A method for calculating the loss and junction temperature of power semiconductor switching devices

Abstract

The present invention discloses a method, storage medium, and electronic device for calculating the loss and junction temperature of a power semiconductor switching device. The method comprises: obtaining the output current waveform of a single semiconductor switching device under stable operating conditions based on a model of an inverter composed of semiconductor switching devices to be tested, and determining various parameters for calculating the loss of the single semiconductor switching device under stable operating conditions based on the output current waveform; determining the loss of the semiconductor switching device at an initial junction temperature based on the various parameters; and inferring the junction temperature of the semiconductor switching device using the heat sink table temperature of the inverter and the loss of the semiconductor switching device. If the difference between the inferred junction temperature and the initial junction temperature does not meet a convergence condition, setting the initial junction temperature equal to the inferred junction temperature, iteratively recalculating the loss of the semiconductor switching device until the convergence condition is met, and outputting the loss and inferred junction temperature results that meet the convergence condition as steady-state results.

Description

Technical Field

[0001] The present invention relates to the technical field of power semiconductor switching devices, and in particular to a method, a storage medium and an electronic device for calculating the loss and junction temperature of a power semiconductor switching device. Background Art

[0002] During continuous operation, power semiconductor devices must maintain a safe junction temperature to ensure proper function. Otherwise, overheating and failure are likely to occur. Junction temperature is directly related to device losses during switching. Therefore, understanding the junction temperature and losses of a device under specific operating conditions is crucial.

[0003] Traditional direct measurement methods for junction temperature typically use thermal imaging or thermocouple placement, but these methods are not well-suited for device products in engineering practice. Another approach is to indirectly calculate junction temperature and losses through simulation, offering advantages such as simplicity and portability. However, obtaining highly accurate results from simulation calculations is difficult, requiring support from highly accurate measured dynamic and static data, as well as the use of a sound algorithm model. Summary of the Invention

[0004] To address the above issues, the present invention provides a simulation method for calculating the junction temperature and losses of a power semiconductor switching device during stable operation in an inverter device. Specifically, a method for calculating the losses and junction temperature of a power semiconductor switching device, as well as corresponding storage media and electronic devices, is provided.

[0005] According to a first aspect, the present invention provides a method for calculating the loss and junction temperature of a power semiconductor switching device, comprising:

[0006] Construct a model of the inverter consisting of the semiconductor switching devices to be tested;

[0007] Obtaining an output current waveform of a single semiconductor switching device under a stable operating condition according to a model of the inverter, and determining various parameters for calculating the loss of the single semiconductor switching device under the stable operating condition according to the output current waveform;

[0008] Determining the loss of the semiconductor switch device at an initial junction temperature based on the various parameters;

[0009] The junction temperature of the semiconductor switching device is reversed using the heat sink table temperature of the inverter and the loss of the semiconductor switching device. If the difference between the reversed junction temperature and the initial junction temperature does not meet a preset convergence condition, the initial junction temperature is set equal to the reversed junction temperature, and the loss of the semiconductor switching device is iteratively recalculated until the convergence condition is met.

[0010] When the convergence condition is satisfied, the loss of the semiconductor switching device and the inversely calculated junction temperature are output as steady-state results.

[0011] In some embodiments of the present invention, the step of constructing a model of an inverter composed of semiconductor switching devices to be tested includes:

[0012] Obtaining measured dynamic and static data of semiconductor switching devices, and determining operating parameters of an inverter composed of the semiconductor switching devices under a proposed stable operating condition; the operating parameters include fundamental frequency;

[0013] An inverter model is constructed based on the measured dynamic and static data of the semiconductor switching device and the operating parameters of the inverter under the proposed stable working conditions.

[0014] In some embodiments of the present invention, the loss of the semiconductor switching device is the switching loss P sw , conduction loss P cond , reverse conduction loss P cond_diode and reverse recovery loss P rec sum.

[0015] In some embodiments of the present invention, the various parameters include the starting point and ending point of the chopping half-cycle of the semiconductor switching device, the starting point and ending point of the freewheeling half-cycle, the on-current value corresponding to each on-time and the off-current value corresponding to each off-time.

[0016] In some embodiments of the present invention,

[0017] The switching loss is calculated as:

[0018] P sw =f b ·(∑E on (I on ,T)+∑E off (I off ,T))

[0019] Among them, E on (I on , T) is the turn-on loss energy corresponding to the current of a single turn-on process in the positive half cycle of the semiconductor switching device chopping, which is calculated by the junction temperature T and the conduction current I on Obtained after quadratic interpolation; E off (I off , T) is the turn-off loss energy corresponding to the current of a single turn-off process in the positive half cycle of the semiconductor switching device chopping, which is calculated by the junction temperature T and the turn-off current I off Obtained after quadratic interpolation;

[0020] E on (Ion ,T) and E off (I off , T) are accumulated to get the switching loss in a single fundamental wave cycle, and then the switching loss in a single fundamental wave cycle is multiplied by the fundamental wave frequency f b Get the chopper switching loss P sw ;

[0021] The conduction loss is calculated as:

[0022] P cond =f b ·∫I0·V ds (I0,T)dt

[0023] Among them, I0 is the current waveform in half cycle of chopping, V ds (I0, T) is the on-state voltage drop obtained after the secondary interpolation of the junction temperature T and the current I0. It is integrated over the entire chopping cycle and then multiplied by the fundamental frequency f b The chopping conduction loss P is obtained cond ;

[0024] The reverse conduction loss is calculated as follows:

[0025] P cond_diode =f b ·∫I0·V sd (I0,T)dt

[0026] Among them, I0 is the current waveform in the half cycle of freewheeling, V sd (I0, T) is the on-state voltage drop obtained after the secondary interpolation of the junction temperature T and the current I0. It is integrated over the entire freewheeling cycle and then multiplied by the fundamental frequency f b Get the freewheeling reverse conduction loss P cond_diode ;

[0027] The reverse recovery loss is calculated as follows:

[0028] P rec =f b ·∑E rec (I on ,T)

[0029] Among them, E rec (I on , T) is the diode reverse recovery loss energy corresponding to the current of a single turn-on process in the half cycle when the tube is chopped, which is calculated by the junction temperature T and the conduction current I on Obtained after quadratic interpolation;

[0030] E rec (I on,T) is accumulated to obtain the reverse recovery loss within a single fundamental wave cycle, and then the reverse recovery loss within a single fundamental wave cycle is multiplied by the fundamental wave frequency f b Get the freewheeling reverse recovery loss P sw .

[0031] In some embodiments of the present invention, the junction temperature of the semiconductor switching device is inversely calculated using the heat sink table temperature of the inverter and the loss of the semiconductor switching device according to the following formula:

[0032] T n+1 =T plate +P n ·R jc

[0033] Where Rjc is the thermal resistance between the junction and case of the device, P n is the loss of the semiconductor switching device, T plate is the radiator surface temperature, T n+1 The junction temperature is deduced in reverse.

[0034] In some embodiments of the present invention, the convergence condition is that the difference between the inversely calculated junction temperature and the initial junction temperature is less than a given temperature difference threshold.

[0035] In some embodiments of the present invention, the given temperature difference threshold is 1 degree Celsius.

[0036] According to a second aspect, the present invention provides a storage medium having program code stored thereon. When the program code is executed by a processor, the method for calculating the loss and junction temperature of a power semiconductor switching device as described above is implemented.

[0037] According to a third aspect, the present invention provides an electronic device comprising a memory and a processor, wherein the memory stores program code that can be run on the processor, and when the program code is executed by the processor, the method for calculating the loss and junction temperature of a power semiconductor switching device as described above is implemented.

[0038] Compared with the prior art, one or more embodiments of the above solutions of the present invention may have the following advantages or beneficial effects:

[0039] 1) The technical solution of the present invention uses the measured dynamic and static performance parameters of the device and the actual operating heat sink table temperature as a benchmark, and iteratively calculates the steady-state junction temperature and loss. This can effectively prevent possible overheating failure and damage of the device in advance, and can provide strong data support for device performance research and inverter system parameter selection.

[0040] 2) The technical solution of the present invention only needs to import the test results of dynamic and static experiments, input the operating parameters of stable operation and the measured table temperature, and then perform simulation calculations. This eliminates the real-time current and voltage data acquisition in general solutions, simplifies the workload, and obtains results more conveniently and quickly.

[0041] 3) Compared with the general fixed junction temperature simulation algorithm, the technical solution of the present invention is based on the measured dynamic and static data at multiple temperatures, and performs cyclic interpolation and iteration on the junction temperature and loss until steady-state convergence. In comparison, the simulation results are more accurate.

[0042] 4) Compared with the simulation algorithm based on the data in the data sheet, the technical solution of the present invention uses all the measured data and the measured table temperature, which is more in line with the working conditions at the time and therefore has higher accuracy.

[0043] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the structures particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The scope of the present disclosure may be better understood by reading the following detailed description of exemplary embodiments in conjunction with the accompanying drawings, which include:

[0045] Figure 1 A flow chart of the method shown in the first embodiment of the present invention is shown. DETAILED DESCRIPTION

[0046] In order to make the objectives, technical solutions and advantages of the present invention clearer, the implementation method of the present invention will be described in detail below with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0047] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0048] Example 1

[0049] like Figure 1 As shown, this embodiment provides a method for calculating the loss and junction temperature of a power semiconductor switching device, which mainly includes the following steps:

[0050] Read the measured dynamic and static data of semiconductor switching devices;

[0051] Defining operating parameters of the inverter composed of the semiconductor switching devices under a predetermined stable operating condition; the operating parameters at least include a fundamental frequency;

[0052] Constructing an inverter model based on measured dynamic and static data of semiconductor switching devices and operating parameters of the inverter under a proposed stable operating condition; obtaining an output current waveform of a single semiconductor switching device under the stable operating condition based on the inverter model; and determining various parameters for calculating the loss of the single semiconductor switching device under the stable operating condition based on the output current waveform;

[0053] Determining the loss of the semiconductor switch device at an initial junction temperature based on the various parameters;

[0054] Reversely inferring the junction temperature of the semiconductor switching device using the heat sink table temperature of the inverter and the loss of the semiconductor switching device;

[0055] If the difference between the inversely calculated junction temperature and the initial junction temperature does not meet a preset convergence condition, the initial junction temperature is set equal to the inversely calculated junction temperature, and the iteration is returned to recalculate the loss of the semiconductor switching device until the convergence condition is met;

[0056] When the convergence condition is satisfied, the loss of the semiconductor switching device and the inversely calculated junction temperature are output as steady-state results.

[0057] It should be noted that the present invention is primarily applicable to the simulation of junction temperature and loss of power semiconductor devices in inverters operating under conditions where they continuously and stably output sinusoidal current. The power devices described include various common fully controlled switching devices such as silicon-based MOSFETs, IGBTs, and silicon carbide-based MOSFETs.

[0058] Here, the fully controlled switching device can be a single integrated switch and antiparallel diode. However, the technical solution of the present invention also applies to chips with integrated body diodes, but the simulation results are the losses and junction temperature of the chip. If the switch and freewheeling diode are separate, the average junction temperature and total losses of the switch and freewheeling diodes are used.

[0059] Among them, the switching tube loss is mainly divided into conduction loss and switching loss:

[0060] For conduction loss, it can be obtained by integrating the product of the instantaneous value of the current flowing through the device and the corresponding conduction voltage drop at that moment, and then dividing it by the corresponding time to obtain the corresponding average conduction loss;

[0061] For switching loss, it is necessary to obtain it by interpolating the current value and the corresponding loss energy value, and accumulate it according to the switching cycle.

[0062] Among them, the freewheeling diode loss is mainly divided into reverse conduction loss and reverse recovery loss:

[0063] The reverse conduction loss can be obtained by an integration method similar to the forward conduction loss mentioned above.

[0064] For reverse recovery loss, the corresponding loss value can be found through current interpolation in the same way as the switching loss mentioned above, and the reverse recovery loss value can be obtained by accumulating it over the switching cycle;

[0065] The total loss of the semiconductor switching device can be equal to the sum of the switching loss and conduction loss of the above-mentioned switch tube and the reverse conduction loss and reverse recovery loss of the freewheeling tube.

[0066] It's important to note that all of the aforementioned loss values ​​fluctuate with temperature. Therefore, when integrating or accumulating losses, the temperature variable must be incorporated. Adjust the corresponding loss values ​​as the junction temperature changes to ensure the accuracy of the algorithm model.

[0067] Example 2

[0068] The working principle of the technical solution of the present invention is further explained below with reference to specific examples.

[0069] In this embodiment, based on the idea described in Example 1, the core idea of ​​the simulation program developed is to calculate the loss based on an arbitrary initial temperature input, and then match this loss with the measured radiator table temperature to infer the corresponding junction temperature. If the difference between the two junction temperatures converges to within 1°C, it means that the steady state has been reached. If the convergence condition is not met, the iteration continues until stability is achieved.

[0070] The specific process is as follows.

[0071] ① Read the measured dynamic and static data of the device and set it as a global variable to facilitate direct calling of subsequent functions.

[0072] ② Define the stable operating conditions of the inverter, including the working parameters of the device under stable operating conditions, such as the switching frequency f sw , fundamental frequency f b , output phase current effective value I ac , DC bus voltage U d , power factor cos_fai and modulation ratio m_inv; and the heat sink surface temperature T plate .

[0073] ③ Use the above data to build an inverter model, and according to the inverter model, derive the waveform of the output current of a single device changing with time, referred to as the output current waveform. Then process this waveform and extract key information points, including the starting and ending points of the chopping half-cycle, the starting and ending points of the freewheeling half-cycle, the current value corresponding to each turn-on moment, and the turn-off current value at each turn-off moment.

[0074] ④ Define a function for calculating the loss based on an arbitrary junction temperature input. For convenience, this function is named "jt2ploss". Its specific implementation is as follows:

[0075] a. Give the function input variables and call global variable data for calculation.

[0076] b. The specific calculation method of the switching loss of the chopper tube is:

[0077] P sw =f b ·(∑E on (I on ,T)+∑E off (I off ,T))

[0078] Among them, E on (I on , T) is the turn-on loss energy corresponding to the current of a single turn-on process in the positive half cycle of the switching device chopping, which is calculated by the junction temperature T and the turn-on current I on Obtained after quadratic interpolation; E off (I off , T) is the turn-off loss energy corresponding to the current of a single turn-off process in the positive half cycle of the switching device chopping, which is calculated by the junction temperature T and the turn-off current I off Obtained after quadratic interpolation.

[0079] E on (I on ,T) and E off (I off , T) are accumulated to obtain the switching loss in a single fundamental wave cycle, and then the switching loss in a single fundamental wave cycle is multiplied by the fundamental wave frequency f b The total switching loss P can be obtained sw .

[0080] c. The specific calculation method of the conduction loss of the chopper tube is:

[0081] P cond =f b ·∫I0·V ds (I0,T)dt

[0082] Among them, I0 is the current waveform in half cycle of chopping, V ds (I0, T) is the on-state voltage drop obtained after the secondary interpolation of current I0 and junction temperature T, which is integrated over the entire chopping cycle and then multiplied by the fundamental frequency f b The conduction loss P can be obtained cond In the specific implementation method of integration, the step size of I0 data can be used as the integration time interval to perform numerical integration to calculate the loss.

[0083] d. The specific calculation method of the reverse conduction loss of the freewheeling tube is:

[0084] P cond_diode =f b ·∫I0·V sd (I0,T)dt

[0085] Among them, I0 is the current waveform in the half cycle of freewheeling, V sd (I0, T) is the on-state voltage drop obtained after the secondary interpolation of current I0 and junction temperature T, which is integrated over the entire freewheeling cycle and then multiplied by the fundamental frequency f b The conduction loss P can be obtained cond_diode In the specific implementation method of integration, the step size of I0 data can be used as the integration time interval to perform numerical integration to calculate the loss.

[0086] e. The specific calculation method of the reverse recovery loss of the freewheeling tube is:

[0087] P rec =f b ·∑E rec (I on ,T)

[0088] Among them, E rec (I on , T) is the diode reverse recovery loss energy corresponding to the current of a single turn-on process in the half cycle when the tube is chopped, which is calculated by the junction temperature T and the turn-on current I on After the quadratic interpolation, E rec (I on ,T) is accumulated to obtain the reverse recovery loss within a single fundamental wave cycle, and then the reverse recovery loss within a single fundamental wave cycle is multiplied by the fundamental wave frequency f b The total switching loss P can be obtained sw .

[0089] f. Add the above four losses as the total loss P loss .

[0090] P loss =P sw +P cond +Pcond_diode +P rec

[0091] ⑤ Set any initial junction temperature T0, call the function jt2ploss, and perform loop iteration.

[0092] The specific implementation method is: based on the input of any initial junction temperature T0, the loss is calculated, and then this loss is matched with the measured heat sink table temperature to infer the corresponding junction temperature. If the difference between the inferred junction temperature and the initial junction temperature converges to within 1°C, it means that the temperature has reached a steady state. If it cannot converge to within 1°C, the initial junction temperature is set to be equal to the inferred junction temperature, and the loss calculation is continued iteratively until stability is achieved.

[0093] In this embodiment, the convergence condition is 1°C, which can of course be adjusted according to actual conditions. If you want to obtain a more accurate result, you can further reduce this value.

[0094] The calculation formula for inversely calculating the junction temperature of the semiconductor switching device using the heat sink table temperature of the inverter and the loss of the semiconductor switching device is as follows:

[0095] T n+1 =T plate +P n ·R jc

[0096] Among them, R jc is the thermal resistance between the device and the case, P n is the loss of the semiconductor switching device, T plate is the radiator surface temperature, T n+1 The junction temperature is deduced in reverse.

[0097] If the convergence condition is met, T n+1 and P n Output as the final steady-state result.

[0098] The present invention uses dynamic data measured in a real circuit environment when the device is operating at different temperatures and static data of the device as a basis, and adopts an interpolation loop iteration method to calculate the steady-state junction temperature and loss of the device, so as to eliminate the risk of over-temperature failure during device operation as much as possible. It also provides a corresponding quantifiable basis for selecting the optimal operating conditions and matching the heat sink for the application of the device in the converter.

[0099] Example 3

[0100] According to an embodiment of the present invention, a storage medium is further provided, on which program code is stored. When the program code is executed by a processor, the method for calculating the loss and junction temperature of a power semiconductor switching device as described in any of the above embodiments is implemented.

[0101] Example 4

[0102] According to an embodiment of the present invention, an electronic device is also provided, which includes a memory and a processor, wherein the memory stores program code that can be run on the processor, and when the program code is executed by the processor, the method for calculating the loss and junction temperature of a power semiconductor switching device as described in any of the above embodiments is implemented.

[0103] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is merely a logical functional division. In actual implementation, other division methods may be used, such as combining or integrating multiple units or components into another system, or ignoring or not implementing certain features.

[0104] It should be noted that the method of the embodiment of the present invention can be performed by a single device, such as a computer or server. The method of this embodiment can also be applied in a distributed scenario, where multiple devices cooperate to perform the method. In such a distributed scenario, one of the multiple devices may only perform one or more steps of the method of the embodiment of the present invention, and the multiple devices will interact with each other to complete the method.

[0105] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0106] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0107] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0108] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing module, or each unit may exist physically separately, or two or more units may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or in the form of software functional modules. If the integrated modules are implemented in the form of software functional modules and sold or used as independent products, they may also be stored in a computer-readable storage medium.

[0109] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0110] Although the embodiments disclosed herein are as described above, the contents described herein are merely embodiments for facilitating understanding of the present invention and are not intended to limit the present invention. Any person skilled in the art may make any modifications and variations in the form and details of the embodiments without departing from the spirit and scope of the present invention. However, the scope of protection of the present invention shall remain subject to the scope defined by the appended claims.

Claims

1. A method for calculating the loss and junction temperature of a power semiconductor switching device, comprising: Construct a model of the inverter consisting of the semiconductor switching devices to be tested; Obtaining an output current waveform of a single semiconductor switching device under a stable operating condition according to a model of the inverter, and determining various parameters for calculating the loss of the single semiconductor switching device under the stable operating condition according to the output current waveform; Determining the loss of the semiconductor switch device at an initial junction temperature based on the various parameters; The junction temperature of the semiconductor switching device is inversely calculated using the heat sink table temperature of the inverter and the loss of the semiconductor switching device. If the difference between the inversely calculated junction temperature and the initial junction temperature does not meet a preset convergence condition, the initial junction temperature is set equal to the inversely calculated junction temperature, and the loss of the semiconductor switching device is recalculated using an interpolation loop iteration method until the convergence condition is met. When the convergence condition is satisfied, the loss of the semiconductor switching device and the inversely calculated junction temperature are output as steady-state results.

2. The method for calculating the loss and junction temperature of a power semiconductor switching device according to claim 1, wherein: Build a model of the inverter consisting of the semiconductor switching devices to be tested, including: Obtaining measured dynamic and static data of semiconductor switching devices, and determining operating parameters of an inverter composed of the semiconductor switching devices under a proposed stable operating condition; the operating parameters include fundamental frequency; An inverter model is constructed based on the measured dynamic and static data of the semiconductor switching device and the operating parameters of the inverter under the proposed stable working conditions.

3. The method for calculating the loss and junction temperature of a power semiconductor switching device according to claim 2, wherein: The loss of the semiconductor switching device is the switching loss P sw , conduction loss P cond , reverse conduction loss P cond_diode and reverse recovery loss P rec sum.

4. The method for calculating the loss and junction temperature of a power semiconductor switching device according to claim 3, wherein: The various parameters include the starting point and ending point of the chopping half cycle of the semiconductor switching device, the starting point and ending point of the freewheeling half cycle, the on-current value corresponding to each on-time and the off-current value corresponding to each off-time.

5. The method for calculating the loss and junction temperature of a power semiconductor switching device according to claim 4, wherein: The switching loss is calculated as: P sw =f b ·(ΣE on (I on ,T)+ΣE off (I off ,T)) Among them, E on (I on , T) is the turn-on loss energy corresponding to the current of a single turn-on process in the positive half cycle of the semiconductor switching device chopping, which is calculated by the junction temperature T and the conduction current I on Obtained after quadratic interpolation; E off (I off , T) is the turn-off loss energy corresponding to the current of a single turn-off process in the positive half cycle of the semiconductor switching device chopping, which is calculated by the junction temperature T and the turn-off current I off Obtained after quadratic interpolation; E on (I on ,T) and E off (I off , T) are accumulated to get the switching loss in a single fundamental wave cycle, and then the switching loss in a single fundamental wave cycle is multiplied by the fundamental wave frequency f b Get the chopper switching loss P sw ; The conduction loss is calculated as: P cond =f b ·∫I0·V ds (I0,T)dt Among them, I0 is the current waveform in half cycle of chopping, V ds (I0, T) is the on-state voltage drop obtained after the secondary interpolation of the junction temperature T and the current I0. It is integrated over the entire chopping cycle and then multiplied by the fundamental frequency f b The chopping conduction loss P is obtained cond ; The reverse conduction loss is calculated as follows: P cond_diode =f b ·∫I0·V sd (I0,T)dt Among them, I0 is the current waveform in the half cycle of freewheeling, V sd (I0, T) is the on-state voltage drop obtained after the secondary interpolation of the junction temperature T and the current I0. It is integrated over the entire freewheeling cycle and then multiplied by the fundamental frequency f b Get the freewheeling reverse conduction loss P cond_diode ; The reverse recovery loss is calculated as follows: P rec =f b ·∑E rec (I on ,T) Among them, E rec (I on , T) is the diode reverse recovery loss energy corresponding to the current of a single turn-on process in the half cycle when the tube is chopped, which is calculated by the junction temperature T and the conduction current I on Obtained after quadratic interpolation; E rec (I on ,T) is accumulated to obtain the reverse recovery loss within a single fundamental wave cycle, and then the reverse recovery loss within a single fundamental wave cycle is multiplied by the fundamental wave frequency f b Get the freewheeling reverse recovery loss P sw .

6. The method for calculating the loss and junction temperature of a power semiconductor switching device according to claim 1, wherein: According to the following formula, the junction temperature of the semiconductor switching device is reversely calculated using the heat sink table temperature of the inverter and the loss of the semiconductor switching device: T n+1 =T plate +P n ·R jc Among them, R jc is the thermal resistance between the device and the case, P n is the loss of the semiconductor switching device, T plate is the radiator surface temperature, T n+1 The junction temperature is deduced in reverse.

7. The method for calculating the loss and junction temperature of a power semiconductor switching device according to claim 6, wherein: The convergence condition is that the difference between the inversely calculated junction temperature and the initial junction temperature is less than a given temperature difference threshold.

8. The method for calculating the loss and junction temperature of a power semiconductor switching device according to claim 7, wherein: The given temperature difference threshold is 1 degree Celsius.

9. A storage medium having program code stored thereon, characterized in that: When the program code is executed by a processor, the method for calculating the loss and junction temperature of a power semiconductor switching device according to any one of claims 1 to 8 is implemented.

10. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a program code that can be run on the processor, and when the program code is executed by the processor, the method for calculating the loss and junction temperature of a power semiconductor switching device according to any one of claims 1 to 8 is implemented.

Images