A method for calculating a junction temperature, a calculation circuit and a power switch

Abstract

The application discloses a junction temperature calculation method, an operation circuit and a power switch. The method comprises the following steps: calculating the instantaneous heat power of an IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power, the instantaneous heat power of a diode and the reverse recovery loss power; calculating the heat power of the IGBT switch tube according to the instantaneous heat power, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, and calculating the heat power of the diode according to the instantaneous heat power and the reverse recovery loss power of the diode; and calculating the junction temperature of the IGBT switch tube and the diode according to the heat power of the IGBT switch tube and the heat power of the diode. According to the application, the junction temperature can be directly calculated through the heat power of the IGBT switch tube and the diode, the accuracy of temperature calculation is improved, and the junction temperature of the IGBT switch tube and the diode can be predicted in advance so as to perform high-temperature protection in advance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor, in particular to a junction temperature calculation method, an operation circuit and a power switch. BACKGROUND

[0002] The traditional IGBT power device does not have built-in temperature detection and protection components, and in actual use, peripheral temperature detection and protection circuits must be configured, such as arranging temperature sensing bags or thermocouples and other temperature detection devices on the heat sink close to the IGBT power device to realize temperature detection. This design has great disadvantages. On the one hand, the temperature sensing bag or thermocouple is too far away from the PN junction inside the IGBT power device that generates heat. The heat generated by the PN junction is transmitted to the heat sink, and the heat on the heat sink is transmitted to the temperature sensing bag, resulting in low detection accuracy, and it is difficult to accurately detect the temperature of the IGBT power device. On the other hand, this passive temperature detection has great delay and hysteresis, resulting in untimely temperature detection and untimely protection, which is not conducive to high-temperature protection of the system.

[0003] In view of the problems of low accuracy and detection hysteresis of the temperature detection device such as temperature sensing bag or thermocouple for detecting the temperature of the IGBT power device in the prior art, no effective solution has been proposed so far. SUMMARY

[0004] The junction temperature calculation method, the operation circuit and the power switch provided in the embodiments of the present application solve the problem of low accuracy and detection hysteresis of the temperature detection device such as temperature sensing bag or thermocouple for detecting the temperature of the IGBT power device in the prior art.

[0005] To solve the above technical problems, the present application provides a junction temperature calculation method applied to a power device, wherein the power device comprises an IGBT switch tube and a diode connected in reverse parallel, and the method comprises the following steps:

[0006] calculating the instantaneous heat generation power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, the instantaneous heat generation power of the diode, and the reverse recovery loss power of the diode;

[0007] calculating the heat generation power of the IGBT switch tube according to the instantaneous heat generation power of the IGBT switch tube and the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, and calculating the heat generation power of the diode according to the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode;

[0008] calculating the junction temperature of the IGBT switch tube according to the heat generation power of the IGBT switch tube, and calculating the junction temperature of the diode according to the heat generation power of the diode.

[0009] Further, the instantaneous heat power of the IGBT switch tube is calculated, comprising:

[0010] detecting the current and voltage of the power device;

[0011] calculating the instantaneous heat power of the IGBT switch tube according to the current, voltage of the power device and the internal resistance of the IGBT switch tube.

[0012] Further, when calculating the instantaneous heat power of the IGBT switch tube according to the current, voltage of the power device and the internal resistance of the IGBT switch tube, the following formula is used:

[0013]

[0014] wherein P t-igbt is the instantaneous heat power of the IGBT switch tube, D T is the duty ratio of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R i is the internal resistance of the IGBT switch tube.

[0015] Further, when calculating the turn-on instantaneous loss power and turn-off instantaneous loss power of the IGBT switch tube, the following formula is used:

[0016] P on = f c · E on ;

[0017] P off = f c · E off ;

[0018] wherein P on is the turn-on instantaneous loss power of the IGBT switch tube, f c is the reference frequency, E on is the turn-on instantaneous loss energy, P off is the turn-off instantaneous loss power of the IGBT switch tube, and E off is the turn-off instantaneous loss energy.

[0019] Further, the instantaneous heat power of the diode is calculated, comprising:

[0020] detecting the current and voltage of the power device;

[0021] calculating the instantaneous heat power of the diode according to the current, voltage of the power device and the internal resistance of the diode.

[0022] Further, when calculating the instantaneous heat power of the diode according to the current, voltage of the power device and the internal resistance of the diode, the following formula is used:

[0023]

[0024] wherein P t-diode is the instantaneous heat power of the diode, D F is the duty cycle of the diode, R d is the internal resistance of the diode.

[0025] Further, when calculating the reverse recovery loss power of the diode, the following formula is used:

[0026] P rr = f c · E rr ;

[0027] wherein P rr is the reverse recovery loss power of the diode, E rr is the reverse recovery loss energy of the diode.

[0028] Further, when calculating the heat power of the IGBT switch according to the instantaneous heat power of the IGBT switch, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch, the following formula is used:

[0029] P IGBT = P t-igbt + P on + P off ;

[0030] wherein P IGBT is the heat power of the IGBT switch.

[0031] Further, when calculating the heat power of the diode according to the instantaneous heat power of the diode and the reverse recovery loss power of the diode, the following formula is used:

[0032] P Diode = P t-diode + P rr ;

[0033] wherein P Diode is the heat power of the switch.

[0034] Further, when calculating the junction temperature of the IGBT switch according to the heat power of the IGBT switch, the following formula is used:

[0035] T IGBT = P IGBT × (Rthjc-I +R thch-I )+(P IGBT +P Diode )×R thHA +T A ;

[0036] wherein, T IGBT is the junction temperature of the IGBT switch tube, R thjc-I is the thermal resistance between the junction and the shell of the IGBT, R thch-I is the thermal resistance between the shell of the IGBT and the heat sink, T A is the junction temperature of the environment.

[0037] Further, when the junction temperature of the diode is calculated according to the heat generation power of the diode, the following formula is used:

[0038] T Diode = P Diode ×(R thjc-D +R thch-D )+(P IGBT +P Diode )×R thHA +T A ;

[0039] wherein, T Diode is the junction temperature of the diode, R thjc-D is the thermal resistance between the junction and the shell of the diode, R thch-D is the thermal resistance between the diode and the heat sink.

[0040] The application further provides an operation circuit applied to a power device, wherein the power device comprises an IGBT switch tube and a diode in reverse parallel connection, and the operation circuit comprises:

[0041] a first operation unit, which is used to calculate the instantaneous heat generation power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode;

[0042] a second operation unit, which is used to calculate the heat generation power of the IGBT switch tube according to the instantaneous heat generation power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, and to calculate the heat generation power of the diode according to the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode;

[0043] a third operation unit, which is used to calculate the junction temperature of the IGBT switch tube according to the heat generation power of the IGBT switch tube, and to calculate the junction temperature of the diode according to the heat generation power of the diode.

[0044] The application further provides a power device, comprising an IGBT switch tube and a diode in reverse parallel connection, and the power device further comprises the operation circuit.

[0045] The application further provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to implement the junction temperature calculation method.

[0046] According to the technical scheme of the application, the heat generation power of the IGBT switch tube is calculated according to the instantaneous heat generation power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, the heat generation power of the diode is calculated according to the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode, the junction temperature of the IGBT switch tube is calculated according to the heat generation power of the IGBT switch tube, and the junction temperature of the diode is calculated according to the heat generation power of the diode, so that the junction temperature can be directly calculated according to the heat generation power of the IGBT switch tube and the diode, the accuracy of temperature calculation is improved, and the junction temperature of the IGBT switch tube and the diode can be predicted in advance to facilitate high-temperature protection in advance. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 a connection diagram of the power device and the operation circuit according to the embodiment of the application;

[0048] Figure 2 a flowchart of the junction temperature calculation method according to the embodiment of the application;

[0049] Figure 3 a structure block diagram of the operation circuit according to the embodiment of the application. DETAILED DESCRIPTION

[0050] In order to make the objects, technical schemes and advantages of the application clearer, the application will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0051] The terms used in the embodiments of the application are only for the purpose of describing the specific embodiments, and are not intended to limit the application. The singular forms "a", "an" and "the" used in the embodiments of the application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. "Plural" generally includes at least two.

[0052] It should be understood that the term "and / or" as used herein merely describes an associated relationship among associated objects, and indicates that there can be three relationships, for example, A and / or B can indicate that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " herein generally indicates that the front and rear associated objects are in an "or" relationship.

[0053] It should be understood that although the terms first, second, third, etc. can be used in embodiments of the present application to describe various operations, these operations should not be limited to these terms. These terms are only used to distinguish one operation from another. For example, a first operation can also be referred to as a second operation, and similarly, a second operation can also be referred to as a first operation, without departing from the scope of embodiments of the present application.

[0054] Depending on the context, the word "if" as used herein can be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting". Similarly, the phrase "if determined" or "if detecting (a stated condition or event)" can be interpreted to mean "when determined" or "in response to determining" or "when detecting (a stated condition or event)" or "in response to detecting (a stated condition or event)", depending on the context.

[0055] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that a product or device that includes a list of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent in such product or device. Without more limitations, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the product or device that includes the element.

[0056] The optional embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0057] Embodiment 1

[0058] The existing IGBT power device generally arranges temperature detecting devices such as temperature sensing bags or thermocouples on the heat sink close to the IGBT power device to realize temperature detection. On the one hand, the temperature sensing bag or thermocouple is too far away from the PN junction inside the IGBT power device that generates heat. After the PN junction generates heat, the heat is transmitted to the heat sink, and then the heat on the heat sink is transmitted to the temperature sensing bag, resulting in low detection accuracy, and it is difficult to realize accurate detection of the temperature of the IGBT power device. On the other hand, this passive temperature detection has great delay and hysteresis, resulting in untimely temperature detection and untimely protection, which is not conducive to high-temperature protection of the system.

[0059] To solve the above problems, the embodiment provides a junction temperature calculation method, Figure 1 For the connection diagram of the power device and the operation circuit according to the embodiment of the application, as shown in Figure 1 The power device includes an IGBT switch tube and a diode in reverse parallel connection, a voltage detector is arranged between the collector C and the emitter E of the IGBT switch tube, for detecting the voltage U of the power device, a current detector is arranged at the emitter of the IGBT switch tube, for detecting the current I of the power device, the voltage detector and the current detector of the power device are connected to the operation circuit, the operation circuit calculates the junction temperature of the IGBT switch tube and the junction temperature of the diode according to the voltage U and the current I and the inherent parameters of the power device stored in the operation circuit, and then generates a temperature signal and outputs the temperature signal through a pin T.

[0060] Specifically, the voltage detection is connected between the collector and the emitter of the power device, the voltage acquisition can be performed through resistance voltage division or voltage induction, the strong voltage between the power device can be converted into a weak voltage signal, the conversion ratio is determined by the resistance value and the proportion of the sampling resistor, and the acquired voltage is input into the operation circuit; the current detector can be a mutual inductor ringed around the emitter of the power device, the current flowing through the power device is acquired through the mutual inductance principle, the strong current flowing through the power device is converted into a weak current signal, the conversion ratio is determined by the turns ratio of the mutual inductor, and the acquired current signal is input into the operation circuit; the operation circuit operates the acquired voltage and current signals, calculates the heat power value, and further calculates the junction temperature of the IGBT switch tube and the junction temperature of the diode.

[0061] Figure 2 For the flow chart of the junction temperature calculation method according to the embodiment of the application, as shown in Figure 2 The method includes the following steps.

[0062] S101, the instantaneous heat power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, the instantaneous heat power of the diode, and the reverse recovery loss power of the diode are calculated.

[0063] S102, the heat power of the IGBT switch tube is calculated according to the instantaneous heat power of the IGBT switch tube and the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, and the heat power of the diode is calculated according to the instantaneous heat power of the diode and the reverse recovery loss power of the diode.

[0064] S103, the junction temperature of the IGBT switch tube is calculated according to the heat power of the IGBT switch tube, and the junction temperature of the diode is calculated according to the heat power of the diode.

[0065] The junction temperature calculation method of the embodiment calculates the heat generation power of the IGBT switch tube according to the instantaneous heat generation power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, simultaneously calculates the heat generation power of the diode according to the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode, finally calculates the junction temperature of the IGBT switch tube according to the heat generation power of the IGBT switch tube, and simultaneously calculates the junction temperature of the diode according to the heat generation power of the diode, so that the junction temperature can be directly calculated through the heat generation power of the IGBT switch tube and the diode, the accuracy of temperature calculation is improved, and the junction temperature of the IGBT switch tube and the diode can be predicted in advance to facilitate high-temperature protection in advance.

[0066] Specifically, the instantaneous heat generation power of the IGBT switch tube is calculated, including: detecting the current I and the voltage U of the power device; calculating the instantaneous heat generation power of the IGBT switch tube according to the current I, the voltage U of the power device and the internal resistance R of the IGBT switch tube i The instantaneous heat generation power of the IGBT switch tube is calculated. When the instantaneous heat generation power of the IGBT switch tube is calculated according to the current I, the voltage U of the power device and the internal resistance of the IGBT switch tube, the following formula is realized:

[0067]

[0068] Wherein, P t-igbt is the instantaneous heat generation power of the IGBT switch tube, D T is the duty ratio of the IGBT switch tube, I is the current of the power device, U is the voltage U of the power device, and R i is the internal resistance of the IGBT switch tube.

[0069] When the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube are calculated, the following formula is realized:

[0070] P on =f c ·E on ;

[0071] P off =f c ·E off ;

[0072] Wherein, P on is the turn-on instantaneous loss power of the IGBT switch tube, f c is the reference frequency, E on is the turn-on instantaneous loss energy, P off is the turn-off instantaneous loss power of the IGBT switch tube, and E off is the turn-off instantaneous loss energy.

[0073] The instantaneous heat power of the diode is calculated, including: detecting the current I and voltage U of the power device; calculating the instantaneous heat power of the diode according to the current I, voltage U of the power device and the internal resistance R of the diode d The instantaneous heat power of the diode is calculated. When calculating the instantaneous heat power of the diode according to the current I, voltage U of the power device and the internal resistance R of the diode, the following formula is realized:

[0074]

[0075] Wherein, P t-diode is the instantaneous heat power of the diode, D F is the duty cycle of the diode, R d is the internal resistance of the diode.

[0076] When calculating the reverse recovery loss power of the diode, the following formula is realized:

[0077] P rr =f c ·E rr ;

[0078] Wherein, P rr is the reverse recovery loss power of the diode, E rr is the reverse recovery loss energy of the diode.

[0079] When calculating the heat power of the IGBT switch tube according to the instantaneous heat power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, the following formula is realized:

[0080] P IGBT =P t-igbt +P on +P off ;

[0081] Wherein, P IGBT is the heat power of the IGBT switch tube.

[0082] When calculating the heat power of the diode according to the instantaneous heat power of the diode and the reverse recovery loss power of the diode, the following formula is realized:

[0083] P Diode =P t-diode +P rr ;

[0084] Wherein, P Diode is the heat power of the switch tube.

[0085] When calculating the junction temperature of the IGBT switch tube according to the heat power of the IGBT switch tube, the following formula is realized:

[0086] TIGBT =P IGBT ×(R thjc-I +R thch-I )+(P IGBT +P Diode )×R thHA +T A ;

[0087] Among them, T IGBT R is the junction temperature of the IGBT switch. thjc-I R is the inter-junction-to-case thermal resistance of the IGBT. thch-I T represents the thermal resistance between the IGBT case and the heatsink, and T represents the thermal resistance between the heatsink and the surrounding environment. A For environmental temperature.

[0088] The junction temperature of a diode is calculated based on its heat dissipation power using the following formula:

[0089] T Diode =P Diode ×(R thjc-D +R thch-D )+(P IGBT +P Diode )×R thHA +T A ;

[0090] Among them, T Diode R is the junction temperature of the diode. thjc-D R is the junction-to-case thermal resistance of the diode. thch-D This represents the thermal resistance between the diode and the heat sink.

[0091] This embodiment directly integrates the temperature detection and calculation components inside the power device package, enabling local detection. Furthermore, by analyzing the source of temperature and heat, a temperature increase is inevitably caused by a large accumulation of heat, which in turn is caused by the heat generation power of the current flowing through the device. Two important parameters for heat generation are current I and voltage drop U. Using these two parameters, along with some inherent parameters of the power device, the heat generation power can be calculated in real time. Therefore, passive temperature detection can fundamentally calculate the heat generation power by detecting and calculating current and voltage, then calculate the junction temperature using the heat generation power, and finally output the junction temperature data to the control system via pin T for high-temperature protection control.

[0092] Example 2

[0093] This embodiment provides an operational circuit applied to power devices, which include IGBT switches and diodes connected in reverse parallel. Figure 3 This is a block diagram of the operational circuit according to an embodiment of the present invention, such as... Figure 3 As shown, the operational circuit includes:

[0094] The first operation unit is configured to calculate the instantaneous heat generation power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, the instantaneous heat generation power of the diode, and the reverse recovery loss power of the diode.

[0095] The second operation unit is configured to calculate the heat generation power of the IGBT switch tube according to the instantaneous heat generation power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, and to calculate the heat generation power of the diode according to the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode.

[0096] The third operation unit is configured to calculate the junction temperature of the IGBT switch tube according to the heat generation power of the IGBT switch tube, and to calculate the junction temperature of the diode according to the heat generation power of the diode.

[0097] The operation circuit of the embodiment calculates the instantaneous heat generation power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, the instantaneous heat generation power of the diode, and the reverse recovery loss power of the diode through the first operation unit. The second operation unit calculates the heat generation power of the IGBT switch tube according to the instantaneous heat generation power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, and calculates the heat generation power of the diode according to the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode. Finally, the third operation unit calculates the junction temperature of the IGBT switch tube according to the heat generation power of the IGBT switch tube, and calculates the junction temperature of the diode according to the heat generation power of the diode. The junction temperature can be directly calculated through the heat generation power of the IGBT switch tube and the diode, which improves the accuracy of temperature calculation, and the junction temperature of the IGBT switch tube and the diode can be predicted in advance to facilitate high-temperature protection in advance.

[0098] Embodiment 3

[0099] The embodiment provides a power device including an IGBT switch tube and a diode connected in reverse parallel. The power device further includes the operation circuit of the above-mentioned embodiment, which is configured to directly calculate the junction temperature through the heat generation power of the IGBT switch tube and the diode, thereby improving the accuracy of temperature calculation and realizing the prediction of the junction temperature of the IGBT switch tube and the diode in advance to facilitate high-temperature protection in advance.

[0100] Embodiment 4

[0101] The embodiment provides a computer readable storage medium having a computer program stored thereon. The program, when executed by a processor, realizes the above-mentioned junction temperature calculation method.

[0102] The apparatus embodiments described above are merely illustrative, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed to multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purposes of the embodiments.

[0103] Through the description of the above embodiments, those skilled in the art can clearly understand that the embodiments can be implemented by means of software and necessary universal hardware platforms, and of course can also be implemented by hardware. Based on such understanding, the above technical solutions can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0104] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of calculating a junction temperature applied to a power device including an IGBT switching transistor and a diode connected in antiparallel, characterized by, The method comprises: The instantaneous heat power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, the instantaneous heat power of the diode, and the reverse recovery loss power of the diode are calculated; wherein the instantaneous heat power of the IGBT switch tube is calculated by detecting the current and the voltage of the power device, and calculating the instantaneous heat power of the IGBT switch tube according to the current, the voltage of the power device and the internal resistance of the IGBT switch tube based on the formula , wherein, is the instantaneous heat power of the IGBT switch tube, is the duty cycle of the IGBT switch tube, is the current of the power device, is the voltage of the power device, is the internal resistance of the IGBT switch tube; the instantaneous heat power of the diode is calculated by detecting the current and the voltage of the power device, and calculating the instantaneous heat power of the diode according to the current, the voltage of the power device and the internal resistance of the diode based on the formula , wherein, is the instantaneous heat power of the diode, is the duty cycle of the diode, is the internal resistance of the diode. calculating the heat generation power of the IGBT switch according to the instantaneous heat generation power of the IGBT switch, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch, and calculating the heat generation power of the diode according to the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode; calculating the junction temperature of the IGBT switch according to the heat generation power of the IGBT switch, and calculating the junction temperature of the diode according to the heat generation power of the diode.

2. The method of claim 1, wherein, When calculating the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch, the following formula is used: wherein, is the turn-on transient loss power of the IGBT switch, is the reference frequency, is the turn-on transient loss energy, is the turn-off transient loss power of the IGBT switch, is the turn-off transient loss energy.

3. The method of claim 1, wherein, When calculating the reverse recovery loss power of the diode, the following formula is used: wherein, is the diode reverse recovery loss power, is the diode reverse recovery loss energy.

4. The method of claim 1, wherein, When calculating the heat generation power of the IGBT switch according to the instantaneous heat generation power of the IGBT switch, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch, the following formula is used: = + + ; wherein, Pheat is the heat power of the IGBT switch.

5. The method of claim 1, wherein, When calculating the heat generation power of the diode according to the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode, the following formula is used: = + ; wherein, Pheat is the heat power of the switch tube.

6. The method of claim 1, wherein, When calculating the junction temperature of the IGBT switch according to the heat generation power of the IGBT switch, the following formula is used: ; wherein, Tj is the junction temperature of the IGBT switch, Rthjc is the IGBT junction-to-case thermal resistance, Rthcs is the IGBT case-to-sink thermal resistance, Rthsk is the sink-to-ambient thermal resistance, Tamb is the ambient junction temperature.

7. The method of claim 1, wherein, When calculating the junction temperature of the diode according to the heat generation power of the diode, the following formula is used: ; wherein, Tj is the junction temperature of the diode, Rth is the thermal resistance between the diode junction and the case, Rsa is the thermal resistance between the diode and the heat sink.

8. An operation circuit applied to a power device including an IGBT switching tube and a diode in anti-parallel, characterized in that, The operation circuit comprises: The first operation unit is configured to calculate the instantaneous heat power of the IGBT switch tube, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch tube, the instantaneous heat power of the diode, and the reverse recovery loss power of the diode; wherein the instantaneous heat power of the IGBT switch tube is calculated by detecting the current and the voltage of the power device, and calculating the instantaneous heat power of the IGBT switch tube according to the current, the voltage of the power device, and the internal resistance of the IGBT switch tube based on the formula , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R is the internal resistance of the IGBT switch tube. , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R is the internal resistance of the IGBT switch tube. , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R is the internal resistance of the IGBT switch tube. , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R is the internal resistance of the IGBT switch tube. , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R is the internal resistance of the IGBT switch tube. , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R is the internal resistance of the IGBT switch tube. , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R is the internal resistance of the IGBT switch tube. , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R is the internal resistance of the IGBT switch tube. , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the power device, U is the voltage of the power device, and R is the internal resistance of the IGBT switch tube. , wherein P is the instantaneous heat power of the IGBT switch tube, D is the duty cycle of the IGBT switch tube, I is the current of the a second operation unit configured to calculate the heat generation power of the IGBT switch according to the instantaneous heat generation power of the IGBT switch, the turn-on instantaneous loss power and the turn-off instantaneous loss power of the IGBT switch, and to calculate the heat generation power of the diode according to the instantaneous heat generation power of the diode and the reverse recovery loss power of the diode; a third operation unit configured to calculate the junction temperature of the IGBT switch according to the heat generation power of the IGBT switch, and to calculate the junction temperature of the diode according to the heat generation power of the diode.

9. A power device comprising an IGBT switching transistor and a diode connected in antiparallel, characterized by The power device further comprises the operation circuit of claim 8.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program, when executed by a processor, implements the method of any one of claims 1 to 7. The program, when executed by a processor, implements the method of any one of claims 1 to 7.

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