IGBT state monitoring circuit and method

Abstract

The embodiment of the application discloses a kind of state monitoring circuit and method, including processing circuit, first detection circuit, power amplifier circuit and IGBT module;Wherein, first detection circuit includes at least three parallel comparators and conduction voltage drop detection circuit;Conduction voltage drop detection circuit is used to obtain the saturation conduction voltage drop that power amplifier circuit outputs when IGBT module works under target condition at IGBT module complete conduction;At least three parallel comparators are used to obtain the level type outputted under the action of saturation conduction voltage drop;Processing circuit is used to identify the aging degree of IGBT based on the level type output by at least three parallel comparators in the case where saturation conduction voltage drop is less than threshold voltage.Due to the implementation of the application, the aging degree of IGBT module can be accurately identified.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to an IGBT state monitoring circuit and method. Background Technology

[0002] Insulated-gate bipolar transistors (IGBTs) are power semiconductor switching devices widely used in medium and large power equipment. They improve the reliability of power electronic systems to a certain extent and can effectively prevent unexpected failures. Approximately 42% of the switches used in power electronic systems are IGBTs. However, power semiconductor devices are also the most vulnerable components in power electronic converters. About 34% of power electronic system failures are caused by chip or soldering failures of power electronic devices. Failure to take rapid and effective maintenance measures in real time can lead to serious consequences and huge economic losses.

[0003] Condition assessment is a crucial method for monitoring IGBT modules. Failure to detect and protect against faults in a timely and accurate manner can lead to permanent damage to the IGBT. In existing technologies, the traditional solution for IGBT module condition monitoring primarily involves connecting a resistor divider circuit in parallel between the collector and emitter of the IGBT to obtain the collector and emitter voltages. This state voltage is then compared with a predetermined voltage to determine the IGBT's operating status. The applicant's research revealed that the collector-emitter voltage is easily affected by aging and junction temperature, as well as changes in external electrical parameters, all of which can impact the accuracy of IGBT module monitoring. Summary of the Invention

[0004] This application provides an IGBT state monitoring circuit and method, which can solve the problem of low monitoring accuracy of IGBT modules in the prior art.

[0005] In a first aspect, embodiments of this application provide an IGBT state monitoring circuit, including a processing circuit, a first detection circuit, a power amplifier circuit, and an IGBT module; wherein, the first detection circuit includes at least three parallel comparators and a conduction voltage drop detection circuit;

[0006] The first terminal of the processing circuit is connected to the first terminal of the at least three parallel comparators; the second terminal of the processing circuit is connected to the first terminal of the power amplifier circuit; the third terminal of the processing circuit is connected to the emitter of the IGBT module; the second terminal of the at least three parallel comparators is connected to the first terminal of the on-state voltage drop detection circuit; the second terminal of the on-state voltage drop detection circuit is connected to the collector of the IGBT module; the second terminal of the power amplifier circuit is connected to the gate of the IGBT module.

[0007] The on-state voltage drop detection circuit is used to obtain the saturation on-state voltage drop output by the power amplifier circuit when the IGBT module is fully turned on and the IGBT module is operating under the target conditions.

[0008] The at least three parallel comparators are used to obtain the output level type under the influence of the saturation on-state voltage drop;

[0009] The processing circuit is used to identify the aging degree of the IGBT based on the level type of the output of the at least three parallel comparators when it is determined that the saturation on-state voltage drop is less than the threshold voltage.

[0010] By implementing the embodiments of this application, the processing circuit can identify the aging degree of the IGBT based on the saturation conduction voltage and the level type of the output of at least three parallel comparators, which can accurately determine the operating state of the IGBT compared with existing detection methods.

[0011] In one possible implementation, the processing circuit is specifically used for:

[0012] If the output level of each of the at least three parallel comparators is low, the IGBT module is determined to be in a normal state.

[0013] In one possible implementation, the at least three parallel comparators include a first comparator, a second comparator, and a third comparator; the processing circuit is specifically used for:

[0014] If the level output of the first comparator is high, and the level outputs of the second and third comparators are both low, the IGBT module is determined to be in the early aging state.

[0015] In one possible implementation, the at least three parallel comparators include a first comparator, a second comparator, and a third comparator; the processing circuit is specifically used for:

[0016] If the output level of the first comparator and the second comparator is both high, and the output level of the third comparator is low, the IGBT module is determined to be in the late aging state.

[0017] In one possible implementation, the at least three parallel comparators include a first comparator, a second comparator, and a third comparator; the processing circuit is specifically used for:

[0018] If the output level of each of the at least three parallel comparators is high, the IGBT module is determined to be in a critical failure state.

[0019] In one possible implementation, the at least three parallel comparators further include a fourth comparator.

[0020] The processing circuit is further configured to initiate a soft shutdown when it is determined that the saturation on-state voltage drop is greater than the threshold voltage and the level type of the output of the fourth comparator is high.

[0021] Secondly, embodiments of this application provide an IGBT state monitoring method. This method is applied to an IGBT state monitoring circuit, wherein the IGBT state monitoring circuit includes a processing circuit, a first detection circuit, a power amplifier circuit, and an IGBT module. The first detection circuit includes at least three parallel comparators and a forward voltage drop detection circuit. A first terminal of the processing circuit is connected to the first terminals of the at least three parallel comparators. A second terminal of the processing circuit is connected to the first terminal of the power amplifier circuit. A third terminal of the processing circuit is connected to the first terminal of the IGBT module. The second terminals of the at least three parallel comparators are connected to the first terminal of the forward voltage drop detection circuit. The second terminal of the forward voltage drop detection circuit is connected to the second terminal of the IGBT module. The second terminal of the power amplifier circuit is connected to the third terminal of the IGBT module. The method may include the following steps:

[0022] When the IGBT module is fully turned on, the on-state voltage drop detection circuit obtains the saturation on-state voltage drop output by the power amplifier circuit under the target operating conditions of the IGBT module.

[0023] The output level type is obtained by using the at least three parallel comparators under the influence of the saturation on-state voltage drop;

[0024] When the processing circuit determines that the saturation on-state voltage drop is less than the threshold voltage, it identifies the aging degree of the IGBT based on the level type of the output of the at least three parallel comparators. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0026] Figure 1 This is a schematic diagram of the structure of an IGBT state monitoring circuit provided in an embodiment of this application;

[0027] Figure 2 This is a schematic flowchart of an IGBT state monitoring method provided in an embodiment of this application. Detailed Implementation

[0028] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0029] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] To facilitate a better understanding of the technical solutions described in this application, the following detailed description of this application is provided in conjunction with the accompanying drawings.

[0032] See Figure 1 This is a schematic diagram of an IGBT state monitoring circuit provided in an embodiment of this application, including a processing circuit 10, a first detection circuit 20, a power amplifier circuit 30, and an IGBT module 40. The first detection circuit 20 includes comparators 201, 202, 203, and 204, and a forward voltage drop detection circuit 205. Furthermore, comparators 201, 202, 203, and 204 are arranged in parallel. The IGBT module includes a collector, an emitter, and a gate.

[0033] In a specific implementation, at least three parallel comparators are coupled to a node. For example, this node may be the first terminal of the at least three parallel comparators, or it may be the second terminal of the at least three parallel comparators. The first terminal of the processing circuit 10 is connected to the first terminal of the at least three parallel comparators; the second terminal of the processing circuit 10 is connected to the first terminal of the power amplifier circuit 30; the third terminal of the processing circuit 10 is connected to the emitter of the IGBT module 40; the second terminal of the at least three parallel comparators is connected to the first terminal of the on-state voltage drop detection circuit 205; the second terminal of the on-state voltage drop detection circuit 205 is connected to the collector of the IGBT module 40; and the second terminal of the power amplifier circuit 20 is connected to the gate of the IGBT module 40.

[0034] For example, the processing circuit may include a circuit composed of a CPLD, or the processing circuit may include a circuit composed of an FPGA.

[0035] Among them, the on-state voltage drop detection circuit is used to obtain the saturation on-state voltage drop of the power amplifier circuit output when the IGBT module is operating under the target conditions;

[0036] At least three parallel comparators are used to obtain the output level type under the influence of the saturation on-state voltage drop;

[0037] The processing circuit is used to identify the aging degree of the IGBT based on the level type of the output of at least three parallel comparators, provided that the saturation on-state voltage drop is less than the threshold voltage.

[0038] For example, the aging level of an IGBT can include the IGBT being in a normal state, the IGBT being in an early aging state, the IGBT being in a late aging state, and the IGBT being in a critical failure state.

[0039] For example, the threshold voltage can be a specific value set at the factory by the IGBT state monitoring circuit described in this application; in one example, the threshold voltage can be an empirical value obtained by those skilled in the art through continuous experimentation (for example, this empirical value can be a standard value in the semiconductor field by default). Furthermore, in practical applications, the threshold voltage can be adjusted, and the value of the threshold voltage can be different in different application scenarios.

[0040] For example, the target conditions may include, but are not limited to, at least one of a set junction temperature and a set elapsed time.

[0041] For example, each comparator is set with a corresponding aging threshold. For instance, the first comparator has a first aging threshold, the second comparator has a second aging threshold, the third comparator has a third aging threshold, and the fourth comparator has a fourth aging threshold. The order of aging thresholds is: first aging threshold > second aging threshold > third aging threshold > fourth aging threshold. When determining the level type, if the detected circuit parameter value is greater than the aging threshold, the level type is high; if the detected circuit parameter value is less than the aging threshold, the level type is low.

[0042] by Figure 1Taking the IGBT state monitoring circuit shown as an example, when the IGBT is fully turned on, the output voltage of the differential amplifier included in the power amplifier circuit 30 is the saturation on-state voltage drop. The saturation on-state voltage drop is obtained by the on-state voltage drop detection circuit 205, and the output level type under the action of the above-mentioned saturation on-state voltage drop is obtained by the first comparator 201, the second comparator 202, the third comparator 203, and the fourth comparator 204. Thus, the output results of the four parallel comparators and the obtained saturation on-state voltage drop can be sent to the processing circuit 10. The processing circuit 10 further determines whether the obtained saturation on-state voltage drop is less than the threshold voltage. If it is determined that the saturation on-state voltage drop is less than the threshold voltage, the aging degree of the IGBT is identified based on the level type of the output of each of the four parallel comparators.

[0043] In one example, the processing circuit 10 can be specifically used to determine that the IGBT module is in a normal state when the output level of at least three parallel comparators is low.

[0044] In one example, the processing circuit 10 can be specifically used to determine that the IGBT module is in the early aging state when the level type of the first comparator 201 output is high and the level type of the second comparator 202 and the third comparator 203 are both low.

[0045] In one example, the processing circuit 10 can be specifically used to determine that the IGBT module is in a late-stage aging state when the output level of the first comparator 201 and the second comparator 202 is both high and the output level of the third comparator 203 is low.

[0046] In one example, the processing circuit 10 can be specifically used to determine that the IGBT module is in a critical failure state when the output levels of the first comparator 201, the second comparator 202, and the third comparator 203 are all high.

[0047] In one example, the processing circuit 10 can be specifically used to initiate a soft shutdown when it is determined that the saturation on-state voltage drop is greater than the threshold voltage and the level type of the fourth comparator output is high, in order to avoid damage to the IGBT module.

[0048] In summary, the IGBT state monitoring circuit proposed in this application can identify the aging degree of the IGBT based on the saturation conduction voltage and the level type of the output of at least three parallel comparators. Compared with existing detection methods, it can accurately determine the operating state of the IGBT.

[0049] This specification also provides an IGBT state monitoring method, which is applied to the IGBT state monitoring circuit of any of the above embodiments. The method may include, but is not limited to, the following steps:

[0050] Step S201: When the IGBT module is fully turned on, the saturation on-state voltage drop of the power amplifier circuit is obtained by the on-state voltage drop detection circuit when the IGBT module is operating under the target conditions.

[0051] Step S202: Obtain the output level type under the action of saturation on-state voltage drop through at least three parallel comparators;

[0052] Step S203: When the saturation on-state voltage drop is determined to be less than the threshold voltage by the processing circuit, the aging degree of the IGBT is identified based on the level type of the output of at least three parallel comparators.

[0053] It should be understood that while the steps in the flowchart of the above embodiments are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the above flowchart may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the steps or stages in other steps.

[0054] Another embodiment of this application provides a detection device, which includes the IGBT state monitoring circuit provided in the embodiments of this application. The IGBT state monitoring circuit is used to execute each step in the IGBT state monitoring method flow provided in the above method embodiments.

[0055] In another embodiment of this application, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processing circuit, implements the various steps in the data communication method flow as described in the embodiments of this application.

[0056] In another embodiment of this application, a computer program product is also provided, which includes computer instructions that, when executed on a processing circuit, cause the processing circuit to perform various steps in the data communication method flow shown in the above method embodiment.

[0057] Those skilled in the art will understand that the contents disclosed herein can be varied and modified in many ways. For example, the various devices or components described above can be implemented in hardware, or in software, firmware, or a combination of some or all of the three.

[0058] Furthermore, while this disclosure makes various references to certain units in systems according to embodiments of this disclosure, any number of different units may be used and operated on clients and / or servers. The units are merely illustrative, and different aspects of the system and processing circuitry may use different units.

[0059] This disclosure uses flowcharts to illustrate the steps of a processing circuit according to embodiments of this disclosure. It should be understood that the preceding or following steps are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes.

[0060] Those skilled in the art will understand that all or part of the steps in the above-described processing circuit can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium, such as a read-only memory. Optionally, all or part of the steps in the above embodiments can also be implemented using one or more integrated circuits. Accordingly, each module / unit in the above embodiments can be implemented in hardware or as a software functional module. This disclosure is not limited to any particular combination of hardware and software.

[0061] Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms such as those defined in a common dictionary should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0062] The foregoing description is intended to illustrate the present disclosure and should not be construed as limiting it. While several exemplary embodiments of the present disclosure have been described, those skilled in the art will readily understand that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure as defined by the claims. It should be understood that the foregoing description is intended to illustrate the present disclosure and should not be construed as limiting it to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The present disclosure is defined by the claims and their equivalents.

Claims

1. An IGBT state monitoring circuit, characterized in that, include: The system comprises a processing circuit, a first detection circuit, a power amplifier circuit, and an IGBT module; wherein the first detection circuit includes at least three parallel comparators and a forward voltage drop detection circuit. The first terminal of the processing circuit is connected to the first terminal of the at least three parallel comparators; the second terminal of the processing circuit is connected to the first terminal of the power amplifier circuit; the third terminal of the processing circuit is connected to the emitter of the IGBT module; the second terminal of the at least three parallel comparators is connected to the first terminal of the on-state voltage drop detection circuit; the second terminal of the on-state voltage drop detection circuit is connected to the collector of the IGBT module; the second terminal of the power amplifier circuit is connected to the gate of the IGBT module. The on-state voltage drop detection circuit is used to obtain the saturation on-state voltage drop output by the power amplifier circuit when the IGBT module is fully turned on under the target conditions; the at least three parallel comparators are used to obtain the output level type under the action of the saturation on-state voltage drop. The processing circuit is used to identify the aging degree of the IGBT based on the level type of the output of the at least three parallel comparators when it is determined that the saturation on-state voltage drop is less than the threshold voltage.

2. The circuit as described in claim 1, characterized in that, The processing circuit is specifically used for: If the output level of each of the at least three parallel comparators is low, the IGBT module is determined to be in a normal state.

3. The circuit as described in claim 1, characterized in that, The at least three parallel comparators include a first comparator, a second comparator, and a third comparator; the processing circuit is specifically used for: If the level output of the first comparator is high, and the level outputs of the second and third comparators are both low, the IGBT module is determined to be in the early aging state.

4. The circuit as described in claim 1, characterized in that, The at least three parallel comparators include a first comparator, a second comparator, and a third comparator; the processing circuit is specifically used for: If the output level of the first comparator and the second comparator is both high, and the output level of the third comparator is low, the IGBT module is determined to be in the late aging state.

5. The circuit as described in claim 1, characterized in that, The at least three parallel comparators include a first comparator, a second comparator, and a third comparator; the processing circuit is specifically used for: If the output level of each of the at least three parallel comparators is high, the IGBT module is determined to be in a critical failure state.

6. The circuit according to any one of claims 1-5, characterized in that, The at least three parallel comparators also include a fourth comparator. The processing circuit is further configured to initiate a soft shutdown when it is determined that the saturation on-state voltage drop is greater than the threshold voltage and the level type of the output of the fourth comparator is high.

7. A method for monitoring the condition of an IGBT, characterized in that, The method is applied to an IGBT state monitoring circuit, wherein the IGBT state monitoring circuit includes a processing circuit, a first detection circuit, a power amplifier circuit, and an IGBT module; wherein the first detection circuit includes at least three parallel comparators and a conduction voltage drop detection circuit; a first terminal of the processing circuit is connected to the first terminal of the at least three parallel comparators; a second terminal of the processing circuit is connected to the first terminal of the power amplifier circuit; a third terminal of the processing circuit is connected to the first terminal of the IGBT module; a second terminal of the at least three parallel comparators is connected to the first terminal of the conduction voltage drop detection circuit; a second terminal of the conduction voltage drop detection circuit is connected to the second terminal of the IGBT module; a second terminal of the power amplifier circuit is connected to the third terminal of the IGBT module; the method includes: When the IGBT module is fully turned on, the on-state voltage drop detection circuit obtains the saturation on-state voltage drop output by the power amplifier circuit under the target operating conditions of the IGBT module. The output level type is obtained by using the at least three parallel comparators under the influence of the saturation on-state voltage drop; When the processing circuit determines that the saturation on-state voltage drop is less than the threshold voltage, it identifies the aging degree of the IGBT based on the level type of the output of the at least three parallel comparators.

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