Junction temperature determination method of power device, power conversion module and storage medium

Abstract

The invention provides a junction temperature determination method of a power device, a power conversion module and a storage medium, and relates to the technical field of power conversion modules. The power conversion module comprises a power conversion circuit formed by power devices and a temperature detection unit. The method comprises the following steps: acquiring the actually measured temperature of the temperature detection unit and the circuit state information of the power conversion circuit; and inputting the circuit state information into a preset joint model to obtain a first temperature rise of the target power device and a second temperature rise of the temperature detection unit. And determining a compensation temperature based on the actually measured temperature and the second temperature rise. And determining the junction temperature of the target power device based on the compensation temperature and the first temperature rise. According to the method, the influence of the temperature rise of the temperature detection unit on the detection temperature of the temperature detection unit is considered, the influence of the temperature rise generated by the target power device in the working process on the junction temperature of the target power device is considered, and the junction temperature of the target power device determined by the method is more accurate by integrating the two aspects.

Description

Technical Field

[0001] The present application relates to the technical field of power conversion modules, and in particular to a method for determining the junction temperature of a power device, a power conversion module and a storage medium. Background Art

[0002] In the field of new energy vehicles, the main function of the motor controller is to convert the direct current of the battery into alternating current that can drive the motor. The integrated power module inside the motor controller is an important power electronic component. The integrated power module usually contains an IGBT (Insulated Gate Bipolar Transistor Module) chip and a reverse freewheeling diode. However, the IGBT will be damaged when the maximum operating temperature is exceeded, so good temperature control can not only extend the life of the IGBT, but also prevent it from thermal damage.

[0003] Integrated power modules are usually equipped with temperature-measuring thermistors for temperature protection. However, due to the requirement of insulation withstand voltage, the thermistor is usually placed at a certain distance from the hottest point of the IGBT and the reverse freewheeling diode when they are working. Therefore, there is a certain delay in its temperature measurement, and it is impossible to reflect the maximum temperature of the IGBT and the reverse freewheeling diode in real time. If the temperature measured by NTC is used for temperature protection, a large margin needs to be reserved. However, for performance and cost considerations, a more accurate IGBT junction temperature needs to be estimated to use the full output capacity of the IGBT as much as possible. Summary of the invention

[0004] The present application provides a method for determining the junction temperature of a power device, a power conversion module and a storage medium, so as to provide a technical solution capable of accurately determining the junction temperature of a power device in a power conversion module.

[0005] In a first aspect, the present application provides a method for determining the junction temperature of a power device in a power conversion module, wherein the power conversion module includes a power conversion circuit composed of power devices and a temperature detection unit, and the method includes:

[0006] The measured temperature of the temperature detection unit and the circuit state information of the power conversion circuit are obtained.

[0007] The circuit state information is input into a preset joint model to obtain a first temperature rise of a target power device and a second temperature rise of the temperature detection unit.

[0008] A compensation temperature is determined based on the measured temperature and the second temperature rise.

[0009] A junction temperature of the target power device is determined based on the compensation temperature and the first temperature rise.

[0010] In an optional implementation, the preset joint model includes a power loss model and an equivalent thermal model target power device;

[0011] Inputting the circuit state information into a preset joint model to obtain a first temperature rise of the power device and a second temperature rise of the temperature detection unit comprises:

[0012] Inputting the circuit state information into the power loss model to obtain the power loss of the target power device;

[0013] The power loss of the target power device is input into the equivalent thermal model to obtain a first temperature rise of the target power device and a second temperature rise of the temperature detection unit.

[0014] In an optional embodiment, the power loss model is used to determine the switching energy loss and conduction energy loss of the target power device in each calculation cycle according to the circuit state information, and determine the loss power of the target power device based on the switching energy loss and the conduction energy loss.

[0015] In an optional implementation, the junction temperature determination method further includes:

[0016] Based on the junction temperature of the target power device, the switch energy loss is calibrated according to a first formula, where the first formula is:

[0017]

[0018] Among them, E switch is the switching loss of the target power device after calibration, E switch_T1 is the switching loss of the target power device at temperature T1, E switch_T2 is the switching loss of the target power device at temperature T2, T1 is the first temperature at which the target power device can operate in the switching state, T2 is the second temperature at which the target power device can operate in the switching state, and T is the junction temperature of the target power device determined in the previous calculation cycle.

[0019] In an optional implementation, the junction temperature determination method further includes: based on the junction temperature of the target power device, calibrating the conduction energy loss according to a second formula, where the second formula is:

[0020]

[0021] Among them, E Cond is the conduction energy loss of the target power device after calibration, E Cond_T3 is the conduction energy loss of the target power device at temperature T3, E Cond_T4is the conduction energy loss of the target power device at T4 temperature, T3 is the first temperature at which the target power device can operate during the conduction process, T4 is the second temperature at which the target power device can operate during the conduction process, and T is the junction temperature of the target power device determined in the previous calculation cycle.

[0022] In an optional embodiment, the equivalent thermal model includes a first equivalent parameter, and the equivalent thermal model is used to determine the first temperature rise based on at least the power loss of each target power device and the first equivalent thermal parameter; wherein the first equivalent parameter includes the first equivalent thermal resistance and the first equivalent thermal time constant of the target power device.

[0023] In an optional implementation, the power conversion module further includes a heat dissipation channel, and the equivalent thermal model further includes a second equivalent parameter; wherein the second equivalent parameter at least includes a flow coefficient of the power device relative to the heat dissipation channel;

[0024] The equivalent thermal model is used to determine the first temperature rise according to the power loss of the target power device, the first equivalent thermal parameter and the second equivalent parameter.

[0025] In an optional implementation, the power conversion module includes a plurality of target power devices;

[0026] The equivalent thermal model also includes a third equivalent parameter, and the equivalent thermal model is used to determine the first temperature rise based on at least the power loss of each target power device, the first equivalent thermal parameter and the third equivalent parameter; wherein the third equivalent parameter includes a plurality of fourth equivalent thermal resistances and a third equivalent thermal time constant of the target power device coupled in pairs with other power devices respectively.

[0027] In an optional embodiment, the multiple power devices include at least a first power device, a second power device, a third power device, and a fourth power device, the first power device and the second power device are connected in series, the third power device is connected in reverse parallel to the first power device, and the fourth power device is connected in reverse parallel to the second power device; at least the first power device, the second power device, the third power device, and the fourth power device constitute an integrated power module.

[0028] In an optional implementation, the first power device, the second power device, the third power device, and the fourth power device constitute an integrated power module, the power conversion module includes at least two integrated power modules, and the at least two integrated power modules constitute an inverter circuit.

[0029] In an optional implementation, the circuit state information includes a DC bus voltage of the inverter circuit, a current of the integrated power module, a duty cycle of the inverter circuit, and an operating frequency of the inverter circuit.

[0030] In an optional implementation, the equivalent thermal model can be characterized as:

[0031]

[0032] Among them, T Thermal is the first temperature rise, P loss is the power loss of the target power device, R ntci is the first equivalent thermal resistance or the third equivalent thermal resistance, τ ntci is the first thermal equivalent time constant or the third thermal equivalent time constant, t is the time variable, C flowi is the second equivalent parameter, n is the number of power devices included in the power conversion module, and i represents the i-th power device.

[0033] In an optional embodiment, the equivalent thermal model includes a fourth equivalent parameter, and the equivalent thermal model is used to determine the second temperature rise based on at least the power loss of each target power device and the fourth equivalent thermal parameter; wherein the fourth equivalent parameter includes the fourth equivalent thermal resistance and the fourth equivalent thermal time constant of the power loss of the target power device relative to the temperature detection unit.

[0034] In an optional embodiment, the power conversion module further includes a heat dissipation channel, and the equivalent thermal model further includes a fifth equivalent parameter; wherein the fifth equivalent parameter at least includes a flow coefficient of the temperature detection unit relative to the heat dissipation channel;

[0035] The power conversion module is used to determine the second temperature rise according to the power loss of the target power device, the fourth equivalent thermal parameter and the fifth equivalent parameter.

[0036] In an optional implementation, the equivalent thermal model can be characterized as:

[0037]

[0038] Among them, T relative For the second temperature rise, P loss is the power loss of the target power device, R ntc is the fourth equivalent thermal resistance, τ ntc is the fourth equivalent thermal time constant, t is the time variable, C flow is the fifth equivalent parameter.

[0039] In a second aspect, the present application provides a power conversion module, comprising:

[0040] At least one integrated power module, each of which includes at least one power device to form a power conversion circuit;

[0041] Temperature detection unit;

[0042] a heat dissipation device, used to dissipate heat for the at least one integrated power module;

[0043] A controller, used to implement the method described in any one of the first aspects.

[0044] In an optional embodiment, the integrated power module includes at least a first power device, a second power device, a third power device and a fourth power device, the first power device and the second power device are connected in series, the third power device is connected in reverse parallel to the first power device, and the fourth power device is connected in reverse parallel to the second power device.

[0045] In an optional implementation, the first power device, the second power device, the third power device and the fourth power device constitute an integrated power module, the power conversion module includes at least two integrated power modules, and the at least two integrated power modules constitute an inverter circuit.

[0046] In an optional implementation, the controller is further configured to calculate a duty cycle of each inverter circuit.

[0047] In an optional implementation, the system further includes at least one sensor corresponding to at least one integrated power module, and configured to respectively sample current on the corresponding integrated power module.

[0048] In an optional embodiment, the heat dissipation device is a water-cooled heat dissipation device, wherein the heat dissipation channel of the water-cooled heat dissipation device is a water channel.

[0049] In a third aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in the first aspect.

[0050] The method for determining the junction temperature of a power device in a power conversion module provided in the present application determines a compensation temperature based on the measured temperature of a temperature detection unit and a second temperature rise, wherein the second temperature rise is to input the circuit state information of the power conversion circuit into a preset joint model to obtain the temperature rise of the temperature detection unit. And the junction temperature of a target power device is determined based on the compensation temperature and the first temperature rise, wherein the first temperature rise is to input the circuit state information of the power conversion circuit into a preset joint model to obtain the temperature rise of the target power device. In summary, the method for determining the junction temperature in the present application takes into account the influence of the temperature rise of the temperature detection unit itself on the detection temperature of the temperature detection unit, and also takes into account the influence of the temperature rise generated by the target power device in the working process on its own junction temperature. Combining the above two aspects, the method for determining the junction temperature in the present application makes the junction temperature of the target power device more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0052] Figure 1 A schematic diagram of the structure of a power conversion module provided in an embodiment of the present application;

[0053] Figure 2 A schematic diagram of the structure of an integrated power module provided in an embodiment of the present application;

[0054] Figure 3 A flow chart of a method for determining the junction temperature of a power device in a power conversion module provided in an embodiment of the present application;

[0055] Figure 4 A schematic diagram of a principle for determining a target power device junction temperature using a preset joint model provided in an embodiment of the present application;

[0056] Figure 5 An equivalent thermal model of an upper bridge IGBT is provided in an embodiment of the present application.

[0057] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0058] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. It is understood that the terms "first", "second", etc. used in the present application can be used to describe various information or data in this article, but these elements are not limited by these terms. These terms are only used to distinguish the first information from another information. For example, without departing from the scope of the present application, the first action information can be referred to as the second action information, and similarly, the second action information can be referred to as the first action information. Both the first action information and the second action information are action information, but they are not the same action information.

[0060] In the field of new energy vehicles, the power conversion module included in the motor controller converts the direct current of the battery into alternating current that can drive the motor, and the power conversion module can be composed of at least one integrated power module. The integrated power module may include at least one power device, such as IGBT (Insulated Gate Bipolar Transistor Module), MOSFET and freewheeling diode. However, power devices, such as IGBT, will be damaged when the maximum operating temperature is exceeded, so good temperature control can not only extend the life of the IGBT, but also prevent it from thermal damage.

[0061] Integrated power modules are usually equipped with temperature-measuring thermistors for temperature protection. However, due to the insulation withstand voltage requirement, the thermistor is usually placed at a certain distance from the hottest point of power devices, such as IGBTs and reverse freewheeling diodes, during operation. Therefore, its temperature measurement has a certain delay and cannot reflect the maximum temperature of the IGBTs and reverse freewheeling diodes in real time. If the temperature measured by thermistors is used for temperature protection, a large margin needs to be reserved. However, for cost considerations, a more accurate estimate of the junction temperature of the power device is required to use the full output capacity of the power device as much as possible. Therefore, the junction temperature of the power device is very necessary for the power conversion module.

[0062] The power conversion module includes at least one integrated power module, and at least one integrated power module constitutes a power conversion circuit. Figure 1 As shown, in a three-phase power conversion circuit, the power conversion module may include three integrated power modules, and the power conversion module also includes a heat sink 102 and a controller. Figure 21 shows a schematic diagram of the structure of an integrated power module provided by the present application. Each integrated power module 101 includes a power device and a temperature detection unit 103. The temperature detection unit 103 is arranged in the integrated power module 101 and is arranged close to the power device to detect the temperature of the integrated power module; Figure 1 The heat dissipation device 102 includes but is not limited to a water channel of a liquid cooling device, which can be arranged below the multiple integrated power modules to dissipate heat for the multiple integrated power modules 101.

[0063] Figure 3 The present application proposes a flow chart of a method for determining the junction temperature of a power device in a power conversion module, referring to Figure 3 , the method comprises the following steps:

[0064] S301, obtaining the measured temperature of the temperature detection unit and the circuit state information of the power conversion circuit.

[0065] In this embodiment, the temperature detection unit is arranged near the power device, and is used to detect the measured temperature of the location in real time, and provide temperature information to assist in determining whether the power device operates within a safe temperature range. The controller can be used to obtain the measured temperature, and when the measured temperature exceeds a set safety threshold, the controller can take protective measures, such as reducing the power output of the power device or shutting down the power device, to prevent overheating damage.

[0066] The temperature detection unit may be any unit that can be integrated into the power conversion module and has a temperature detection function. For example, the temperature detection unit is an NTC (Negative Temperature Coefficient) thermistor.

[0067] The circuit state information of the power conversion circuit refers to the real-time information of each key parameter and state of the circuit during operation, including but not limited to current, voltage, duty cycle and switching frequency, etc. Therefore, in this embodiment, by obtaining the circuit state information, in addition to timely discovering the abnormal situation of the circuit, taking protective measures to prevent circuit damage and improve its reliability, the junction temperature of the power device can be accurately estimated based on the circuit state information and the measured temperature of the temperature detection unit, so as to maximize the full output capacity of the power device and improve the efficiency of the power conversion module.

[0068] S302, inputting the circuit state information into a preset joint model to obtain a first temperature rise of a target power device and a second temperature rise of a temperature detection unit.

[0069] In this embodiment, the preset joint model can be a model for simulating and predicting thermal behavior and temperature changes of power devices. For example, the circuit state information is input into the preset joint model, and the theoretical temperature rise of the target power device in the current working state, i.e., the first temperature rise, is obtained according to the parameters and calculation formula set in the preset model, and the second temperature rise can reflect the theoretical temperature rise of the temperature detection unit in the current working state.

[0070] Based on this, the circuit status information is input into the preset joint model, which can accurately predict the theoretical temperature rise of the power device and the temperature detection unit to provide accurate temperature information, including but not limited to the application of the first temperature rise and the second temperature rise to real-time temperature monitoring of the power device and the temperature detection unit, timely detection and handling of abnormal conditions, and prevention of overheating damage. Effective temperature management and protection measures can also be used to extend the service life of the power device and the temperature detection unit and reduce maintenance and replacement costs.

[0071] S303: Determine a compensation temperature based on the measured temperature and the second temperature rise.

[0072] In this embodiment, the actual temperature measured by the temperature detection unit and the second temperature rise may be combined to determine the compensation temperature. Specifically, the compensation temperature may be obtained by subtracting the second temperature rise from the actual temperature.

[0073] It should be understood that the measured temperature is the real-time detected temperature of the temperature detection unit, and the second temperature rise reflects the ideal temperature rise of the temperature detection unit under the current working state. Therefore, the compensation temperature can be obtained by subtracting the ideal temperature rise from the measured temperature. Figure 1 As shown, the position of the temperature detection unit is at a relatively large distance from the hottest position of the actual power module, and the measured temperature cannot accurately reflect the junction temperature of the power device. The heat dissipation device is a water-cooled heat dissipation device, and its water channel is arranged below the integrated power device. Due to the large specific heat capacity of the heat dissipation medium, the heat emitted by the integrated power module can be uniformly absorbed. Therefore, the compensation temperature is obtained by the measured temperature of the temperature detection unit and its second temperature rise. The compensation temperature can more accurately reflect the cooling reference temperature, eliminating the error caused by the measured temperature of the temperature detection unit that can only represent the temperature at its location to the junction temperature measurement of the power device. Those skilled in the art should know that the compensation temperature can be reflected by the temperature of the heat dissipation medium, but is not limited to this.

[0074] S304 , determining a junction temperature of a target power device based on the compensation temperature and the first temperature rise.

[0075] In this embodiment, the compensation temperature and the first temperature rise are combined to determine the junction temperature of the target power device. Specifically, the compensation temperature and the first temperature rise are added to obtain the junction temperature of the target power device.

[0076] In this embodiment, the compensation temperature is the temperature difference determined by the real-time monitoring temperature of the temperature detection unit and its ideal temperature rise under the current working state, and the first temperature rise is the ideal temperature rise of the target power device under the current working state. Therefore, by determining the junction temperature of the target power device based on the sum of the compensation temperature and the first temperature rise, the compensation temperature can be used to accurately reflect the overall temperature of the integrated power module, and by adding the compensation temperature to the ideal temperature rise of the target power device, the junction temperature of the target power device can be closer to the actual situation of the power device and more accurate.

[0077] In some embodiments, the present application predicts the temperature rise of the power device and the temperature detection unit under the current working state based on the preset joint model. Figure 4 The schematic diagram of the method of obtaining the first temperature rise and the second temperature rise by using the preset joint model in the present application is shown as follows: Figure 4 As shown, the preset joint model provided by the present application may include a power loss model and an equivalent thermal model, wherein the output of the power loss model serves as an input parameter of the equivalent thermal model. Based on this, inputting the circuit state information into the preset joint model, and obtaining the first temperature rise of the power device and the second temperature rise of the temperature detection unit may include the following steps:

[0078] Step a1, such as Figure 4 As shown, the circuit state information is input into a power loss model to obtain the power loss of the target power device.

[0079] In this embodiment, the circuit state information may generally include parameters such as current, voltage, temperature, switching frequency, etc. Figure 1 and Figure 2 The power conversion module shown may include a three-phase inverter circuit, and the circuit state information used in the method for determining the junction temperature of the power device may include bridge arm current, DC bus voltage, duty cycle, switching frequency, etc. The circuit state information may be obtained by sampling through sensors, etc., and this embodiment does not specifically limit this.

[0080] Power loss usually includes conduction loss and switching loss. Among them, conduction loss is due to the loss of the device in the on state, and switching loss is due to the loss generated by the power device during the switching process.

[0081] In this embodiment, the circuit state information is input into the power loss model to calculate the power loss of the power device. It should be understood that the power loss model is used to calculate the power loss of the power device during the operation of each cycle due to the switching process and the power loss during the conduction time. The power loss will cause the power device to heat up and the temperature detection unit adjacent to it to generate a temperature rise.

[0082] Step a2, refer to Figure 4, inputting the power loss of the target power device into the equivalent thermal model to obtain a first temperature rise of the target power device and a second temperature rise of the temperature detection unit.

[0083] Alternatively, the equivalent thermal model can be understood as a mathematical model used to simulate and calculate heat transfer and temperature rise, which is based on physical principles such as heat conduction, heat convection and thermal radiation to predict the temperature changes of power devices and other related components.

[0084] The power loss of the target power device is input into the equivalent thermal model. The equivalent thermal model calculates the theoretical temperature rise of the target power device, i.e., the first temperature rise, and the temperature rise of the temperature detection unit, i.e., the second temperature rise, based on the input power loss and the thermal characteristics of the target power device itself and the interaction between the target power device and other devices. These are used as parameters for determining the junction temperature of the power device. Accurate junction temperature prediction can enable the power device to exert its maximum power as much as possible and help the controller determine and take necessary cooling measures to ensure its normal operation.

[0085] In an optional embodiment, the power loss model can be specifically used to: determine the switching loss and conduction loss of the target power device in each calculation cycle according to the circuit state information, and determine the loss power of the target power device based on the switching loss and conduction loss.

[0086] In this embodiment, the circuit state information is input into the power loss model, and the switching loss and conduction loss of the target power device are obtained based on each sampling cycle. The calculation cycle can be one switching cycle of the power conversion circuit or multiple switching cycles, which is determined according to the actual situation and is not specifically limited in this embodiment.

[0087] Optionally, this embodiment may adopt any existing method to determine the switching loss and conduction loss of the target power device, and this embodiment does not make any specific limitation to this.

[0088] Exemplarily, this embodiment can use the turn-on loss, turn-off loss and reverse recovery loss of the target power device obtained through a double-pulse experiment with an integrated power module and the voltage, current and temperature data to perform curve fitting to obtain the relationship between the energy loss of the switch of the target power device and the current and voltage as follows.

[0089] The calculation formula for the energy loss when the target power device is turned on can be expressed as:

[0090] E on =(μ3+μ4·I C +μ5·I C 2 )·V efficient

[0091] The calculation formula for the energy loss when the target power device is turned off can be expressed as:

[0092] E off =(μ6+μ7·I C +μ8·I C 2 )·V efficient

[0093] The calculation formula of the voltage calibration coefficient in the calculation formula of the target power device turn-on and turn-off energy loss can be expressed as:

[0094] V efficient =C+(1-C)*0.00385*(U DC -210)

[0095] Among them, μ3, μ4, μ5, μ6, μ7, μ8 are constants, Ic is the sampling current, V efficient is the voltage-dependent coefficient, U DC is the DC bus voltage, and C is a constant related to the voltage.

[0096] Optionally, an integrated power module with a thermocouple can be used to measure the relationship curve between the on-state voltage drop, current and temperature of the power device and calibrate it. The relationship between the on-state voltage drop and current can be calculated using a lookup table, and the on-state relationship can be determined by the positive and negative current to calculate the on-state energy loss.

[0097] The calculation formula of conduction energy is as follows: E Cond =I c ·V cond ·Duty·T switch .

[0098] Among them, I c is the current, V cond is the voltage, Duty is the duty cycle, T switch is the switching cycle.

[0099] For example, the target power device is an IGBT (Insulated Gate Bipolar Transistor). The target power device in this embodiment may also be a freewheeling diode, etc., which is not specifically limited in this embodiment. Therefore, the formula for the relationship between the switching loss of the target power device and the current and voltage can be further simplified as follows: E switch =U DC ·(k1·I C +k2·I C 2 +k3). The conduction relationship is determined by the positive and negative current, and the conduction energy formula is as follows: E Cond =I c·V cond Duty T switc h.

[0100] In this embodiment, the turn-on / off energy loss and the conduction energy loss are calculated in each calculation cycle, and the overall energy loss is obtained by accumulating the loss energy of the IGBT and the reverse freewheeling diode, and the P loss =E sum / time, the power loss of IGBT and reverse freewheeling diode is calculated. In the process of calculating energy loss, the energy loss is also calibrated by linear interpolation based on the previously estimated IGBT or reverse freewheeling diode temperature.

[0101] Based on this, this embodiment calculates the switching energy loss and conduction energy loss of the target power device, and then superimposes the switching loss and conduction loss of the target power device to obtain the total energy loss during the operation of the power device, and determines the loss power of the target power device through the total energy loss and the duration of the calculation cycle.

[0102] Reference Figure 4 In this embodiment, the switching energy loss and the conduction energy loss of the target power device can be calibrated according to the junction temperature of the target power device.

[0103] Exemplarily, calibrating the switching energy loss of the target power device according to the junction temperature of the target power device may include:

[0104] Based on the junction temperature of the target power device, the switching energy loss is calibrated according to the first formula, which can be represented as:

[0105]

[0106] Among them, E switch is the switching loss of the target power device after calibration, E switch_T1 is the switching loss of the target power device at temperature T1, E switch_T2 is the switching loss of the target power device at temperature T2, T1 is the first temperature at which the target power device can operate in the switching state, T2 is the second temperature at which the target power device can operate in the switching state, and T is the junction temperature of the target power device determined in the previous calculation cycle.

[0107] Optionally, the above T1 is the lowest temperature at which the target power device can operate in the switch state, and T2 is the highest temperature at which the target power device can operate in the switch state. It should be understood that the lowest temperature and the highest temperature can be determined according to the type, structure or other parameters of the target power device, and the embodiments of the present application do not make specific limitations on this.

[0108] Optionally, when the target power device is an IGBT, T1 may be -40°C and T2 may be 150°C.

[0109] Based on this, this embodiment can calibrate the switching energy loss of the power device based on the junction temperature of the power device, and can more accurately calculate the power loss of the power device at the current junction temperature.

[0110] Exemplarily, calibrating the conduction energy loss of the target power device according to the junction temperature of the target power device may include:

[0111] Based on the junction temperature of the target power device, the conduction energy loss is calibrated according to the second formula, which can be expressed as:

[0112]

[0113] Among them, E Cond is the conduction energy loss of the target power device after calibration, E Cond_T3 is the conduction energy loss of the target power device at temperature T3, E Cond_T4 is the conduction energy loss of the target power device at T4 temperature, T3 is the first temperature at which the target power device can operate during the conduction process, T4 is the second temperature at which the target power device can operate during the conduction process, and T is the junction temperature of the target power device determined in the previous calculation cycle.

[0114] Optionally, the above T3 is the lowest temperature at which the target power device can operate during the conduction process, and T4 is the highest temperature at which the target power device can operate during the conduction process. It should be understood that the lowest temperature and the highest temperature can be determined according to the type, structure or other parameters of the target power device, and the embodiments of the present application do not make specific limitations on this.

[0115] Exemplarily, when the target power device is an IGBT, T3 may be 25° C., and T2 may be 110° C.

[0116] Based on this, this embodiment can calibrate the conduction energy loss of the power device based on the junction temperature of the power device, so the conduction energy loss of the power device under different working conditions can be calculated more accurately.

[0117] The above embodiment describes the power loss model in the preset joint model in detail. The following section describes how to determine the first temperature rise of the target power device and the second temperature rise of the temperature detection unit based on the equivalent thermal model in the preset joint model.

[0118] Optionally, the embodiment of the present application may include determining the first temperature rise of the target power device based on the equivalent thermal model:

[0119] In some embodiments, the equivalent thermal model includes a first equivalent parameter, and the equivalent thermal model is used to determine a first temperature rise based on at least the power loss of each target power device and the first equivalent thermal parameter; wherein the first equivalent parameter includes a first equivalent thermal resistance and a first equivalent thermal time constant of the target power device.

[0120] It should be understood that the equivalent thermal model is an important model for analyzing and predicting thermal behavior of power devices. Therefore, this embodiment can determine the first temperature rise based on the equivalent thermal model according to the first equivalent thermal resistance and the first equivalent thermal time constant of the target power device.

[0121] The first equivalent thermal resistance of the target power device is used to describe the ease with which heat is transferred from the inside of the target power device to the external environment. The lower the first equivalent thermal resistance, the better the heat dissipation performance of the target power device. The first equivalent thermal resistance can usually be obtained by experimental measurement or simulation calculation. For example, a steady-state measurement method or a transient measurement method.

[0122] The first equivalent thermal time constant of the target power device is used to describe the time required for the target power device to reach a steady-state temperature under thermal excitation. It reflects the dynamic response characteristics of the thermal system and is a key indicator in thermal management and thermal design. The first equivalent thermal time constant can usually be obtained through experimental measurement or simulation calculation. For example, the transient thermal response method or the step response method.

[0123] It can be seen from the above description that the power loss of the target power device is reflected in the form of heat dissipation. The first equivalent thermal resistance of the target power device is used to describe the ease of heat transfer from the inside of the target power device to the external environment, and the first equivalent thermal time constant of the power device is used to describe the time required for the target power device to reach a steady-state temperature under thermal excitation. Therefore, in this embodiment, the first temperature rise of the target power device can be calculated based on the power loss of the target power device and the heat, the first equivalent thermal resistance and the first equivalent time constant.

[0124] In other embodiments, the equivalent thermal model includes a first equivalent parameter and a second equivalent parameter. The power conversion module includes a water-cooled heat dissipation channel, and the equivalent thermal model can determine the first temperature rise according to the power loss of the target power device, the first equivalent thermal parameter, and the second equivalent parameter. The second equivalent parameter at least includes a flow coefficient of the target power device relative to the heat dissipation channel.

[0125] The flow coefficient of the target power device relative to the heat dissipation channel is used to describe the flow characteristics of the cooling medium (such as air or liquid) in the heat dissipation channel. The flow coefficient can directly affect the heat dissipation efficiency and the temperature rise of the power device. However, it should be understood that for devices with stable heat dissipation flow, the second equivalent parameter may not be considered.

[0126] In one example, in the application of electric vehicles, the heat dissipation channel can be a water channel, and on this basis, the flow coefficient can be the flow coefficient of the water channel. When the first temperature rise is determined by using the power loss of the target power device, the first equivalent thermal resistance of the target power device, the first equivalent thermal time constant, and the flow coefficient of the water channel, this embodiment provides a solution for determining the numerical relationship between the flow coefficient and the first equivalent thermal resistance, which can be specifically: when the flow coefficient is 8L / min, the first equivalent thermal resistance of the target power device is 1. For the determination of other flow coefficients, the product of the ratio of the thermal resistance under different flow conditions to the thermal resistance under 8L / min and 8L / min can be used to determine. In practical applications, the flow coefficient under different flow rates can be calculated by table lookup, wherein each power device has a corresponding flow coefficient table.

[0127] When determining the first temperature rise of a power device in a power conversion module having a heat dissipation channel, this method not only takes into account the power loss of the power device, the first equivalent thermal resistance and the first equivalent thermal time constant of the power device, but also takes into account the influence of the flow coefficient of the power device relative to the heat dissipation channel on the temperature rise. Therefore, the first temperature rise is closer to the actual temperature rise of the power device during operation.

[0128] In another embodiment, the power conversion module includes multiple target power devices, the equivalent thermal model includes a first equivalent parameter and a third equivalent parameter, and the equivalent thermal model is used to determine the first temperature rise based on at least the power loss of each target power device, the first equivalent thermal parameter and the third equivalent parameter.

[0129] The third equivalent parameters include a plurality of third equivalent thermal resistances and third equivalent thermal time constants of the target power device coupled with other power devices in pairs.

[0130] This method is used to determine the first temperature rise of each target power device when the power conversion module includes multiple target power devices.

[0131] It should be understood that in the case where the power conversion module includes more than one power device, thermal coupling between multiple power devices is an important consideration. Each power device not only generates heat, but also exchanges heat with other power devices through heat conduction, convection and radiation. In order to accurately estimate the temperature rise of each power device, it is necessary to consider the thermal coupling effect between the power devices, which is described by multiple third equivalent thermal resistances and third equivalent thermal time constants in this embodiment.

[0132] The third equivalent thermal resistance reflects the ease with which heat is transferred from one power device to another power device, and the third equivalent thermal time constant reflects the time required for heat to be transferred from one power device to another power device.

[0133] Exemplarily, the equivalent thermal model in this method can be characterized as:

[0134]

[0135] Among them, T Thermal is the first temperature rise, P loss is the power loss of the target power device, R thi is the first equivalent thermal resistance or the third equivalent thermal resistance, τ ti is the first thermal equivalent time constant or the third thermal equivalent time constant, t is the time variable, C flowi is the second equivalent parameter, n is the number of power devices included in the power conversion module, and i represents the i-th power device.

[0136] It is worth noting here that the above-mentioned time variable t is a time domain parameter, which can be calculated through discretization processing in practical applications.

[0137] Based on this, this method provides a situation in which the thermal coupling between multiple power devices is considered using an equivalent thermal model, and the first temperature rise of the power device can be determined more accurately based on the first equivalent parameter and the third equivalent parameter.

[0138] Based on this, this method determines the first temperature rise according to the power loss of the target power device, the first equivalent thermal resistance and the first equivalent thermal time constant of the target power device, and multiple third equivalent thermal resistances and third equivalent thermal time constants of the target power device coupled with other power devices in pairs. This method takes into account factors such as the heat generated during the operation of the target power device, the difficulty of transferring the heat from the inside of the target power device to the external environment, the time required for the target power device to reach a steady-state temperature under thermal excitation, and the thermal coupling effect between power devices. Therefore, the determined first temperature rise of the target power device can be closer to its actual temperature rise during operation.

[0139] In some examples, thermal management of multiple power devices in a power conversion module is a complex and critical task, and the thermal coupling effect becomes more significant considering the connection method of the multiple power devices.

[0140] Optionally, the plurality of power devices may include at least a first power device, a second power device, a third power device, and a fourth power device to form an integrated power module; wherein the first power device and the second power device are connected in series, the third power device is connected in reverse parallel to the first power device, and the fourth power device is connected in reverse parallel to the second power device. For example, the power devices may be IGBTs, reverse freewheeling diodes, etc. When the first power device and the second power device are IGBTs, and the third power device and the fourth power device are reverse freewheeling diodes, the first power device and the third power device may form an upper bridge arm, and the second power device and the fourth power device may form a lower bridge arm.

[0141] In an example, the above-mentioned multiple power devices may further include other power devices except the first power device, the second power device, the third power device, and the fourth power device to form a power conversion circuit of a common power conversion module, and the multiple power devices constitute an integrated power module.

[0142] In another example, the first power device, the second power device, the third power device, and the fourth power device constitute an integrated power module, and the power conversion module may include multiple integrated power modules. For example, depending on the circuit type, two of the above integrated power modules may constitute a single-phase full-bridge power conversion module, and three of the above integrated power modules may constitute a three-phase power conversion module.

[0143] This embodiment provides a method for determining a first temperature rise of each power device in an integrated power module, wherein the power conversion module further includes a heat dissipation channel formed by a water channel.

[0144] The method may include: measuring the thermal resistance and thermal time constant of IGBT and Diode in the integrated power module by experimental means, establishing an equivalent thermal model from the water channel to the IGBT, Diode and thermistor in the power module, and considering the mutual heat transfer influence of IGBT and Diode between the upper and lower bridge arms within the same phase module in the model.

[0145] Reference Figure 5 Taking the equivalent thermal model of the upper bridge IGBT as an example, it can be decomposed into a linear superposition of a third-order RC model 40 and three first-order RC models. The input of the equivalent thermal model is the output of the power loss model. In addition, in the process of equivalent thermal modeling, the equivalent thermal model of the thermistor is used to calculate the stable water temperature, which reduces the large error in the IGBT and Diode temperature calculation results caused by inaccurate water channel temperature measurement.

[0146] Optionally, in the process of determining the first temperature rise, this method also takes into account the mutual heat flow influence of different IGBTs and Diodes inside the integrated power module when they are turned on.

[0147] Taking the upper bridge IGBT as an example, the equivalent thermal model is used to determine the thermal resistance and thermal time constant of the upper bridge IGBT to itself, the thermal resistance and thermal time constant of the lower bridge IGBT to the upper bridge IGBT, the thermal resistance and thermal time constant of the upper bridge diode to the upper bridge IGBT, and the thermal resistance and thermal time constant of the lower bridge diode to the upper bridge IGBT.

[0148] Based on this, the thermal network model is as follows Figure 5 As shown, it is equivalent to the linear superposition of a third-order parallel RC model 40 and three first-order RC models.

[0149] The thermal network model can be discretized according to the actual sampling time during implementation, which is convenient for implementation in embedded systems.

[0150] It should be understood that in each integrated power module, the thermal network model of each power semiconductor is modeled in the same way. For a power conversion module composed of multiple integrated power modules, one of the integrated power modules can be selected for experiment when performing thermal resistance calibration. For example, for a three-phase power conversion module, the internal structures of the three single-phases are basically the same, so when performing thermal resistance calibration, one of the integrated power modules can be selected for experiment. This method is similar for integrated power modules including two or three phases.

[0151] It is worth noting that Figure 1 The temperature of the power devices between the three-phase full-bridge power modules may be different due to the different temperatures of the coolant flowing through the bottom. In the process of thermal resistance calibration of the power device, it can be considered that the coolant flows in through phase A and flows out through phase C. The water temperature of phase C corresponds to the outlet temperature, and the water temperature of phase A corresponds to the inlet temperature.

[0152] Optionally, the embodiment of the present application may include determining the second temperature rise of the target power device based on the equivalent thermal model:

[0153] In some embodiments, the equivalent thermal model includes a fourth equivalent parameter, and the equivalent thermal model is used to determine the second temperature rise based on at least the power loss of each target power device and the fourth equivalent thermal parameter; wherein the fourth equivalent parameter includes the fourth equivalent thermal resistance and the fourth equivalent thermal time constant of the power loss of the power device relative to the temperature detection unit.

[0154] The fourth equivalent thermal resistance can be understood as the thermal resistance between the power device and the temperature detection unit. The fourth equivalent thermal resistance can also be further understood as how the power loss affects the temperature of the temperature detection unit under steady-state conditions.

[0155] The fourth equivalent thermal time constant can be understood as the thermal time constant between the power loss of the power device and the temperature detection unit. The fourth equivalent thermal resistance can also be further understood as how the power loss affects the temperature change speed of the temperature detection unit under transient conditions.

[0156] The fourth equivalent thermal resistance and the fourth equivalent thermal time constant in this embodiment can be obtained by experimental measurement or simulation calculation, and the specific calculation method is not specifically limited in this embodiment.

[0157] In this embodiment, the fourth equivalent thermal resistance and the fourth equivalent thermal time are important parameters for describing the heat transfer behavior between the power device and the temperature detection unit, and can be used to predict the temperature rise of the temperature detection unit, thereby effectively managing the thermal behavior of the power device and ensuring the reliability and safety of the power device.

[0158] From the above description, it can be seen that the power loss of a power device refers to the heat generated by the resistance and other loss mechanisms of the current passing through the device during the operation of the power device. The fourth equivalent thermal resistance is the thermal resistance between the power loss of the power device and the temperature detection unit, which is used to describe the difficulty of heat transfer from the inside of the target power device to the temperature detection unit. The fourth equivalent thermal time constant can be understood as the thermal time constant between the power loss of the power device and the temperature detection unit, which is used to describe the time required for the temperature detection unit to reach a steady-state temperature under thermal excitation of the target power device. Therefore, this embodiment can calculate the second temperature rise of the temperature detection unit based on the power loss of the target power device, the fourth equivalent thermal resistance and the fourth equivalent time constant.

[0159] In other embodiments: the power conversion module also includes a heat dissipation channel, the equivalent thermal model also includes a fifth equivalent parameter, and the equivalent thermal model is used to determine the second temperature rise based on the power loss of the target power device, the fourth equivalent thermal parameter and the fifth equivalent parameter.

[0160] The fifth equivalent parameter at least includes a flow coefficient of the temperature detection unit relative to the heat dissipation channel.

[0161] Optionally, this embodiment further provides a calculation formula for a second temperature rise which can be represented as:

[0162]

[0163] Among them, T relative is the first temperature rise, P loss is the power loss of the target power device, R ntc is the fourth equivalent thermal resistance, τ ntc is the fourth thermal time constant, t is the time variable, which can be discretized according to the actual application, C flow is the fifth equivalent parameter.

[0164] Similar to the calculation of the first temperature rise in the above embodiment, in this embodiment, when determining the second temperature rise of the temperature detection unit in the power conversion module with a heat dissipation channel, not only the power loss of the power device and the fourth equivalent thermal parameter are considered, but also the influence of the flow coefficient of the temperature detection unit relative to the heat dissipation channel on the temperature rise is considered. Therefore, in some cases, the second temperature rise can more accurately calculate the temperature rise of the temperature detection unit during operation.

[0165] The above describes in detail the structure of the thermal network model and how to use the thermal network model to determine the first temperature rise of the target power device in the power conversion module and the second temperature rise of the temperature detection unit. The following section will focus on the structure and function of the power conversion module.

[0166] In some examples, the power conversion module includes at least three integrated power modules, and the at least three integrated power modules can constitute an inverter circuit. The inverter circuit is a type of the above-mentioned power conversion circuit, which is used to convert direct current into alternating current. In other examples, the power conversion module includes an integrated power module, and the at least integrated power module includes a three-phase bridge arm to form a three-phase inverter circuit. It is worth noting that the power conversion circuit in the present application can not only be an inverter circuit, but also other circuits that convert one form of electrical energy into another form of electrical energy, and the present application does not make specific limitations on this.

[0167] In some examples, when the power conversion circuit is an inverter circuit, the circuit state information of the power conversion circuit includes a DC bus voltage of the inverter circuit, a current of the integrated power module, a duty cycle of the inverter circuit, and an operating frequency of the inverter circuit.

[0168] The DC bus voltage of the inverter circuit is the DC voltage input to the inverter circuit, which is usually provided by a DC power supply (such as a battery or a rectifier). Its stability directly affects the output voltage and efficiency of the inverter circuit. Too high or too low DC bus voltage may cause system instability or damage.

[0169] The current of an integrated power module refers to the current passing through a power switch such as an IGBT or MOSFET. Monitoring the current of an integrated power module can prevent overcurrent conditions and protect the power switch and other circuit components.

[0170] The duty cycle of the inverter circuit refers to the ratio of the high level time of the PWM (pulse width modulation) signal to the total cycle time, usually expressed as a percentage, which directly affects the output voltage and power of the inverter circuit. By adjusting the duty cycle, the amplitude of the output voltage can be controlled.

[0171] The operating frequency of the inverter circuit refers to the switching frequency of the PWM signal in the inverter circuit, which can affect the efficiency of the inverter circuit and the quality of the output waveform. However, a higher operating frequency may increase switching losses.

[0172] Based on this, inputting the circuit state information into the above-mentioned preset joint model can simulate the actual working conditions of each power device in the integrated power module, so the first temperature rise of the target power device and the second temperature rise of the temperature detection unit are closer to the actual temperature rise.

[0173] In a second aspect, an embodiment of the present application further provides a power conversion module, including:

[0174] It includes at least one integrated power module, and each integrated power module includes at least one power device to form a power conversion circuit.

[0175] The temperature detection unit is arranged in the integrated power module.

[0176] A heat dissipation device is used to dissipate heat for multiple integrated power modules.

[0177] A controller is used to implement the junction temperature determination method in the first aspect.

[0178] In this embodiment, the power conversion circuit is a circuit for converting one form of electrical energy into another form of electrical energy. This conversion may involve changes in voltage, current, frequency, or waveform. Power conversion circuits are widely used in modern electronic devices, including power adapters, chargers, inverters, and electric vehicles.

[0179] The power conversion circuit may be an inverter circuit, wherein the integrated power device includes a power device, and the power device may be an IGBT and a freewheeling diode.

[0180] The temperature detection unit can be arranged in each integrated power module to monitor the temperature of the power device in real time. The temperature detection unit can be a thermistor, a thermocouple or an integrated temperature sensor, which is not limited in this embodiment.

[0181] The heat dissipation device is used to dissipate heat for at least one integrated power module to ensure that the power device operates within a safe temperature range. The heat dissipation device may include a heat sink, a fan or a liquid cooling device, which is not limited in this embodiment.

[0182] The controller is used to implement the solution in the method for determining the junction temperature in the first aspect. Specifically, it may include:

[0183] The measured temperature of the temperature detection unit and the circuit state information of the power conversion circuit are obtained.

[0184] The circuit state information is input into a preset joint model to obtain a first temperature rise of a target power device and a second temperature rise of the temperature detection unit.

[0185] A compensation temperature is determined based on the measured temperature and the second temperature rise.

[0186] A junction temperature of the target power device is determined based on the compensation temperature and the first temperature rise.

[0187] The controller in this embodiment may be a digital signal processor (DSP) or a microcontroller unit (MCU), and execute the above-mentioned junction temperature determination method.

[0188] In some examples, the integrated power module includes at least a first power device, a second power device, a third power device and a fourth power device, the first power device and the second power device are connected in series, the third power device is connected in reverse parallel to the first power device, and the fourth power device is connected in reverse parallel to the second power device.

[0189] The first to fourth power devices mentioned above can be IGBTs or reverse freewheeling diodes. When the first power device and the second power device are IGBTs, and the third power device and the fourth power device are reverse freewheeling diodes, the first power device and the third power device can form an upper bridge hip, and the second power device and the fourth power device can form a lower bridge hip.

[0190] In one example, the power conversion module may include at least one integrated power module to form an inverter circuit. For example, the first power device, the second power device, the third power device and the fourth power device form an integrated power module, and the power conversion module includes at least one integrated power module to form an inverter circuit.

[0191] In one example, the integrated power module further includes other power devices except the first power device, the second power device, the third power device, and the fourth power device to form a power conversion circuit of the power conversion module. For example, the power conversion module includes an inverter circuit composed of an integrated power module.

[0192] It should be understood that the power conversion circuit in the present application can be not only an inverter circuit, but also other circuits that convert one form of electrical energy into another form of electrical energy, and the present application does not make specific limitations on this.

[0193] Optionally, when the power conversion circuit is an inverter circuit, the circuit state information of the power conversion circuit includes the DC bus voltage of the inverter circuit, the current of the integrated power module, the duty cycle of the inverter circuit and the operating frequency of the inverter circuit.

[0194] Based on this, the controller in the present application is also used to calculate the duty cycle of the inverter circuit in each sampling period.

[0195] In order to obtain the current of the integrated power module, the power conversion module in the embodiment of the present application further includes a plurality of sensors, so as to utilize the plurality of sensors to respectively sample the current on the corresponding integrated power modules. The plurality of sensors may be current sensors.

[0196] The DC bus voltage of the inverter circuit can be provided by a DC power supply (such as a battery or a rectifier). The operating frequency of the inverter circuit can be obtained by a control circuit or an electronic measuring instrument, which is not specifically limited in this embodiment.

[0197] Based on the above description, the power conversion module provided in this embodiment determines the compensation temperature based on the measured temperature of the temperature detection unit and the second temperature rise, wherein the second temperature rise is to input the circuit state information of the power conversion circuit into the preset joint model to obtain the temperature rise of the temperature detection unit. And the junction temperature of the target power device is determined based on the compensation temperature and the first temperature rise, wherein the first temperature rise is to input the circuit state information of the power conversion circuit into the preset joint model to obtain the temperature rise of the target power device. In summary, the present application takes into account the influence of the position of the temperature detection unit on the junction temperature detection temperature, obtains the compensation temperature by subtracting the temperature rise of the temperature detection unit itself from the detected temperature, and obtains the junction temperature of the power device in combination with the temperature rise generated by the target power device in the working process, thereby eliminating the influence of the detection position of the temperature detection unit on the accuracy of the junction temperature detection, so that the junction temperature of the target power device determined by the power conversion module provided in this embodiment is more accurate.

[0198] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in the first aspect.

[0199] In a fourth aspect, an embodiment of the present application also provides a computer program product, which includes a computer program stored in a computer-readable storage medium. At least one processor can read the computer program from the computer-readable storage medium. When at least one processor executes the computer program, the technical solution of the linkage control method in the above embodiment can be implemented.

[0200] In the several embodiments provided in the present application, it should be understood that the disclosed methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules is only a logical function division, and there may be other division methods in actual implementation, such as multiple modules can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or modules, which can be electrical, mechanical or other forms.

[0201] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to implement the solution of this embodiment.

[0202] In addition, each functional module in each embodiment of the present application can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The above-mentioned module-composed unit can be implemented in the form of hardware or in the form of hardware plus software functional units.

[0203] The above-mentioned integrated module implemented in the form of a software function module can be stored in a computer-readable storage medium. The above-mentioned software function module is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to perform some steps of the methods of various embodiments of the present application.

[0204] It should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the invention may be directly implemented as being executed by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor.

[0205] The memory may include a high-speed RAM memory, and may also include a non-volatile storage NVM, such as at least one disk memory, and may also be a USB flash drive, a mobile hard disk, a read-only memory, a magnetic disk or an optical disk, etc.

[0206] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of the present application is not limited to only one bus or one type of bus.

[0207] The above storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The storage medium can be any available medium that can be accessed by a general or special purpose computer.

[0208] An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the storage medium can also exist as discrete components in an electronic control unit or a main control device.

[0209] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0210] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining the junction temperature of a power device in a power conversion module, characterized in that: The power conversion module includes a power conversion circuit composed of power devices and a temperature detection unit, and the method includes: Acquiring the measured temperature of the temperature detection unit and circuit state information of the power conversion circuit; Inputting the circuit state information into a preset joint model to obtain a first temperature rise of a target power device and a second temperature rise of the temperature detection unit; determining a compensation temperature based on the measured temperature and the second temperature rise; A junction temperature of the target power device is determined based on the compensation temperature and the first temperature rise.

2. The method for determining the junction temperature of a power device in a power conversion module according to claim 1, characterized in that: The preset joint model includes a power loss model and an equivalent thermal model; Inputting the circuit state information into a preset joint model to obtain a first temperature rise of the power device and a second temperature rise of the temperature detection unit comprises: Inputting the circuit state information into the power loss model to obtain the power loss of the target power device; The power loss of the target power device is input into the equivalent thermal model to obtain a first temperature rise of the target power device and a second temperature rise of the temperature detection unit.

3. The method for determining the junction temperature of a power device in a power conversion module according to claim 2, characterized in that: The power loss model is used to determine the switching energy loss and conduction energy loss of the target power device in each calculation cycle according to the circuit state information, and determine the loss power of the target power device based on the switching energy loss and the conduction energy loss.

4. The method for determining the junction temperature of a power device in a power conversion module according to claim 3, characterized in that: The junction temperature determination method further includes: Based on the junction temperature of the target power device, the switch energy loss is calibrated according to a first formula, which can be represented as: Among them, E switch is the switching loss of the target power device after calibration, E switch_T1 is the switching loss of the target power device at temperature T1, E switch_T2 is the switching loss of the target power device at temperature T2, T1 is the first temperature at which the target power device can operate in the switching state, T2 is the second temperature at which the target power device can operate in the switching state, and T is the junction temperature of the target power device determined in the previous calculation cycle.

5. The method for determining the junction temperature of a power device in a power conversion module according to claim 3, characterized in that: The junction temperature determination method further includes: based on the junction temperature of the target power device, calibrating the conduction energy loss according to a second formula, where the second formula can be represented as: Among them, E Cond is the conduction energy loss of the target power device after calibration, E Cond_T3 is the conduction energy loss of the target power device at temperature T3, E Cond_T4 is the conduction energy loss of the target power device at T4 temperature, T3 is the first temperature at which the target power device can operate during the conduction process, T4 is the second temperature at which the target power device can operate during the conduction process, and T is the junction temperature of the target power device determined in the previous calculation cycle.

6. The method for determining the junction temperature of a power device in a power conversion module according to claim 2, characterized in that: The equivalent thermal model includes a first equivalent parameter, and the equivalent thermal model is used to determine the first temperature rise based on at least the power loss of each target power device and the first equivalent thermal parameter; wherein the first equivalent parameter includes a first equivalent thermal resistance and a first equivalent thermal time constant of the target power device.

7. The method for determining the junction temperature of a power device in a power conversion module according to claim 6, characterized in that: The power conversion module further includes a heat dissipation channel, and the equivalent thermal model further includes a second equivalent parameter; wherein the second equivalent parameter at least includes a flow coefficient of the target power device relative to the heat dissipation channel; The equivalent thermal model is used to determine the first temperature rise according to the power loss of the target power device, the first equivalent thermal parameter and the second equivalent parameter.

8. The method for determining the junction temperature of a power device in a power conversion module according to claim 6, characterized in that: The power conversion module includes a plurality of power devices; The equivalent thermal model also includes a third equivalent parameter, and the equivalent thermal model is used to determine the first temperature rise based on at least the power loss of the target power device, the first equivalent thermal parameter and the third equivalent parameter; wherein the third equivalent parameter includes a plurality of third equivalent thermal resistances and third equivalent thermal time constants of the target power device coupled in pairs with other power devices respectively.

9. The method for determining the junction temperature of a power device in a power conversion module according to claim 8, characterized in that: The multiple power devices include at least a first power device, a second power device, a third power device, and a fourth power device. The first power device and the second power device are connected in series, the third power device is connected in reverse parallel to the first power device, and the fourth power device is connected in reverse parallel to the second power device. At least the first power device, the second power device, the third power device, and the fourth power device constitute an integrated power module.

10. The method for determining the junction temperature of a power device in a power conversion module according to claim 9, characterized in that: The first power device, the second power device, the third power device, and the fourth power device constitute an integrated power module. The power conversion module includes at least two of the integrated power modules. The at least two integrated power modules constitute an inverter circuit.

11. The method for determining the junction temperature of a power device in a power conversion module according to claim 10, characterized in that: The circuit state information includes the DC bus voltage of the inverter circuit, the current of the integrated power module, the duty cycle of the inverter circuit, and the operating frequency of the inverter circuit.

12. The method for determining the junction temperature of a power device in a power conversion module according to claim 8, characterized in that: The equivalent thermal model can be characterized as: Among them, T Thermal is the first temperature rise, P loss is the power loss of the target power device, R ntci is the first equivalent thermal resistance or the third equivalent thermal resistance, τ ntci is the first thermal equivalent time constant or the third thermal equivalent time constant, t is the time variable, C flowi is the second equivalent parameter, n is the number of power devices included in the power conversion module, and i represents the i-th power device.

13. The method for determining the junction temperature of a power device in a power conversion module according to claim 2, characterized in that: The equivalent thermal model includes a fourth equivalent parameter, and the equivalent thermal model is used to determine the second temperature rise based on at least the power loss of each target power device and the fourth equivalent thermal parameter; wherein the fourth equivalent parameter includes the fourth equivalent thermal resistance and the fourth equivalent thermal time constant of the power loss of the target power device relative to the temperature detection unit.

14. The method for determining the junction temperature of a power device in a power conversion module according to claim 13, characterized in that: The power conversion module further includes a heat dissipation channel, and the equivalent thermal model further includes a fifth equivalent parameter; wherein the fifth equivalent parameter at least includes a flow coefficient of the temperature detection unit relative to the heat dissipation channel; The power conversion module is used to determine the second temperature rise according to the power loss of the target power device, the fourth equivalent thermal parameter and the fifth equivalent parameter.

15. The method for determining the junction temperature of a power device in a power conversion module according to claim 14, characterized in that: The equivalent thermal model can be characterized as: Among them, T relative For the second temperature rise, P loss is the power loss of the target power device, R ntc is the fourth equivalent thermal resistance, τ ntc is the fourth equivalent thermal time constant, t is the time variable, C flow is the fifth equivalent parameter.

16. A power conversion module, characterized in that: include: At least one integrated power module, each of which includes at least one power device to form a power conversion circuit; Temperature detection unit; a heat dissipation device, used to dissipate heat for the at least one integrated power module; A controller, configured to implement the method according to any one of claims 1 to 15.

17. The power conversion module according to claim 16, characterized in that: The integrated power module includes at least a first power device, a second power device, a third power device and a fourth power device, the first power device and the second power device are connected in series, the third power device is connected in reverse parallel to the first power device, and the fourth power device is connected in reverse parallel to the second power device.

18. The power conversion module according to claim 17, characterized in that: The first power device, the second power device, the third power device and the fourth power device constitute an integrated power module, the power conversion module includes at least two integrated power modules, and the at least two integrated power modules constitute an inverter circuit.

19. The power conversion module according to claim 18, characterized in that: The controller is also used to calculate the duty cycle of the inverter circuit.

20. The power conversion module according to claim 16, characterized in that: It also includes at least one sensor arranged corresponding to the at least one integrated power module, and the sensor is used to sample the current on the corresponding integrated power module.

21. The power conversion module according to claim 16, characterized in that: The heat dissipation device is a water-cooled heat dissipation device, wherein the heat dissipation channel of the water-cooled heat dissipation device is a water channel.

22. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 15 when executed by a processor.

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