimum and maximum junction temperatures of the electric drive power control switch in the current desaturation event are calculated using a junction temperature estimation algorithm. The difference between the maximum junction temperature and the minimum junction temperature is determined as the junction temperature rise of the electric drive power control switch in the current desaturation event.

4. The method according to claim 2, characterized in that, The health model includes a power cycling capability curve characterizing the relationship between junction temperature rise and rated cycle number, wherein the rated cycle number is the maximum number of cycles that the electric drive power control switch can withstand for the corresponding junction temperature rise. The step of determining the health loss value of the electric drive power control switch in the current desaturation event based on the junction temperature rise and using a pre-built health model for the electric drive power control switch includes: Based on the junction temperature rise, find the corresponding rated number of cycles in the power cycle capability curve; The reciprocal of the rated number of cycles is determined as the health loss value of the electric drive power control switch in the current desaturation event.

5. The method according to claim 4, characterized in that, The calculation of the health status value of the electric drive power control switch based on the health loss values ​​of the electric drive power control switch in the current desaturation event and historical desaturation events includes: The health status value of the electric drive power control switch is calculated using the following formula: in, This indicates the health status value of the electric drive power control switch; Indicates that the electric drive power control switch is in the first... Health loss value in the sub-desaturation event.

6. The method according to claim 2, characterized in that, After calculating the health status value of the electric drive power control switch, the method further includes: Based on the health status value, the current health level of the electric drive power control switch is determined, and the health level is positively correlated with the health status value; If the current health level is lower than the health level determined in the last assessment, the desaturation current threshold is lowered according to the dereasing factor corresponding to the current health level.

7. The method according to claim 6, characterized in that, The method further includes: Determine an early warning strategy that matches the health level; According to the aforementioned early warning strategy, an early warning is issued for the electric drive power control switch.

8. A device for monitoring the health status of an electric drive power control switch, characterized in that, The device includes: The acquisition unit is used to acquire the operating status parameters of the electric drive power control switch; The first determining unit is configured to determine the junction temperature rise of the electric drive power control switch in the current desaturation event based on the operating state parameters and a junction temperature estimation algorithm if the operating state parameters meet the event triggering conditions set for the desaturation event. The second determining unit is used to determine the health loss value of the electric drive power control switch in the current desaturation event based on the junction temperature rise and through a health model pre-built for the electric drive power control switch. The calculation unit is used to calculate the health status value of the electric drive power control switch based on the health loss value of the electric drive power control switch in the current desaturation event and historical desaturation events. The health status value is used to characterize the health degree of the electric drive power control switch.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one piece of program code, which is loaded and executed by a processor to perform the operations performed by the method as described in any one of claims 1 to 7.

10. A vehicle, characterized in that, The vehicle includes one or more processors and one or more memories, wherein at least one piece of program code is stored in the one or more memories, and the at least one piece of program code is loaded and executed by the one or more processors to implement the method as described in any one of claims 1 to 7.

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