IGBT (Insulated Gate Bipolar Translator) detection method and system and vehicle

Abstract

The invention discloses an IGBT detection method and system and a vehicle, relates to the technical field of IGBTs, and is applied to the IGBT detection system comprising an IGBT driving module, a current source module and a temperature sensor, the current source module is connected with the IGBT driving module, the temperature sensor collects a radiator temperature value of a radiator corresponding to the system, and the temperature value of the radiator is calculated. An IGBT detection instruction is received to control the IGBT driving module and the current source module, so that the system is in a first current working state, and the current value at the moment is greater than a preset current value; under the condition that the duration of the first current working state is equal to a preset duration threshold value, the IGBT driving module and the current source module are controlled to enable the system to be in a second current working state, and the current value at the moment is smaller than or equal to a preset current value; and obtaining the conduction voltage drop of the IGBT at the moment, and detecting the IGBT according to the conduction voltage drop of the IGBT and the temperature value of the radiator. According to the invention, the detection accuracy of the IGBT is improved.

Description

Technical Field

[0001] This application relates to the field of IGBT technology, and in particular to an IGBT detection method, system, and vehicle. Background Technology

[0002] With the widespread use of IGBTs (Insulated Gate Bipolar Transistors) in various fields, users have also placed higher demands on IGBT testing methods (generally testing IGBTs to determine their lifespan).

[0003] Traditional IGBT testing methods rely on temperature sensors to estimate the thermal resistance of the IGBT chip junction (i.e., defining an ideal situation where the thermal resistance of the chip junction remains constant). The lifespan of the IGBT is then determined based on this estimated thermal resistance. However, this method has certain drawbacks. Due to the different coefficients of thermal expansion of the IGBT's constituent materials, the thermal resistance of the IGBT chip junction can vary. In other words, this method's accuracy is low because the assumption that the thermal resistance of the IGBT chip junction remains constant under ideal conditions is broken.

[0004] The above content is only used to help understand the technical solution of this application and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main purpose of this application is to provide a method, system and vehicle for detecting IGBTs, aiming to solve the technical problem of low detection accuracy of IGBTs.

[0006] To achieve the above objectives, this application provides a method for detecting IGBTs. This method is applied to an IGBT detection system, which includes an IGBT driving module, a current source module, and a temperature sensor. The current source module is connected to the IGBT driving module. The temperature sensor is used to collect the heatsink temperature value corresponding to the heatsink in the IGBT detection system. The IGBT detection method includes:

[0007] If an IGBT detection command is received, the IGBT drive module and the current source module are controlled to put the IGBT detection system into a first current operating state, wherein the first current value in the first current operating state is greater than a preset current value.

[0008] When the duration of the first current operating state is equal to a preset duration threshold, the IGBT drive module and the current source module are controlled to make the IGBT detection system be in a second current operating state, wherein the second current value in the second current operating state is less than or equal to the preset current value.

[0009] Obtain the IGBT on-state voltage drop under the second current operating state, and detect the IGBT based on the IGBT on-state voltage drop and the heat sink temperature value.

[0010] In one embodiment, the step of controlling the IGBT drive module and the current source module to put the IGBT detection system into a first current operating state includes:

[0011] The IGBT drive module and the current source module are controlled to be in a first connection state, wherein the first connection state includes the power battery in the IGBT drive module being connected to the three-phase drive bridge arm in the IGBT drive module, and the constant current source in the current source module being disconnected from the three-phase drive bridge arm.

[0012] In the first connection state, the IGBT turn-on state in the three-phase drive bridge arm is controlled based on a preset detection timing sequence. The first current operating state includes the connection state of the IGBT detection system as the first connection state and the IGBT operating state as the IGBT turn-on state. In the second current operating state, the connection state of the IGBT detection system is the opposite of the first connection state, and the IGBT operating state of the IGBT detection system is the same as the IGBT turn-on state.

[0013] In one embodiment, the IGBT detection method further includes:

[0014] Determine the IGBT on-state voltage drop of each IGBT in the first current operating state, or determine the IGBT on-state voltage drop of each IGBT in the second current operating state.

[0015] For each IGBT, if the IGBT on-state voltage drop is greater than a first preset voltage drop threshold, the IGBT is controlled based on a preset lifetime protection command. The preset lifetime protection command includes at least one of reducing the IGBT switching frequency and reducing the IGBT peak operating time.

[0016] When the IGBT conduction voltage drop is greater than a second preset voltage drop threshold, an alarm replacement command corresponding to the IGBT is generated, wherein the second preset voltage drop threshold is greater than a first preset voltage drop threshold.

[0017] In one embodiment, the step of detecting the IGBT based on the IGBT on-state voltage drop and the heat sink temperature includes:

[0018] For each IGBT's IGBT on-state voltage drop, the junction temperature value corresponding to the IGBT on-state voltage drop is determined in a preset junction temperature and voltage drop correspondence table, and the temperature difference between the junction temperature value and the heat sink temperature value is determined.

[0019] The thermal resistance value of the IGBT is determined based on the IGBT on-state voltage drop, the temperature difference, and the operating parameters of the IGBT, and the IGBT is tested based on the thermal resistance value.

[0020] In one embodiment, the step of determining the IGBT thermal resistance value based on the IGBT on-state voltage drop, the temperature difference, and the IGBT operating parameters includes:

[0021] The IGBT on-current and IGBT turn-on duration are determined in the operating parameters of the IGBT, and the product of the IGBT on-voltage drop, the IGBT on-current, and the IGBT turn-on duration is determined as the IGBT on-loss value.

[0022] The product of the IGBT conduction loss value and the temperature difference value is determined as the IGBT thermal resistance value.

[0023] In one embodiment, the step of detecting the IGBT based on the IGBT thermal resistance value includes:

[0024] When the IGBT thermal resistance value is greater than a first preset thermal resistance threshold, the IGBT is controlled based on a preset life protection command, wherein the preset life protection command includes at least one of reducing the IGBT switching frequency and reducing the IGBT peak operating time.

[0025] If the thermal resistance value of the IGBT is greater than the second preset thermal resistance threshold, an alarm replacement command corresponding to the IGBT is generated, wherein the second preset thermal resistance threshold is greater than the first preset thermal resistance threshold.

[0026] In addition, to achieve the above objectives, this application provides an IGBT detection system, which includes a main control chip, an IGBT drive module, a current source module, and a temperature sensor. The current source module is connected to the IGBT drive module, and the main control chip is connected to the IGBT drive module, the current source module, and the temperature sensor. The temperature sensor is used to collect the heat sink temperature value on the heat sink corresponding to the IGBT detection system.

[0027] The main control chip is used to execute the IGBT detection method described above.

[0028] In one embodiment, the IGBT driver module includes:

[0029] Driven devices;

[0030] The driving bridge arm circuit includes three-phase driving bridge arms. The first end of each phase driving bridge arm is connected together and serves as the positive terminal of the driving bridge arm circuit. The second end of each phase driving bridge arm is connected together and serves as the negative terminal of the driving bridge arm circuit. The midpoint of each phase driving bridge arm is connected to the driving device. Each phase driving bridge arm includes two IGBTs. The gate of each IGBT is connected to the main control chip. The collector of one IGBT serves as the positive terminal of the driving bridge arm circuit, and the emitter of the other IGBT serves as the positive terminal of the driving bridge arm circuit. The emitter of one IGBT and the collector of the other IGBT are connected together and serve as the midpoint of the driving bridge arm of that phase.

[0031] A power supply capacitor, wherein the first end of the power supply capacitor is connected to the positive terminal of the drive bridge arm circuit, and the second end of the power supply capacitor is connected to the negative terminal of the drive bridge arm circuit.

[0032] A power battery, the negative terminal of which is connected to the negative terminal of the drive axle arm circuit;

[0033] The first switch has a first terminal connected to the positive terminal of the power battery, a second terminal connected to the positive terminal of the drive axle arm circuit, and a control terminal connected to the main control chip.

[0034] In one embodiment, the current source module includes:

[0035] A constant current source, the first end of which is connected to the negative terminal of the drive bridge arm circuit;

[0036] The second switch has its first terminal connected to the second terminal of the constant current source, and its control terminal connected to the main control chip.

[0037] A diode, wherein the anode of the diode is connected to the second terminal of the second switch, and the cathode of the diode is connected to the positive terminal of the drive bridge arm circuit.

[0038] In addition, to achieve the above objectives, this application also provides a vehicle that includes the aforementioned IGBT detection system.

[0039] This application provides an IGBT detection method applied to an IGBT detection system. The IGBT detection system includes an IGBT driver module, a current source module, and a temperature sensor. The current source module is connected to the IGBT driver module. The temperature sensor is used to collect the heatsink temperature value on the heatsink corresponding to the IGBT detection system. If an IGBT detection command is received, the IGBT driver module and the current source module are controlled to put the IGBT detection system into a first current operating state, wherein the first current value in the first current operating state is greater than a preset current value. If the duration of the first current operating state is equal to a preset duration threshold, the IGBT driver module and the current source module are controlled to put the IGBT detection system into a second current operating state, wherein the second current value in the second current operating state is less than or equal to a preset current value. The IGBT on-state voltage drop in the second current operating state is obtained, and the IGBT is detected based on the IGBT on-state voltage drop and the heatsink temperature value. This IGBT detection method prioritizes controlling the IGBT detection system to be in the first current operating state, and then, when the preset duration threshold is reached, the IGBT detection system is put into a second current operating state. After setting a time threshold, the IGBT detection system is controlled to operate in the second current state, and the IGBT on-state voltage drop under the second current state is acquired. The IGBT is then detected based on the IGBT on-state voltage drop and the heatsink temperature. At this point, a large current (greater than a preset current value) from the first current state is preferentially used to prevent the IGBT junction temperature from dropping rapidly. Using a small current (less than or equal to the preset current value) in the second current state allows the determination of the junction temperature corresponding to the IGBT on-state voltage drop (it is found that the junction temperature and IGBT on-state voltage drop are inversely proportional under small current). This allows for IGBT detection based on the junction temperature and heatsink temperature, avoiding the thermal resistance variation caused by the different thermal expansion coefficients of the IGBT's constituent materials. This method of IGBT lifespan detection is based on the junction temperature and heatsink temperature determined by the IGBT on-state voltage drop under the small current relationship (i.e., real-time numerical detection, not estimated value detection), avoiding errors caused by the thermal expansion of the IGBT's constituent materials, thus improving the accuracy of IGBT detection. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating the first embodiment of the IGBT detection method of this application;

[0041] Figure 2 This is a schematic diagram of the expansion coefficient of the material inside an existing IGBT;

[0042] Figure 3a This is a waveform diagram showing the on-state voltage drop and collector current of the IGBT in this application;

[0043] Figure 3b This is a waveform diagram showing the on-state voltage drop versus junction temperature of the IGBT in this application;

[0044] Figure 4 This is a circuit connection diagram of the IGBT detection system of this application;

[0045] Figure 5 This is a schematic diagram of IGBT single-wave control in the IGBT detection system of this application;

[0046] Figure 6 This is a flowchart illustrating the first method for testing IGBTs in this application;

[0047] Figure 7 This is a control diagram of the IGBT detection system of this application;

[0048] Figure 8 This is another control diagram of the IGBT detection system of this application;

[0049] Figure 9 This is a schematic diagram of the main control chip module in this application;

[0050] Figure 10 This is a schematic diagram of the hardware operating environment involved in the device in this application.

[0051] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0052] Explanation of icon numbers:

[0053] 1001. Processing device; 1002. Read-only memory; 1003. Storage device; 1004. Random access memory; 1005. Bus; 1006. Input / output interface; 1007. Input device; 1008. Output device; 1009. Communication device; 200. Heat sink; VCE, IGBT on-state voltage drop; Tj, Junction temperature; 10. IGBT driver module; 20. Current source module; 30. Main control chip; VCC, Constant current source; S2, Second switch; D1, Diode; BT1, Power battery; S1, First switch; T1, First IGBT; T2, Second IGBT; T3, Third IGBT; T4, Fourth IGBT; T5, Fifth IGBT;

[0054] T6, Sixth IGBT; A, First Phase; B, Second Phase; C, Third Phase; 11, Driving Device; C1, Power Supply Capacitor; 12, Driving Bridge Arm Circuit; 121, First Phase Driving Bridge Arm; 122, Second Phase Driving Bridge Arm; 123, Third Phase Driving Bridge Arm; L1, First Winding; L2, Second Winding; L3, Third Winding; IC, IGBT On-State Current (Collector Current); NTC, Temperature Sensor. Detailed Implementation

[0055] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0056] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0057] With the increasing application of IGBTs in new energy vehicles, primarily for driving the vehicle's motor, IGBTs are the most expensive and easily damaged key components in the drive motor hardware of new energy vehicles. Therefore, their reliability and health status must be precisely monitored. For IGBTs that have been operating for a long time but have not yet reached the end of their lifespan, effective measures to extend their service life should be implemented, such as reducing the IGBT switching frequency and peak operating time. IGBTs nearing the end of their service life should be replaced to ensure the safe and reliable power output of new energy vehicles. IGBT monitoring (mainly detecting failure) generally involves two parameters: a 5% increase in the IGBT on-state voltage drop confirms failure; a 20% increase in the thermal resistance from the IGBT chip to the heatsink confirms failure. However, due to limitations in IGBT packaging technology, temperature sensors cannot be directly attached to the chip surface. Temperature sensors are only placed within a certain range close to the chip, and are usually estimated based on the thermal resistance from the temperature sensor location within the power module to the chip junction temperature, as specified by the IGBT manufacturer. However, references can be made to... Figure 2 , Figure 2 This diagram illustrates the thermal expansion coefficients of materials within an existing IGBT. The different thermal expansion coefficients of the various materials comprising an IGBT module accelerate aging. An IGBT module includes a semiconductor chip, bonding wires, a baseplate, a substrate, and solder layers (Sn, Ag, Pb) connecting these materials. Due to these differences in thermal expansion coefficients, cracks and gaps can appear under high temperatures and vibrations, leading to increased thermal resistance. This increased thermal resistance worsens heat dissipation, further accelerating IGBT aging. Therefore, because the constituent materials of the IGBT have different thermal expansion coefficients, the thermal resistance used to estimate the temperature sensor location to the IGBT chip junction temperature will also increase over time and with accumulated operating time. Consequently, the IGBT junction temperature estimation becomes inaccurate, affecting the safe operation of the drive motor controller and the entire vehicle.

[0058] Therefore, based on the shortcomings of the above-mentioned IGBT detection methods, the IGBT detection method of this application is proposed. The solution of this application embodiment is as follows: The IGBT detection system is preferentially controlled to operate in a first current state. After reaching a preset time threshold, the IGBT detection system is controlled to operate in a second current state, and the IGBT on-state voltage drop under the second current state is obtained. The IGBT is detected based on the IGBT on-state voltage drop and the heatsink temperature. At this time, a large current (greater than a preset current value) is preferentially used in the first current state to prevent the IGBT junction temperature from dropping rapidly. A small current (less than or equal to the preset current value) in the second current state is used to determine the junction temperature value corresponding to the IGBT on-state voltage drop (detecting a small voltage drop). Since the junction temperature and IGBT on-state voltage drop are inversely proportional, IGBTs can be tested based on the junction temperature and heatsink temperature. This avoids the problem of varying thermal resistance due to differences in the thermal expansion coefficients of the IGBT's constituent materials. This method of IGBT lifespan testing is based on the junction temperature and heatsink temperature determined by the IGBT on-state voltage drop under low current conditions (i.e., real-time numerical testing, not estimated testing), thus avoiding errors caused by the thermal expansion of the IGBT's constituent materials and improving the accuracy of IGBT testing.

[0059] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or a device capable of performing the above functions, such as an IGBT lifespan detector. The following description uses an IGBT lifespan detector as an example to illustrate this embodiment and the subsequent embodiments.

[0060] Based on this, embodiments of this application provide a method for detecting IGBTs, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the IGBT detection method of this application.

[0061] Reference Figure 1 This application provides a method for detecting IGBTs. In a first embodiment, the IGBT detection method is applied to an IGBT detection system. The IGBT detection system includes an IGBT driver module 10, a current source module 20, and a temperature sensor NTC. The current source module 20 is connected to the IGBT driver module 10. The temperature sensor NTC is used to collect the heat sink temperature value on the heat sink 200 corresponding to the IGBT detection system. The IGBT detection method includes:

[0062] Step S10: If an IGBT detection command is received, control the IGBT drive module 10 and the current source module 20 to make the IGBT detection system be in the first current working state, wherein the first current value in the first current working state is greater than the preset current value.

[0063] For example, refer to Figure 3a , Figure 3a This is a waveform diagram illustrating the relationship between the on-state voltage drop and collector current of the IGBT in this application. The figure shows the waveforms of the change between the collector current IC and the IGBT on-state voltage drop VCE under different junction temperatures Tj. Based on these waveforms, the relationship between the junction temperature Tj and the IGBT on-state voltage drop VCE can be determined. (Refer to...) Figure 3b , Figure 3b This is a waveform diagram illustrating the relationship between the on-state voltage drop and junction temperature of the IGBT in this application. Figure 3b It can be concluded that when the collector current IC is relatively small (e.g., typically ≤5A), the junction temperature Tj is inversely proportional to the IGBT on-state voltage drop VCE; that is, the higher the junction temperature Tj, the lower the IGBT on-state voltage drop VCE. Therefore, based on the above relationship, the IGBT detection method of this application is proposed.

[0064] In this embodiment, the IGBT detection method is applied to an IGBT detection system. The IGBT detection system includes an IGBT driver module 10, a current source module 20, and a temperature sensor NTC. The current source module 20 is connected to the IGBT driver module 10. The temperature sensor NTC is used to collect the heatsink temperature value on the heatsink 200 corresponding to the IGBT detection system. Both the IGBT driver module 10 and the temperature sensor NTC in the IGBT detection system can use existing hardware; only the current source module 20 needs to be added. (See reference...) Figure 4 , Figure 4This is a circuit connection diagram of the IGBT detection system of this application. In this system, only the current source module 20 is added to achieve IGBT detection. The detection principle is that when the collector current IC is less than or equal to 5A, the junction temperature Tj is inversely proportional to the IGBT on-state voltage drop VCE. The junction temperature Tj is determined based on this relationship, and then the thermal resistance is determined for IGBT detection. The IGBT to be tested can be the Infineon automotive-grade IGBT module FS820R08A6P2B. Because the drive bridge arm circuit 12 in the IGBT drive module 10 is a two-level three-phase full bridge, that is, it is composed of six IGBTs divided into three-phase upper and lower drive bridge arms. The main control chip 30 (in this embodiment, taking the drive device 11 as a motor as an example, the main control chip 30 is the motor controller at this time) outputs three-phase AC current to drive the motor. The IGBT drive chip in the main control chip 30 detects the saturation diode voltage drop and feeds it back to the main control chip 30 via SPI communication. The output three-phase currents iA, iB, and iC are recorded by the current sensor inside the motor control unit and fed back to the main control chip 30. Further details can be found in the following section. Figure 5 , Figure 5 This is a schematic diagram of IGBT waveform control in the IGBT detection system of this application. According to SVPWM (Space Vector Pulse Width Modulation), the three-phase AC currents iA, iB, and iC and the corresponding IGBT on / off states can be calculated. Since the current sensor has a detection delay (generally 0.5 to 100 μs), this detection delay needs to be compensated during the calculation in order to control the IGBT waveform based on SVPWM, thereby realizing the drive of the motor.

[0065] In one embodiment, to ensure the accuracy of the determined junction temperature value Tj, the power supply inside the IGBT drive module 10 can be used to power the motor first when the IGBT detection command is received. This is because the first current value under the first current operating state can be greater than the preset current value. The preset current value can be set to 3A (i.e., the current value other than the one inversely proportional to the determined junction temperature value Tj and the IGBT on-state voltage drop VCE). Of course, it can also be selected according to the actual windings in the motor. For example, if there is a winding material, inductance value, and preset current value, the IGBT detection command refers to the command to detect the IGBTs. It can be the detection of all IGBTs or the detection of some IGBTs. That is, at this time, the first current operating state uses the large current inside the IGBT drive module 10 to power the motor, and the current source module 20 stops powering out. Because the current driving time is too short to obtain an accurate junction temperature value Tj (there is a problem of cooling down after the action), when the IGBT is turned on and a large current flows through it (compared to the subsequent second current working state), and then it is turned off again, the junction temperature value Tj will not drop rapidly, thus ensuring the accuracy of subsequent IGBT detection.

[0066] Step S20: When the duration of the first current working state is equal to the preset duration threshold, control the IGBT drive module 10 and the current source module 20 to make the IGBT detection system be in the second current working state, wherein the second current value in the second current working state is less than or equal to the preset current value.

[0067] In this embodiment, to ensure that the junction temperature Tj does not decrease, the IGBT drive module 10 and current source module 20 are controlled after the duration of the first current operating state is equal to a preset duration threshold. This puts the IGBT detection system into a second current operating state, where the second current value is less than or equal to a preset current value. This ensures that the junction temperature Tj does not drop rapidly. A small current from the current source module 20 is then used to drive the same IGBT. Given a small collector current IC (typically ≤5A), the junction temperature Tj is inversely proportional to the IGBT on-state voltage drop VCE, thus determining the parameters to be detected by the IGBT and ensuring accurate IGBT detection. It is worth noting that the preset duration threshold is the duration of the first current operating state set by the user. This can be determined based on the stable duration of the junction temperature Tj and relevant parameters of the inductor in the motor, and is not limited here. Among them, the current source module 20 refers to a module that can provide a small current (defined in this application as ≤5A, and a large current as >5A) to the entire system, such as a current of ≤5A.

[0068] Step S30: Obtain the IGBT on-state voltage drop VCE under the second current operating state, and detect the IGBT based on the IGBT on-state voltage drop and the heat sink temperature value.

[0069] In this embodiment, because the junction temperature Tj is inversely proportional to the IGBT on-state voltage drop VCE under low current conditions, the junction temperature Tj under low current conditions can be determined based on the IGBT on-state voltage drop under the second current operating state. Since the temperature sensor NTC is used to collect the heatsink temperature value on the heatsink 200 corresponding to the IGBT detection system at this time, the thermal resistance Rth can be calculated based on the heatsink temperature value and the junction temperature Tj, and the IGBT can be detected based on the thermal resistance Rth. Alternatively, the IGBT can also be detected based on the IGBT on-state voltage drop VCE. The IGBT detection is performed by the IGBT driver chip in the main control chip 30, and the heatsink temperature value is detected by the temperature sensor built into the main control chip 30, without the need for additional hardware circuitry. Because this application can obtain the IGBT voltage drop after high current turn-on using a small current, it will not affect the IGBT lifespan or cause Tj to continue to rise, and it can obtain a relatively accurate IGBT junction temperature Tj, thus ensuring the accuracy of IGBT detection. Meanwhile, the entire system only needs to add a small current source to detect the IGBT on-state voltage drop VCE to detect the IGBT's lifespan, which can reduce the IGBT testing cost.

[0070] In this embodiment, an IGBT detection method is provided, applied to an IGBT detection system. The IGBT detection system includes an IGBT driver module 10, a current source module 20, and a temperature sensor NTC. The current source module 20 is connected to the IGBT driver module 10. The temperature sensor NTC is used to collect the heat sink temperature value on the heat sink 200 corresponding to the IGBT detection system. If an IGBT detection command is received, the IGBT driver module 10 and the current source module 20 are controlled to put the IGBT detection system into a first current operating state, wherein the first current value in the first current operating state is greater than a preset current value. If the duration of the first current operating state is equal to a preset duration threshold, the IGBT driver module 10 and the current source module 20 are controlled to put the IGBT detection system into a second current operating state, wherein the second current value in the second current operating state is less than or equal to a preset current value. The IGBT on-state voltage drop in the second current operating state is obtained, and the IGBT is detected based on the IGBT on-state voltage drop and the heat sink temperature value. This IGBT detection method prioritizes controlling the IGBT detection system to... In the first current operating state, after reaching a preset time threshold, the IGBT detection system is controlled to switch to the second current operating state, and the IGBT on-state voltage drop under the second current operating state is acquired. The IGBT is then detected based on the IGBT on-state voltage drop and the heatsink temperature. At this point, the larger current (greater than the preset current value) of the first current operating state is preferentially used to prevent the IGBT junction temperature from dropping rapidly. Then, the smaller current (less than or equal to the preset current value) of the second current operating state is used to determine the junction temperature corresponding to the IGBT on-state voltage drop (it is observed that the junction temperature and IGBT on-state voltage drop are relatively close under the smaller current). By using an inverse proportional relationship, IGBTs can be tested based on junction temperature and heatsink temperature, avoiding the problem of thermal resistance changes in the IGBT chip junction temperature due to the different thermal expansion coefficients of the IGBT's constituent materials. This method of IGBT lifespan testing is based on the junction temperature and heatsink temperature determined by the IGBT's on-state voltage drop under low current conditions (i.e., real-time numerical testing, not estimated testing), thus avoiding the determination error caused by the thermal expansion of the IGBT's constituent materials and improving the accuracy of IGBT testing.

[0071] Furthermore, based on the first embodiment of this application described above, a second embodiment of the IGBT detection method of this application is proposed. In this embodiment, step S10, which controls the IGBT drive module 10 and the current source module 20 to put the IGBT detection system into a first current operating state, includes:

[0072] Step S11: Control the IGBT drive module 10 and the current source module 20 to be in the first connection state, wherein the first connection state includes the power battery BT1 in the IGBT drive module 10 being connected to the three-phase drive bridge arm in the IGBT drive module 10, and the constant current source VCC in the current source module 20 being disconnected from the three-phase drive bridge arm.

[0073] Step S12: In the first connection state, the IGBT turn-on state in the three-phase drive bridge arm is controlled based on the preset detection timing. The first current working state includes the connection state of the IGBT detection system as the first connection state and the IGBT working state as the IGBT turn-on state. In the second current working state, the connection state of the IGBT detection system is the opposite of the first connection state, and the IGBT working state of the IGBT detection system is the same as the IGBT turn-on state.

[0074] In this embodiment, the first current operating state includes the IGBT detection system being connected in a first connection state and the IGBT operating state being the IGBT on state. In the second current operating state, the connection state of the IGBT detection system is the opposite of the first connection state, and the IGBT operating state of the IGBT detection system is the same as the IGBT on state, thus enabling the detection of IGBTs with the same IGBT on state. In the first current operating state, the power battery BT1 in the IGBT drive module 10 is connected to the three-phase drive arm in the IGBT drive module 10, so that the power battery BT1 supplies power to the three-phase drive arm. In the first connection state, the IGBTs in the three-phase drive bridge arm are controlled based on a preset detection timing sequence. For example, if T1, T3, and T6 need to be detected, T1, T3, and T6 will be turned on, while the other IGBTs will be turned off. This allows the IGBT on-state voltage drop VCE of T1, T3, and T6 to be determined under high current, thus detecting the lifespan of T1, T3, and T6. The preset detection timing sequence can either only detect T1, T3, and T6, or detect the remaining IGBTs after detecting T1, T3, and T6; this is not limited here. Because the first current operating state is to ensure that the junction temperature Tj does not drop rapidly, subsequent judgment is still based on determining the thermal resistance using low current control. In the second current operating state, the connection state of the IGBT detection system is the opposite of the first connection state. In the second current operating state, the constant current source VCC in the current source module 20 is used to power the three-phase drive bridge arm, and the thermal resistance is determined under low current to achieve IGBT lifespan detection. Therefore, the accuracy of the junction temperature value Tj can be ensured based on the above methods, and the accuracy of IGBT detection can be improved by ensuring the accuracy of the thermal resistance determined based on the junction temperature value Tj.

[0075] Furthermore, based on the first and / or second embodiments of this application described above, a third embodiment of the IGBT detection method of this application is proposed. In this embodiment, the IGBT detection method further includes:

[0076] Step S40: Determine the IGBT on-state voltage drop VCE of each IGBT in the first current operating state, or determine the IGBT on-state voltage drop VCE of each IGBT in the second current operating state.

[0077] Step S50: For the IGBT on-state voltage drop VCE of each IGBT, if the IGBT on-state voltage drop VCE is greater than the first preset voltage drop threshold, the IGBT is controlled based on a preset lifetime protection command. The preset lifetime protection command includes at least one of reducing the IGBT switching frequency and reducing the IGBT peak operating time.

[0078] Step S60: When the IGBT conduction voltage drop VCE is greater than the second preset voltage drop threshold, generate an alarm replacement command corresponding to the IGBT, wherein the second preset voltage drop threshold is greater than the first preset voltage drop threshold.

[0079] In this embodiment, since the parameters for determining the IGBT can be thermal resistance and IGBT on-state voltage drop (VCE), the IGBT can also be judged based on the IGBT on-state voltage drop (VCE). That is, the IGBT on-state voltage drop (VCE) of each conducting IGBT in the first current operating state, or the IGBT on-state voltage drop (VCE) of each conducting IGBT in the second current operating state, is determined to determine the lifespan of each conducting IGBT based on its VCE. During the judgment, the IGBT on-state voltage drop (VCE) of each IGBT can be processed sequentially. If the IGBT on-state voltage drop (VCE) is greater than a first preset voltage drop threshold, the IGBT is controlled based on a preset lifespan protection command. This preset lifespan protection command includes at least one of reducing the IGBT switching frequency and reducing the IGBT peak operating time. That is, it is determined that the upper limit of the service life value is about to be reached. For example, if the first preset voltage drop threshold is within 3% of the increase in IGBT on-state voltage drop (VCE), then the IGBT switching frequency and peak operating time can be reduced to slow down the IGBT damage rate. When the IGBT's on-state voltage drop (VCE) exceeds a second preset voltage drop threshold, an alarm replacement command is generated for the corresponding IGBT. If the second preset voltage drop threshold is greater than the first preset voltage drop threshold, it indicates that the IGBT has reached its maximum service life, and the user is prompted to replace it. In other words, the alarm replacement command refers to the IGBT whose on-state voltage drop (VCE) exceeds the second preset voltage drop threshold. For example, the second preset voltage drop threshold is defined as an increase of more than 5% in the IGBT's on-state voltage drop (VCE). Judgments are made based on different preset voltage drop thresholds, which ensures the accuracy of IGBT detection. At the same time, the control of different control commands can ensure the balance of IGBT service life.

[0080] Furthermore, based on the first, second, and / or third embodiments of this application described above, a fourth embodiment of the IGBT detection method of this application is proposed. In this embodiment, the step of detecting the IGBT based on the IGBT on-state voltage drop and the heat sink temperature includes:

[0081] Step S31: For the IGBT on-state voltage drop VCE of each IGBT, determine the junction temperature value Tj corresponding to the IGBT on-state voltage drop in the preset junction temperature-voltage drop correspondence table, and determine the temperature difference between the junction temperature value Tj and the heat sink temperature value.

[0082] Step S32: Determine the IGBT thermal resistance value based on the IGBT on-state voltage drop VCE, temperature difference, and IGBT operating parameters, and then test the IGBT based on the IGBT thermal resistance value.

[0083] In this embodiment, besides using the IGBT on-state voltage drop VCE for judgment, the IGBT thermal resistance value can also be used. In this case, for each IGBT's on-state voltage drop VCE, the corresponding junction temperature value Tj is determined from a preset junction temperature-voltage drop correspondence table. That is, the preset junction temperature-voltage drop correspondence table refers to... Figure 3b A defined correspondence table, such as VCE = DF * Tj, allows us to uniquely determine the junction temperature Tj corresponding to each IGBT's on-state voltage drop VCE. Furthermore, determining the temperature difference between Tj and the heatsink temperature allows us to determine the IGBT's thermal resistance based on this temperature difference, the IGBT's on-state voltage drop VCE, and the IGBT's operating parameters. This determined thermal resistance enables IGBT testing, ultimately leading to the determination of the IGBT's lifespan. Because this method uses the real-time monitored IGBT on-state voltage drop VCE to determine the IGBT's thermal resistance, and consequently the lifespan determination, avoids the limitations of estimations in existing technologies, ensuring the accuracy of IGBT testing.

[0084] In one embodiment, reference may be made to Figure 6 , Figure 6This is a flowchart illustrating the first method for testing the IGBT in this application. After entering the testing mode, the vehicle is stopped. The diagnostic tool or related commands enter the IGBT testing mode of the drive motor controller and control the first switch S1 and the second switch S2 to make the entire system operate in different current operating states. When S2 is open and S1 is closed, the power battery BT1 provides a large current output to make the system operate in the first current operating state. Assuming the preset detection sequence is all IGBTs detected, the SVPWM control method will control the output current to drive the motor in the same direction as the D-axis (i.e., D-axis 0°), and record the corresponding IGBT number that is turned on (assuming V6 is at D-axis 0°, T1, T3, and T6 are turned on, and T2, T4, and T5 are turned off). The collector current IC and IGBT on-state voltage drop VCE (specifically, the on-state voltage drop VCE of T1, T3, and T6) are recorded by the current sensor inside the main control chip 30. At this time, it can be determined whether the collector current IC exceeds the user-defined low current range, such as the preset current value of 5A. If it does not exceed 5A, the collector current IC can be increased. At the same time, it can also be directly detected based on the IGBT on-state voltage drop VCE determined at this time to determine whether it exceeds the preset voltage drop threshold. If it exceeds different preset voltage drop thresholds, it can control alarm replacement or reduce the switching frequency to extend the IGBT's service life. Simultaneously, the high-current control in the first current operating state prevents the junction temperature Tj from dropping rapidly. After a certain period, it controls S1 to open and S2 to close, providing a detection current output from the small-current constant current source VCC. This establishes a correspondence between the junction temperature Tj and the IGBT on-state voltage drop VCE. The recorded IGBT on-state voltage drop VCE is then used to determine the IGBT's junction temperature Tj. Combined with the acquired heatsink temperature Tntc, the IGBT's thermal resistance is determined. This thermal resistance value is then used for detection to determine if it exceeds a preset thermal resistance threshold. If it exceeds different preset thresholds, an alarm is triggered to replace the IGBT, or the switching frequency is reduced to extend its lifespan. It's worth noting that since the IGBT on-state voltage drop VCE is also determined at this point, detection can also be based on VCE to determine if it exceeds a preset voltage drop threshold. If it exceeds different preset thresholds, an alarm is triggered to replace the IGBT, or the switching frequency is reduced to extend its lifespan.Furthermore, to achieve the detection of all IGBTs, after this round of detection is completed, the steps of S2 opening and S1 closing can be repeated, but this time different IGBTs can be selected for conduction. For example, the control output current can be aligned with the D-axis of the drive motor (i.e., D-axis 180°), and the corresponding IGBT numbers can be recorded (assuming V1 is in D-axis 180°, at which point T1, T3, and T6 are open, and T2, T4, and T5 are on). This completes the detection of T2, T4, and T5, thus completing the detection of all IGBTs. Of course, the IGBTs to be detected can also be selected according to actual needs, i.e., different preset detection sequences can be set. Alternatively, the control of D-axis 180° and D-axis 0° can be prioritized for detection to ensure that the motor has no torque output, i.e., there is no need to control the motor to work, so that the detection can be completed when the motor is in standby mode.

[0085] Furthermore, the steps for determining the IGBT thermal resistance value based on the IGBT on-state voltage drop, temperature difference, and IGBT operating parameters include:

[0086] Step S321: Determine the IGBT on-state current and IGBT turn-on duration in the IGBT operating parameters, and determine the product of the IGBT on-state voltage drop VCE, IGBT on-state current and IGBT turn-on duration as the IGBT conduction loss value.

[0087] Step S322: Determine the product between the IGBT conduction loss value and the temperature difference value as the IGBT thermal resistance value.

[0088] In this embodiment, determining the IGBT thermal resistance value requires determining the IGBT on-current and IGBT turn-on duration among the IGBT operating parameters. Here, the IGBT on-current is the collector current, and the IGBT turn-on duration refers to the duration during which the IGBT is turned on. Therefore, the product of the IGBT on-voltage drop VCE, the IGBT on-current, and the IGBT turn-on duration is used as the IGBT conduction loss value, i.e., IGBT conduction loss value P = Vce * Ic * ton, where ton is the IGBT turn-on duration, Ic is the IGBT collector current, and VCE is the IGBT on-voltage drop. The product of the IGBT conduction loss and the temperature difference is then used as the IGBT thermal resistance value, i.e., IGBT thermal resistance value Rth = ΔT / P, where ΔT is the temperature difference, i.e., the difference between the IGBT junction temperature Tj and the temperature Tntc collected by the heat sink sensor. Thus, the IGBT thermal resistance value can be determined, so that the IGBT can be tested based on the IGBT thermal resistance value. Because the IGBT thermal resistance value is determined based on real-time information, rather than an estimated value, the accuracy of IGBT testing can be guaranteed.

[0089] In one embodiment, when the vehicle needs to be equipped with IGBT detection, after entering the IGBT detection mode, the six IGBTs are controlled by SVPWM to output a large current (i.e., the upper and lower IGBTs of each bridge arm are not simultaneously turned on or off). At this time, the entire system is powered by the power battery BT1 and operates for a preset time threshold. If the preset time threshold is <3s, to ensure that the junction temperature Tj does not drop rapidly, all IGBTs can be measured in two steps. In the first measurement, the motor has no torque output (the d-axis of the permanent magnet synchronous motor is in the same direction at 0°), and 3 of the 6 groups of IGBTs in the three-phase full bridge are turned on, with a large current output (powered by the power battery BT1 and operating for a preset time threshold). After the duration reaches the set value, the IGBTs are turned off. The current source VCC, which detects a small current, outputs to control the IGBTs with the same sequence number to turn on and control the output current ≤1A (by...). Figure 3b It is known that anything below 3A is acceptable. The IGBT conduction voltage drop VCE is measured at this time to detect the IGBT currently in operation. In the second measurement, the motor has no torque output (the d-axis of the permanent magnet synchronous motor is reversed 180°). The other three groups of the six IGBTs in the three-phase full-bridge (the remaining three groups from the first measurement) are turned on, resulting in a large current output (powered by the BT1 battery and operating for a preset time threshold). The IGBT is turned off after the set value is reached. The current source VCC, which detects small currents, controls the IGBTs with the same serial number to turn on, controlling the output current to ≤1A (by...). Figure 3b (It is known that voltages below 3A are acceptable). The on-state voltage drop (VCE) of the IGBT is measured to detect the IGBT currently in operation. When determining the IGBT's lifespan based on the on-state voltage drop (VCE), the judgment can be made directly based on VCE, or by leveraging the linear relationship between VCE and the junction temperature (Tj) to obtain the current junction temperature (Tj). Then, based on the junction temperature (Tj) and the temperature (Tntc) detected by the heatsink's temperature sensor, the IGBT's thermal resistance (Rth) is calculated. The lifespan of the IGBT is then determined based on this Rth. Because the judgment is based on real-time information, rather than estimated values, the accuracy of the IGBT detection is guaranteed.

[0090] Furthermore, the steps for testing the IGBT based on its thermal resistance include:

[0091] Step S323: When the thermal resistance of the IGBT is greater than the first preset thermal resistance threshold, the IGBT is controlled based on the preset life protection command, wherein the preset life protection command includes at least one of reducing the IGBT switching frequency and reducing the peak operating time of the IGBT.

[0092] Step S324: If the thermal resistance value of the IGBT is greater than the second preset thermal resistance threshold, generate an alarm replacement command corresponding to the IGBT, wherein the second preset thermal resistance threshold is greater than the first preset thermal resistance threshold.

[0093] In this embodiment, since the parameters for judging the IGBT can be thermal resistance and IGBT on-state voltage drop VCE, the IGBT can be judged based on its thermal resistance value. That is, the on-state voltage drop VCE of each conducting IGBT under the second current operating state is determined, and the thermal resistance value of each conducting IGBT is determined based on its VCE value to determine its service life. During the judgment, the thermal resistance value of each IGBT can be processed sequentially. If the IGBT thermal resistance value is greater than a first preset thermal resistance threshold, the IGBT is controlled based on a preset lifespan protection command. This preset lifespan protection command includes at least one of reducing the IGBT switching frequency and reducing the IGBT peak operating time. That is, it is determined that the upper limit of the service life value is about to be reached. For example, if the first preset thermal resistance threshold is within 10% of the IGBT thermal resistance value increase, then the IGBT switching frequency and peak operating time can be reduced to slow down the IGBT damage rate. When the IGBT's thermal resistance exceeds the second preset thermal resistance threshold, an alarm replacement command is generated for the corresponding IGBT. If the second preset thermal resistance threshold is greater than the first preset thermal resistance threshold, it indicates that the IGBT has reached its maximum service life, and the user is prompted to replace it. In other words, the alarm replacement command refers to the alarm to replace the IGBT whose thermal resistance exceeds the second preset thermal resistance threshold. For example, the second preset thermal resistance threshold is an increase of more than 20% in the IGBT's thermal resistance. Judgments are made based on different preset thermal resistance thresholds, which can ensure the accuracy of IGBT detection. At the same time, the control of different control commands can ensure the balance of the IGBT's service life.

[0094] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the detection method of IGBT in this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0095] Based on the above embodiments of IGBT detection, this application also provides a first embodiment of an IGBT detection system. The IGBT detection system includes a main control chip 30, an IGBT drive module 10, a current source module 20, and a temperature sensor TC. The current source module 20 is connected to the IGBT drive module 10, and the main control chip 30 is connected to the IGBT drive module 10, the current source module 20, and the temperature sensor NTC. The temperature sensor NTC is used to collect the heat sink temperature value on the heat sink 200 corresponding to the IGBT detection system.

[0096] The main control chip 30 is used to perform the IGBT detection method described above.

[0097] In one embodiment, the main control chip 30 includes:

[0098] The first state control module A10 is used to control the IGBT drive module 10 and the current source module 20 if an IGBT detection command is received, so that the IGBT detection system is in the first current working state, wherein the first current value in the first current working state is greater than the preset current value.

[0099] The second state control module A20 is used to control the IGBT drive module 10 and the current source module 20 when the duration of the first current working state is equal to a preset duration threshold, so that the IGBT detection system is in the second current working state, wherein the second current value in the second current working state is less than or equal to the preset current value.

[0100] The IGBT detection module A30 is used to obtain the IGBT on-state voltage drop under the second current operating state, and to detect the IGBT based on the IGBT on-state voltage drop and the heat sink temperature.

[0101] In this embodiment, the IGBT detection system provided in this application adopts the IGBT detection method in the above embodiment. It prioritizes controlling the IGBT detection system to operate in a first current state, and after reaching a preset time threshold, controls the IGBT detection system to operate in a second current state. The system acquires the IGBT on-state voltage drop under the second current state and detects the IGBT based on the IGBT on-state voltage drop and the heatsink temperature. At this time, a large current (greater than a preset current value) is preferentially used in the first current state to prevent the IGBT junction temperature from dropping rapidly. Using a small current (less than or equal to the preset current value) in the second current state allows for determination of the IGBT's on-state voltage drop. The junction temperature corresponding to the on-state voltage drop (it was found that the junction temperature and IGBT on-state voltage drop are inversely proportional under low current) allows for IGBT testing based on the junction temperature and heatsink temperature. This avoids the problem of thermal resistance variations in the IGBT chip junction temperature due to differences in the thermal expansion coefficients of the IGBT's constituent materials. This method of IGBT lifespan testing is based on the junction temperature and heatsink temperature determined by the IGBT on-state voltage drop under low current (i.e., real-time numerical testing, not estimated testing), thus avoiding errors caused by the thermal expansion of the IGBT's constituent materials and improving the accuracy of IGBT testing. Compared with the prior art, the beneficial effects of the IGBT testing system provided in this application are the same as those of the IGBT testing method provided in the above embodiments, and other technical features of the IGBT testing system are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0102] Furthermore, based on the first embodiment of this application described above, a second embodiment of the IGBT detection system of this application is proposed. In this embodiment, the IGBT driver module 100 includes:

[0103] Drive device 11;

[0104] The drive bridge arm circuit 12 includes three-phase drive bridge arms. The first end of each phase drive bridge arm is connected together and serves as the positive terminal of the drive bridge arm circuit 12. The second end of each phase drive bridge arm is connected together and serves as the negative terminal of the drive bridge arm circuit 12. The midpoint of each phase drive bridge arm is connected to the drive device 11. Each phase drive bridge arm includes two IGBTs. The gate of each IGBT is connected to the main control chip 30. The collector of one IGBT serves as the positive terminal of the drive bridge arm circuit 12, and the emitter of the other IGBT serves as the positive terminal of the drive bridge arm circuit 12. The emitter of one IGBT and the collector of the other IGBT are connected together and serve as the midpoint of the phase drive bridge arm.

[0105] Power supply capacitor C1, the first end of power supply capacitor C1 is connected to the positive terminal of drive bridge arm circuit 12, and the second end of power supply capacitor C1 is connected to the negative terminal of drive bridge arm circuit 12.

[0106] The negative terminal of the power battery BT1 is connected to the negative terminal of the drive axle arm circuit 12.

[0107] The first switch S1 has its first end connected to the positive terminal of the power battery BT1, its second end connected to the positive terminal of the drive bridge arm circuit 12, and its control terminal connected to the main control chip 30.

[0108] In this embodiment, the IGBT drive module 100 includes a drive device 11, a drive bridge arm circuit 12, a power supply capacitor C1, a power battery BT1, and a first switch S1. The first switch S1 can be controlled by the main control chip 30, thereby enabling the power battery BT1 to supply power to or stop supplying power to the drive bridge arm circuit 12. Therefore, the first switch S1 can be set at the positive or negative terminal of the power battery BT1, as long as the above control requirements are met. The drive arm circuit includes three-phase drive arms. The first end of each phase drive arm is connected together and serves as the positive terminal of the drive arm circuit 12. The second end of each phase drive arm is connected together and serves as the negative terminal of the drive arm circuit 12. The midpoint of each phase drive arm is connected to the driving device 11. Each phase drive arm includes two IGBTs. The gate of each IGBT is connected to the main control chip 30. The collector of one IGBT serves as the positive terminal of the drive arm circuit 12, and the emitter of the other IGBT serves as the positive terminal of the drive arm circuit 12. The midpoint of the drive arm is formed by connecting the emitter of one IGBT to the collector of the other IGBT. This is the same as the existing three-phase deterministic drive circuit, and will not be described in more detail here. At this time, each IGBT in the drive arm circuit 12 can be tested based on the above IGBT detection method to determine the service life of the IGBT based on the real-time acquired information, thereby ensuring the accuracy of IGBT detection.

[0109] In one embodiment, the current source module 20 includes:

[0110] The constant current source VCC is connected to the negative terminal of the drive bridge arm circuit 12.

[0111] The second switch S2 has its first end connected to the second end of the constant current source VCC, and its control end connected to the main control chip 30.

[0112] Diode D1, the anode of diode D1 is connected to the second terminal of the second switch S2, and the cathode of diode D1 is connected to the positive terminal of the drive bridge arm circuit 12.

[0113] In this embodiment, the current source module 20 includes a constant current source VCC, a second switch S2, and a diode D1. The second switch S2 can be controlled by the main control chip 30, thereby enabling or disabling the constant current source VCC from supplying power to the drive bridge arm circuit 12. Therefore, the second switch S2 can be set at either the positive or negative terminal of the constant current source VCC, as long as the above control requirements are met. The diode D1 prevents reverse current flow from the constant current source VCC. This allows for the use of the constant current source VCC alone to power the drive bridge arm circuit 12 after a large current control, thus providing power even under low current conditions. Figure 3b The relationship between the IGBT on-state voltage drop VCE and the junction temperature can be found in [reference]. Figure 7 , Figure 7 This is a control diagram of the IGBT detection system of this application. At this point, the thermal resistance values ​​of IGBTs T1, T3, and T6 are detected (dashed IGBTs represent open circuits, solid IGBTs represent closed circuits) to determine the service life of T1, T3, and T6. After detecting T1, T3, and T6, the IGBTs can be controlled as follows: Figure 8 The conduction method, Figure 8 This is another control diagram of the IGBT detection system of this application. At this time, the thermal resistance values ​​of IGBTs T2, T4, and T5 are detected (the dashed IGBT is disconnected, and the solid IGBT is conductive) to determine the service life of T2, T4, and T5. Because the actual collected and calculated values ​​are used for detection throughout the operation, the determination error will not be caused by the thermal expansion of the IGBT's constituent materials, thereby improving the detection accuracy of IGBTs.

[0114] Furthermore, this application provides a vehicle comprising: the aforementioned IGBT detection system, and may further include at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the IGBT detection method of the aforementioned embodiment 1.

[0115] The following is for reference. Figure 10 The diagram illustrates a structural schematic of a vehicle suitable for implementing embodiments of this application. The vehicle in these embodiments may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 10 The vehicle shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of this application.

[0116] like Figure 10As shown, the vehicle may include a processing system 1001 (e.g., a central processing unit, a graphics processing unit, etc.) that can perform various appropriate actions and processes based on programs stored in read-only memory (ROM) 1002 or programs loaded from storage system 1003 into random access memory (RAM) 1004. RAM 1004 also stores various programs and data required for vehicle operation. The processing system 1001, ROM 1002, and RAM 1004 are interconnected via bus 1005. Input / output interface 1006 is also connected to the bus. Typically, the following systems may be connected to input / output interface 1006: input system 1007 including, for example, a touchscreen, touchpad, keyboard, mouse, image sensor, microphone, accelerometer, gyroscope, etc.; output system 1008 including, for example, a liquid crystal display (LCD), speaker, vibrator, etc.; storage system 1003 including, for example, magnetic tape, hard disk, etc.; and communication system 1009. Communication system 1009 allows the vehicle to communicate wirelessly or wiredly with other devices to exchange data. While the figure shows a vehicle with various systems, it should be understood that implementation or possession of all the systems shown is not required. More or fewer systems may be implemented alternatively.

[0117] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication system, or installed from storage system 1003, or installed from read-only memory 1002. When the computer program is executed by processing system 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0118] The vehicle provided in this application, employing the IGBT detection method described in the above embodiments, can solve the technical problem of low IGBT detection accuracy. Compared with the prior art, the beneficial effects of the vehicle provided in this application are the same as those of the IGBT detection method provided in the above embodiments, and other technical features of the vehicle are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0119] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0120] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0121] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the IGBT detection method in the above embodiments.

[0122] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0123] The aforementioned computer-readable storage medium may be included in the vehicle or may exist independently and not installed in the vehicle.

[0124] The aforementioned computer-readable storage medium carries one or more programs that, when executed by a vehicle, cause the vehicle to:

[0125] If an IGBT detection command is received, the IGBT drive module and current source module are controlled to put the IGBT detection system into the first current operating state, wherein the first current value in the first current operating state is greater than the preset current value.

[0126] When the duration of the first current operating state is equal to a preset duration threshold, the IGBT drive module and the current source module are controlled to put the IGBT detection system into the second current operating state, wherein the second current value in the second current operating state is less than or equal to the preset current value.

[0127] Obtain the IGBT on-state voltage drop under the second current operating condition, and detect the IGBT based on the IGBT on-state voltage drop and the heat sink temperature.

[0128] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0129] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0130] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0131] This application provides a computer-readable storage medium storing computer-readable program instructions (i.e., a computer program) for executing the above-described IGBT detection method, which can solve the technical problem of low detection accuracy of IGBTs. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as the beneficial effects of the IGBT detection method provided in the above embodiments, and will not be repeated here.

[0132] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the IGBT detection method described above.

[0133] The computer program product provided in this application can solve the technical problem of low detection accuracy of IGBTs. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the IGBT detection method provided in the above embodiments, and will not be repeated here.

[0134] The above are only some embodiments of this application and do not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A method for detecting IGBTs, characterized in that, The IGBT detection method is applied to an IGBT detection system, which includes an IGBT driver module, a current source module, and a temperature sensor. The current source module is connected to the IGBT driver module. The temperature sensor is used to collect the heatsink temperature value corresponding to the heatsink in the IGBT detection system. The IGBT detection method includes: If an IGBT detection command is received, the IGBT drive module and the current source module are controlled to put the IGBT detection system into a first current operating state, wherein the first current value in the first current operating state is greater than a preset current value. When the duration of the first current operating state is equal to a preset duration threshold, the IGBT drive module and the current source module are controlled to make the IGBT detection system be in a second current operating state, wherein the second current value in the second current operating state is less than or equal to the preset current value. Obtain the IGBT on-state voltage drop under the second current operating state, and detect the IGBT based on the IGBT on-state voltage drop and the heat sink temperature value.

2. The IGBT detection method as described in claim 1, characterized in that, The step of controlling the IGBT drive module and the current source module to put the IGBT detection system into a first current operating state includes: The IGBT drive module and the current source module are controlled to be in a first connection state, wherein the first connection state includes the power battery in the IGBT drive module being connected to the three-phase drive bridge arm in the IGBT drive module, and the constant current source in the current source module being disconnected from the three-phase drive bridge arm. In the first connection state, the IGBT turn-on state in the three-phase drive bridge arm is controlled based on a preset detection timing sequence. The first current operating state includes the connection state of the IGBT detection system as the first connection state and the IGBT operating state as the IGBT turn-on state. In the second current operating state, the connection state of the IGBT detection system is the opposite of the first connection state, and the IGBT operating state of the IGBT detection system is the same as the IGBT turn-on state.

3. The IGBT detection method as described in claim 1, characterized in that, The IGBT detection method further includes: Determine the IGBT on-state voltage drop of each IGBT in the first current operating state, or determine the IGBT on-state voltage drop of each IGBT in the second current operating state. For each IGBT, if the IGBT on-state voltage drop is greater than a first preset voltage drop threshold, the IGBT is controlled based on a preset lifetime protection command. The preset lifetime protection command includes at least one of reducing the IGBT switching frequency and reducing the IGBT peak operating time. When the IGBT conduction voltage drop is greater than a second preset voltage drop threshold, an alarm replacement command corresponding to the IGBT is generated, wherein the second preset voltage drop threshold is greater than a first preset voltage drop threshold.

4. The IGBT detection method as described in claim 1, characterized in that, The step of detecting the IGBT based on the IGBT on-state voltage drop and the heat sink temperature includes: For each IGBT's IGBT on-state voltage drop, the junction temperature value corresponding to the IGBT on-state voltage drop is determined in a preset junction temperature and voltage drop correspondence table, and the temperature difference between the junction temperature value and the heat sink temperature value is determined. The thermal resistance value of the IGBT is determined based on the IGBT on-state voltage drop, the temperature difference, and the operating parameters of the IGBT, and the IGBT is tested based on the thermal resistance value.

5. The IGBT detection method as described in claim 4, characterized in that, The step of determining the IGBT thermal resistance value based on the IGBT on-state voltage drop, the temperature difference, and the IGBT operating parameters includes: The IGBT on-current and IGBT turn-on duration are determined in the operating parameters of the IGBT, and the product of the IGBT on-voltage drop, the IGBT on-current, and the IGBT turn-on duration is determined as the IGBT on-loss value. The product of the IGBT conduction loss value and the temperature difference value is determined as the IGBT thermal resistance value.

6. The IGBT detection method as described in claim 4, characterized in that, The step of detecting the IGBT based on the IGBT thermal resistance value includes: When the IGBT thermal resistance value is greater than a first preset thermal resistance threshold, the IGBT is controlled based on a preset life protection command, wherein the preset life protection command includes at least one of reducing the IGBT switching frequency and reducing the IGBT peak operating time. If the thermal resistance value of the IGBT is greater than the second preset thermal resistance threshold, an alarm replacement command corresponding to the IGBT is generated, wherein the second preset thermal resistance threshold is greater than the first preset thermal resistance threshold.

7. A detection system for IGBTs, characterized in that, The IGBT detection system includes a main control chip, an IGBT drive module, a current source module, and a temperature sensor. The current source module is connected to the IGBT drive module, and the main control chip is connected to the IGBT drive module, the current source module, and the temperature sensor. The temperature sensor is used to collect the heat sink temperature value on the heat sink corresponding to the IGBT detection system. The main control chip is used to execute the IGBT detection method as described in any one of claims 1 to 6.

8. The IGBT detection system as described in claim 7, characterized in that, The IGBT driver module includes: Driven devices; The driving bridge arm circuit includes three-phase driving bridge arms. The first end of each phase driving bridge arm is connected together and serves as the positive terminal of the driving bridge arm circuit. The second end of each phase driving bridge arm is connected together and serves as the negative terminal of the driving bridge arm circuit. The midpoint of each phase driving bridge arm is connected to the driving device. Each phase driving bridge arm includes two IGBTs. The gate of each IGBT is connected to the main control chip. The collector of one IGBT serves as the positive terminal of the driving bridge arm circuit, and the emitter of the other IGBT serves as the positive terminal of the driving bridge arm circuit. The emitter of one IGBT and the collector of the other IGBT are connected together and serve as the midpoint of the driving bridge arm of that phase. A power supply capacitor, wherein the first end of the power supply capacitor is connected to the positive terminal of the drive bridge arm circuit, and the second end of the power supply capacitor is connected to the negative terminal of the drive bridge arm circuit. A power battery, the negative terminal of which is connected to the negative terminal of the drive axle arm circuit; The first switch has a first terminal connected to the positive terminal of the power battery, a second terminal connected to the positive terminal of the drive axle arm circuit, and a control terminal connected to the main control chip.

9. The IGBT detection system as described in claim 8, characterized in that, The current source module includes: A constant current source, the first end of which is connected to the negative terminal of the drive bridge arm circuit; The second switch has its first terminal connected to the second terminal of the constant current source, and its control terminal connected to the main control chip. A diode, wherein the anode of the diode is connected to the second terminal of the second switch, and the cathode of the diode is connected to the positive terminal of the drive bridge arm circuit.

10. A vehicle, characterized in that, The vehicle includes a detection system for IGBTs as described in any one of claims 7 to 9.

Images