An IGBT power device online detection method and system

Abstract

The present invention relates to an online detection method and system for IGBT power devices, comprising: determining the accumulated thermal strain of the IGBT power device based on the temperature variation of the IGBT power device; and performing online detection of the IGBT power device based on the accumulated thermal strain of the IGBT power device. The technical solution provided by the present invention fully considers the impact of the temperature variation of the IGBT power device and the electric field in which the IGBT power device is located on the thermal strain of the IGBT power device, thereby improving the accuracy of online detection of IGBT power devices.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible direct current transmission, and in particular to an online detection method and system for an IGBT power device. Background Art

[0002] Since the adoption of direct current (DC) transmission for electric energy, after the mercury arc valve era, DC transmission has played a unique role in long-distance, large-capacity transmission, submarine cable transmission, and networking of different frequencies; after the crystalline tube era, the development of DC transmission has made rapid progress, showing more advantages in the interconnection of large power grids; and then the rapid development of high-power turn-off devices has promoted the rapid development of high-voltage DC transmission technology based on voltage source converters (VSC-HVDC), expanding DC transmission to broader areas such as distribution networks and new energy development.

[0003] The technical core of a DC transmission system lies in high-power power electronics devices such as converters or inverters. Traditional HVDC transmission equipment uses current-source converters comprised of semi-controlled devices such as thyristors, while VSC-HVDC uses voltage-source converters comprised of fully controlled devices such as IGBTs. The converter valve, a key component of the converter and a core component of DC transmission, is primarily composed of IGBT power devices.

[0004] Currently, the overcurrent and overvoltage specifications for IGBT power devices in device manufacturers' datasheets are often reference values ​​under specific test conditions. To ensure device reliability, extensive, empirically-based design guidelines, often "pushing a small cart with a large horse," are often employed. These guidelines largely fail to maximize the lifespan of IGBT power devices, resulting in a waste of resources. Furthermore, they cannot guarantee the safe operation of IGBT power devices, and consequently, the safe operation of converter valves. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide an online detection method for IGBT power devices, which fully considers the influence of the temperature change of the IGBT power device and the electric field in which it is located on the thermal strain of the IGBT power device, thereby improving the accuracy of online detection of IGBT power devices.

[0006] The purpose of the present invention is achieved by adopting the following technical solutions:

[0007] The present invention provides an online detection method for an IGBT power device, the improvement of which comprises:

[0008] Determine the accumulated thermal strain of the IGBT power device according to the temperature change of the IGBT power device;

[0009] The IGBT power device is tested online based on its accumulated thermal strain.

[0010] Preferably, before determining the accumulated thermal strain of the IGBT power device according to the temperature variation of the IGBT power device, the method includes:

[0011] Use optical fiber temperature measurement technology to measure the external temperature change of IGBT power devices;

[0012] Use the IGBT parameter method to measure the junction temperature change of the IGBT power device;

[0013] The sum of the external temperature variation of the IGBT power device and the junction temperature variation of the IGBT power device is used as the temperature variation of the IGBT power device.

[0014] Preferably, determining the accumulated thermal strain of the IGBT power device according to the temperature change of the IGBT power device includes:

[0015] Determine the thermal strain of the IGBT power device on the X, Y, and Z axes at the corresponding moment according to the temperature change of the IGBT power device at each moment;

[0016] The sum of the thermal strains of the IGBT power device in the X, Y, and Z axes from the start of use to the current moment is taken as the cumulative thermal strain of the IGBT power device in the X, Y, and Z axes.

[0017] Furthermore, determining the thermal strain of the IGBT power device on the X, Y, and Z axes at the corresponding moment according to the temperature change of the IGBT power device at each moment includes:

[0018] Determine the thermal strain ε of the IGBT power device on the X axis at time t by the following formula: x (t):

[0019]

[0020] Where u(t) is the displacement of the IGBT power device on the X axis at time t, e(t) is the electric field strength of the IGBT power device at time t, and △T t,t-1 is the temperature change of the IGBT power device between time t and time t-1, α is the expansion coefficient of the IGBT power device, σ x (t) is the thermal stress of the IGBT power device on the X-axis at time t, and μ is the constant coefficient of the IGBT power device;

[0021] Determine the thermal strain ε of the IGBT power device on the Y axis at time t by the following formula: y (t):

[0022]

[0023] Where v(t) is the displacement of the IGBT power device on the Y axis at time t, σ y (t) is the thermal stress of the IGBT power device on the Y axis at time t;

[0024] Determine the thermal strain ε of the IGBT power device on the Z axis at time t by the following formula: z (t):

[0025]

[0026] Where w(t) is the displacement of the IGBT power device on the Z axis at time t, σ z (t) is the thermal stress of the IGBT power device on the Z axis at time t.

[0027] Furthermore, the online detection of the IGBT power device based on the accumulated thermal strain of the IGBT power device includes:

[0028] When the accumulated thermal strain of the IGBT power device in the X, Y, and Z axes is not greater than the accumulated thermal strain damage threshold of the IGBT power device in the X, Y, and Z axes, the IGBT power device is not damaged; otherwise, the IGBT power device is damaged.

[0029] The present invention provides an IGBT power device online detection system, the improvement of which is that it includes:

[0030] A determination module, configured to determine the accumulated thermal strain of the IGBT power device according to a temperature change of the IGBT power device;

[0031] The detection module is used to perform online detection of the IGBT power device based on the accumulated thermal strain of the IGBT power device.

[0032] Preferably, the system further comprises:

[0033] The first measurement module is used to measure the external temperature change of the IGBT power device using optical fiber temperature measurement technology;

[0034] The second measurement module is used to measure the junction temperature change of the IGBT power device using the IGBT parameter method;

[0035] As a module: used to take the sum of the external temperature variation of the IGBT power device and the junction temperature variation of the IGBT power device as the temperature variation of the IGBT power device.

[0036] Preferably, the determining module includes:

[0037] A determination unit, configured to determine the thermal strain of the IGBT power device on the X, Y, and Z axes at the corresponding moment according to the temperature change of the IGBT power device at each moment;

[0038] As a unit, the sum of the thermal strains of the IGBT power device in the X, Y, and Z axes from the start of use to the current moment is used as the accumulated thermal strain of the IGBT power device in the X, Y, and Z axes.

[0039] Furthermore, the determining unit is configured to:

[0040] Determine the thermal strain ε of the IGBT power device on the X axis at time t by the following formula: x (t):

[0041]

[0042] Where u(t) is the displacement of the IGBT power device on the X axis at time t, e(t) is the electric field strength of the IGBT power device at time t, and △T t,t-1 is the temperature change of the IGBT power device between time t and time t-1, α is the expansion coefficient of the IGBT power device, σ x (t) is the thermal stress of the IGBT power device on the X-axis at time t, and μ is the constant coefficient of the IGBT power device;

[0043] Determine the thermal strain ε of the IGBT power device on the Y axis at time t by the following formula: y (t):

[0044]

[0045] Where v(t) is the displacement of the IGBT power device on the Y axis at time t, σ y (t) is the thermal stress of the IGBT power device on the Y axis at time t;

[0046] Determine the thermal strain ε of the IGBT power device on the Z axis at time t by the following formula: z (t):

[0047]

[0048] Where w(t) is the displacement of the IGBT power device on the Z axis at time t, σ z (t) is the thermal stress of the IGBT power device on the Z axis at time t.

[0049] Furthermore, the detection module is used to:

[0050] When the accumulated thermal strain of the IGBT power device in the X, Y, and Z axes is not greater than the accumulated thermal strain of the IGBT power device in the X 、 Y 、Z When the cumulative thermal strain of the shaft reaches the damage threshold, the IGBT power device is not damaged; otherwise, the IGBT power device is damaged.

[0051] Compared with the closest prior art, the present invention has the following beneficial effects:

[0052] The technical solution provided by the present invention determines the thermal strain of the IGBT power device according to the temperature change of the IGBT power device; performs online detection of the IGBT power device based on the thermal strain of the IGBT power device, fully considers the influence of the multi-physical field environment of the electrothermal force in which the IGBT power device is located on the thermal strain of the IGBT power device, proposes a calculation relationship between the temperature change of the IGBT power device and the electric field in which the IGBT power device is located and the thermal strain of the IGBT power device, and performs online detection of the IGBT power device based on this calculation relationship, thereby improving the accuracy of detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a flow chart of an online detection method for an IGBT power device;

[0054] Figure 2 This is a structural diagram of an IGBT power device online detection system. DETAILED DESCRIPTION

[0055] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0057] The present invention provides an IGBT power device online detection method, such as Figure 1 Shown, including:

[0058] Step 101: Determine the accumulated thermal strain of the IGBT power device according to the temperature variation of the IGBT power device;

[0059] Step 102: Perform online detection on the IGBT power device based on the accumulated thermal strain of the IGBT power device.

[0060] Specifically, before step 101, the following steps are included:

[0061] Step a. Measure the external temperature change of the IGBT power device using optical fiber temperature measurement technology;

[0062] Step b. measuring the junction temperature change of the IGBT power device using the IGBT parameter method;

[0063] step c . The sum of the external temperature change of the IGBT power device and the junction temperature change of the IGBT power device is used as the temperature change of the IGBT power device.

[0064] Specifically, step 101 includes:

[0065] Step 101-1. Determine the temperature of the IGBT power device at the corresponding moment according to the temperature change of the IGBT power device at each moment. X , thermal strain in Y and Z axes;

[0066] Step 101 - 2 . The sum of the thermal strains of the IGBT power device in the X, Y, and Z axes from the start of use to the current moment is used as the accumulated thermal strain of the IGBT power device in the X, Y, and Z axes.

[0067] Furthermore, the step 101-1 includes:

[0068] Determine the thermal strain ε of the IGBT power device on the X axis at time t by the following formula: x (t):

[0069]

[0070] Where u(t) is the displacement of the IGBT power device on the X axis at time t, e(t) is the electric field strength of the IGBT power device at time t, and △T t,t-1 is the temperature change of the IGBT power device between time t and time t-1, α is the expansion coefficient of the IGBT power device, σ x (t) is the thermal stress of the IGBT power device on the X-axis at time t, and μ is the constant coefficient of the IGBT power device;

[0071] Determine the thermal strain ε of the IGBT power device on the Y axis at time t by the following formula: y (t):

[0072]

[0073] Where v(t) is the displacement of the IGBT power device on the Y axis at time t, σ y (t) is the thermal stress of the IGBT power device on the Y axis at time t;

[0074] Determine the thermal strain ε of the IGBT power device on the Z axis at time t by the following formula:z (t):

[0075]

[0076] Where w(t) is the displacement of the IGBT power device on the Z axis at time t, σ z (t) is the thermal stress of the IGBT power device on the Z axis at time t.

[0077] In the preferred embodiment of the present invention, when current flows through the IGBT power device, both the IGBT and the fast recovery diode in the IGBT power device will generate conduction loss and switching loss. The generation of this loss is accompanied by the generation of a large amount of heat energy. The generated heat energy will be transferred inside the IGBT power device, thereby causing the temperature inside the IGBT power device to change. At the same time, the temperature change inside the IGBT power device will cause the conductivity of the IGBT power device to change, thereby affecting the loss of the power device. The electrical-thermal coupling relationship between the two can be expressed as:

[0078]

[0079] Where E is the electric field intensity, [Π], [λ], [σ], [α], and [ε] are the Peltier coefficient matrix, thermal conductivity matrix, electrical conductivity matrix, Seebeck coefficient matrix, and dielectric constant matrix, respectively. is the temperature gradient. q is the heat flow, J is the heat;

[0080] At the same time, thermal stress is generated during the energy flow, which can cause deformation of the IGBT power device and lead to damage. Based on this, considering the multi-physical field environment of the electrothermal force in which the IGBT power device is located, the corresponding relationship between the temperature change of the IGBT power device and the electric field conditions in which it is located and the thermal strain of the IGBT power device is proposed:

[0081]

[0082] Where, ε x , ε y , ε z is the thermal strain in each direction of the coordinate axis, u, v, w are the displacement components, σ x , σ y , σ z is the thermal stress, α is the thermal expansion coefficient, △T is the temperature change of the IGBT power device. E is the electric field, μ is a constant;

[0083] In a preferred embodiment of the present invention, the temperature variation of the IGBT power device is the difference between the temperature of the power device at a current moment and the temperature of the power device at a moment before the current moment.

[0084] In the best embodiment of the present invention, the method for obtaining the electric field strength of the IGBT power device may be:

[0085] The operating voltage and current of the IGBT power device are measured using a voltage sensor and a current sensor respectively;

[0086] The operating voltage and operating current of the IGBT power device are substituted into the CUMSUL simulation model to obtain the electric field strength of the IGBT power device.

[0087] Specifically, step 102 includes:

[0088] When the accumulated thermal strain of the IGBT power device in the X, Y, and Z axes is not greater than the accumulated thermal strain damage threshold of the IGBT power device in the X, Y, and Z axes, the IGBT power device is not damaged; otherwise, the IGBT power device is damaged.

[0089] The present invention provides an IGBT power device online detection system, such as Figure 2 Shown, including:

[0090] A determination module, configured to determine the accumulated thermal strain of the IGBT power device according to a temperature change of the IGBT power device;

[0091] The detection module is used to perform online detection of the IGBT power device based on the accumulated thermal strain of the IGBT power device.

[0092] Specifically, the system further includes:

[0093] The first measurement module is used to measure the external temperature change of the IGBT power device using optical fiber temperature measurement technology;

[0094] The second measurement module is used to measure the junction temperature change of the IGBT power device using the IGBT parameter method;

[0095] As a module: used to take the sum of the external temperature variation of the IGBT power device and the junction temperature variation of the IGBT power device as the temperature variation of the IGBT power device.

[0096] Furthermore, the determining module includes:

[0097] A determination unit, configured to determine the thermal strain of the IGBT power device on the X, Y, and Z axes at the corresponding moment according to the temperature change of the IGBT power device at each moment;

[0098] As a unit, the sum of the thermal strains of the IGBT power device in the X, Y, and Z axes from the start of use to the current moment is used as the accumulated thermal strain of the IGBT power device in the X, Y, and Z axes.

[0099] Furthermore, the determining unit is configured to:

[0100] Determine the thermal strain ε of the IGBT power device on the X axis at time t by the following formula: x (t):

[0101]

[0102] Where u(t) is the displacement of the IGBT power device on the X axis at time t, e(t) is the electric field strength of the IGBT power device at time t, and △T t,t-1 is the temperature change of the IGBT power device between time t and time t-1, α is the expansion coefficient of the IGBT power device, σ x (t) is the thermal stress of the IGBT power device on the X-axis at time t, and μ is the constant coefficient of the IGBT power device;

[0103] Determine the thermal strain ε of the IGBT power device on the Y axis at time t by the following formula: y (t):

[0104]

[0105] Where v(t) is the displacement of the IGBT power device on the Y axis at time t, σ y (t) is the thermal stress of the IGBT power device on the Y axis at time t;

[0106] Determine the thermal strain ε of the IGBT power device on the Z axis at time t by the following formula: z (t):

[0107]

[0108] Where w(t) is the displacement of the IGBT power device on the Z axis at time t, σ z (t) is the thermal stress of the IGBT power device on the Z axis at time t.

[0109] Specifically, the detection module is used to:

[0110] When the accumulated thermal strain of the IGBT power device in the X, Y, and Z axes is not greater than the accumulated thermal strain damage threshold of the IGBT power device in the X, Y, and Z axes, the IGBT power device is not damaged; otherwise, the IGBT power device is damaged.

[0111] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0112] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0113] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0114] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. An IGBT power device online detection method, characterized in that: include: Determine the accumulated thermal strain of the IGBT power device according to the temperature change of the IGBT power device; Perform online detection of IGBT power devices based on their accumulated thermal strain; Determining the accumulated thermal strain of the IGBT power device according to the temperature change of the IGBT power device includes: Determine the thermal strain of the IGBT power device on the x, y, and z axes at the corresponding moment according to the temperature change of the IGBT power device at each moment; The sum of the thermal strains of the IGBT power device in the x, y, and z axes from the start of use to the current moment is taken as the cumulative thermal strain of the IGBT power device in the x, y, and z axes; Determining the thermal strain of the IGBT power device on the x, y, and z axes at the corresponding moment according to the temperature change of the IGBT power device at each moment includes: Determine the thermal strain ε of the IGBT power device on the x-axis at time t by the following formula: x (t): Where u(t) is the displacement of the IGBT power device on the x-axis at time t, e(t) is the electric field strength of the IGBT power device at time t, and ΔT t,t-1 is the temperature change of the IGBT power device between time t and time t-1, α is the expansion coefficient of the IGBT power device, σ x (t) is the thermal stress of the IGBT power device on the x-axis at time t, and μ is the constant coefficient of the IGBT power device; Determine the thermal strain ε of the IGBT power device on the y-axis at time t by the following formula: y (t): Where v(t) is the displacement of the IGBT power device on the y-axis at time t, σ y (t) is the thermal stress of the IGBT power device on the y-axis at time t; Determine the thermal strain ε of the IGBT power device on the z-axis at time t by the following formula: z (t): Where w(t) is the displacement of the IGBT power device on the z-axis at time t, σ z (t) is the thermal stress of the IGBT power device on the z-axis at time t; The steps of obtaining the electric field strength of the IGBT power device include: The operating voltage and current of the IGBT power device are measured using a voltage sensor and a current sensor respectively; The operating voltage and operating current of the IGBT power device are substituted into the COMSOL simulation model to obtain the electric field strength of the IGBT power device.

2. The method according to claim 1, wherein Before determining the accumulated thermal strain of the IGBT power device according to the temperature variation of the IGBT power device, the method includes: Use optical fiber temperature measurement technology to measure the external temperature change of IGBT power devices; Use the IGBT parameter method to measure the junction temperature change of the IGBT power device; The sum of the external temperature variation of the IGBT power device and the junction temperature variation of the IGBT power device is used as the temperature variation of the IGBT power device.

3. The method according to claim 1, wherein The online detection of the IGBT power device based on the accumulated thermal strain of the IGBT power device includes: When the accumulated thermal strain of the IGBT power device in the x, y, and z axes is not greater than the accumulated thermal strain damage threshold of the IGBT power device in the x, y, and z axes, the IGBT power device is not damaged; otherwise, the IGBT power device is damaged.

4. An IGBT power device online detection system, characterized in that: include: A determination module, configured to determine the accumulated thermal strain of the IGBT power device according to a temperature change of the IGBT power device; A detection module, used for performing online detection of IGBT power devices based on the accumulated thermal strain of the IGBT power devices; The determining module includes: A determination unit, configured to determine the thermal strain of the IGBT power device on the x, y, and z axes at the corresponding moment according to the temperature change of the IGBT power device at each moment; As a unit, it is used to take the sum of the thermal strains of the IGBT power device in the x, y, and z axes from the start of use to the current moment as the cumulative thermal strain of the IGBT power device in the x, y, and z axes; Determine the thermal strain ε of the IGBT power device on the x-axis at time t by the following formula: x (t): Where u(t) is the displacement of the IGBT power device on the x-axis at time t, e(t) is the electric field strength of the IGBT power device at time t, and ΔT t,t-1 is the temperature change of the IGBT power device between time t and time t-1, α is the expansion coefficient of the IGBT power device, σ x (t) is the thermal stress of the IGBT power device on the x-axis at time t, and μ is the constant coefficient of the IGBT power device; Determine the thermal strain ε of the IGBT power device on the y-axis at time t by the following formula: y (t): Where v(t) is the displacement of the IGBT power device on the y-axis at time t, σ y (t) is the thermal stress of the IGBT power device on the y-axis at time t; Determine the thermal strain ε of the IGBT power device on the z-axis at time t by the following formula: z (t): Where w(t) is the displacement of the IGBT power device on the z-axis at time t, σ z (t) is the thermal stress of the IGBT power device on the z-axis at time t; The step of obtaining the electric field strength of the IGBT power device includes: The operating voltage and current of the IGBT power device are measured using a voltage sensor and a current sensor respectively; The operating voltage and operating current of the IGBT power device are substituted into the COMSOL simulation model to obtain the electric field strength of the IGBT power device.

5. The system according to claim 4, wherein: The system further comprises: The first measurement module is used to measure the external temperature change of the IGBT power device using optical fiber temperature measurement technology; The second measurement module is used to measure the junction temperature change of the IGBT power device using the IGBT parameter method; As a module: used to take the sum of the external temperature variation of the IGBT power device and the junction temperature variation of the IGBT power device as the temperature variation of the IGBT power device.

6. The system according to claim 4, wherein: The detection module is used to: When the accumulated thermal strain of the IGBT power device in the x, y, and z axes is not greater than the accumulated thermal strain damage threshold of the IGBT power device in the x, y, and z axes, the IGBT power device is not damaged; otherwise, the IGBT power device is damaged.

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