A time-domain evaluation method for switching transient model based on safe working area of IGBT device

Abstract

The present invention belongs to the field of semiconductor technology, and is specifically a time-domain evaluation method for a switching transient model based on the safe operating area of ​​an IGBT device. This method solves the problem of a lack of quantitative indicators for time-domain evaluation of a switching transient model, including: S1: obtaining the voltage V obtained from the simulation model test and actual device test during the IGBT device turn-on and turn-off process. ce and current I c ; S2: According to the voltage V in S1 ce and current I c , get the voltage V of simulation model test and actual device test ce With current I c The phase plane curve is composed of the following: S3: The accuracy of the switching transient model is determined based on the overlap between the area enclosed by the simulated curve and the area enclosed by the measured curve. This invention proposes clear quantitative indicators to enhance the evaluation capability of IGBT transient models, providing better support for the full-operating design and selection of devices such as inverters, improving design efficiency while reducing R&D cycles and costs.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and in particular is a time domain evaluation method for a switching transient model based on an IGBT device safe operating area. Background Art

[0002] The semiconductor device, IGBT, boasts advantages such as fully controlled switching, high withstand voltage, high current capability, high switching frequency, and low drive power, making it the most widely used power electronic switching device in medium- and high-power applications such as inverters. IGBTs are most susceptible to damage during transient switching. Numerous studies have investigated the normal transient switching process of IGBTs through simulation modeling and analysis, comparing the overlap between simulated and measured voltage and current waveforms during turn-on and turn-off. However, no suitable quantitative metrics exist to assess the accuracy of these models.

[0003] To prevent device failure during normal IGBT switching, the IGBT's safe operating area (SAA) must be adhered to. This includes the forward-biased SAA, reverse-biased SAA, and short-circuit SAA. To this end, this application combines the device's forward- and reverse-biased SAA with the voltage and current waveforms during switching transients to form evaluation metrics within the device's SAA.

[0004] The IGBT device transient model is used to analyze the voltage and current stress changes during the turn-on and turn-off processes of an IGBT device. When this device model is used to conduct full-operation simulation tests of devices such as inverters, the electrical stress changes of the IGBT device under various operating conditions can be better analyzed, thus providing guidance for IGBT device selection and circuit design during device design. Currently, there is no quantitative indicator for evaluating the accuracy of IGBT device transient models. Most literature simply compares the peak and slope of the voltage and current curves during the turn-on and turn-off processes. This non-quantitative comparison is sufficient for the stable operation of inverter devices, but it does not provide a comprehensive and intuitive reflection of the transient model's accuracy when studying the switching characteristics of IGBT devices under all inverter operating conditions, especially during transient transitions. Summary of the Invention

[0005] Aiming at the problem that there is no quantitative index in the time domain evaluation of a switch transient model, the present invention provides a time domain evaluation method for a switch transient model based on a safe operating area of ​​an IGBT device.

[0006] The present invention adopts the following technical solution: a time domain evaluation method for a switching transient model based on the safe operating area of ​​an IGBT device, comprising:

[0007] S1: Get the voltage V obtained from the simulation model test and actual device test during the IGBT device turn-on and turn-off process ce and current I c ;

[0008] S2: According to the voltage V in S1 ce and current I c , get the voltage V of simulation model test and actual device test ce With current I c The phase plane curve of the composition;

[0009] S3: Enclosed area according to simulation curve The area enclosed by the measured curve The accuracy of the switching transient model is determined by the overlap degree of the switching transient model.

[0010] In some embodiments, the phase plane curve in step S2 includes: a phase plane curve of the IGBT device in a turn-on transient state and a phase plane curve of the turn-off transient state.

[0011] In some embodiments, in step S3, the area enclosed by the simulation curve is The area enclosed by the measured curve The higher the overlap, the higher the accuracy of the switching transient model, and the more consistent it is with the actual switching characteristics of the device.

[0012] In some embodiments, step S3 specifically includes:

[0013] S31: Calculate the instantaneous overlap of the opening ;

[0014] S32: Calculate the transient closing degree of the shutdown ;

[0015] S33: The accuracy of the final device transient model P, .

[0016] In some embodiments, step S31 includes: taking multiple intersection points of the two curves of the simulation test and the actual test in the phase plane curve of the IGBT device turn-on process, and respectively adding V ce The axis is perpendicular to the ground, and multiple areas are divided into S1, S2, and S n ;

[0017] The top boundary of each region is the curve with the lower absolute value in the simulation test and the actual test, which is consistent with the bottom V ce The area enclosed by the coordinate axis and the left and right boundaries is the overlapping area of ​​the region. Finally, the overlapping area of ​​each region is added together to get the overlapping area of ​​the two curves. The overlap area divided by the area enclosed by the actual test curve is the opening transient overlap degree. , .

[0018] In some embodiments, step S32 includes: taking multiple intersection points of the two curves of the simulation test and the actual test in the phase plane curve of the shutdown process, and respectively adding them to I c The axis is perpendicular to the ground, and multiple areas are divided into S1, S2, and S n ;

[0019] The right boundary of each area is the curve with the lower absolute value in the simulation test and the actual test, which is consistent with the left I c The area enclosed by the coordinate axis and the upper and lower boundaries is the overlapping area of ​​the region. Finally, the overlapping area of ​​each region is added together to get the overlapping area of ​​the two curves. The overlap area divided by the area enclosed by the actual test curve is the turn-off transient overlap degree. , .

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention aims to solve the problem that there is no quantitative index in the time domain evaluation of the switching transient model. It proposes to use the collector-emitter voltage V during the turn-on and turn-off process based on the safe working area of ​​the IGBT device. ce and collector current I c The overlap of the composed curve areas is used as a quantitative indicator for the consistency test of the transient model switching characteristic curve and the measured switching characteristic curve.

[0022] Compared with the current method of manually comparing switching characteristic curves, the present invention proposes clear quantitative indicators, improves the evaluation ability of IGBT transient models, provides better support for the full-operating-condition design and selection of devices such as inverters, improves design efficiency, and reduces R&D cycles and costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The simulated and measured voltage and current waveforms during the turn-on transient process of an IGBT device provided by the present invention;

[0024] Figure 2 The simulated and measured voltage and current waveforms during the turn-off transient process of an IGBT device provided by the present invention;

[0025] Figure 3 The invention provides a method for dividing the overlapping area of ​​the opening transient process;

[0026] Figure 4 The method for dividing the overlap area of ​​the shutdown transient process provided by the present invention;

[0027] Figure 5 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] A time-domain evaluation method for a switching transient model based on an IGBT device safe operating area includes:

[0030] S1: Get the voltage V obtained from the simulation model test and actual device test during the IGBT device turn-on and turn-off process ce and current I c .

[0031] After building and opening a transient simulation model in mathematical calculation software or power electronics simulation software, given specific working conditions, the probe model in the software can be used to obtain the corresponding voltage and current signals.

[0032] In the IGBT turn-on transient simulation model, the turn-on and turn-off are controlled by the IGBT base, which can be understood as an IGBT behavior switch, and the voltage V is measured during the switching process. ce , current signal I c .

[0033] Figure 1 The figure shows the transient curve of the IGBT device during the turn-on process, including the V curve obtained from the simulation model test and the actual device test. ce and I c . Figure 2 The figure shows the transient curve of the IGBT device during the turn-off process, including the V curve obtained from the simulation model test and the actual device test. ce and I c .

[0034] S2: According to the voltage V in S1 ce and current I c , get the voltage V of simulation model test and actual device test ce With current I c The phase plane curve.

[0035] A phase plane curve is a continuous curve formed by the continuous change of two sets of physical quantities in a one-to-one relationship on a rectangular coordinate system over a period of time, with each point corresponding to a unique moment in time. This method is often used in principles such as power and automatic control. Its horizontal and vertical coordinates are usually the first-order and second-order signals of specific physical quantities, used to describe the movement and change of physical quantities. This method is used in the present invention to transform the single high-order signal in the phase plane curve into two sets of signals, the voltage and current, based on the electrical characteristics of the IGBT.

[0036] The phase plane curve refers to a continuous curve formed by the continuous change process of two sets of physical quantities that correspond one to one in a rectangular coordinate system over a period of time. Each point corresponds to a unique moment.

[0037] In the present invention, the phase plane curve during the IGBT turn-off transient process specifically refers to a continuous curve formed by the voltage and current corresponding to each other in time within the reverse bias safe operating area of ​​the IGBT device.

[0038] S3: Enclosed area according to simulation curve The area enclosed by the measured curve The accuracy of the switching transient model is determined by the overlap degree of the switching transient model.

[0039] Figure 3 The device is in the forward bias safe operating area, Figure 1 V obtained under curve simulation test and actual test conditions ce with I c The phase plane curve is composed of the forward bias safe operating area of ​​the device, which consists of the AB segment (collector maximum rated current limit area), the BC segment (collector power consumption limit area), the CD segment (secondary breakdown limit area) and the DE segment (collector-emitter maximum rated voltage limit area). The trajectory of the phase plane curve that does not exceed this area is safe for device failure. Under this premise, the present invention proposes that the simulation curve encloses an area of The area enclosed by the measured curve The higher the overlap, the higher the accuracy of the switching transient model, and the more it conforms to the actual switching characteristics of the device.

[0040] Figure 3 The figure shows the method for solving the overlap degree of the opening transient process. In the phase plane curve of the opening process, multiple intersection points of the two curves of the simulation test and the actual test are taken, and the V ce The axis is perpendicular to the ground, and multiple areas are divided into S1, S2, and S n The top boundary of each region is the curve with the lower absolute value in the simulation test and the actual test, which is consistent with the bottom V ceThe area enclosed by the coordinate axis and the left and right boundaries is the overlapping area of ​​the region. Finally, the overlapping area of ​​each region is added together to get the overlapping area of ​​the two curves. The overlap area divided by the area enclosed by the actual test curve is the opening transient overlap degree. .

[0041] (1)

[0042] Figure 4 The device is in the reverse bias safe operating area, Figure 2 The V curve obtained under simulation test and real test conditions ce with I c The device reverse bias safe operating area consists of the AB segment (collector maximum rated current limit area) and the BC segment (collector emitter maximum rated voltage limit area). The trajectory of the phase plane curve that does not exceed this area is safe for device failure. Under this premise, this patent proposes the simulation curve enclosing area The area enclosed by the measured curve The higher the overlap, the higher the accuracy of the switching transient model, and the more it conforms to the actual switching characteristics of the device.

[0043] Figure 4 The figure shows the method for solving the coincidence degree of the shutdown transient process. In the phase plane curve of the shutdown process, multiple intersection points of the two curves of the simulation test and the actual test are taken, and the intersection points of the two curves of I c The axis is perpendicular to the ground, and multiple areas are divided into S1, S2, and S n The right boundary of each region is the curve with the lower absolute value in the simulation test and the actual test, which is consistent with the left I c The area enclosed by the coordinate axis and the upper and lower boundaries is the overlapping area of ​​the region. Finally, the overlapping area of ​​each region is added together to get the overlapping area of ​​the two curves. The overlap area divided by the area enclosed by the actual test curve is the turn-off transient overlap degree. .

[0044] (2)

[0045] The accuracy P of the final device transient model is:

[0046] (3)

[0047] S 开实 It is the area enclosed by the phase plane curve of the measured device and the collector-emitter voltage coordinate axis, which can be obtained by the curve area integral operation in mathematics;

[0048] S 开仿It is the area enclosed by the phase plane curve of the simulation model and the collector-emitter voltage coordinate axis, which can be obtained through the curve area integral operation in mathematics;

[0049] S 关实 It is the area enclosed by the phase plane curve of the measured device and the collector current coordinate axis, which can be obtained through the curve area integral operation in mathematics;

[0050] S 开仿 It is the area enclosed by the phase plane curve of the simulation model and the collector current coordinate axis, which can be obtained through the curve area integral operation in mathematics.

[0051] This invention mainly performs time domain evaluation on the switching transient model of semiconductor IGBT devices. For the switching transient models of other similar semiconductor devices, including semiconductor devices with different packaging forms, voltage levels and capacity levels, the method provided by this patent can be referred to.

[0052] Taking a certain type of IGBT as the experimental object, an IGBT turn-on and turn-off transient model was established. This model has sufficient simulation capability for the IGBT turn-on and turn-off transient characteristics. The time domain evaluation method of the IGBT turn-on and turn-off transient simulation model proposed in this invention was used for evaluation.

[0053] The actual and model-simulated voltage and current waveforms of the device under the on state are as follows: Figure 1 As shown, the actual and model-simulated voltage and current waveforms of the device under shutdown are as follows Figure 2 According to the method proposed in this patent, a phase plane curve diagram of the voltage and current when the IGBT is turned on is drawn in the forward bias safe working area of ​​the IGBT model, and a phase plane curve diagram of the voltage and current when the IGBT is turned off is drawn in the reverse bias safe working area of ​​the IGBT model.

[0054] When calculating the phase plane curve area under opening, according to the method of the present invention, the curve area can be divided into S1~S5 at the intersection of the measured and simulated phase plane curves, such as Figure 3 As shown, S 开实 The area of ​​​​S is 6.205e5, 开仿 The area of ​​​​S is 5.586e5, 开重 The area of ​​​​is 5.291e5, so P 开 It is 0.8527.

[0055] Similarly, when calculating the phase plane curve area under shutdown, according to the method of the present invention, the curve area can be divided into S1~S5 at the intersection of the measured and simulated phase plane curves, such as Figure 3 As shown, S 关实 The area of ​​​​S is 3.834e5, 关仿 The area of ​​​​S is 3.838e5, 关重The area of ​​​​is 3.479e5, so P 关 is 0.9075.

[0056] Finally, the calculable transient model accuracy P is 0.8801. Since the model is valid, the validity of the transient model accuracy P is verified and a quantitative indicator is provided to what extent the model is valid.

[0057] The transient model accuracy P can obviously directly determine the model with poor IGBT turn-on and turn-off effects, so the experimental data are no longer listed.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above 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 invention.

Claims

1. A time domain evaluation method for a switching transient model based on the safe operating area of ​​an IGBT device, characterized in that: include: S1: Get the voltage V obtained from the simulation model test and actual device test during the IGBT device turn-on and turn-off process ce and current I c ; S2: According to the voltage V in S1 ce and current I c , get the voltage V of simulation model test and actual device test ce With current I c The phase plane curve of the composition; S3: Enclosed area according to simulation curve The area enclosed by the measured curve The accuracy of the switching transient model is determined by the overlap degree of the switching transient model.

2. The time domain evaluation method for a switching transient model based on the safe operating area of ​​an IGBT device according to claim 1, characterized in that: The phase plane curve in step S2 includes: a phase plane curve of the IGBT device in a turn-on transient state and a phase plane curve of the turn-off transient state.

3. The time domain evaluation method for a switching transient model based on the safe operating area of ​​an IGBT device according to claim 2, characterized in that: In step S3, the area enclosed by the simulation curve The area enclosed by the measured curve The higher the overlap, the higher the accuracy of the switching transient model, and the more consistent it is with the actual switching characteristics of the device.

4. The time domain evaluation method for a switching transient model based on the safe operating area of ​​an IGBT device according to claim 3, characterized in that: The step S3 specifically includes: S31: Calculate the instantaneous overlap of the opening ; S32: Calculate the transient closing degree of the shutdown ; S33: The accuracy of the final device transient model P, .

5. The time domain evaluation method for a switching transient model based on the safe operating area of ​​an IGBT device according to claim 4, characterized in that: The step S31 comprises: taking multiple intersection points of the two curves of the simulation test and the actual test in the phase plane curve of the IGBT device turn-on process, and respectively adding V ce The axis is perpendicular to the ground, and multiple areas are divided into S1, S2, and S n ; In each area; The top boundary of each region is the curve with the lower absolute value in the simulation test and the actual test, which is consistent with the bottom V ce The area enclosed by the coordinate axis and the left and right boundaries is the overlapping area of ​​the region. Finally, the overlapping area of ​​each region is added together to get the overlapping area of ​​the two curves. The overlap area divided by the area enclosed by the actual test curve is the opening transient overlap degree. , .

6. The time domain evaluation method for a switching transient model based on the safe operating area of ​​an IGBT device according to claim 4, characterized in that: The step S32 includes: taking multiple intersection points of the two curves of the simulation test and the actual test in the phase plane curve of the shutdown process, and respectively adding them to I c The axis is perpendicular to the ground, and multiple areas are divided into S1, S2, and S n ; The right boundary of each area is the curve with the lower absolute value in the simulation test and the actual test, which is consistent with the left I c The area enclosed by the coordinate axis and the upper and lower boundaries is the overlapping area of ​​the region. Finally, the overlapping area of ​​each region is added together to get the overlapping area of ​​the two curves. The overlap area divided by the area enclosed by the actual test curve is the turn-off transient overlap degree. , .

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