Motor controller service life monitoring method and device

Abstract

The invention provides a method and device for monitoring the service life of a motor controller, and relates to the technical field of motor controllers, and the method comprises the steps: determining the service life damage degree of an inverter module according to the operation condition of a vehicle and the working parameters of the inverter module, and integrating the mutual influence among multiple factors to obtain the service life damage degree of the inverter module. The estimated life damage degree of the inverter module is more accurate; according to the working parameters and the performance parameters of the bus capacitor, the expected cycle life of the bus capacitor is determined, the expected cycle life can reflect the operation state and sustainability of the bus capacitor, and potential risks are found in advance; according to the service life damage degree of the inverter module and the expected cycle life of the bus capacitor, the service life monitoring result of the motor controller is determined, the service life state of the inverter module and the service life state of the bus capacitor are monitored at the same time, and the service life monitoring result of the motor controller is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor controllers, and in particular to a method and device for monitoring the life of a motor controller. Background Art

[0002] The performance and reliability of electric vehicles are directly affected by core components such as batteries, motors and motor controllers. Among them, the motor controller, as one of the key components, is used to adjust the motor's operating state to meet the vehicle's operating requirements under different working conditions. Its service life is closely related to vehicle safety.

[0003] The motor controller contains power modules, etc. The main devices used in the power module are IGBT (Insulated Gate Bipolar Transistor), MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) and other power devices and bus capacitors and other components. In the prior art, the overall life of the motor controller is usually monitored by estimating the life of the power devices in the power module, but the monitoring and analysis results are often quite different from the actual situation, and the accuracy needs to be improved. Summary of the invention

[0004] The problem to be solved by the present invention is that the accuracy of the overall life monitoring and analysis of the motor controller in the prior art is poor.

[0005] To solve the above problems, in a first aspect, the present invention provides a motor controller life monitoring method, wherein the motor controller includes an inverter module and a bus capacitor, and the motor controller life monitoring method includes:

[0006] Determining the life damage degree of the inverter module according to the operating conditions of the vehicle and the operating parameters of the inverter module;

[0007] Determining the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor;

[0008] The life monitoring result of the motor controller is determined according to the life damage degree of the inverter module or the expected cycle life of the bus capacitor.

[0009] Optionally, before determining the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module, the motor controller life monitoring method further includes:

[0010] Analyze the life cycle historical operation data of the same type of vehicle to obtain multiple operating conditions within the life cycle of the vehicle, and determine the number of cycles of each operating condition;

[0011] According to each of the operating conditions and preset boundary conditions, a simulation experiment is performed on the vehicle of the same type to obtain a temperature change curve of the inverter module corresponding to each of the operating conditions.

[0012] Optionally, determining the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module includes:

[0013] According to the operating condition of the vehicle, calling the temperature change curve of the inverter module corresponding to the operating condition;

[0014] According to the operating parameters of the inverter module, query the called temperature change curve of the inverter module to determine the junction temperature curve segment corresponding to the operating parameters of the inverter module and the junction temperature data of the junction temperature curve segment;

[0015] The life damage degree of the inverter module is determined according to the junction temperature data corresponding to the working parameters of the inverter module.

[0016] Optionally, the junction temperature data includes a junction temperature difference and a minimum junction temperature in a junction temperature curve segment corresponding to operating parameters of the inverter module, and the operating parameters of the inverter module include a conduction duration, a DC terminal current, and a blocking voltage;

[0017] Determining the life damage degree of the inverter module according to the junction temperature data corresponding to the working parameters of the inverter module includes:

[0018] Inputting the junction temperature difference, the minimum junction temperature, the on-time, the DC terminal current, the blocking voltage and the bonding wire diameter of the inverter module into an inverter expected cycle life calculation model to determine the expected cycle life of the inverter module;

[0019] Analyze the called temperature change curve of the inverter module and the junction temperature curve segment corresponding to the operating parameters of the inverter module to determine the occurrence frequency of the junction temperature curve segment under the operating condition;

[0020] Determining a single-operating-condition life damage degree of the inverter module according to the occurrence frequency of the junction temperature curve segment and the expected cycle life of the inverter module;

[0021] The life damage degree of the inverter module is determined according to the single operating condition life damage degree of the inverter module under each operating condition and the number of cycles of each operating condition.

[0022] Optionally, the operating parameters of the bus capacitor include actual operating temperature and internal temperature rise of the capacitor caused by actual ripple current;

[0023] Determining the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor includes:

[0024] The actual operating temperature, the internal temperature rise of the capacitor caused by the actual ripple current, and the performance parameters are input into a capacitor expected cycle life calculation model to determine the expected cycle life of the bus capacitor.

[0025] Optionally, determining the life monitoring result of the motor controller according to the life damage degree of the inverter module or the expected cycle life of the bus capacitor includes:

[0026] Determining whether the life damage degree of the inverter module is less than a first damage threshold;

[0027] If the life damage degree of the inverter module is greater than or equal to the first damage threshold, it is determined that the motor controller does not meet the vehicle use requirements;

[0028] If the life damage degree of the inverter module is less than the first damage threshold, determining whether the life damage degree is less than a second damage threshold, wherein the second damage threshold is less than the first damage threshold;

[0029] If the life damage degree is greater than or equal to a second damage threshold, a motor controller life warning signal is generated.

[0030] Optionally, determining the life monitoring result of the motor controller according to the life damage degree of the inverter module or the expected cycle life of the bus capacitor includes:

[0031] Determining whether the expected cycle life of the bus capacitor is less than the full life cycle of the vehicle;

[0032] If the expected cycle life of the bus capacitor is less than the full life cycle of the vehicle, it is determined that the motor controller does not meet the vehicle use requirements;

[0033] If the expected cycle life of the bus capacitor is greater than or equal to the full life cycle duration of the vehicle, determining whether the expected cycle life of the bus capacitor is less than a bus capacitor life threshold;

[0034] If the expected cycle life of the bus capacitor is less than the bus capacitor life threshold, a motor controller life warning signal is generated.

[0035] Optionally, before determining whether the expected cycle life of the bus capacitor is less than the full life cycle duration of the vehicle, the motor controller life monitoring method further includes:

[0036] The full life cycle duration of the vehicle is obtained based on the working time of each operating condition and the number of cycles of each operating condition during the full life cycle of the vehicle.

[0037] Optionally, before determining the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module, the motor controller life monitoring method further includes:

[0038] In response to the life monitoring trigger signal, determining whether a preset trigger condition of the motor controller is met, wherein the preset trigger condition includes that the motor controller is in a normal working state, the inverter module has no failure fault, and the bus capacitor has no failure fault;

[0039] If the preset trigger condition is met, performing life monitoring on the motor controller;

[0040] If the preset trigger condition is not met, it is determined that the motor controller is damaged, and the life monitoring of the motor controller is not performed.

[0041] In a second aspect, the present invention provides a motor controller life monitoring device, the motor controller includes an inverter module and a bus capacitor, and the motor controller life monitoring device includes:

[0042] A first life assessment module, used to determine the life damage degree of the inverter module according to the operating conditions of the vehicle and the operating parameters of the inverter module;

[0043] A second life evaluation module, used to determine the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor;

[0044] The life monitoring module is used to determine the life monitoring result of the motor controller according to the life damage degree of the inverter module and the expected cycle life of the bus capacitor.

[0045] The beneficial effects of the motor controller life monitoring method and device of the present invention are:

[0046] According to the operating conditions of the vehicle and the working parameters of the inverter module, the life damage degree of the inverter module is determined. In addition to paying attention to the working parameters of the inverter module, the operating conditions of the vehicle are also considered. The mutual influence between multiple factors is integrated to make the estimated life damage degree of the inverter module more accurate, reduce misjudgment, and improve user trust; according to the working parameters and performance parameters of the bus capacitor, the expected cycle life of the bus capacitor is determined, and the expected cycle life of the bus capacitor at different times can be obtained more accurately. The length of the expected cycle life can reflect the operating status and sustainability of the bus capacitor, and then potential risks can be discovered in advance and avoided in time to reduce losses when the motor controller itself does not show abnormalities; according to the life damage degree of the inverter module and the expected cycle life of the bus capacitor, the life monitoring result of the motor controller is determined, and the life status of the inverter module and the bus capacitor are monitored at the same time, further improving the comprehensiveness and accuracy of the life monitoring result of the motor controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of the structure of an electric drive system provided by an embodiment of the present invention;

[0048] Figure 2 A schematic flow chart of a motor controller life monitoring method provided by an embodiment of the present invention;

[0049] Figure 3 A schematic flow chart of another motor controller life monitoring method provided by an embodiment of the present invention;

[0050] Figure 4 A schematic diagram of the structure of a motor controller life monitoring device provided by an embodiment of the present invention;

[0051] Figure 5 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention.

[0052] Description of reference numerals:

[0053] 1. Battery; 2. Electric drive system; 21. Motor controller; 211. Control module; 212. Driver module; 213. Power module; 2131. Inverter module; 2132. Bus capacitor; 214. Life monitoring device; 22. Motor; 23. Reducer; 3. Wheel. DETAILED DESCRIPTION

[0054] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0055] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0056] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0057] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0058] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes, and are not used to limit the scope of these messages or information.

[0059] In view of the problems existing in the above-mentioned related technologies, this embodiment provides a motor controller life monitoring method, device, electronic device and storage medium.

[0060] In related technologies, such as Figure 1As shown, the electric drive system 2 includes a motor controller 21, a motor 22 and a reducer 23. The input end of the motor controller 21 is connected to the battery 1, and the output end of the motor controller 21 is connected to the motor 22 for controlling the operation of the motor 22. The output shaft of the motor 22 is connected to the input shaft of the reducer 23, and the output shaft of the reducer 23 is connected to the axle of the wheel 3. The motor 22 drives the wheel 3 to rotate through the reducer 23, thereby driving the vehicle to move. The motor controller 21 includes a control module 211, a driver module 212 and a power module 213, wherein the power module 213 includes an inverter module 2131 and a bus capacitor 2132. The motor controller 21 processes the input signal of the control module 211. The motor controller 21 processes the actual speed of the motor according to the motor rotor position signal detected by the position sensor; processes the required speed of the motor according to the operation signals such as the gear position, acceleration, and brake pedal; analyzes the difference between the required speed and the actual speed to obtain the input signal of the control module 211, and the control module 211 sends a vector control signal to the driver module 212. The driver module 212 sends the generated control signal to the power module 213 to control the switch tube in the inverter module 2131 in the power module 213 to turn on or off, thereby changing the voltage and current output by the inverter module, and then changing the speed and direction of the motor, thereby controlling the vehicle's starting operation, driving speed, braking and other driving states. The motor controller 21 can also share the running state of the electric drive system 2 through the CAN network and send it to the controller of the whole vehicle to realize the feedback of the vehicle's driving state. In the present application, a life monitoring device 214 may be further provided in the electric drive system 2, and the device may be provided inside the motor controller 21; the life monitoring device 214 may also be provided separately and located outside the motor controller 21. Figure 1 In the process, the control module 211 sends some acquired data to the life monitoring device 214. The life monitoring device 214 also acquires some working data of the inverter module 2131 and the bus capacitor 2132, comprehensively evaluates the service life status of the motor controller 21, and monitors the life of the motor controller.

[0061] The control of the motor 22 by the motor controller 21 is divided into drive control, speed control, direction control and brake control. The inverter module 2131 of the motor controller 21 inverts the DC power output by the battery 1 into three-phase AC power with adjustable voltage and frequency, supplies it to the motor 22, and transmits it to the wheels 3 at a reduced speed through the reducer 23 to drive the vehicle. The driver module 212 controls the voltage and frequency of the AC power output by the inverter module 2131 to change the speed and torque of the motor 22, thereby adjusting the speed of the vehicle. By changing the IGBT ( Figure 1The triangle in the inverter module represents the switch tube. The conduction sequence of the switch tube can change the phase sequence of the output three-phase AC power, realize the reverse rotation of the motor 22, and thus change the running direction of the car. The motor 22 can also be used as a generator to convert the recovered kinetic energy into electrical energy, generate three-phase AC power, and convert it into DC power through the inverter module 2131 and feed it back to the battery 1 for energy recovery braking.

[0062] like Figure 2 As shown, an embodiment of the present invention provides a motor controller life monitoring method, the motor controller includes an inverter module and a bus capacitor, and the motor controller life monitoring method includes:

[0063] S1: Determine the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module.

[0064] Specifically, during the actual operation of the vehicle, under different vehicle operating conditions, even if the working parameters of the inverter module are the same, the power devices in the inverter module may also show different states. For example, when the vehicle is running in a plain area and running in a plateau area, due to the different air pressure and temperature, the heat dissipation performance of the power device itself is affected, and the junction temperature of the inverter module is different; for example, when the vehicle is driving on a sunny day and driving on a rainy day, the air humidity on a rainy day is higher than that on a sunny day, which may affect the insulation resistance of the power device, or cause leakage current to increase when the power device is working, or even insulation breakdown and other problems, so that the inverter module shows different states under the same operating parameters. Therefore, when monitoring the life of the inverter module, it is necessary not only to consider the working parameters of the inverter module itself, but also the operating conditions of the vehicle. The comprehensive consideration of the two and the evaluation of the life of the motor controller based on the operating conditions of the entire life cycle of the vehicle are more in line with the actual use needs, and improve the accuracy of the evaluation of the life of the inverter module.

[0065] S2: Determine the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor.

[0066] Specifically, in the motor controller, in addition to the inverter module, which needs to be paid special attention to, the normality of the bus capacitor also has a direct impact on the life of the motor controller, so the life of the bus capacitor also limits the life of the motor controller. The life of the bus capacitor is closely related to the performance of the bus capacitor itself and the working parameters of the bus capacitor. When the bus capacitor is operated under certain abnormal working parameters, short-term operation may not cause damage to the bus capacitor or abnormality of the motor controller, but it will accelerate the damage speed of the bus capacitor, greatly shortening the life of the bus capacitor. Therefore, according to the working parameters and performance parameters of the bus capacitor, the expected cycle life of the bus capacitor can be estimated, and the length of the expected cycle life can indirectly reflect the health of the bus capacitor.

[0067] S3: Determine the life monitoring result of the motor controller according to the life damage degree of the inverter module or the expected cycle life of the bus capacitor.

[0068] Specifically, when monitoring the life of the motor controller, we first need to pay attention to the life of the consumable parts, such as the life of the power devices in the inverter module or the life of the bus capacitor. These components are the "short board" of the life of the motor controller. Most of the faults or failures of the motor controller are caused by damage to these components. Therefore, as long as the life of the inverter module and the life of the bus capacitor are normal, the probability of normal operation of the motor controller will be greatly improved. On the contrary, if the life of the inverter module and the life of the bus capacitor show abnormalities, the life of the motor controller will inevitably be affected. For example, when the bus capacitor operates under certain working parameters, the temperature rise of the bus capacitor is large, and the estimated life of the bus capacitor is significantly less than the required life span. At this time, it means that the bus capacitor is abnormal, which will cause problems in the operation of the motor controller. At this time, the user can be reminded to perform inspection and maintenance to avoid the problem from expanding.

[0069] In this embodiment, the life damage degree of the inverter module is determined according to the operating conditions of the vehicle and the operating parameters of the inverter module. In addition to paying attention to the operating parameters of the inverter module, the operating conditions of the vehicle are also considered. The mutual influence between multiple factors is integrated to make the estimated life damage degree of the inverter module more accurate, reduce misjudgment, and improve user trust; according to the operating parameters and performance parameters of the bus capacitor, the expected cycle life of the bus capacitor is determined, and the expected cycle life of the bus capacitor at different times can be obtained more accurately. The length of the expected cycle life can reflect the operating status and sustainability of the bus capacitor, and then potential risks can be discovered in advance and avoided in time to reduce losses when the motor controller itself does not show abnormalities; according to the life damage degree of the inverter module and the expected cycle life of the bus capacitor, the life monitoring result of the motor controller is determined, and the life status of the inverter module and the bus capacitor are monitored at the same time, so as to further improve the life monitoring result of the motor controller. For example, as long as the life of any component is abnormal, the life of the motor controller is determined to be abnormal. In addition, the monitoring of inverter modules and bus capacitors focuses on different life parameters. The life damage degree of the inverter module focuses on the historical cumulative usage status of the inverter module, and can also reflect the future availability of the inverter module. The expected cycle life of the bus capacitor focuses on the overall life duration of the bus capacitor, and considers the future sustainability of the bus capacitor more. Through the life damage degree of the inverter module and the expected cycle life of the bus capacitor, the performance of the motor controller is comprehensively analyzed from the historical usage and future sustainability, reflecting the timing characteristics of the motor controller life, making the monitoring more comprehensive and the life monitoring results more accurate.

[0070] Optionally, before determining the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module, the motor controller life monitoring method further includes:

[0071] Analyze the historical operation data of the same type of vehicles throughout their life cycle to obtain the multiple operating conditions within the life cycle of the vehicle, and determine the number of cycles of each operating condition.

[0072] Specifically, we collect information on road conditions such as road slope, curves, vehicle speed, and traffic lights in different cities, information on the altitude, ambient temperature, and ambient humidity of the vehicle, and information on usage scenarios such as daily travel, long-distance driving, and passenger transportation by users. Based on the above information collected on similar vehicles, we analyze the operating conditions of similar vehicles during operation. Based on big data, we analyze and disassemble the operating conditions of similar vehicles throughout their life cycle to obtain multiple operating conditions, such as operating condition 1 and operating condition 2. …… Operating condition n, these disassembled sub-conditions constitute the operating condition set. Each operating condition will appear multiple times in the entire vehicle life cycle. For example, if the route to work is relatively fixed, the vehicle operating condition may be the same, and this operating condition may appear frequently. Therefore, it is possible to count the number of times each operating condition appears repeatedly in the vehicle's historical operation records (number of cycles). In this way, only one analysis is required for the cyclic operating conditions, and there is no need to analyze the repeated operating conditions of the vehicle multiple times, reducing the number of calculations.

[0073] According to each of the operating conditions and preset boundary conditions, a simulation experiment is performed on the vehicle of the same type to obtain a temperature change curve of the inverter module corresponding to each of the operating conditions.

[0074] Specifically, based on the big data analysis, a set of operating conditions is obtained. In order to facilitate subsequent analysis, a simulation experiment is performed for each operating condition in the operating condition set. Preset boundary conditions such as local environmental conditions or usage scenario conditions can be added in the model laboratory to make the simulated results consistent with the actual operating conditions. The simulation experiment can be an actual vehicle simulation, or it can be a simulation of the operating conditions on the simulation software, so as to obtain the temperature change curve of the inverter module corresponding to each operating condition. The temperature change curve is used to represent the relationship between the working parameters of the inverter module and the junction temperature. The working parameters of the inverter module can be the working current, working voltage or working time, etc. When the temperature of the power device in the inverter module is subsequently monitored, it is not necessary to use the measured shell temperature as the junction temperature of the inverter module. Instead, according to other working parameters of the inverter module, the temperature change curve is queried to obtain a more accurate junction temperature. Compared with using the shell temperature measured by the sensor as the junction temperature, the junction temperature has higher accuracy, which is conducive to improving the accuracy of the life monitoring of the inverter module.

[0075] Optionally, determining the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module includes:

[0076] According to the operating condition of the vehicle, the temperature change curve of the inverter module corresponding to the operating condition is called.

[0077] According to the working parameters of the inverter module, the temperature change curve of the inverter module is queried and called to determine the junction temperature curve segment corresponding to the working parameters of the inverter module and the junction temperature data of the junction temperature curve segment, wherein the part with the highest temperature of the inverter module is taken as the temperature change of the entire inverter module.

[0078] Specifically, more accurate thermosensitive electrical parameters are used to monitor the temperature changes of the inverter module. Thermosensitive electrical parameters are the operating current or operating voltage of the inverter module, etc., which can be accurately measured electrical parameters. These parameters can be accurately measured by precise measuring instruments. The correlation between thermosensitive electrical parameters and temperature is used to monitor temperature changes according to changes in thermosensitive electrical parameters. Compared with the infrared measuring instrument measurement method, real-time temperature monitoring can be achieved non-destructively; compared with the embedded thermocouple test method, there is no need to specially customize the test sample, and it is irrelevant to factors such as the depth of the thermocouple position. This method obtains the junction temperature of the power device itself, and the junction temperature data is more accurate.

[0079] The life damage degree of the inverter module is determined according to the junction temperature data corresponding to the working parameters of the inverter module.

[0080] In this embodiment, according to the operating condition, the temperature change curve corresponding to the operating condition is called, and according to the working parameters of the inverter module, the temperature change curve is queried to determine the junction temperature data. In combination with the actual operating condition of the vehicle, different temperature change curves are called under different operating conditions, and then the actual working parameters of the inverter module are used to determine the junction temperature data on the temperature change curve. The obtained junction temperature data is more consistent with the actual situation, and based on this junction temperature data, the life damage degree of the inverter module obtained is more accurate.

[0081] Optionally, the junction temperature data includes a junction temperature difference and a minimum junction temperature in a junction temperature curve segment corresponding to operating parameters of the inverter module, and the operating parameters of the inverter module include on-time, DC terminal current and blocking voltage.

[0082] Determining the life damage degree of the inverter module according to the junction temperature data corresponding to the working parameters of the inverter module includes:

[0083] The junction temperature difference, the minimum junction temperature, the on-time, the DC terminal current, the blocking voltage and the bonding wire diameter of the inverter module are input into an inverter expected cycle life calculation model to determine the expected cycle life of the inverter module.

[0084] Specifically, the inverter expected cycle life calculation model is:

[0085]

[0086] Among them, N f represents the expected cycle life of the inverter module corresponding to the i-th operating parameter of the inverter module under the x-th operating condition, A represents the parameter correction coefficient, ΔT j represents the junction temperature difference, e represents the natural constant, T jmin represents the minimum junction temperature, t on represents the conduction duration, I represents the DC current, V represents the blocking voltage, d represents the bonding wire diameter of the inverter module, β1 represents the preset index of the junction temperature difference, β2 represents the preset index corresponding to the natural constant, β3 represents the preset index of the conduction duration, β4 represents the preset index of the DC current, β5 represents the preset index of the blocking voltage, and β6 represents the preset index of the bonding wire diameter.

[0087] Combined with the actual working parameters of the inverter module, such as junction temperature difference, average junction temperature, time interval, conduction duration and other parameters, the possible life of the inverter module is estimated after the inverter module continues to work according to this working parameter, and the cycle life is corrected in combination with the current working parameters to eliminate the deviation of the power cycle life caused by different boundary conditions (such as environmental conditions) during the cycle use. Therefore, the expected cycle life of the inverter module is not a fixed value, but it must be corrected in real time according to the current real-time working parameters of the inverter module. The expected cycle life indicates the number of times the inverter module continues to operate according to the working parameters.

[0088] The called temperature change curve of the inverter module and the junction temperature curve segment corresponding to the operating parameters of the inverter module are analyzed to determine the occurrence frequency of the junction temperature curve segment under the operating condition.

[0089] Specifically, the rain flow counting method is used to divide the temperature change curve of the inverter module into different junction temperature segments and count the frequency of each junction temperature segment. i , according to the current actual working parameters of the inverter module, the corresponding junction temperature curve segment and the frequency of occurrence of the junction temperature curve segment can be found on the temperature change curve.

[0090] The single-operating-condition life damage degree of the inverter module is determined according to the occurrence frequency of the junction temperature curve segment and the expected cycle life of the inverter module.

[0091] Specifically, the single operating condition life damage degree is:

[0092] Among them, D x represents the single operating condition life damage degree under the xth operating condition, n i represents the occurrence frequency of the junction temperature curve segment corresponding to the ith operating parameter of the inverter module under the xth operating condition, and N is the total number of types of operating parameters.

[0093] Under the actual operating conditions of the vehicle, the junction temperature data corresponding to the real-time operating parameters of the inverter module and the frequency of occurrence of the junction temperature data under the actual operating conditions are determined, and the expected cycle life is calculated in real time using the real-time operating parameters. At this time, the frequency of occurrence of the junction temperature curve segment and the expected cycle life of the inverter module are obtained under the same real-time operating conditions of the vehicle and the real-time operating parameters of the inverter module. Finally, the frequency of occurrence of the junction temperature curve segment and the expected cycle life of the inverter module obtained in real time are used to obtain the single-condition life damage degree of the inverter module in the motor controller of the vehicle under the operating conditions, thereby improving the assessment accuracy of the single-condition life damage degree.

[0094] The life damage degree of the inverter module is determined according to the single-condition life damage degree of the inverter module under each operating condition and the number of cycles of each operating condition. The life damage degree indicates the cumulative damage degree of the inverter module during use. When the value reaches 100%, it means that the inverter module is completely damaged.

[0095] Specifically, the lifespan damage degree is:

[0096] Where α is the life attenuation correction factor, n x represents the number of cycles of the xth operating condition, and n represents the total number of types of the operating condition.

[0097] The single-condition life damage degree and the number of cycles of each condition calculated under the historical operating conditions of the inverter module are used to obtain the accumulated life damage degree. The loss degree of the inverter module can be known through the life damage degree, so as to judge the historical use of the inverter module and predict the possibility of the inverter module's continued use in the future, thereby improving the accuracy of the junction temperature data and cycle life of the inverter module under actual operating conditions. As the use time of electrical components increases, the use status of the motor controller will gradually decay compared to the factory state. The life decay correction coefficient is increased for appropriate real-time correction to ensure the accuracy of the motor controller life assessment.

[0098] Optionally, the operating parameters of the bus capacitor include actual operating temperature and internal temperature rise of the capacitor caused by actual ripple current.

[0099] Determining the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor includes:

[0100] The actual operating temperature, the internal temperature rise of the capacitor caused by the actual ripple current, and the performance parameters are input into a capacitor expected cycle life calculation model to determine the expected cycle life of the bus capacitor.

[0101] Specifically, the expected cycle life calculation model of the capacitor is: L x =min(L max *K T *K R *KV),

[0102] Among them, L x Expected cycle life of busbar capacitor, L max For L O or L R , L O Indicates the accelerated life of the capacitor at the highest operating temperature, L R Indicates the capacitor life at the highest operating temperature and maximum ripple current, K R K R1 or K R2 , K R1 Indicates the ripple current influence coefficient at the highest operating temperature, K R2 Indicates the ripple current influence coefficient at the highest operating temperature and maximum ripple current, L O With K R1 Corresponding, L R With K R2 Corresponding to; K T Indicates the ambient temperature influence coefficient, K V Indicates the operating voltage influence coefficient. K R1 =2 -T / 5 , T O Indicates the maximum operating temperature of the capacitor, T m Indicates the internal temperature rise of the capacitor caused by the maximum allowable ripple current, T X represents the actual operating temperature, T represents the internal temperature rise of the capacitor caused by the actual ripple current, mm i n (·) indicates taking the minimum value.

[0103] In this embodiment, the real-time working parameters of the bus capacitor, such as the actual working temperature and the internal temperature rise of the capacitor caused by the actual ripple current, are input into the expected cycle life calculation model of the capacitor to determine the expected cycle life of the bus capacitor. O / L R Can be obtained in advance from the busbar capacitor specification, if only L is given in the capacitor specification O , then use the formula L x =L O *K T *K R1 *K V Calculate the expected cycle life of the busbar capacitor; if the capacitor specification only gives L R , then use the formula L x =L R *K T *K R2 *K V Calculate the expected cycle life of the busbar capacitor; if L is given in the capacitor specification O and L R The expected cycle life of the bus capacitor is calculated based on the expected cycle life of the bus capacitor. The smaller of the two expected cycle life values ​​is selected as the expected cycle life of the bus capacitor L. x .

[0104] Alternatively, if Figure 3 As shown, the determining of the life monitoring result of the motor controller according to the life damage degree of the inverter module and the expected cycle life of the bus capacitor includes:

[0105] It is determined whether the life damage degree of the inverter module is less than a first damage threshold.

[0106] Specifically, for example, the first damage threshold can be set to 100%, indicating that the inverter module is completely damaged; in addition, the first damage threshold can also be set to 98% or other values ​​to reserve a certain reaction time for the user. In actual use, the first damage threshold can be adjusted according to actual needs, and the above example values ​​do not limit the specific value of the first damage threshold. If the life damage degree of the inverter module is greater than or equal to the first damage threshold, it means that the inverter module has failed, and the life monitoring of the motor controller is terminated.

[0107] If the life damage degree of the inverter module is greater than or equal to the first damage threshold, it is determined that the motor controller does not meet the requirements for vehicle use.

[0108] If the life damage degree of the inverter module is less than the first damage threshold, determining whether the life damage degree is less than a second damage threshold, wherein the second damage threshold is less than the first damage threshold;

[0109] Specifically, if the life damage degree of the inverter module is less than the first damage threshold, it means that the inverter module has not failed and can continue to operate. At this time, it can be further determined whether the life damage degree of the inverter module is less than the second damage threshold.

[0110] If the life damage degree is greater than or equal to the second damage threshold, a life warning signal of the motor controller is generated. If the life damage degree is less than the second damage threshold, it is determined that the motor controller is in good condition.

[0111] Specifically, the second damage threshold can be set to a value less than 1, and the specific value can be adjusted according to actual needs. If the life damage degree of the inverter module is greater than or equal to the second damage threshold, it means that the damage to the inverter module is more serious and the probability of failure is high. In order to ensure the stable operation of the motor controller, an early warning signal will be generated to remind the user to promptly inspect or replace the inverter module.

[0112] Alternatively, if Figure 3 As shown, the determining of the life monitoring result of the motor controller according to the life damage degree of the inverter module or the expected cycle life of the bus capacitor includes:

[0113] Determine whether the expected cycle life of the bus capacitor is less than the full life cycle duration of the vehicle.

[0114] Specifically, the vehicle life cycle duration can be the designed operating life of the vehicle or the average actual operating life of vehicles of the same type. The vehicle life cycle operating conditions can also be converted into duration, that is, the vehicle life cycle duration can be obtained based on the working time of each operating condition and the number of cycles of each operating condition during the vehicle life cycle. For example, the motor controller working time t of operating condition 1, operating condition 2, ... operating condition n can be calculated. x And the number of cycles n corresponding to each operating condition x , using the calculation formula The full life cycle of the vehicle is obtained, and the bus capacitor also needs to support the operating life of the motor controller to meet this requirement, so the bus capacitor itself also needs to meet the requirements of the full life cycle of the vehicle.

[0115] If the expected cycle life of the bus capacitor is less than the full life cycle of the vehicle, it means that the bus capacitor may be completely damaged and cannot continue to work before the vehicle is scrapped. It is determined that the bus capacitor life does not meet the requirements for the use of the entire vehicle, and then it is determined that the motor controller does not meet the requirements for the use of the entire vehicle.

[0116] If the expected cycle life of the bus capacitor is greater than or equal to the full life cycle duration of the vehicle, it is determined whether the expected cycle life of the bus capacitor is less than a bus capacitor life threshold.

[0117] Specifically, if the expected cycle life of the bus capacitor is greater than or equal to the full life cycle duration of the vehicle, it is determined that the bus capacitor life meets the vehicle use requirements, indicating that the bus capacitor can maintain normal operation until the vehicle is scrapped.

[0118] If the expected cycle life of the bus capacitor is less than the bus capacitor life threshold, a motor controller life warning signal is generated. If the expected cycle life of the bus capacitor is greater than or equal to the bus capacitor life threshold, the motor controller is determined to be in good condition.

[0119] Specifically, the busbar capacitor life threshold can be set to rL O or rL R , where r<1, the value can be adjusted according to actual needs, such as L x <rL O or L x <rL R ,, indicating that the expected life of the bus capacitor may not meet the subsequent use requirements of the vehicle, prompting the user to pay attention to the status of the bus capacitor, generating a life warning signal, and performing a life warning for the motor controller. Prior to this, the life monitoring trigger signal can also be obtained to determine whether the preset trigger conditions of the motor controller are met. If the motor controller life monitoring is met, the service life of the motor controller is verified. If the preset trigger conditions of the motor controller are not met, the motor controller is determined to be damaged.

[0120] Optionally, before determining the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module, the motor controller life monitoring method further includes:

[0121] In response to the life monitoring trigger signal, it is determined whether the preset trigger conditions of the motor controller are met, wherein the preset trigger conditions include that the motor controller is in a normal working state, the inverter module has no failure faults, and the bus capacitor has no failure faults.

[0122] If the preset trigger condition is met, life monitoring of the motor controller is performed.

[0123] If the preset trigger condition is not met, it is determined that the motor controller is damaged, and the life monitoring of the motor controller is not performed.

[0124] Specifically, when the user wants to monitor the life of the motor controller, obtain the life monitoring trigger signal, first determine whether the current motor controller is working normally, for example, monitor the input voltage and current parameters of the motor controller through the vehicle controller, as well as the enable signal, status signal, overcurrent and overvoltage protection trigger signals, to determine the working state of the motor controller; when the motor controller is in a normal working state, continue to perform the life monitoring of the motor controller; if the motor controller is in an abnormal working state, suspend the life monitoring of the motor controller; you can also further analyze the reasons why the motor controller is in an abnormal working state. If the motor controller is in an abnormal working state due to a fault in the motor controller itself, suspend the life monitoring of the motor controller; if the motor controller cannot work normally due to other components of the vehicle, continue to monitor the life of the motor controller after the fault is removed. Similarly, it is also necessary to monitor whether the inverter module and bus capacitor in the motor controller fail. If these two parts fail, the motor controller may be in an abnormal working state. It is also possible that the failure of the inverter module or bus capacitor will not be immediately reflected in the running state of the motor controller, so it is also necessary to monitor the inverter module and bus capacitor separately. By monitoring whether the inverter module has mechanical failure or electrical failure, it is determined whether the inverter module has failed; by extracting signals such as the temperature, voltage, switching frequency or ripple current of the bus capacitor, it is determined whether the bus capacitor has abnormal working phenomena such as overcooling, overvoltage or overheating. For example, if the actual working temperature of the capacitor is higher than the maximum working temperature limit of the capacitor, the capacitor is overheated; if the actual working temperature of the capacitor is lower than the minimum working temperature limit of the capacitor, the capacitor is overcooled; if the actual working voltage of the capacitor is higher than the maximum working voltage limit of the capacitor, the capacitor is overvoltage; if the above abnormal working phenomena occur, the voltage across the capacitor or the current passing through it is used to continue to determine whether the bus capacitor has failed. In addition, the monitoring of whether the inverter module and the bus capacitor have failed can also be placed before the life assessment of the inverter module and the bus capacitor, respectively.

[0125] The motor controller may have occasional faults such as overcurrent and overvoltage, which may lead to failure of the bus capacitor, inverter module failure, and functional failures of the control module and driver module, resulting in the motor controller not working or working abnormally. Monitor occasional faults in advance. If occasional faults cause the motor controller not working or working abnormally, stop monitoring the life of the motor controller, because the motor controller has already had problems and needs to be repaired or replaced. Continuing life monitoring takes up computing resources.

[0126] like Figure 4 As shown, an embodiment of the present invention provides a motor controller life monitoring device, the motor controller includes an inverter module and a bus capacitor, and the motor controller life monitoring device includes:

[0127] The first life assessment module 410 is used to determine the life damage degree of the inverter module according to the operating conditions of the vehicle and the operating parameters of the inverter module.

[0128] The second life evaluation module 420 is used to determine the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor.

[0129] The life monitoring module 430 is used to determine the life monitoring result of the motor controller according to the life damage degree of the inverter module and the expected cycle life of the bus capacitor.

[0130] In this embodiment, the first life assessment module 410 determines the life damage degree of the inverter module according to the operating conditions of the vehicle and the working parameters of the inverter module. In addition to paying attention to the working parameters of the inverter module, the operating conditions of the vehicle are also considered, and the mutual influence between multiple factors is integrated to make the estimated life damage degree of the inverter module more accurate, reduce misjudgment, and improve user trust; the second life assessment module 420 determines the expected cycle life of the bus capacitor according to the working parameters and performance parameters of the bus capacitor, and can more accurately obtain the expected cycle life of the bus capacitor at different times. The length of the expected cycle life can reflect the operating status and sustainability of the bus capacitor, and then when the motor controller itself does not show abnormalities, potential risks can be discovered in advance, avoided in time, and losses can be reduced; the life monitoring module 430 determines the life monitoring result of the motor controller according to the life damage degree of the inverter module and the expected cycle life of the bus capacitor, and monitors the life status of the inverter module and the bus capacitor at the same time, further improving the life monitoring result of the motor controller.

[0131] like Figure 5 As shown, an electronic device 500 provided by an embodiment of the present invention includes a memory 510 and a processor 520; the memory 510 is used to store a computer program; the processor 520 is used to implement the motor controller life monitoring method as described above when executing the computer program.

[0132] In other words, an electronic device 500 includes a memory 510 and a processor 520 coupled to the memory 510; the memory 510 is configured to store a computer program; and the processor 520 is configured to perform the following operations when executing the computer program:

[0133] Determining the life damage degree of the inverter module according to the operating conditions of the vehicle and the operating parameters of the inverter module;

[0134] Determining the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor;

[0135] The life monitoring result of the motor controller is determined according to the life damage degree of the inverter module and the expected cycle life of the bus capacitor.

[0136] In this embodiment, the beneficial effects of the electronic device 500 are the same as the beneficial effects of the motor controller life monitoring method, which will not be repeated here.

[0137] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the motor controller life monitoring method as described above is implemented.

[0138] In other words, a non-volatile computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the processor performs the following operations:

[0139] Determining the life damage degree of the inverter module according to the operating conditions of the vehicle and the operating parameters of the inverter module;

[0140] Determining the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor;

[0141] The life monitoring result of the motor controller is determined according to the life damage degree of the inverter module and the expected cycle life of the bus capacitor.

[0142] In this embodiment, the beneficial effects of the storage medium are the same as the beneficial effects of the motor controller life monitoring method, which will not be repeated here.

[0143] Electronic device 500 is intended to represent various forms of digital electronic computer equipment, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers and other suitable computers. Electronic device 500 can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices and other similar computing devices. The examples described above can be used as electronic devices 500 of servers or clients of the present invention, which are examples of hardware devices that can be applied to various aspects of the present invention. The components shown herein, their connections and relationships, and their functions are only examples, and are not intended to limit the implementation of the present invention described and / or required herein.

[0144] The electronic device 500 includes a computing unit, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) or a computer program loaded from a storage unit into a random access memory (RAM). In the RAM, various programs and data required for the operation of the device can also be stored. The computing unit, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0145] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc. In the present application, the unit described as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the present invention. In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

[0146] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A motor controller life monitoring method, characterized in that: The motor controller includes an inverter module and a bus capacitor, and the motor controller life monitoring method includes: Determining the life damage degree of the inverter module according to the operating conditions of the vehicle and the operating parameters of the inverter module; Determining the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor; The life monitoring result of the motor controller is determined according to the life damage degree of the inverter module or the expected cycle life of the bus capacitor.

2. The motor controller life monitoring method according to claim 1, characterized in that: Before determining the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module, the method further includes: Analyze the life cycle historical operation data of the same type of vehicle to obtain multiple operating conditions within the life cycle of the vehicle, and determine the number of cycles of each operating condition; According to each of the operating conditions and preset boundary conditions, a simulation experiment is performed on the vehicle of the same type to obtain a temperature change curve of the inverter module corresponding to each of the operating conditions.

3. The motor controller life monitoring method according to claim 2, characterized in that: Determining the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module includes: According to the operating condition of the vehicle, calling the temperature change curve of the inverter module corresponding to the operating condition; According to the operating parameters of the inverter module, query the called temperature change curve of the inverter module to determine the junction temperature curve segment corresponding to the operating parameters of the inverter module and the junction temperature data of the junction temperature curve segment; The life damage degree of the inverter module is determined according to the junction temperature data corresponding to the working parameters of the inverter module.

4. The motor controller life monitoring method according to claim 3, characterized in that: The junction temperature data includes a junction temperature difference and a minimum junction temperature in a junction temperature curve segment corresponding to operating parameters of the inverter module, wherein the operating parameters of the inverter module include a conduction duration, a DC terminal current, and a blocking voltage; Determining the life damage degree of the inverter module according to the junction temperature data corresponding to the working parameters of the inverter module includes: Inputting the junction temperature difference, the minimum junction temperature, the on-time, the DC terminal current, the blocking voltage and the bonding wire diameter of the inverter module into an inverter expected cycle life calculation model to determine the expected cycle life of the inverter module; Analyze the called temperature change curve of the inverter module and the junction temperature curve segment corresponding to the operating parameters of the inverter module to determine the occurrence frequency of the junction temperature curve segment under the operating condition; Determining a single-operating-condition life damage degree of the inverter module according to the occurrence frequency of the junction temperature curve segment and the expected cycle life of the inverter module; The life damage degree of the inverter module is determined according to the single operating condition life damage degree of the inverter module under each operating condition and the number of cycles of each operating condition.

5. The motor controller life monitoring method according to claim 1, characterized in that: The working parameters of the bus capacitor include the actual working temperature and the internal temperature rise of the capacitor caused by the actual ripple current; Determining the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor includes: The actual operating temperature, the internal temperature rise of the capacitor caused by the actual ripple current, and the performance parameters are input into a capacitor expected cycle life calculation model to determine the expected cycle life of the bus capacitor.

6. The motor controller life monitoring method according to claim 1, characterized in that: Determining the life monitoring result of the motor controller according to the life damage degree of the inverter module or the expected cycle life of the bus capacitor includes: Determining whether the life damage degree of the inverter module is less than a first damage threshold; If the life damage degree of the inverter module is greater than or equal to the first damage threshold, it is determined that the motor controller does not meet the vehicle use requirements; If the life damage degree of the inverter module is less than the first damage threshold, determining whether the life damage degree is less than a second damage threshold, wherein the second damage threshold is less than the first damage threshold; If the life damage degree is greater than or equal to a second damage threshold, a motor controller life warning signal is generated.

7. The motor controller life monitoring method according to claim 1, characterized in that: Determining the life monitoring result of the motor controller according to the life damage degree of the inverter module or the expected cycle life of the bus capacitor includes: Determining whether the expected cycle life of the bus capacitor is less than the full life cycle of the vehicle; If the expected cycle life of the bus capacitor is less than the full life cycle of the vehicle, it is determined that the motor controller does not meet the vehicle use requirements; If the expected cycle life of the bus capacitor is greater than or equal to the full life cycle duration of the vehicle, determining whether the expected cycle life of the bus capacitor is less than a bus capacitor life threshold; If the expected cycle life of the bus capacitor is less than the bus capacitor life threshold, a motor controller life warning signal is generated.

8. The motor controller life monitoring method according to claim 7, characterized in that: Before determining whether the expected cycle life of the bus capacitor is less than the full life cycle duration of the vehicle, the method further includes: The full life cycle duration of the vehicle is obtained based on the working duration of each operating condition and the number of cycles of each operating condition during the full life cycle of the vehicle.

9. The motor controller life monitoring method according to claim 1, characterized in that: Before determining the life damage degree of the inverter module according to the operating condition of the vehicle and the operating parameters of the inverter module, the method further includes: In response to the life monitoring trigger signal, determining whether a preset trigger condition of the motor controller is met, wherein the preset trigger condition includes that the motor controller is in a normal working state, the inverter module has no failure fault, and the bus capacitor has no failure fault; If the preset trigger condition is met, performing life monitoring on the motor controller; If the preset trigger condition is not met, it is determined that the motor controller is damaged, and the life monitoring of the motor controller is not performed.

10. A motor controller life monitoring device, characterized in that: The motor controller includes an inverter module and a bus capacitor, and the motor controller life monitoring device includes: A first life assessment module, used to determine the life damage degree of the inverter module according to the operating conditions of the vehicle and the operating parameters of the inverter module; A second life evaluation module, used to determine the expected cycle life of the bus capacitor according to the operating parameters and performance parameters of the bus capacitor; The life monitoring module is used to determine the life monitoring result of the motor controller according to the life damage degree of the inverter module and the expected cycle life of the bus capacitor.

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