A method, device and vehicle for detecting faults in a motor controller cooling system

Abstract

The present invention discloses a fault detection method, device and vehicle for a motor controller cooling system. The motor controller includes an IGBT chip and a thermistor, including: during the operation of the motor controller, continuously obtaining the actual heat loss between the IGBT chip and the thermistor; according to the actual heat loss at each sampling moment, obtaining adjacent minimum actual heat loss and maximum actual heat loss; the sampling moment of the minimum actual heat loss is before the sampling moment of the maximum actual heat loss; obtaining a first detection temperature of the thermistor when the actual heat loss is the minimum actual heat loss; obtaining a second detection temperature of the thermistor when the actual heat loss is the maximum actual heat loss; obtaining the fault condition of the cooling system according to the minimum actual heat loss, the maximum actual heat loss, the first detection temperature and the second detection temperature, so as to accurately detect the heat dissipation capacity of the cooling system, and the detection method is simple, which can effectively improve the fault detection efficiency of the cooling system.

Description

Technical Field

[0001] The present invention relates to the field of vehicle fault detection, and in particular to a method and device for detecting a fault of a motor controller cooling system, and a vehicle. Background Art

[0002] The motor is an indispensable and important part of electric vehicles. In order to achieve reliable control of the motor, the reliable operation of the motor controller is particularly important.

[0003] During operation, the motor controller drives the motor through the IGBT chip inside it, causing a large current to flow through the IGBT chip, generating a lot of heat. A cooling system is usually set up in the motor controller to dissipate the heat of the IGBT chip. If the cooling system is abnormal, the heat generated by the IGBT chip cannot be dissipated in time, which will cause the temperature of the IGBT chip to continue to rise and eventually burn the chip. Summary of the invention

[0004] The present invention provides a method, a device and a vehicle for detecting a fault of a motor controller cooling system, so as to realize timely, accurate and effective detection of a fault of the motor controller cooling system.

[0005] According to one aspect of the present invention, a fault detection method for a motor controller cooling system is provided, wherein the motor controller includes an IGBT chip and a thermistor, including:

[0006] During the operation of the motor controller, continuously obtaining actual heat loss between the IGBT chip and the thermistor;

[0007] According to the actual heat loss at each sampling moment, the adjacent minimum actual heat loss and maximum actual heat loss are obtained; the sampling moment of the minimum actual heat loss is before the sampling moment of the maximum actual heat loss;

[0008] Acquire a first detection temperature of the thermistor when the actual heat loss is a minimum actual heat loss;

[0009] Acquiring a second detected temperature of the thermistor when the actual heat loss is a maximum actual heat loss;

[0010] A fault condition of the cooling system of the motor controller is acquired according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature.

[0011] Optionally, according to the actual heat loss at each sampling moment, obtaining adjacent minimum actual heat loss and maximum actual heat loss includes:

[0012] Determine a change sign of the actual heat loss according to the actual heat loss at each sampling moment; the change sign includes a decrease sign, a keep-alive sign, and an increase sign;

[0013] When the change sign changes from the decrease sign to the increase sign, the actual heat loss corresponding to the last decrease sign is determined as the minimum actual heat loss; or, when the change sign changes from the flat sign to the increase sign, the actual heat loss corresponding to the last flat sign is determined as the minimum actual heat loss;

[0014] After determining the minimum actual heat loss, continue to determine a change sign of the actual heat loss according to the actual heat loss at each sampling moment;

[0015] Until the change mark changes from the increase mark to the flat mark, or until the change mark changes from the increase mark to the decrease mark, the actual heat loss corresponding to the last increase mark is determined as the maximum actual heat loss.

[0016] Optionally, obtaining a fault condition of the cooling system of the motor controller according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature includes:

[0017] determining an actual fault parameter value according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature;

[0018] Determining whether the actual fault parameter value is greater than a preset fault parameter value;

[0019] If yes, it is determined that there is a fault in the cooling system of the motor controller;

[0020] If not, it is determined that the motor controller cooling system has no faults.

[0021] Optionally, determining an actual fault parameter value according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature includes:

[0022] Obtaining a calculation formula for the actual fault parameter value;

[0023] Based on the calculation formula, the actual fault parameter value is determined according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature and the second detected temperature;

[0024] The calculation formula is: Q1=(NTC2-NTC1) / (E2-E1);

[0025] Among them, Q1 is the actual fault parameter value, E1 is the minimum actual heat loss, E2 is the maximum actual heat loss, NTC1 is the first detection temperature of the thermistor when the heat loss is the minimum actual heat loss, and NTC2 is the second detection temperature of the thermistor when the heat loss is the maximum actual heat loss.

[0026] Optionally, during the operation of the motor controller, continuously obtaining actual heat loss between the IGBT chip and the thermistor includes:

[0027] During the operation of the motor controller, continuously obtaining the operating condition information of the motor controller;

[0028] At least according to the operating condition information at each sampling moment, the actual heat loss between the IGBT chip and the thermistor at each sampling moment is obtained.

[0029] Optionally, obtaining the actual heat loss between the IGBT chip and the thermistor at each sampling moment at least according to the operating condition information at each sampling moment includes:

[0030] Acquiring a first preset relationship between operating condition information and heat loss;

[0031] Based on the first preset relationship, the actual heat loss at each sampling moment is obtained according to the operating condition information at each sampling moment.

[0032] Optionally, obtaining a first preset relationship between the operating condition information and the heat loss includes:

[0033] Obtain working condition information under each working condition;

[0034] Obtaining the thermal resistance between the IGBT chip and the thermistor;

[0035] Obtaining a first test temperature of the IGBT chip and a second test temperature of the thermistor under each of the operating conditions;

[0036] According to the first test temperature, the second test temperature and the thermal resistance under each of the working conditions, obtaining the test heat loss under each of the working conditions;

[0037] The first preset relationship between the operating condition information and the heat loss is determined based on the operating condition information under each of the operating conditions and the tested heat loss under each of the operating conditions.

[0038] Optionally, obtaining the actual heat loss between the IGBT chip and the thermistor at each sampling moment at least according to the operating condition information at each sampling moment includes:

[0039] According to the operating condition information at the current sampling moment, obtaining the original heat loss between the IGBT chip and the thermistor at the current sampling moment;

[0040] Acquire the actual heat loss between the IGBT chip and the thermistor at the previous sampling moment;

[0041] Get the filter function of heat loss;

[0042] Based on the filter function, the actual heat loss between the IGBT chip and the thermistor at the current sampling moment is obtained according to the original heat loss between the IGBT chip and the thermistor at the current sampling moment and the actual heat loss between the IGBT chip and the thermistor at the previous sampling moment.

[0043] According to another aspect of the present invention, a fault detection device for a motor controller cooling system is provided, wherein the motor controller includes an IGBT chip and a thermistor, including:

[0044] An actual heat loss acquisition module, used for continuously acquiring the actual heat loss between the IGBT chip and the thermistor during the operation of the motor controller;

[0045] A heat loss extreme value acquisition module, used to acquire adjacent minimum actual heat loss and maximum actual heat loss according to the actual heat loss at each sampling moment; the sampling moment of the minimum actual heat loss is before the sampling moment of the maximum actual heat loss;

[0046] A first detection temperature acquisition module, used for acquiring a first detection temperature of the thermistor when the actual heat loss is a minimum actual heat loss;

[0047] A second detection temperature acquisition module, used for acquiring a second detection temperature of the thermistor when the actual heat loss is a maximum actual heat loss;

[0048] A fault condition acquisition module is used to acquire the fault condition of the motor controller cooling system according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature and the second detected temperature.

[0049] According to another aspect of the present invention, there is provided a vehicle, comprising: a motor controller, a motor controller cooling system and a vehicle controller;

[0050] The vehicle controller is used to execute the above-mentioned fault detection method for the motor controller cooling system.

[0051] The fault detection method for the cooling system of the motor controller provided by the present invention continuously obtains the actual heat loss between the IGBT chip and the thermistor during the operation of the motor controller, so that the adjacent minimum actual heat loss and maximum actual heat loss can be obtained according to the actual heat loss at each sampling moment. By setting the sampling moment of the minimum actual heat loss before the sampling moment of the maximum actual heat loss, the accuracy of the fault detection of the cooling system of the motor controller can be effectively improved. Then, the first detection temperature of the thermistor when the actual heat loss is the minimum actual heat loss is obtained, and the second detection temperature of the thermistor when the actual heat loss is the maximum actual heat loss is obtained. Therefore, the fault condition of the cooling system of the motor controller can be obtained according to the minimum actual heat loss, the maximum actual heat loss, the first detection temperature and the second detection temperature. The heat dissipation capacity of the cooling system of the motor controller can be accurately detected according to the temperature rise of the IGBT chip and the change of the actual heat loss. In addition, the method for obtaining the actual heat loss, the first detection temperature and the second detection temperature is simple, so that the fault detection method for the cooling system of the motor controller provided by the embodiment of the present invention is simple and the fault detection efficiency of the cooling system of the motor controller can be effectively improved.

[0052] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0054] Figure 1 is a flow chart of a fault detection method for a motor controller cooling system provided by an embodiment of the present invention;

[0055] Figure 2 is a flow chart of another method for fault detection of a motor controller cooling system provided by an embodiment of the present invention;

[0056] Figure 3 is a flow chart of a method for obtaining a first preset relationship between operating condition information and heat loss provided by an embodiment of the present invention;

[0057] Figure 4 is a flow chart of another method for fault detection of a motor controller cooling system provided by an embodiment of the present invention;

[0058] Figure 5It is a structural schematic diagram of a fault detection device for a motor controller cooling system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0060] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0061] An embodiment of the present invention provides a fault detection method for a motor controller cooling system, which can accurately detect fault conditions of the cooling system. The fault detection method for a motor controller cooling system can be executed by a fault detection device for a motor controller cooling system provided by an embodiment of the present invention. The fault detection device for a motor controller cooling system can be implemented in the form of software and / or hardware, and the fault detection device for a motor controller cooling system can be configured in a vehicle controller of a vehicle.

[0062] The motor controller includes at least an IGBT chip and a thermistor. The IGBT chip is used to output a driving current to the motor in response to a control signal (such as a PWM signal) from the motor controller to drive the motor to rotate. The thermistor is usually arranged on the same circuit board as the IGBT chip and is arranged close to the IGBT chip on the basis of insulation to achieve more accurate detection of the temperature of the IGBT chip.

[0063] Figure 1 is a flow chart of a fault detection method for a motor controller cooling system provided by an embodiment of the present invention. Figure 1 As shown, the fault detection method of the motor controller cooling system includes:

[0064] S110. During the operation of the motor controller, the actual heat loss between the IGBT chip and the thermistor is continuously obtained.

[0065] Specifically, since the IGBT chip and the thermistor are insulated and there is a certain distance between them, there will be thermal resistance (in Kelvin per Watt (K / W) or Celsius per Watt (℃ / W)) between the IGBT chip and the thermistor, and due to the setting of the motor controller cooling system, the thermal resistance can also reflect the heat dissipation capacity of the motor controller cooling system. In one embodiment, the actual temperature of the IGBT chip and the sampled temperature collected by the thermistor can be obtained, and the actual temperature of the IGBT chip and the sampled temperature collected by the thermistor can be subtracted to obtain the temperature drop ΔT generated in the process of transferring the heat generated by the IGBT chip to the thermistor. The temperature drop ΔT, thermal resistance RT and heat loss E satisfy ΔT=RT×E, so according to the temperature drop ΔT and the thermal resistance RT between the IGBT chip and the thermistor, the actual heat loss between the IGBT chip and the thermistor can be determined. The actual heat loss between the IGBT chip and the thermistor can reflect the actual temperature of the IGBT and the sampled temperature of the thermistor on the one hand, and the temperature drop between the IGBT and the thermistor on the other hand, and can be used as an effective parameter for detecting abnormal conditions of the motor controller cooling system.

[0066] The above only exemplifies a method for obtaining the actual heat loss between the IGBT chip and the thermistor, but is not limited to this. In other feasible embodiments of the present invention, other methods can also be used to obtain the actual heat loss between the IGBT chip and the thermistor. For example, the actual heat loss between the IGBT chip and the thermistor can be obtained based on the operating condition information of the motor controller. The specific method will be introduced in the following embodiments and will not be repeated here.

[0067] S120. Obtain adjacent minimum actual heat losses and maximum actual heat losses according to the actual heat losses at each sampling moment.

[0068] Among them, the sampling time of the minimum actual heat loss is before the sampling time of the maximum actual heat loss.

[0069] Specifically, the actual heat loss obtained at each sampling moment may fluctuate up and down over time. The minimum actual heat loss is the minimum value in the actual heat loss fluctuation process, and the maximum actual heat loss is the maximum value in the actual heat loss fluctuation process. The sampling moment of the adjacent minimum actual heat loss obtained is set before the sampling moment of the maximum actual heat loss, so that the minimum actual heat loss and the maximum actual heat loss obtained are the minimum and maximum values ​​in the process of increasing the actual heat loss. The actual heat loss is mainly generated by two parts. The heat of the IGBT chip is transferred to the position of the thermistor, which will generate a part of the heat loss due to the circuit board itself, and another part of the heat loss will be generated due to the heat dissipation of the motor controller cooling system. The thermal resistance of the circuit board itself is less affected by the working conditions, so the heat loss caused by the thermal resistance of the circuit board itself can be approximately equal to a fixed value, while the heat loss caused by the cooling system will change due to the change of the heat of the IGBT chip.

[0070] Furthermore, in the process of gradually decreasing the heat generated by the IGBT chip, the heat loss between the IGBT chip and the thermistor will also decrease, and the detection temperature of the thermistor will also decrease, because the heat loss will not exceed the total heat generated by the IGBT chip. That is, the reason for the decrease in the detection temperature of the thermistor is not only due to the motor controller cooling system, and the heat dissipation capacity of the motor controller cooling system cannot be effectively detected in this process. In the process of gradually increasing the heat generated by the IGBT chip, the detection temperature of the thermistor will also gradually increase, and the heat loss between the IGBT chip and the thermistor will also be greater, so that the heat dissipation of the motor controller cooling system can be accurately and effectively detected by analyzing the IGBT chip heating process. Therefore, the adjacent minimum actual heat loss and maximum actual heat loss can be obtained as the minimum and maximum values ​​in the process of increasing the actual heat loss, so that the fault detection result of the motor controller cooling system is more accurate.

[0071] S130, obtaining a first detection temperature of the thermistor when the actual heat loss is a minimum actual heat loss.

[0072] S140, obtaining a second detection temperature of the thermistor when the actual heat loss is a maximum actual heat loss.

[0073] Specifically, in the process of obtaining the actual heat loss, the resistance value of the thermistor can be obtained at the same time, and the detection temperature collected by the thermistor can be determined by the resistance value of the thermistor. At the sampling moment when the actual heat loss is the minimum actual heat loss, the detection temperature collected by the thermistor is the first detection temperature. Similarly, at the sampling moment when the actual heat loss is the maximum actual heat loss, the detection temperature collected by the thermistor is the second detection temperature.

[0074] For example, the thermistor may be a thermistor with a negative temperature coefficient (NTC) or a thermistor with a positive temperature coefficient (PTC). Unless otherwise specified, the embodiments of the present invention are explained with the thermistor being a thermistor with a negative temperature coefficient (NTC).

[0075] S150, obtaining a fault condition of a cooling system of a motor controller according to a minimum actual heat loss, a maximum actual heat loss, a first detected temperature, and a second detected temperature.

[0076] Specifically, the change of the detection temperature of the thermistor can be determined according to the first temperature and the second temperature, which can also be understood as determining the temperature rise of the IGBT chip according to the first detection temperature and the second detection temperature. And the change of the actual heat loss during the temperature rise of the IGBT chip can be determined according to the minimum actual heat loss and the maximum actual heat loss, so that the heat dissipation capacity of the motor controller cooling system can be accurately detected according to the temperature rise of the IGBT chip and the change of the actual heat loss, so that when the heat dissipation capacity is poor, it can be determined that there is a fault in the motor controller cooling system, such as the coolant is not flowing, or the coolant flow is too small.

[0077] The fault detection method for the cooling system of the motor controller provided by the embodiment of the present invention continuously obtains the actual heat loss between the IGBT chip and the thermistor during the operation of the motor controller, so that the adjacent minimum actual heat loss and maximum actual heat loss can be obtained according to the actual heat loss at each sampling moment. By setting the sampling moment of the minimum actual heat loss before the sampling moment of the maximum actual heat loss, the accuracy of the fault detection of the cooling system of the motor controller can be effectively improved. Then, the first detection temperature of the thermistor when the actual heat loss is the minimum actual heat loss is obtained, and the second detection temperature of the thermistor when the actual heat loss is the maximum actual heat loss is obtained. Therefore, the fault condition of the cooling system of the motor controller can be obtained according to the minimum actual heat loss, the maximum actual heat loss, the first detection temperature and the second detection temperature. The heat dissipation capacity of the cooling system of the motor controller can be accurately detected according to the temperature rise of the IGBT chip and the change of the actual heat loss. In addition, the method for obtaining the actual heat loss, the first detection temperature and the second detection temperature is simple, so that the fault detection method for the cooling system of the motor controller provided by the embodiment of the present invention is simple and can effectively improve the fault detection efficiency of the cooling system of the motor controller.

[0078] Optional, Figure 2 FIG. 1 is a flow chart of another method for detecting a fault in a motor controller cooling system provided by an embodiment of the present invention. Figure 2 As shown, the fault detection method of the motor controller cooling system includes:

[0079] S211. During the operation of the motor controller, continuously obtain the working condition information of the motor controller.

[0080] S212: Obtain actual heat loss between the IGBT chip and the thermistor at each sampling moment at least according to the operating condition information at each sampling moment.

[0081] Specifically, the operating condition information may include the operating current of the IGBT chip during operation (which may be the driving current output by the IGBT chip to the motor), the speed of the motor, and the duty cycle of the driving signal (such as a PWM signal) that drives each IGBT in the IGBT chip to turn on or off. During the operation of the motor controller, the operating condition information of the motor controller can be continuously obtained, and the actual heat loss between the IGBT chip and the thermistor at each sampling moment can be determined according to the operating condition information at each sampling moment.

[0082] Exemplarily, when obtaining the actual heat loss between the IGBT chip and the thermistor at each sampling moment at least based on the operating condition information at each sampling moment, the first preset relationship between the operating condition information and the heat loss can be first obtained; based on the first preset relationship, the actual heat loss at each sampling moment is obtained according to the operating condition information at each sampling moment.

[0083] Specifically, the corresponding relationship between the operating condition information and the heat loss can be calibrated first through bench testing, so as to determine the first preset relationship between the operating condition information and the heat loss. The first preset relationship can be a multidimensional relationship table of multiple operating condition information and heat loss. In this way, when the actual heat loss at each sampling moment is obtained according to the operating condition information at each sampling moment based on the first preset relationship, the operating condition information at each sampling moment can be mapped to the table by looking up the table, so as to achieve the acquisition of the actual heat loss at each sampling moment.

[0084] The embodiment of the present invention also provides a method for obtaining a first preset relationship between operating condition information and heat loss. Figure 3 is a flow chart of a method for obtaining a first preset relationship between operating condition information and heat loss provided by an embodiment of the present invention, such as Figure 3 As shown, the method for obtaining the first preset relationship between the operating condition information and the heat loss includes:

[0085] S01. Obtain working condition information under each working condition.

[0086] S02. Obtain the thermal resistance between the IGBT chip and the thermistor.

[0087] S03. Obtain a first test temperature of the IGBT chip and a second test temperature of the thermistor under each working condition.

[0088] S04. Obtain the test heat loss under each working condition according to the first test temperature, the second test temperature and the thermal resistance under each working condition.

[0089] S05. Determine a first preset relationship between the operating condition information and the heat loss according to the operating condition information under each operating condition and the tested heat loss under each operating condition.

[0090] Specifically, the temperature of the IGBT can be collected by a thermal imager as the first test temperature under the current working condition, and the detection temperature of the thermistor can be determined as the second test temperature under the current working condition according to the resistance value of the thermistor. Due to the existence of thermal resistance, the second test temperature at the same sampling moment will be lower than the first test temperature. Therefore, the difference between the first test temperature and the second test temperature can be determined as the temperature drop ΔT between the IGBT chip and the thermistor. Since the temperature drop ΔT, thermal resistance RT and heat loss E satisfy ΔT=RT×E, the test heat loss E under the current working condition can be determined according to the temperature drop ΔT and thermal resistance RT, so that the test heat loss E under the current working condition can be associated with the working condition information under the current working condition. The heat loss and working condition information under each working condition can be associated in the same way, so that the first preset relationship between the working condition information and the heat loss can be determined. The first preset relationship can be stored so that it can be directly called when the actual heat loss is obtained.

[0091] S213. Determine a change sign of the actual heat loss according to the actual heat loss at each sampling moment.

[0092] Among them, the change signs include decrease sign, remain unchanged sign and increase sign.

[0093] Specifically, the change of the actual heat loss can be represented by a change sign, so when obtaining the change of the actual heat loss, it can be determined whether the actual heat loss is in a decreasing process or an increasing process according to the change sign. Exemplarily, the change sign can be represented by a number, for example, a decreasing sign can be -1, a flat sign can be 0, and an increasing sign can be 1.

[0094] S214. When the change sign changes from a decrease sign to an increase sign, the actual heat loss corresponding to the last decrease sign is determined as the minimum actual heat loss, or, when the change sign changes from a flat sign to an increase sign, the actual heat loss corresponding to the last flat sign is determined as the minimum actual heat loss.

[0095] Specifically, if the actual heat loss at the current moment is greater than the actual heat loss at the previous moment, it means that the actual heat loss is in the process of increasing, and the change mark of the actual heat loss is the increase mark 1, and the actual heat loss at the current moment may not be recorded. Until the actual heat loss at the current moment is less than the actual heat loss at the previous moment, it means that the actual heat loss is in the process of decreasing, and the change mark of the actual heat loss is the decrease mark -1, at this time the actual heat loss at the current moment can be recorded, and in the subsequent sampling process, if the actual heat loss continues to decrease, the actual heat loss can be continuously recorded until the actual heat loss at the current moment is greater than the actual heat loss at the previous moment, indicating that the actual heat loss changes from a decreasing process to an increasing process, and the change mark of the actual heat loss at this time changes to an increase mark 1 again, then the actual heat loss corresponding to the change mark at the previous moment as the decrease mark -1 can be determined as the minimum actual heat loss, that is, the actual heat loss corresponding to the last decrease mark is determined as the minimum actual heat loss, and the minimum actual heat loss is the minimum value of the current increase process of the actual heat loss.

[0096] Alternatively, if the actual heat loss at the current moment is greater than the actual heat loss at the previous moment, it means that the actual heat loss is in an increasing process, and the change mark of the actual heat loss is an increasing mark 1, and the actual heat loss at the current moment may not be recorded. Until the actual heat loss at the current moment is equal to the actual heat loss at the previous moment, it means that the actual heat loss is in a leveling process, and the change mark of the actual heat loss is a decreasing mark 0. At this time, the actual heat loss at the current moment can be recorded. In the subsequent sampling process, if the actual heat loss continues to be level or decrease, the actual heat loss can be continuously recorded until the actual heat loss at the current moment is greater than the actual heat loss at the previous moment, indicating that the actual heat loss changes from a leveling process to an increasing process, or from a decreasing process to an increasing process. At this time, the change mark of the actual heat loss changes to an increasing mark 1 again. At this time, the actual heat loss corresponding to the previous moment change mark being a leveling mark of 0 or a decreasing mark of -1 can be determined as the minimum actual heat loss, that is, the actual heat loss corresponding to the last leveling mark or decreasing mark is determined as the minimum actual heat loss, and the minimum actual heat loss is the minimum value of the current increasing process of the actual heat loss.

[0097] S215. After determining the minimum actual heat loss, continue to determine the change sign of the actual heat loss according to the actual heat loss at each sampling moment.

[0098] Specifically, after the minimum actual heat loss is determined, it means that the actual heat loss is in the process of increasing. At this time, the actual heat loss can continue to be obtained, and the change sign of the actual heat loss can be determined according to the actual heat loss at each sampling moment to detect the change of the actual heat loss.

[0099] S216. Until the change sign changes from an increase sign to a flat sign, or until the change sign changes from an increase sign to a decrease sign, the actual heat loss corresponding to the last increase sign is determined as the maximum actual heat loss.

[0100] Specifically, if the actual heat loss at the current moment is equal to or less than the actual heat loss at the previous moment, it means that the actual heat loss has stopped increasing, and the actual heat loss corresponding to the increase sign at the previous moment can be determined as the maximum actual heat loss, that is, the actual heat loss corresponding to the last increase sign is determined as the maximum actual heat loss, and the maximum actual heat loss is the maximum value of the current increase process of the actual heat loss.

[0101] S217, obtaining a first detection temperature of the thermistor when the actual heat loss is a minimum actual heat loss.

[0102] S218, obtaining a second detection temperature of the thermistor when the actual heat loss is a maximum actual heat loss.

[0103] S219. Determine an actual fault parameter value according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature.

[0104] Specifically, the temperature rise of the IGBT chip can be determined according to the first detection temperature and the second detection temperature, and the change of the actual heat loss during the heating process of the IGBT chip can be determined according to the minimum actual heat loss and the maximum actual heat loss. Thus, the actual fault parameter value can be determined according to the temperature rise of the IGBT chip and the change of the actual heat loss.

[0105] Exemplarily, the calculation formula of the actual fault parameter value can be first obtained; based on the calculation formula, the actual fault parameter value is determined according to the minimum actual heat loss, the maximum actual heat loss, the first detection temperature and the second detection temperature; the calculation formula is: Q1=(NTC2-NTC1) / (E2-E1); wherein Q1 is the actual fault parameter value, E1 is the minimum actual heat loss, E2 is the maximum actual heat loss, NTC1 is the first detection temperature of the thermistor when the heat loss is the minimum actual heat loss, and NTC2 is the second detection temperature of the thermistor when the heat loss is the maximum actual heat loss.

[0106] Specifically, (NTC2-NTC1) is the maximum temperature rise of the thermistor during the IGBT chip heating process, and (E2-E1) is the actual increase in heat loss during the IGBT chip heating process. The ratio of the two can be used as a fault parameter for detecting the fault of the motor controller cooling system. Substituting the corresponding data into the calculation formula, the actual fault parameter value Q1 can be determined.

[0107] S220, determine whether the actual fault parameter value is greater than the preset fault parameter value; if so, execute step S221; if not, execute step S222.

[0108] S221. Determine that there is a fault in the cooling system of the motor controller.

[0109] S222: Determine that the motor controller cooling system has no faults.

[0110] Specifically, the preset fault parameter value can be set according to the design requirements, and the preset fault parameter value is preferably set to be greater than 1. When the actual fault parameter value Q1 is greater than the preset fault parameter value, it means that the temperature rise value of the thermistor exceeds the heat loss increase value too much, indicating that in the process of increasing the heat generated by the IGBT chip, the temperature rise of the thermistor is too large and the heat loss increase value is too small, then it can be determined that the heat dissipation capacity of the motor controller cooling system is poor and there is a fault. When the actual fault parameter value Q1 is less than or equal to the preset fault parameter value, it means that the temperature difference value of the thermistor exceeds the heat loss increase value by a small amount, indicating that in the process of increasing the heat generated by the IGBT chip, the temperature rise of the thermistor is equivalent to the heat loss increase value, then it can be determined that the heat dissipation capacity of the motor controller cooling system is normal and there is no fault.

[0111] Optional, Figure 4 FIG. 1 is a flow chart of another method for detecting a fault in a motor controller cooling system provided by an embodiment of the present invention. Figure 4 As shown, the fault detection method of the motor controller cooling system includes:

[0112] S310: During the operation of the motor controller, continuously obtain the working condition information of the motor controller.

[0113] S320: Obtain the original heat loss between the IGBT chip and the thermistor at the current sampling moment according to the working condition information at the current sampling moment.

[0114] Specifically, based on the first preset relationship between the operating condition information and the heat loss, the corresponding heat loss can be determined according to the operating condition information at the current sampling moment, and the heat loss can be used as the original heat loss at the current sampling moment.

[0115] S330, obtaining the actual heat loss between the IGBT chip and the thermistor at the previous sampling moment.

[0116] Specifically, in this embodiment, the actual heat loss between the IGBT chip and the thermistor at the previous sampling moment is the heat loss filtered by the filter function.

[0117] S340, obtaining a filter function of heat loss.

[0118] S350, based on the filter function, according to the original heat loss between the IGBT chip and the thermistor at the current sampling moment and the actual heat loss between the IGBT chip and the thermistor at the previous sampling moment, obtain the actual heat loss between the IGBT chip and the thermistor at the current sampling moment.

[0119] Specifically, the filter function may be a first-order low-pass filter function, and its expression may be y(t)=a×x(t)+b×y(t-1), wherein y(t) is the actual heat loss at the current sampling moment, y(t-1) is the actual heat loss at the previous sampling moment, x(t) is the original heat loss at the current sampling moment, and a and b are filter parameters, respectively. Since in the aforementioned embodiment, the actual heat loss is obtained by looking up the table through the first preset relationship according to the working condition information, the actual heat loss changes relatively quickly compared to the detection temperature of the thermistor, and the temperature change process of the detection temperature of the thermistor is relatively slow, so that when the actual heat loss suddenly increases in a short time, it will affect the accuracy of the fault detection result. Therefore, in this embodiment, the heat loss obtained according to the operating condition information through the first preset relationship can be used as the original heat loss. At each sampling moment, the original heat loss can be first obtained, and the actual heat loss at the previous sampling moment can be obtained at the same time. The original heat loss at the current sampling moment and the actual heat loss at the previous sampling moment are substituted into the filter function for filtering, and the heat loss determined after filtering is the actual heat loss at the current sampling moment. In this way, the actual heat loss at the current sampling moment can be associated with the actual heat loss at the previous sampling moment, which can prevent the accuracy of the actual heat loss from being affected by a sudden increase in heat loss in a short time, thereby further improving the accuracy of the detection results of faults in the cooling system of the motor controller.

[0120] S360. Obtain adjacent minimum actual heat losses and maximum actual heat losses according to the actual heat losses at each sampling moment.

[0121] Among them, the sampling time of the minimum actual heat loss is before the sampling time of the maximum actual heat loss.

[0122] S370, obtaining a first detection temperature of the thermistor when the actual heat loss is a minimum actual heat loss.

[0123] S380, obtaining a second detection temperature of the thermistor when the actual heat loss is a maximum actual heat loss.

[0124] S390. Obtain a fault condition of a cooling system of a motor controller according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature.

[0125] Based on the same inventive concept, an embodiment of the present invention further provides a fault detection device for a motor controller cooling system, which is used to execute the fault detection method for a motor controller cooling system provided by any embodiment of the present invention. The fault detection device for a motor controller cooling system can be implemented by software and / or hardware. Therefore, the fault detection device for a motor controller cooling system provided by an embodiment of the present invention includes the technical features of the fault detection method for a motor controller cooling system provided by any embodiment of the present invention, and can achieve the beneficial effects of the fault detection method for a motor controller cooling system provided by any embodiment of the present invention. The similarities can be referred to the above description of the fault detection method for a motor controller cooling system provided by an embodiment of the present invention, and will not be repeated here.

[0126] The motor controller may include an IGBT chip and a thermistor. Figure 5 is a schematic diagram of a fault detection device for a motor controller cooling system provided by an embodiment of the present invention. Figure 5 As shown, the fault detection device of the motor controller cooling system includes: an actual heat loss acquisition module 100, which is used to continuously acquire the actual heat loss between the IGBT chip and the thermistor during the operation of the motor controller; a heat loss extreme value acquisition module 200, which is used to acquire adjacent minimum actual heat losses and maximum actual heat losses according to the actual heat losses at each sampling moment; the sampling moment of the minimum actual heat loss is before the sampling moment of the maximum actual heat loss; a first detection temperature acquisition module 300, which is used to acquire the first detection temperature of the thermistor when the actual heat loss is the minimum actual heat loss; a second detection temperature acquisition module 400, which is used to acquire the second detection temperature of the thermistor when the actual heat loss is the maximum actual heat loss; a fault condition acquisition module 500, which is used to acquire the fault condition of the motor controller cooling system according to the minimum actual heat loss, the maximum actual heat loss, the first detection temperature and the second detection temperature.

[0127] The fault detection device for the cooling system of the motor controller provided by the embodiment of the present invention continuously obtains the actual heat loss between the IGBT chip and the thermistor through the actual heat loss acquisition module during the operation of the motor controller, so that the adjacent minimum actual heat loss and maximum actual heat loss can be obtained according to the actual heat loss at each sampling moment through the heat loss extreme value acquisition module. By setting the sampling moment of the minimum actual heat loss before the sampling moment of the maximum actual heat loss, the accuracy of the fault detection of the cooling system of the motor controller can be effectively improved. Then, the first detection temperature acquisition module is used to obtain the first detection temperature of the thermistor when the actual heat loss is the minimum actual heat loss, and the second detection temperature acquisition module is used to obtain the first detection temperature of the thermistor when the actual heat loss is the minimum actual heat loss. The temperature acquisition module acquires the second detection temperature of the thermistor when the actual heat loss is the maximum actual heat loss, so that the fault condition of the motor controller cooling system can be acquired through the fault condition acquisition module according to the minimum actual heat loss, the maximum actual heat loss, the first detection temperature and the second detection temperature. The heat dissipation capacity of the motor controller cooling system can be accurately detected according to the temperature rise of the IGBT chip and the change of the actual heat loss, and the method for acquiring the actual heat loss, the first detection temperature and the second detection temperature is simple, so that the fault detection method of the motor controller cooling system provided by the embodiment of the present invention is simple, and can effectively improve the fault detection efficiency of the motor controller cooling system.

[0128] Optionally, the heat loss extreme value acquisition module includes: a first change sign determination submodule, which is used to determine the change sign of the actual heat loss according to the actual heat loss at each sampling moment; the change sign includes a decrease sign, a flat sign and an increase sign; a minimum actual heat loss determination submodule, which is used to determine the actual heat loss corresponding to the last decrease sign as the minimum actual heat loss when the change sign changes from a decrease sign to an increase sign, or, when the change sign changes from a flat sign to an increase sign, determine the actual heat loss corresponding to the last flat sign as the minimum actual heat loss; a second change sign determination submodule, which is used to continue to determine the change sign of the actual heat loss according to the actual heat loss at each sampling moment after determining the minimum actual heat loss; a maximum actual heat loss determination submodule, which is used to determine the actual heat loss corresponding to the last increase sign as the maximum actual heat loss until the change sign changes from an increase sign to a flat sign, or until the change sign changes from an increase sign to a decrease sign.

[0129] Optionally, the fault condition acquisition module includes: an actual fault parameter value determination submodule, which is used to determine the actual fault parameter value based on the minimum actual heat loss, the maximum actual heat loss, the first detection temperature and the second detection temperature; a judgment submodule, which is used to judge whether the actual fault parameter value is greater than the preset fault parameter value; a fault determination submodule, which is used to determine that there is a fault in the motor controller cooling system when the judgment submodule determines that the actual fault parameter value is greater than the preset fault parameter value; and a fault-free determination submodule, which is used to determine that there is no fault in the motor controller cooling system when the judgment submodule determines that the actual fault parameter value is less than or equal to the preset fault parameter value.

[0130] Optionally, the fault parameter value determination submodule includes: a calculation formula acquisition unit, used to obtain the calculation formula of the actual fault parameter value; an actual fault parameter value determination unit, used to determine the actual fault parameter value based on the calculation formula, according to the minimum actual heat loss, the maximum actual heat loss, the first detection temperature and the second detection temperature; the calculation formula is: Q1=(NTC2-NTC1) / (E2-E1); wherein Q1 is the actual fault parameter value, E1 is the minimum actual heat loss, E2 is the maximum actual heat loss, NTC1 is the first detection temperature of the thermistor when the heat loss is the minimum actual heat loss, and NTC2 is the second detection temperature of the thermistor when the heat loss is the maximum actual heat loss.

[0131] Optionally, the actual heat loss acquisition module includes: an operating condition information acquisition submodule, which is used to continuously acquire the operating condition information of the motor controller during the operation of the motor controller; and an actual heat loss acquisition submodule, which is used to acquire the actual heat loss between the IGBT chip and the thermistor at each sampling moment based at least on the operating condition information at each sampling moment.

[0132] Optionally, the actual heat loss acquisition submodule includes: a first preset relationship acquisition unit, used to acquire a first preset relationship between operating condition information and heat loss; an actual heat loss acquisition unit, used to acquire the actual heat loss at each sampling moment based on the first preset relationship and the operating condition information at each sampling moment.

[0133] Optionally, the first preset relationship acquisition unit includes: an operating condition information acquisition subunit, used to acquire operating condition information under each operating condition; a thermal resistance acquisition subunit, used to acquire the thermal resistance between the IGBT chip and the thermistor; a test temperature acquisition subunit, used to acquire the first test temperature of the IGBT chip and the second test temperature of the thermistor under each operating condition; a test heat loss acquisition subunit, used to acquire the test heat loss under each operating condition based on the first test temperature, the second test temperature and the thermal resistance under each operating condition; and a first preset relationship determination subunit, used to determine the first preset relationship between the operating condition information and the heat loss based on the operating condition information under each operating condition and the test heat loss under each operating condition.

[0134] Optionally, the actual heat loss acquisition submodule includes: an original heat loss acquisition unit, used to acquire the original heat loss between the IGBT chip and the thermistor at the current sampling moment according to the operating condition information at the current sampling moment; a first actual heat loss acquisition unit, used to acquire the actual heat loss between the IGBT chip and the thermistor at the previous sampling moment; a filtering function acquisition unit, used to acquire a filtering function of heat loss; and a second actual heat loss acquisition unit, used to acquire the actual heat loss between the IGBT chip and the thermistor at the current sampling moment based on the filtering function, according to the original heat loss between the IGBT chip and the thermistor at the current sampling moment and the actual heat loss between the IGBT chip and the thermistor at the previous sampling moment.

[0135] Based on the same inventive concept, an embodiment of the present invention also provides a vehicle, including a motor controller, a motor controller cooling system and a vehicle controller, wherein the vehicle controller is used to execute the fault detection method for the motor controller cooling system provided by any embodiment of the present invention. Therefore, the vehicle provided by the embodiment of the present invention includes the technical features of the fault detection method for the motor controller cooling system provided by any embodiment of the present invention, and can achieve the beneficial effects of the fault detection method for the motor controller cooling system provided by any embodiment of the present invention. The similarities can be referred to the above description of the fault detection method for the motor controller cooling system provided by the embodiment of the present invention, and will not be repeated here.

[0136] Exemplarily, the vehicle controller can be electrically and / or communicatively connected to the motor controller. When the vehicle controller determines that there is a fault in the cooling system of the motor controller, it can promptly send a control signal to the motor controller to stop the motor controller from working, i.e., the IGBT chip in the motor controller stops outputting driving current to the motor, so as to avoid damage to the IGBT chip caused by continuous temperature increase.

[0137] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fault detection method for a motor controller cooling system, wherein the motor controller comprises an IGBT chip and a thermistor, characterized in that: include: During the operation of the motor controller, continuously obtaining actual heat loss between the IGBT chip and the thermistor; According to the actual heat loss at each sampling moment, the adjacent minimum actual heat loss and maximum actual heat loss are obtained; the sampling moment of the minimum actual heat loss is before the sampling moment of the maximum actual heat loss; Acquire a first detection temperature of the thermistor when the actual heat loss is a minimum actual heat loss; Acquiring a second detected temperature of the thermistor when the actual heat loss is a maximum actual heat loss; Acquire a fault condition of the cooling system of the motor controller according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature; Wherein, obtaining the fault condition of the cooling system of the motor controller according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature and the second detected temperature includes: determining an actual fault parameter value according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature; Determining whether the actual fault parameter value is greater than a preset fault parameter value; If yes, it is determined that there is a fault in the cooling system of the motor controller; If not, it is determined that the motor controller cooling system has no faults.

2. The fault detection method of the motor controller cooling system according to claim 1, characterized in that: According to the actual heat loss at each sampling moment, the adjacent minimum actual heat loss and maximum actual heat loss are obtained, including: Determine a change sign of the actual heat loss according to the actual heat loss at each sampling moment; the change sign includes a decrease sign, a keep-alive sign, and an increase sign; When the change sign changes from the decrease sign to the increase sign, the actual heat loss corresponding to the last decrease sign is determined as the minimum actual heat loss; or, when the change sign changes from the flat sign to the increase sign, the actual heat loss corresponding to the last flat sign is determined as the minimum actual heat loss; After determining the minimum actual heat loss, continue to determine a change sign of the actual heat loss according to the actual heat loss at each sampling moment; Until the change mark changes from the increase mark to the flat mark, or until the change mark changes from the increase mark to the decrease mark, the actual heat loss corresponding to the last increase mark is determined as the maximum actual heat loss.

3. The fault detection method of the motor controller cooling system according to claim 1, characterized in that: Determining an actual fault parameter value according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature includes: Obtaining a calculation formula for the actual fault parameter value; Based on the calculation formula, the actual fault parameter value is determined according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature and the second detected temperature; The calculation formula is: Q1=(NTC2-NTC1) / (E2-E1); Among them, Q1 is the actual fault parameter value, E1 is the minimum actual heat loss, E2 is the maximum actual heat loss, NTC1 is the first detection temperature of the thermistor when the heat loss is the minimum actual heat loss, and NTC2 is the second detection temperature of the thermistor when the heat loss is the maximum actual heat loss.

4. The fault detection method of the motor controller cooling system according to claim 1, characterized in that: During the operation of the motor controller, continuously obtaining the actual heat loss between the IGBT chip and the thermistor, including: During the operation of the motor controller, continuously obtaining the operating condition information of the motor controller; At least according to the operating condition information at each sampling moment, the actual heat loss between the IGBT chip and the thermistor at each sampling moment is obtained.

5. The fault detection method of the motor controller cooling system according to claim 4, characterized in that: At least according to the operating condition information at each sampling moment, obtaining the actual heat loss between the IGBT chip and the thermistor at each sampling moment, including: Acquiring a first preset relationship between operating condition information and heat loss; Based on the first preset relationship, the actual heat loss at each sampling moment is obtained according to the operating condition information at each sampling moment.

6. The fault detection method of the motor controller cooling system according to claim 5, characterized in that: Obtaining a first preset relationship between operating condition information and heat loss includes: Obtain working condition information under each working condition; Obtaining the thermal resistance between the IGBT chip and the thermistor; Obtaining a first test temperature of the IGBT chip and a second test temperature of the thermistor under each of the operating conditions; According to the first test temperature, the second test temperature and the thermal resistance under each of the working conditions, obtaining the test heat loss under each of the working conditions; The first preset relationship between the operating condition information and the heat loss is determined based on the operating condition information under each of the operating conditions and the tested heat loss under each of the operating conditions.

7. The fault detection method of the motor controller cooling system according to claim 4, characterized in that: At least according to the operating condition information at each sampling moment, obtaining the actual heat loss between the IGBT chip and the thermistor at each sampling moment, including: According to the operating condition information at the current sampling moment, obtaining the original heat loss between the IGBT chip and the thermistor at the current sampling moment; Acquire the actual heat loss between the IGBT chip and the thermistor at the previous sampling moment; Get the filter function of heat loss; Based on the filter function, the actual heat loss between the IGBT chip and the thermistor at the current sampling moment is obtained according to the original heat loss between the IGBT chip and the thermistor at the current sampling moment and the actual heat loss between the IGBT chip and the thermistor at the previous sampling moment.

8. A fault detection device for a motor controller cooling system, wherein the motor controller comprises an IGBT chip and a thermistor, characterized in that: include: An actual heat loss acquisition module, used for continuously acquiring the actual heat loss between the IGBT chip and the thermistor during the operation of the motor controller; A heat loss extreme value acquisition module, used to acquire adjacent minimum actual heat loss and maximum actual heat loss according to the actual heat loss at each sampling moment; the sampling moment of the minimum actual heat loss is before the sampling moment of the maximum actual heat loss; A first detection temperature acquisition module, used for acquiring a first detection temperature of the thermistor when the actual heat loss is a minimum actual heat loss; A second detection temperature acquisition module, used for acquiring a second detection temperature of the thermistor when the actual heat loss is a maximum actual heat loss; a fault condition acquisition module, configured to acquire a fault condition of the cooling system of the motor controller according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature, and the second detected temperature; Wherein, the fault condition acquisition module includes: an actual fault parameter value determination submodule, a judgment submodule, a fault determination submodule and a no-fault determination submodule; The actual fault parameter value determination submodule is used to determine the actual fault parameter value according to the minimum actual heat loss, the maximum actual heat loss, the first detected temperature and the second detected temperature; The judgment submodule is used to judge whether the actual fault parameter value is greater than the preset fault parameter value; The fault determination submodule is used to determine that a fault exists in the cooling system of the motor controller when the judgment submodule determines that the actual fault parameter value is greater than a preset fault parameter value; The no-fault determination submodule is used to determine that the motor controller cooling system has no fault when the judgment submodule determines that the actual fault parameter value is less than or equal to the preset fault parameter value.

9. A vehicle, characterized in that: include: Motor controllers, motor controller cooling systems and vehicle controllers; The vehicle controller is used to execute the fault detection method for the motor controller cooling system according to any one of claims 1 to 7.

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