Motor controller and fault derating control method and device thereof

Abstract

The present application relates to a motor controller and a fault derating control method and device thereof, wherein the method includes: obtaining a current temperature sampling signal of at least one bridge arm of an IGBT module and a historical temperature sampling signal of at least one bridge arm; calculating the temperature rise rate of the IGBT module based on the current temperature sampling signal of at least one bridge arm and / or the historical temperature sampling signal of at least one bridge arm, and judging whether the vehicle's cooling system is in a preset fault state based on the temperature rise rate of the IGBT module; and if the vehicle's cooling system is in a preset fault state, obtaining the number of overtemperature faults of the IGBT module, calculating the derating factor of the vehicle's drive system based on the number of overtemperature faults and the temperature rise rate, and performing derating control on the vehicle's drive system based on the derating factor. Thus, the problem of interference with the temperature signal detection of the IGBT module is solved, and overtemperature protection of the IGBT module is achieved.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a motor controller and a fault derating control method and device thereof. Background Art

[0002] IGBT (Insulated Gate Bipolar Transistor) modules generate a significant amount of heat when operating under high voltage and high current conditions. This heat is dissipated to the external environment through heat exchange using the cooling system in the motor controller, ensuring that the IGBT module always operates within the permitted temperature range. If the heat generated by the IGBT module cannot be effectively dissipated, the IGBT will burn out due to overheating.

[0003] Related technologies achieve accurate junction temperature acquisition by etching thermal diodes on the wafers of the upper and lower six bridge arms of the U, V, and W phases within the module. Etching thermal diodes on the IGBT module wafer allows for direct, real-time acquisition of IGBT junction temperature information, thereby further enhancing the performance of the IGBT module.

[0004] However, temperature is collected by etching a thermistor on the wafer inside the IGBT module. Since the diode is very close to the wafer, the IGBT bridge arm's switching process will cause serious interference to its feedback signal, causing the temperature signal fed back by the thermistor to contain a large amount of interference and invalid signals, thus affecting the accurate analysis of the temperature. There is currently no mature and reliable solution to this problem in the industry. Summary of the Invention

[0005] The present application provides a motor controller and its fault derating control method and device to solve the problem that the temperature signal of an IGBT module with a temperature sensor directly arranged on a wafer is easily interfered by the switching of the IGBT bridge arm state, thereby maximizing the performance of the drive system in a fault state while achieving over-temperature protection for the IGBT module.

[0006] A first aspect embodiment of the present application provides a fault derating control method for a motor controller, comprising the following steps: obtaining a current temperature sampling signal of at least one bridge arm of an IGBT module and a historical temperature sampling signal of at least one bridge arm; calculating the temperature rise rate of the IGBT module based on the current temperature sampling signal of the at least one bridge arm and / or the historical temperature sampling signal of the at least one bridge arm, and judging whether the cooling system of the vehicle is in a preset fault state based on the temperature rise rate of the IGBT module; and if the cooling system of the vehicle is in the preset fault state, obtaining the number of over-temperature faults of the IGBT module, and calculating the derating coefficient of the drive system of the vehicle based on the number of over-temperature faults and the temperature rise rate, and performing derating control on the drive system of the vehicle based on the derating coefficient.

[0007] Optionally, in some embodiments, the temperature rise rate of the IGBT module is calculated based on the current temperature sampling signal of the at least one bridge arm and / or the historical temperature sampling signal of the at least one bridge arm, including: obtaining the temperature signal acquisition time of the at least one bridge arm of the IGBT module; based on the temperature signal acquisition time of the at least one bridge arm, judging whether the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition; if the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition, filtering the current temperature sampling signal of the at least one bridge arm, and calculating the temperature rise rate of the IGBT module based on the historical temperature sampling signal of the at least one bridge arm; otherwise, retaining the current temperature sampling signal of the at least one bridge arm, and calculating the temperature rise rate of the IGBT module based on the current temperature sampling signal of the at least one bridge arm and the historical temperature sampling signal of the at least one bridge arm.

[0008] Optionally, in some embodiments, the determining whether the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition based on the temperature signal acquisition moment of the at least one bridge arm includes: determining whether the temperature signal acquisition moment of the at least one bridge arm is in the state state change interval of the at least one bridge arm; if the temperature signal acquisition moment of the at least one bridge arm is in the state state change interval of the at least one bridge arm, determining that the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition; otherwise, determining that the current temperature sampling signal of the at least one bridge arm does not meet the preset signal filtering condition.

[0009] Optionally, in some embodiments, filtering out the current temperature sampling signal of the at least one bridge arm includes: filtering out the current temperature sampling signal of the at least one bridge arm based on a preset band-stop filter, wherein the preset band-stop filter is:

[0010] D(n)=1·(n)+2·(n-1)+3·(n-2)+4·(n-1)+5·(n-2);

[0011] Wherein, n represents the control period, k1, k2, k3, k4, and k5 are filter coefficients, F is the IGBT temperature sampling signal obtained during the screening process, and D is the IGBT temperature sampling value after being filtered by the band-stop filter.

[0012] Optionally, in some embodiments, determining whether the vehicle's cooling system is in a preset fault state based on the temperature rise rate of the IGBT module includes: determining whether the temperature rise rate is greater than a preset cooling system fault threshold; if the temperature rise rate is greater than the preset cooling system fault threshold, determining that the vehicle's cooling system is in the preset fault state.

[0013] Optionally, in some embodiments, the calculating the derating coefficient of the vehicle's drive system based on the number of over-temperature failures and the temperature rise rate includes: calculating the temperature rise and fall rating coefficient of the IGBT module based on the temperature rise rate; calculating the over-temperature derating coefficient of the IGBT module based on the number of over-temperature failures of the IGBT module; and obtaining the derating coefficient of the vehicle's drive system based on the temperature rise and fall rating coefficient and the over-temperature derating coefficient.

[0014] Optionally, in some embodiments, the derating control of the vehicle's drive system according to the derating coefficient includes: based on a preset derating control formula, derating the vehicle's drive system according to the derating coefficient, wherein the preset derating control formula is:

[0015] T Limit =C Limit ·T q ;

[0016] Among them, T Limit Indicates the maximum allowable output torque of the drive system after limitation, C Limit is the drive system derating factor, T q Output torque for the external characteristic of the drive system.

[0017] Optionally, in some embodiments, after the vehicle's drive system is derated according to the derated coefficient, it also includes: judging whether the temperature rise rate of the IGBT module meets the preset safety conditions; if the temperature rise rate meets the preset safety conditions, stopping the derated control of the vehicle's drive system, otherwise, continuing the derated control of the vehicle's drive system.

[0018] A second aspect of the present application provides a fault derating control device for a motor controller, comprising: an acquisition module for acquiring a current temperature sampling signal of at least one bridge arm of an IGBT module and a historical temperature sampling signal of at least one bridge arm; a calculation module for calculating the temperature rise rate of the IGBT module based on the current temperature sampling signal of the at least one bridge arm and / or the historical temperature sampling signal of the at least one bridge arm, and judging whether the cooling system of the vehicle is in a preset fault state based on the temperature rise rate of the IGBT module; and a control module for acquiring the number of over-temperature faults of the IGBT module when the cooling system of the vehicle is in the preset fault state, and calculating the derating coefficient of the drive system of the vehicle based on the number of over-temperature faults and the temperature rise rate, and performing derating control on the drive system of the vehicle based on the derating coefficient.

[0019] Optionally, in some embodiments, the calculation module further includes: an acquisition unit for acquiring the temperature signal acquisition moment of at least one bridge arm of the IGBT module; a judgment unit for judging whether the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition based on the temperature signal acquisition moment of the at least one bridge arm; a filtering unit for filtering the current temperature sampling signal of the at least one bridge arm when the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition, and calculating the temperature rise rate of the IGBT module based on the historical temperature sampling signal of the at least one bridge arm; otherwise, retaining the current temperature sampling signal of the at least one bridge arm, and calculating the temperature rise rate of the IGBT module based on the current temperature sampling signal of the at least one bridge arm and the historical temperature sampling signal of the at least one bridge arm.

[0020] Optionally, in some embodiments, the judgment unit is further used to: judge whether the temperature signal acquisition moment of the at least one bridge arm is in the state state change interval of the at least one bridge arm; if the temperature signal acquisition moment of the at least one bridge arm is in the state state change interval of the at least one bridge arm, then judge that the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition; otherwise, judge that the current temperature sampling signal of the at least one bridge arm does not meet the preset signal filtering condition.

[0021] Optionally, in some embodiments, the filtering unit is further configured to:

[0022] Based on a preset band-stop filter, the current temperature sampling signal of the at least one bridge arm is filtered out, wherein the preset band-stop filter is:

[0023] D(n)=k1·F(n)+k2·F(n-1)+k3·F(n-2)+k4·D(n-1)+k5·D(n-2);

[0024] Wherein, n represents the control period, k1, k2, k3, k4, and k5 are filter coefficients, F is the IGBT temperature sampling signal obtained during the screening process, and D is the IGBT temperature sampling value after being filtered by the band-stop filter.

[0025] Optionally, in some embodiments, the calculation module is also used to: determine whether the temperature rise rate is greater than a preset cooling system fault threshold; if the temperature rise rate is greater than the preset cooling system fault threshold, determine that the vehicle's cooling system is in the preset fault state.

[0026] Optionally, in some embodiments, the control module is further used to: calculate the temperature rise and de-rating coefficient of the IGBT module based on the temperature rise rate; calculate the over-temperature derating coefficient of the IGBT module based on the number of over-temperature failures of the IGBT module; and obtain the derating coefficient of the vehicle's drive system based on the temperature rise and de-rating coefficient and the over-temperature derating coefficient.

[0027] Optionally, in some embodiments, the control module is further configured to:

[0028] Based on a preset derating control formula, the drive system of the vehicle is derating controlled according to the derating coefficient, wherein the preset derating control formula is:

[0029] T Limit =C Limit ·T q ;

[0030] Among them, T Limit Indicates the maximum allowable output torque of the drive system after limitation, C Limit is the drive system derating factor, T q Output torque for the external characteristic of the drive system.

[0031] Optionally, in some embodiments, after the vehicle's drive system is derated according to the derated coefficient, the control module is further used to: determine whether the temperature rise rate of the IGBT module meets the preset safety conditions; if the temperature rise rate meets the preset safety conditions, stop derated control of the vehicle's drive system; otherwise, continue derated control of the vehicle's drive system.

[0032] A third embodiment of the present application provides a motor controller, which includes the fault derating control device of the motor controller as described in the second embodiment.

[0033] A fourth embodiment of the present application provides a vehicle, which includes a motor controller as described in the third embodiment above.

[0034] Therefore, by stipulating that the IGBT temperature sampling value is invalid within the time range near the IGBT bridge arm state switching moment, the temperature sensor sampling signal that is severely interfered by the bridge arm state switching is filtered out, and a band-stop filter is designed according to the switching cycle of the motor controller IGBT module to filter the signal fed back by the temperature sensor, and by detecting the temperature rise rate of the IGBT module to determine whether a cooling system fault has occurred. When it is determined that a cooling system fault has occurred, the drive system derating factor is calculated according to the temperature rise rate of the IGBT module and the number of over-temperature faults, and the output of the motor controller is adaptively derated using the derating factor. In this way, the problem that the temperature signal of the IGBT module whose temperature sensor is directly arranged on the wafer is easily interfered by the IGBT bridge arm state switching is solved, and the drive system performance is maximized under the fault state while achieving over-temperature protection of the IGBT module.

[0035] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0037] Figure 1 This is a flow chart of a fault derating control method for a motor controller provided according to an embodiment of the present application;

[0038] Figure 2 A schematic diagram of a simplified architecture of a pure electric vehicle drive system provided according to a specific embodiment of the present application;

[0039] Figure 3 This is a flow chart of IGBT module temperature sensor signal processing according to a specific embodiment of the present application;

[0040] Figure 4 This is a flow chart of IGBT module temperature sampling signal screening according to a specific embodiment of the present application;

[0041] Figure 5 A schematic diagram of determining an IGBT bridge arm state transition interval according to a specific embodiment of the present application;

[0042] Figure 6 This is a flow chart of IGBT module cooling fault derating control according to a specific embodiment of the present application;

[0043] Figure 7Schematic diagram of a block diagram of a fault derating control device for a motor controller provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0045] Before introducing the fault derating control method of the motor controller according to the embodiment of the present application, the fault derating control method of the motor controller in the related art is introduced.

[0046] The IGBT module is the core power conversion module of the motor controller. Its primary function is to generate the desired current in the three-phase windings of the motor stator by controlling the conduction and disconnection of the upper and lower bridge arms of the U, V, and W phases, thereby ensuring the desired motor output torque and ultimately driving the vehicle. In electric vehicles, IGBT modules operate under high voltage and high current conditions for a long time, generating a large amount of heat during operation. This heat is dissipated to the external environment through heat exchange using the cooling system in the motor controller, ensuring that the IGBT module always operates within the permitted temperature range. If the heat generated by the IGBT module during operation cannot be effectively dissipated to the outside world, it will cause the IGBT to burn out due to overheating. For example, for the silicon-based IGBT modules commonly used in pure electric vehicle motor controllers, the IGBT junction temperature must be controlled below 150°C to prevent the IGBT module from overheating, shortening its service life, or even burning out. In conventional motor control logic, a derating protection strategy is generally designed to prevent the IGBT module from overheating. When the IGBT module temperature exceeds a predetermined threshold, the drive system power output is reduced to prevent the IGBT module temperature from further rising, thereby protecting the system.

[0047] In the related art, effective detection of IGBT module temperature is generally achieved by pre-embedded temperature sensors in the module. Currently, most automotive-grade IGBT modules implement temperature detection by pre-embedded NTC negative temperature coefficient thermistors near the U, V, and W phase bridge arms. The over-temperature derating protection strategy for IGBT modules is essentially to prevent the junction temperature from exceeding the device's specified threshold. Although pre-embedded NTC (Negative Temperature Coefficient) thermistors can achieve the purpose of detecting IGBT temperature, since the NTC thermistors are not directly arranged on the IGBT module wafer, there is a certain deviation between the temperature they feedback and the actual IGBT junction temperature and they are lower than the actual junction temperature. Therefore, to achieve over-temperature protection for the IGBT module, a certain temperature margin must be designed. For example, derating protection will be implemented when the feedback temperature of the NTC thermistor reaches 100°C. This ensures that the IGBT module will not be damaged due to overheating (junction temperature exceeding 150°C) under various operating conditions. The IGBT module can be well protected by designing a temperature margin, but it also limits the performance of the module. In order to maximize the performance of the IGBT module, the ideal state is to control the IGBT junction temperature near the maximum stable operating temperature limit and ensure that the IGBT junction temperature is always below this limit.

[0048] To achieve these goals, precise detection of the IGBT junction temperature is required. Pre-embedded NTC thermistors are insufficient for this purpose. Consequently, some IGBT module manufacturers are etching thermal diodes on the wafers of the upper and lower six bridge arms (U, V, and W phases) within the module to accurately collect junction temperature. Etching thermal diodes on the IGBT module wafer allows for direct, real-time acquisition of IGBT junction temperature information, thereby further enhancing IGBT module performance. However, this approach has a drawback: signal interference. With the traditional NTC thermistor temperature measurement method, since the NTC thermistor is a certain distance away from the IGBT module wafer, the opening and closing process of the IGBT bridge arm does not cause significant interference to its feedback signal, so the temperature signal fed back by the NTC thermistor is more stable. However, when collecting temperature by etching a thermal diode on the wafer inside the IGBT module, the diode is very close to the wafer, so the opening and closing process of the IGBT bridge arm will cause serious interference to its feedback signal. As a result, the temperature signal fed back by the thermistor contains a large amount of interference and invalid signals, thus affecting the accurate temperature analysis. There is currently no mature and reliable solution to this problem in the industry.

[0049] To solve the above problems, an embodiment of the present application provides a fault derating control method for a motor controller. By stipulating that the IGBT temperature sampling value is invalid within the time range near the IGBT bridge arm state switching moment, the temperature sensor sampling signal that is severely interfered by the bridge arm state switching is filtered out, and a band-stop filter is designed according to the switching cycle of the IGBT module of the motor controller. The signal fed back by the temperature sensor is filtered, and the temperature rise rate of the IGBT module is detected to determine whether a cooling system fault has occurred. When it is determined that a cooling system fault has occurred, the drive system derating coefficient is calculated according to the temperature rise rate of the IGBT module and the number of over-temperature faults. The output of the motor controller is adaptively derating using the derating coefficient. Thus, the problem that the temperature signal of the IGBT module whose temperature sensor is directly arranged on the wafer is easily interfered by the IGBT bridge arm state switching is solved, and the drive system performance is maximized in the fault state while achieving over-temperature protection of the IGBT module.

[0050] Specifically, Figure 1 A flowchart of a fault derating control method for a motor controller provided in an embodiment of the present application.

[0051] like Figure 1 As shown, the fault derating control method of the motor controller includes the following steps:

[0052] In step S101 , a current temperature sampling signal of at least one bridge arm of an IGBT module and a historical temperature sampling signal of at least one bridge arm are acquired.

[0053] The temperature sampling signal can be acquired through a temperature sensor.

[0054] It should be noted that if Figure 2 As shown in the figure, taking the pure electric vehicle drive system as an example, "DC+" and "DC-" represent the positive and negative poles of the DC bus; the dotted boxes indicated by UH, UL, VH, VL, WH, and WL are the upper and lower bridge arms of the three-phase U, V, and W of the IGBT module, namely the first upper bridge arm and the first lower bridge arm; the second upper bridge arm and the second lower bridge arm; the third upper bridge arm and the third lower bridge arm; T1, T2, T3, T4, T5, and T6 represent the 6 control signals of the upper and lower bridge arms of the three-phase U, V, and W of the IGBT module, respectively. Figure 2 Under the influence of the six control signals from T1 to T6, the bridge arms of the IGBT module are turned on and off. The DC bus voltage generates the desired current in the three-phase windings of the motor, which in turn causes the motor to output the desired torque. This is the basic operating principle of the electric vehicle drive system.

[0055] In actual implementation, the temperature sensor can be directly arranged on the IGBT module on the wafer, for example, Figure 2 In the dotted box where the six bridge arms are located, temperature sampling is generally achieved by etching temperature diodes on the wafer, so as to quickly and directly collect the junction temperature of the IGBT.

[0056] In step S102, the temperature rise rate of the IGBT module is calculated based on the current temperature sampling signal of at least one bridge arm and / or the historical temperature sampling signal of at least one bridge arm, and it is determined whether the vehicle's cooling system is in a preset fault state based on the temperature rise rate of the IGBT module.

[0057] Optionally, in some embodiments, the temperature rise rate of the IGBT module is calculated based on the current temperature sampling signal of at least one bridge arm and / or the historical temperature sampling signal of at least one bridge arm, including: obtaining the temperature signal acquisition time of at least one bridge arm of the IGBT module; based on the temperature signal acquisition time of at least one bridge arm, judging whether the current temperature sampling signal of at least one bridge arm meets the preset signal filtering condition; if the current temperature sampling signal of at least one bridge arm meets the preset signal filtering condition, filtering the current temperature sampling signal of at least one bridge arm, and calculating the temperature rise rate of the IGBT module based on the historical temperature sampling signal of at least one bridge arm; otherwise, retaining the current temperature sampling signal of at least one bridge arm, and calculating the temperature rise rate of the IGBT module based on the current temperature sampling signal of at least one bridge arm and the historical temperature sampling signal of at least one bridge arm.

[0058] Optionally, in some embodiments, based on the temperature signal acquisition moment of at least one bridge arm, determining whether the current temperature sampling signal of at least one bridge arm meets the preset signal filtering condition includes: determining whether the temperature signal acquisition moment of at least one bridge arm is in the state state change interval of at least one bridge arm; if the temperature signal acquisition moment of at least one bridge arm is in the state state change interval of at least one bridge arm, determining that the current temperature sampling signal of at least one bridge arm meets the preset signal filtering condition; otherwise, determining that the current temperature sampling signal of at least one bridge arm does not meet the preset signal filtering condition.

[0059] The preset signal filtering condition may be that the temperature signal sampling moment is during the state change period of the corresponding IGBT module bridge arm.

[0060] It is understandable that the feedback signal of the temperature sensor is easily affected by the working state of the bridge arm. Taking the U-phase upper bridge arm UH of the IGBT module, i.e. the first upper bridge arm, as an example, when it switches from the disconnected state to the on state, the bridge arm will instantly generate a large current, which may be as high as hundreds of amperes; when the bridge arm switches from the on state to the disconnected state, the current flowing in the bridge arm will be cut off in a very short time. Under high voltage conditions, this change in current state will cause serious interference to the temperature sensor. How to suppress this interference is still a difficult problem to be overcome in the industry.

[0061] Therefore, the embodiment of the present application can sample and screen the original temperature signal fed back by the temperature sensor, and filter the sampling signal that is greatly interfered by the change of the IGBT bridge arm state according to a predetermined strategy, so as to reduce the impact of the severely interfered temperature sampling signal on the final analyzed temperature. Specifically, after completing the temperature sampling signal screening, the embodiment of the present application filters the sampling signal. The embodiment of the present application can use a band-stop filter to filter the temperature signal, further reducing the impact of the IGBT module bridge arm state switching on the temperature sampling signal, thereby ensuring to the greatest extent that the processed IGBT module temperature signal can truly restore the temperature value of the IGBT. Next, Figure 3 The IGBT temperature signal processing method shown in FIG.

[0062] For the temperature sensor directly arranged on the IGBT module wafer, the temperature signal it feeds back is mainly affected by the IGBT bridge arm state switching, especially in the early stage of the state switching (IGBT bridge arm instantaneously flows a large current or cuts off a large current). Based on this feature, the embodiment of the present application stipulates the following screening method for the temperature sampling signal. The specific screening logic is as follows: Figure 4 shown.

[0063] ①First, record the temperature sensor sampling time points of the upper and lower six bridge arms of the IGBT module U, V, and W phases respectively;

[0064] ② Determine whether the temperature signal sampling moment is during the corresponding IGBT module bridge arm state change period, where the bridge arm state change includes the bridge arm switching from on to off or from off to on;

[0065] ③ If the sampling time of the temperature signal is during the state change period of the corresponding bridge arm, the temperature signal is discarded, that is, the temperature signal is deemed invalid;

[0066] ④ If the sampling time of the temperature signal is not during the state change period of the corresponding bridge arm, the temperature signal will be retained and applied to subsequent signal filtering and temperature analysis.

[0067] according to Figure 4 The IGBT module temperature sampling signal screening method shown can filter out the temperature sampling signal that is seriously interfered by the IGBT bridge arm state change. The key to achieving signal screening lies in step ②, that is, judging whether the temperature sampling moment is during the IGBT module bridge arm state change. The embodiment of the present application adopts the following judgment method, specifically as follows: Figure 5 shown.

[0068] Figure 5The horizontal axis is time, which includes four time points: T, T+t0, F-t1, and F. T and F both represent the moment when the IGBT module bridge arm state switches, that is, the bridge arm state of the IGBT changes at the above moment; t0 represents the time threshold after the bridge arm state switches, t0>0; t1 represents the time threshold before the bridge arm state switches, t1>0. The embodiment of the present application determines the time window for judging the validity of the IGBT temperature sampling signal, according to Figure 5 In the t0 time period after the IGBT bridge arm state switching, considering that the sudden change of the current flowing through the bridge arm will cause serious interference to the temperature sampling signal, the temperature sampling signal obtained in this time period is invalid and discarded; similarly, to ensure that the sampling signal is as unaffected as possible by the IGBT bridge arm state switching, the temperature sampling signal obtained in the t1 time period before the bridge arm state switching is also defined as invalid and discarded; except for the IGBT temperature signal collected in the above time period, it is considered that it is less affected by the IGBT state switching and is therefore retained. The retained signal is used for subsequent filtering and temperature analysis.

[0069] It should be noted that Figure 5 The time thresholds t0 and t1 can be determined through preliminary experiments, that is, the interference degree of the IGBT bridge arm state switching on the temperature sampling signal can be detected through preliminary experiments, so as to determine the time thresholds t0 and t1.

[0070] according to Figure 3 As shown in the figure, the temperature sensor sampling signal is filtered after the screening is completed. For the temperature sensor directly arranged on the IGBT wafer, the temperature signal output by it is greatly affected by the switching of the IGBT bridge arm state. Figure 4 The IGBT module temperature sampling signal screening method shown can filter out portions of the temperature sampling signal that are subject to significant interference, but it cannot further eliminate the interference caused by IGBT bridge arm state switching. To address this issue, the present embodiment of the application designs a band-stop filter. Considering that the interference caused by IGBT bridge arm state switching has a frequency that is directly related to the IGBT state switching frequency, the present embodiment of the application uses a band-stop filter to filter out signals related to the IGBT bridge arm switching frequency from the IGBT temperature sampling signal, thereby minimizing the interference of the IGBT bridge arm state switching on the temperature sampling signal.

[0071]

[0072] Where G(s) is the transfer function of the band-stop filter, ω0 represents the stopband center angular frequency, and Q is the quality factor, where Q>0.

[0073] The present embodiment utilizes a band-stop filter to filter out interference at specific frequencies introduced by IGBT bridge arm state switching in the temperature sensor sampling signal, thereby reducing the impact of interference on the temperature signal. Defining the switching frequency of the IGBT module as H, the stopband center angular frequency ω0 in equation (1) has a fixed linear relationship with it, as specifically expressed by equation (2).

[0074] ω0= f ·;(2)

[0075] Among them, K f is the conversion factor, K f >0, H is the switching frequency. Substituting equation (2) into equation (1), the transfer function of the band-stop filter is transformed into equation (3).

[0076]

[0077] The band-stop filter shown in formula (3) is a continuous form, which cannot be directly implemented by the motor controller and needs to be discretized. Define the IGBT temperature sampling value after the band-stop filter is D, Figure 4 、 5 The IGBT temperature sampling signal obtained by the screening process is F, and the numerical discrete form of the band-stop filter is shown in formula (4).

[0078] D(n)=1·(n)+2·(n-1)+3·(n-2)+4·(n-1)+5·(n-2); (4)

[0079] Where n represents the control period, F is the IGBT temperature sampling signal obtained during the screening process, D is the IGBT temperature sampling value after being filtered by the band-stop filter, k1, k2, k3, k4, and k5 are filter coefficients. The specific expressions are as follows:

[0080]

[0081] Optionally, in some embodiments, whether the vehicle's cooling system is in a preset fault state is determined based on the temperature rise rate of the IGBT module, including: determining whether the temperature rise rate is greater than a preset cooling system fault threshold; if the temperature rise rate is greater than the preset cooling system fault threshold, then determining that the vehicle's cooling system is in a preset fault state.

[0082] It is understandable that the IGBT module of the pure electric vehicle motor controller will generate a large amount of heat under normal working conditions. This heat needs to be discharged to the environment through the cooling system. The performance of the cooling system will directly affect the performance of the IGBT module. When the cooling system fails or its performance degrades, the over-temperature protection mechanism of the IGBT module will be frequently triggered, thereby affecting the power output. In addition, when the cooling system performance degrades or fails, the heat generated by the IGBT module during operation cannot be effectively dissipated to the outside, which makes it more likely to cause overheating. At this time, the conventional IGBT over-temperature protection mechanism will find it difficult to provide complete protection coverage for the IGBT module. In this state, the IGBT module can easily be permanently damaged due to overheating. In response to the above problems, the embodiments of the present application provide an IGBT module cooling fault detection mechanism and a corresponding derating control method.

[0083] Specifically, when the cooling system is in a normal state, the heat generated by the IGBT module can be continuously dissipated into the external environment. Regardless of any driving conditions, the temperature rise rate of the IGBT module will not exceed a certain threshold. A cooling system failure will cause a decrease in cooling efficiency. At this time, the heat generated by the IGBT module will not be dissipated into the external environment in a timely manner. In this state, the IGBT temperature rise rate will show an accelerated characteristic. Based on this characteristic, the embodiment of the present application designs a cooling system fault detection mechanism to judge the fault state of the cooling system based on the temperature rise rate of the IGBT module. The temperature rise rate of the IGBT module is defined as SIGBT, SIGBT>0; the cooling system fault threshold is defined as SERR, SERR>0; when the condition of the temperature rise rate of the IGBT module SIGBT>SERR is met, the cooling system is judged to have failed.

[0084] In step S103, if the vehicle's cooling system is in a preset fault state, the number of over-temperature faults of the IGBT module is obtained, and the derating factor of the vehicle's drive system is calculated based on the number of over-temperature faults and the temperature rise rate, and the vehicle's drive system is derating controlled according to the derating factor.

[0085] Optionally, in some embodiments, the derating coefficient of the vehicle's drive system is calculated based on the number of over-temperature failures and the temperature rise rate, including: calculating the temperature rise and de-rating coefficient of the IGBT module based on the temperature rise rate; calculating the over-temperature derating coefficient of the IGBT module based on the number of over-temperature failures of the IGBT module; and obtaining the derating coefficient of the vehicle's drive system based on the temperature rise and de-rating coefficient and the over-temperature derating coefficient.

[0086] Specifically, the motor controller IGBT module cooling fault derating control method provided in the embodiment of the present application, the core of which is to use the drive system derating coefficient to achieve adaptive adjustment of the motor power output, and to avoid overheating of the IGBT module caused by the decline in cooling system efficiency and the resulting irreversible damage to the IGBT module by limiting the power output of the drive motor.

[0087] In this embodiment of the application, the drive system derating factor is defined as CLimit, which is expressed as follows:

[0088] C Limit =C IGBT ·C ERR ;(6)

[0089] Among them, C IGBT Indicates the IGBT temperature rise and fall coefficient, C IGBT ∈[0,1];C ERR Indicates the IGBT overtemperature derating factor, C ERR ∈[0, 1]. The embodiment of the present application uses these two coefficients to finally calculate the drive system derating coefficient CLimit, and uses this coefficient to implement the output derating of the drive system.

[0090] ① Calculation of IGBT temperature rise and fall coefficient

[0091] To calculate the IGBT temperature rise coefficient, first calculate the IGBT temperature rise rate S IGBT Processing is performed to continuously screen out the maximum value of the IGBT temperature rise rate, which is defined as S MAX , then limit the value as follows:

[0092]

[0093] Among them, S INT Indicates the limited IGBT temperature rise rate; S Limit Indicates the maximum limit of the temperature rise rate, S Limit >0. As mentioned above, the premise for judging whether the system cooling system fails is that the IGBT temperature rise rate is higher than the fault threshold SERR, so S in formula (7) MAX is greater than or equal to S ERR Therefore, formula (7) is actually the IGBT temperature rise rate S INT Limited to [S ERR , S Limit ] range.

[0094] After completing the above restriction processing, the IGBT temperature rise and fall coefficient is calculated, as shown in formula (8)

[0095]

[0096] According to formula (8), the IGBT temperature rise and fall coefficient CIGBT is adaptively adjusted in the range of [0,1] according to the severity of the cooling system fault. When the cooling system fault is serious, the corresponding IGBT temperature rise rate S IGBT Larger, when it exceeds the maximum limit S Limit When the IGBT temperature rise and fall coefficient C IGBT On the contrary, if the cooling system is only in the critical fault state, the corresponding IGBT temperature rise rate S IGBT For S ERR At this time, the IGBT temperature rise and fall coefficient C calculated according to formula (8) is IGBT is 1, and the embodiment of the present application achieves adaptive adjustment of the output torque of the drive system in this way.

[0097] ② Calculation of IGBT overtemperature derating coefficient

[0098] According to formula (5), the drive system derating factor is C Limit is the IGBT temperature rise and fall coefficient C IGBT and IGBT temperature rise and fall coefficient C ERR The product of the IGBT temperature rise and fall coefficient C IGBT As previously mentioned, this coefficient decreases with the severity of the cooling system failure, thereby limiting the drive system's power output and preventing further temperature rise in the IGBT module. The IGBT overtemperature derating coefficient also plays this role, serving as a useful supplement to the IGBT temperature rise and fall coefficient.

[0099] In actual conditions, simply using the IGBT temperature rise and fall coefficient C IGBT The implemented derating treatment may not be sufficient to control the temperature rise problem of the IGBT module caused by the cooling system failure, that is, the IGBT module may still have an overtemperature problem after the derating measures are taken. For the electric vehicle drive system with a cooling failure, its ideal working state is to achieve a balance between the drive system performance output and avoiding IGBT overheating, that is, to avoid overheating of the IGBT module under the condition of fully utilizing the drive system performance output under the fault state. To achieve this goal, the embodiment of the application designs the IGBT overtemperature derating coefficient C ERR , C ERR is determined as follows:

[0100] C ERR The initial value is 1, and a cooling system failure occurs and the IGBT temperature rise and fall coefficient C is calculated. IGBTAfter the output torque derating is implemented, the IGBT over-temperature fault detection is continued. When the IGBT over-temperature fault is detected, it indicates that the current derating measures are not enough to avoid the IGBT over-temperature problem caused by the cooling system failure. In this state, the present invention continues to use the IGBT over-temperature derating coefficient C ERR After implementing derating, the expression of CERR is as follows:

[0101]

[0102] Where N is the number of IGBT over-temperature failures that occur after a cooling system failure. Over-temperature derating factor C ERR The initial value of is 1. According to formula (9), after the cooling system fails, the temperature rise and fall coefficient C IGBT Implement system output derating. If the IGBT overtemperature fault is not triggered after that, it means that relying solely on C IGBT The derating can play the role of IGBT over-temperature protection. At this time, N is 0, and the corresponding over-temperature derating coefficient C ERR If an over-temperature fault occurs, it indicates that the use of C ERR The implemented derating is not enough to solve the IGBT overtemperature problem. In this case, the overtemperature derating factor C ERR Intervention system derating control, according to formula (9), each time an IGBT over-temperature fault occurs, C ERR The value of will decrease by 0.05 (5%), and as the number of over-temperature faults increases, C ERR The value of becomes smaller and smaller until it is reduced to 0. The embodiment of the present application implements system derating under fault conditions in this way, thereby finding a balance between the performance output of the drive system and avoiding IGBT overheating to achieve optimal control.

[0103] Optionally, in some embodiments, after the vehicle's drive system is derated according to the derated coefficient, it also includes: judging whether the temperature rise rate of the IGBT module meets the preset safety conditions; if the temperature rise rate meets the preset safety conditions, stopping the derated control of the vehicle's drive system, otherwise, continuing the derated control of the vehicle's drive system.

[0104] Specifically, the external characteristic output torque of the pure electric vehicle drive system is defined as T q In the embodiment of the present application, the drive system derating process after a cooling system failure is implemented in the following manner.

[0105] T Limit =C Limit ·T q ;(10)

[0106] Among them, T LimitIndicates the maximum allowable output torque of the drive system after limitation. In this embodiment, the drive system derating factor C is used. Limit , the characteristic output torque T of the drive system q By limiting the maximum allowable output torque of the drive system under the condition of cooling system failure, the drive system derating control is realized, thereby ultimately protecting the IGBT module.

[0107] In summary, if Figure 6 As shown, the embodiment of the present application first determines the cooling system failure based on the temperature rise rate of the IGBT module. When the cooling system failure is detected, the drive system derating coefficient is calculated, and the coefficient is used to implement derating control on the drive system to avoid or alleviate the temperature rise impact of the IGBT module caused by the decline in cooling system efficiency; on the basis of implementing the derating, the judgment of the IGBT module overtemperature failure is continuously performed. When it is determined that an overtemperature failure has occurred, it is considered that the previously implemented drive system derating is insufficient to control the temperature rise of the IGBT module. In this case, the drive system derating coefficient is further adjusted, and the power output of the drive system is continued to be reduced, so as to avoid damage to the IGBT module due to overtemperature due to the decline in cooling system efficiency or failure. In the embodiment of the present application, the derating factor of the drive system is related to the number of times the IGBT module over-temperature failure occurs. If the IGBT module repeatedly over-temperature failures occur, the derating factor will continue to decrease. By reducing the power output of the drive system, the unexpected temperature rise of the IGBT module is avoided, thereby achieving a dynamic balance between the cooling system fault protection and the power output of the drive system. On the basis of maximizing the output capacity of the drive system when the cooling system fails, the unexpected temperature rise of the IGBT module and the possible irreversible damage to the IGBT module caused by this are avoided.

[0108] Therefore, by invalidating the IGBT temperature sampling values ​​within the time range near the IGBT arm state switching moment, the temperature sensor sampling signal severely interfered by the arm state switching is filtered out. A band-stop filter is designed based on the switching cycle of the IGBT module of the motor controller to filter the temperature sensor feedback signal, further reducing the interference caused by the IGBT arm state switching on the temperature signal. The temperature rise rate of the IGBT module is detected to determine whether a cooling system fault has occurred. If a cooling system fault is determined to have occurred, the drive system derating factor is calculated based on the temperature rise rate of the IGBT module and the number of overtemperature faults. The derating factor is used to adaptively derate the output of the motor controller, achieving temperature protection for the IGBT module. This ensures that the IGBT module can fully perform its performance without affecting its expected life or causing irreversible damage to the system due to overheating. This solves the signal interference problem of directly detecting the IGBT junction temperature, and provides overtemperature protection for the IGBT module while ensuring maximum performance of the drive system under fault conditions. The system is easy to implement, does not involve hardware changes, and does not increase vehicle manufacturing costs, thus having good promotion value.

[0109] According to the fault derating control method of the motor controller proposed in the embodiment of the present application, the temperature sensor sampling signal that is severely interfered by the bridge arm state switching is filtered out by stipulating that the IGBT temperature sampling value is invalid within the time range near the IGBT bridge arm state switching moment, and a band-stop filter is designed according to the switching cycle of the IGBT module of the motor controller, and the signal fed back by the temperature sensor is filtered. The temperature rise rate of the IGBT module is detected to determine whether a cooling system fault has occurred. When it is determined that a cooling system fault has occurred, the drive system derating coefficient is calculated according to the temperature rise rate of the IGBT module and the number of over-temperature faults, and the output of the motor controller is adaptively derating using the derating coefficient. In this way, the problem that the temperature signal of the IGBT module whose temperature sensor is directly arranged on the wafer is easily interfered by the IGBT bridge arm state switching is solved, and the drive system performance is maximized under the fault state while achieving over-temperature protection of the IGBT module.

[0110] Next, a fault derating control device for a motor controller according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0111] Figure 7 4 is a block diagram of a fault derating control device for a motor controller according to an embodiment of the present application.

[0112] like Figure 7 As shown, the fault derating control device 10 of the motor controller includes: an acquisition module 100 , a calculation module 200 and a control module 300 .

[0113] Among them, the acquisition module 100 is used to obtain the current temperature sampling signal of at least one bridge arm of the IGBT module and the historical temperature sampling signal of at least one bridge arm; the calculation module 200 is used to calculate the temperature rise rate of the IGBT module based on the current temperature sampling signal of at least one bridge arm and / or the historical temperature sampling signal of at least one bridge arm, and judge whether the vehicle's cooling system is in a preset fault state based on the temperature rise rate of the IGBT module; the control module 300 is used to obtain the number of over-temperature faults of the IGBT module when the vehicle's cooling system is in a preset fault state, and calculate the derating factor of the vehicle's drive system based on the number of over-temperature faults and the temperature rise rate, and perform derating control on the vehicle's drive system based on the derating factor.

[0114] Optionally, in some embodiments, the calculation module 200 further includes: an acquisition unit for acquiring the temperature signal acquisition moment of at least one bridge arm of the IGBT module; a judgment unit for judging whether the current temperature sampling signal of at least one bridge arm meets a preset signal filtering condition based on the temperature signal acquisition moment of at least one bridge arm; a filtering unit for filtering the current temperature sampling signal of at least one bridge arm when the current temperature sampling signal of at least one bridge arm meets the preset signal filtering condition, and calculating the temperature rise rate of the IGBT module based on the historical temperature sampling signal of at least one bridge arm; otherwise, retaining the current temperature sampling signal of at least one bridge arm, and calculating the temperature rise rate of the IGBT module based on the current temperature sampling signal of at least one bridge arm and the historical temperature sampling signal of at least one bridge arm.

[0115] Optionally, in some embodiments, the judgment unit is further used to: judge whether the temperature signal acquisition moment of at least one bridge arm is in the state state change interval of at least one bridge arm; if the temperature signal acquisition moment of at least one bridge arm is in the state state change interval of at least one bridge arm, then judge that the current temperature sampling signal of at least one bridge arm meets the preset signal filtering condition; otherwise, judge that the current temperature sampling signal of at least one bridge arm does not meet the preset signal filtering condition.

[0116] Optionally, in some embodiments, the filtering unit is further configured to:

[0117] Based on a preset band-stop filter, the current temperature sampling signal of at least one bridge arm is filtered out, wherein the preset band-stop filter is:

[0118] D(n)=1·(n)+2·(n-1)+3·(n-2)+4·(n-1)+5·(n-2);

[0119] Wherein, n represents the control period, k1, l2, k3, k4, and k5 are filter coefficients, F is the IGBT temperature sampling signal obtained during the screening process, and D is the IGBT temperature sampling value after being filtered by the band-stop filter.

[0120] Optionally, in some embodiments, the calculation module 200 is further used to: determine whether the temperature rise rate is greater than a preset cooling system fault threshold; if the temperature rise rate is greater than the preset cooling system fault threshold, determine that the vehicle's cooling system is in a preset fault state.

[0121] Optionally, in some embodiments, the control module 300 is further used to: calculate the temperature rise and de-rating coefficient of the IGBT module based on the temperature rise rate; calculate the over-temperature derating coefficient of the IGBT module based on the number of over-temperature failures of the IGBT module; and obtain the derating coefficient of the vehicle's drive system based on the temperature rise and de-rating coefficient and the over-temperature derating coefficient.

[0122] Optionally, in some embodiments, the control module 300 is further configured to:

[0123] Based on the preset derating control formula, the vehicle's drive system is derating controlled according to the derating coefficient, wherein the preset derating control formula is:

[0124] T Limit =C Limit ·T q ;

[0125] Among them, T Limit Indicates the maximum allowable output torque of the drive system after limitation, C Limit is the drive system derating factor, T q Output torque for the external characteristic of the drive system.

[0126] Optionally, in some embodiments, after the vehicle's drive system is derated according to the derated coefficient, the control module 300 is further used to: determine whether the temperature rise rate of the IGBT module meets the preset safety conditions; if the temperature rise rate meets the preset safety conditions, stop derated control of the vehicle's drive system; otherwise, continue derated control of the vehicle's drive system.

[0127] It should be noted that the above explanation of the embodiment of the fault derating control method of the motor controller is also applicable to the fault derating control device of the motor controller of this embodiment, and will not be repeated here.

[0128] According to the fault derating control device of the motor controller proposed in the embodiment of the present application, the temperature sensor sampling signal that is severely interfered by the bridge arm state switching is filtered out by stipulating that the IGBT temperature sampling value is invalid within the time range near the IGBT bridge arm state switching moment, and a band-stop filter is designed according to the switching cycle of the IGBT module of the motor controller, and the signal fed back by the temperature sensor is filtered. The temperature rise rate of the IGBT module is detected to determine whether a cooling system fault has occurred. When it is determined that a cooling system fault has occurred, the drive system derating coefficient is calculated according to the temperature rise rate of the IGBT module and the number of over-temperature faults, and the output of the motor controller is adaptively derating using the derating coefficient. In this way, the problem that the temperature signal of the IGBT module whose temperature sensor is directly arranged on the wafer is easily interfered by the IGBT bridge arm state switching is solved, and the drive system performance is maximized in the fault state while achieving over-temperature protection of the IGBT module.

[0129] An embodiment of the present application further provides a motor controller, comprising: the fault derating control device of the motor controller as described above.

[0130] An embodiment of the present application also provides a vehicle, comprising: a motor controller as described above.

[0131] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0132] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0133] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0134] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0135] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0136] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A fault derating control method for a motor controller, characterized in that: The following steps are involved: Acquire a current temperature sampling signal of at least one bridge arm of the IGBT module and a historical temperature sampling signal of at least one bridge arm; calculating a temperature rise rate of the IGBT module according to a current temperature sampling signal of the at least one bridge arm and / or a historical temperature sampling signal of the at least one bridge arm, and determining whether the cooling system of the vehicle is in a preset fault state according to the temperature rise rate of the IGBT module; as well as If the cooling system of the vehicle is in the preset fault state, the number of over-temperature faults of the IGBT module is obtained, and a derating factor of the drive system of the vehicle is calculated according to the number of over-temperature faults and the temperature rise rate, and the drive system of the vehicle is derating controlled according to the derating factor. The calculating the derating factor of the vehicle drive system according to the number of over-temperature faults and the temperature rise rate includes: Calculating the temperature rise and fall coefficient of the IGBT module according to the temperature rise rate; Calculating an over-temperature derating factor of the IGBT module according to the number of over-temperature failures of the IGBT module; Obtaining a derating factor for a drive system of the vehicle according to the temperature rise and fall derating factor and the over-temperature derating factor; The derating control of the drive system of the vehicle according to the derating coefficient includes: Based on a preset derating control formula, the drive system of the vehicle is derating controlled according to the derating coefficient, wherein the preset derating control formula is: ； in, Indicates the maximum allowable output torque of the drive system after limitation. is the drive system derating factor, Output torque for the external characteristic of the drive system The drive system derating factor CLimit is expressed as follows: ； in, Indicates the IGBT temperature rise and fall coefficient, Indicates the IGBT overtemperature derating coefficient, The calculation method of IGBT temperature rise and fall coefficient is as follows: First, the IGBT temperature rise rate Processing is performed to continuously screen out the maximum value of the IGBT temperature rise rate, which is defined as , then limit the value. ； in, Indicates the limited IGBT temperature rise rate; Indicates the maximum limit value of the temperature rise rate, The calculation method of IGBT temperature rise and fall coefficient is: ； The calculation method of IGBT overtemperature derating coefficient is: ； in, Indicates the number of IGBT overtemperature faults that occurred after a cooling system failure.

2. The method according to claim 1, characterized in that The calculating the temperature rise rate of the IGBT module according to the current temperature sampling signal of the at least one bridge arm and / or the historical temperature sampling signal of the at least one bridge arm includes: Obtaining a temperature signal acquisition time of at least one bridge arm of the IGBT module; Based on the temperature signal acquisition time of the at least one bridge arm, determining whether the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition; If the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition, the current temperature sampling signal of the at least one bridge arm is filtered out, and the temperature rise rate of the IGBT module is calculated based on the historical temperature sampling signal of the at least one bridge arm; otherwise, the current temperature sampling signal of the at least one bridge arm is retained, and the temperature rise rate of the IGBT module is calculated based on the current temperature sampling signal of the at least one bridge arm and the historical temperature sampling signal of the at least one bridge arm.

3. The method according to claim 2, characterized in that The determining, based on the temperature signal acquisition moment of the at least one bridge arm, whether the current temperature sampling signal of the at least one bridge arm meets a preset signal filtering condition includes: Determining whether a temperature signal acquisition moment of the at least one bridge arm is in a state change interval of the at least one bridge arm; If the temperature signal acquisition moment of the at least one bridge arm is in the state change interval of the at least one bridge arm, it is determined that the current temperature sampling signal of the at least one bridge arm meets the preset signal filtering condition; otherwise, it is determined that the current temperature sampling signal of the at least one bridge arm does not meet the preset signal filtering condition.

4. The method according to claim 2, characterized in that The filtering out the current temperature sampling signal of the at least one bridge arm includes: Based on a preset band-stop filter, the current temperature sampling signal of the at least one bridge arm is filtered out, wherein the preset band-stop filter is: ； in, To control the cycle, 、 、 、 、 are filter coefficients, is the IGBT temperature sampling signal obtained during the screening process, is the IGBT temperature sampling value after being filtered by the band-stop filter.

5. The method according to claim 1, wherein The determining whether the cooling system of the vehicle is in a preset fault state according to the temperature rise rate of the IGBT module includes: Determining whether the temperature rise rate is greater than a preset cooling system failure threshold; If the temperature rise rate is greater than the preset cooling system failure threshold, it is determined that the cooling system of the vehicle is in the preset failure state.

6. The method according to claim 1, characterized in that After the driving system of the vehicle is derated according to the derated coefficient, the method further includes: Determining whether the temperature rise rate of the IGBT module meets the preset safety conditions; If the temperature rise rate satisfies the preset safety condition, the derating control of the vehicle's drive system is stopped; otherwise, the derating control of the vehicle's drive system is continued.

7. A fault derating control device for a motor controller, characterized in that: include: An acquisition module, configured to acquire a current temperature sampling signal of at least one bridge arm of the IGBT module and a historical temperature sampling signal of at least one bridge arm; a calculation module, configured to calculate a temperature rise rate of the IGBT module based on a current temperature sampling signal of the at least one bridge arm and / or a historical temperature sampling signal of the at least one bridge arm, and determine whether the vehicle's cooling system is in a preset fault state based on the temperature rise rate of the IGBT module; as well as The control module obtains the number of over-temperature faults of the IGBT module when the cooling system of the vehicle is in the preset fault state, calculates a derating factor of the drive system of the vehicle based on the number of over-temperature faults and the temperature rise rate, and performs derating control on the drive system of the vehicle based on the derating factor, wherein the calculating the derating factor of the drive system of the vehicle based on the number of over-temperature faults and the temperature rise rate includes: Calculating the temperature rise and fall coefficient of the IGBT module according to the temperature rise rate; Calculating an over-temperature derating factor of the IGBT module according to the number of over-temperature failures of the IGBT module; Obtaining a derating factor for a drive system of the vehicle according to the temperature rise and fall derating factor and the over-temperature derating factor; The derating control of the drive system of the vehicle according to the derating coefficient includes: Based on a preset derating control formula, the drive system of the vehicle is derating controlled according to the derating coefficient, wherein the preset derating control formula is: ； in, Indicates the maximum allowable output torque of the drive system after limitation. is the drive system derating factor, Output torque for the external characteristic of the drive system The drive system derating factor CLimit is expressed as follows: ；（6） in, Indicates the IGBT temperature rise and fall coefficient, Indicates the IGBT overtemperature derating coefficient, The calculation method of IGBT temperature rise and fall coefficient is as follows: First, the IGBT temperature rise rate Processing is performed to continuously screen out the maximum value of the IGBT temperature rise rate, which is defined as , then limit the value. ；（7） in, Indicates the limited IGBT temperature rise rate; Indicates the maximum limit value of the temperature rise rate, The calculation method of IGBT temperature rise and fall coefficient is: ； The calculation method of IGBT overtemperature derating coefficient is: ； in, Indicates the number of IGBT overtemperature faults that occurred after a cooling system failure.

8. A motor controller, characterized in that: include: The fault derating control device for a motor controller as claimed in claim 7.

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