Monitoring circuit and monitoring method for health state of power device

Abstract

The invention discloses a power device health state monitoring circuit and method, and the circuit comprises a first measurement resistor, a second measurement resistor, a to-be-measured IGBT device, an MOS tube, and an operational amplifier, the collector end of the to-be-measured IGBT device is connected with the drain end of the MOS tube, the source end of the MOS tube is connected with the positive input end of the operational amplifier, and the positive input end of the operational amplifier is connected with the collector end of the to-be-measured IGBT device. The output end of the operational amplifier is connected with the first end of the first measuring resistor, the second end of the first measuring resistor is connected with the negative electrode input end of the operational amplifier and the first end of the second measuring resistor, and the second end of the second measuring resistor is connected with the grid electrode end of the MOS tube and the emitter electrode end of the IGBT device to be measured. According to the invention, the structure is simple, the cost of the monitoring circuit can be reduced, the voltage is directly amplified through the operational amplifier gain for monitoring, the problems of insufficient precision and poor anti-interference capability can be improved, the detection precision is improved, and the monitoring error is reduced.

Description

Background Art

[0002] Power semiconductor devices play an important role in people's production and life. Among them, IGBT (Insulated Gate Bipolar Transistor) is one of the power devices. Due to its advantages such as fast switching speed, low driving power and high current density, it has been widely used in important fields such as rail transportation, new energy power generation, aerospace, etc.

[0003] As a key device for power transmission and conversion, IGBT works under high voltage and high current conditions for a long time. Once the device fails, the whole equipment will be shut down. Therefore, it is necessary to monitor the health status of power devices to avoid losses caused by device failure. Generally, the electrical and thermal signals (such as conduction voltage drop, leakage current, thermal resistance, etc.) of the circuit where the power devices such as IGBT are located are measured when the equipment is running, and the health status of the power device is determined according to the numerical value of the electrical and thermal signals.

[0004] However, the above method has the following technical problems: the circuit where power devices such as IGBT are located will be affected by various factors during operation, causing the monitored signal to fluctuate and change, with large errors; and after a long period of operation, the IGBT will have inconsistent thermal expansion between the chip and the packaging material of the circuit, further causing the monitored signal to deviate from the actual signal, thereby reducing the accuracy of monitoring. Summary of the invention

[0005] The present invention provides a monitoring circuit and a monitoring method for the health status of a power device, and the circuit and the method can solve the technical problems of large monitoring error and low monitoring accuracy in the prior art.

[0006] A first aspect of an embodiment of the present invention provides a monitoring circuit for the health status of a power device, the circuit comprising: a first measuring resistor, a second measuring resistor, an IGBT device to be tested, a MOS tube and an operational amplifier;

[0007] Among them, the collector terminal of the IGBT device to be tested is connected to the drain terminal of the MOS tube, the source terminal of the MOS tube is connected to the positive input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the first end of the first measuring resistor, the second end of the first measuring resistor is respectively connected to the negative input terminal of the operational amplifier and the first end of the second measuring resistor, and the second end of the second measuring resistor is respectively connected to the gate terminal of the MOS tube and the emitter terminal of the IGBT device to be tested.

[0008] In combination with the first aspect, in one implementation, the circuit includes: a delay resistor and a delay capacitor;

[0009] The first end of the delay resistor is connected to the gate terminal of the IGBT device to be tested, the second end of the delay resistor is respectively connected to the emitter terminal of the IGBT device to be tested and the first end of the delay capacitor, and the second end of the delay capacitor is connected to the second end of the second measuring resistor.

[0010] In combination with the first aspect, in one implementation, the circuit includes: an anti-reverse diode;

[0011] The positive terminal of the anti-reverse diode is connected to the source terminal of the MOS tube, and the negative terminal of the anti-reverse diode is connected to the output terminal of the operational amplifier.

[0012] In combination with the first aspect, in one implementation, the circuit includes: a noise reduction capacitor;

[0013] The first end of the noise reduction capacitor is connected to the cathode end of the anti-reverse diode, and the second end of the noise reduction capacitor is connected to the second end of the second measuring resistor.

[0014] In combination with the first aspect, in one implementation, the circuit includes: a voltage dividing resistor;

[0015] The first end of the voltage-dividing resistor is connected to the positive terminal of the anti-reverse diode, and the second end of the voltage-dividing resistor is connected to the second end of the second measuring resistor.

[0016] In combination with the first aspect, in one implementation, the circuit includes: a shunt resistor;

[0017] The first end of the shunt resistor is connected to the emitter terminal of the IGBT device to be measured, and the second end of the shunt resistor is connected to the second end of the second measuring resistor.

[0018] In combination with the first aspect, in one implementation, the circuit includes: a protection capacitor and a protection diode;

[0019] The first end of the second measuring resistor is connected to the first end of the protection capacitor and the negative terminal of the protection diode respectively;

[0020] The second end of the second measuring resistor is connected to the second end of the protection capacitor and the positive terminal of the protection diode respectively.

[0021] A second aspect of an embodiment of the present invention provides a method for monitoring the health status of a power device. The method is applicable to the monitoring circuit for the health status of a power device as described above. The method includes:

[0022] After transmitting a driving signal to the gate terminal of the IGBT device to be tested, detecting a voltage at a connection terminal of the first measuring resistor and the second measuring resistor to obtain a measured voltage value;

[0023] Calculating the on-state voltage drop value of the IGBT device to be tested by using the measured voltage value;

[0024] The health state of the IGBT device to be tested is determined according to the difference between the on-state voltage drop value and a preset voltage value, wherein the preset voltage value is the voltage value of the positive input terminal of the operational amplifier when the IGBT device to be tested is working normally.

[0025] A third aspect of an embodiment of the present invention provides a device for monitoring the health status of a power device. The device is applicable to the monitoring circuit for the health status of a power device as described above. The device includes:

[0026] A voltage measurement module is used to detect the voltage at the connection end of the first measurement resistor and the second measurement resistor after transmitting a driving signal to the gate end of the IGBT device to be measured, so as to obtain a measurement voltage value;

[0027] A voltage calculation module is used to calculate the on-state voltage drop value of the IGBT device to be tested using the measured voltage value;

[0028] The detection status module is used to determine the health status of the IGBT device to be tested according to the difference between the on-state voltage drop value and a preset voltage value. The preset voltage value is the voltage value of the positive input terminal of the operational amplifier when the IGBT device to be tested is working normally.

[0029] Compared with the prior art, the embodiments of the present invention provide a monitoring circuit, status detection method, device and equipment for the health status of a power device, which have the following beneficial effects: the present invention can add an operational amplifier on the basis of the IGBT device to be tested, and directly amplify the on-state voltage drop of the IGBT device to be tested by adjusting the operational amplifier gain of the operational amplifier. Not only is the structure simple, which can reduce the cost of the monitoring circuit, but also the voltage is directly amplified by the operational amplifier gain for monitoring, which can improve the problems of insufficient accuracy and poor anti-interference ability, thereby improving the detection accuracy and reducing the monitoring error. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of a power device health status monitoring circuit provided by an embodiment of the present invention;

[0031] Figure 2 It is a flow chart of a method for monitoring the health status of a power device provided by an embodiment of the present invention;

[0032] Figure 3 It is a structural schematic diagram of a device for monitoring the health status of a power device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in 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 creative work are within the scope of protection of the present invention.

[0034] Power semiconductor devices play an important role in people's production and life. Among them, IGBT (Insulated Gate Bipolar Transistor) is one of the power devices. Due to its advantages such as fast switching speed, low driving power and high current density, it has been widely used in important fields such as rail transportation, new energy power generation, aerospace, etc.

[0035] As a key device for power transmission and conversion, IGBT works under high voltage and high current conditions for a long time. Once the device fails, the whole equipment will be shut down. Therefore, it is necessary to monitor the health status of power devices to avoid losses caused by device failure. Generally, the electrical and thermal signals (such as conduction voltage drop, leakage current, thermal resistance, etc.) of the circuit where the power devices such as IGBT are located are measured when the equipment is running, and the health status of the power device is determined according to the numerical value of the electrical and thermal signals.

[0036] However, the above method has the following technical problems: the circuit where power devices such as IGBT are located will be affected by various factors during operation, causing the monitored signal to fluctuate and change, with large errors; and after a long period of operation, the IGBT will have inconsistent thermal expansion between the chip and the packaging material of the circuit, further causing the monitored signal to deviate from the actual signal, thereby reducing the accuracy of monitoring.

[0037] In order to solve the above problems, a power device health status monitoring circuit, status detection method, device and equipment provided in the embodiments of the present application will be introduced and explained in detail through the following specific embodiments.

[0038] Reference Figure 1 , showing a schematic structural diagram of a power device health status monitoring circuit provided by an embodiment of the present invention.

[0039] As an example, the monitoring circuit of the health status of the power device may include: a first measuring resistor R f , a second measuring resistor R2, an IGBT device to be measured, a MOS tube M1 and an operational amplifier U1;

[0040] The collector terminal of the IGBT device to be tested is connected to the drain terminal of the MOS tube M1, the source terminal of the MOS tube M1 is connected to the positive input terminal of the operational amplifier U1, and the output terminal of the operational amplifier U1 is connected to the first measuring resistor R f The first end of the first measuring resistor R f The second end of is respectively connected to the negative input end of the operational amplifier U1 and the first end of the second measuring resistor R2, and the second end of the second measuring resistor R2 is respectively connected to the gate end of the MOS tube M1 and the emitter end of the IGBT device to be tested.

[0041] When performing specific measurements, a drive signal V can be sent to the IGBT device under test. G , the IGBT device to be tested will be in the on state, and the voltage of the IGBT device to be tested will be transmitted to the positive input terminal of the operational amplifier U1. After being amplified by the operational amplifier U1, the on-state voltage drop of the IGBT device can be measured immediately.

[0042] When there is a driving signal V G When the IGBT device under test is turned on, the voltage of the IGBT device under test will be transmitted to the positive input terminal of the operational amplifier U1. If the voltage of the IGBT device under test is a high voltage value, after repeated use, the high voltage of the IGBT device under test will cause damage to the circuit. To avoid the above situation, refer to Figure 1 , wherein, as an example, the circuit includes: a delay resistor R0 and a delay capacitor C0.

[0043] The first end of the delay resistor R0 is connected to the gate end of the IGBT device to be tested, the second end of the delay resistor R0 is respectively connected to the emitter end of the IGBT device to be tested and the first end of the delay capacitor C0, and the second end of the delay capacitor C0 is connected to the second end of the second measuring resistor R2.

[0044] The delay resistor R0 and the delay capacitor C0 will form a delay circuit. When there is a driving signal V G Due to the existence of the delay circuit, the MOS tube M1 will not be turned on immediately, but will be turned on after a period of time t (t=R0C0). This ensures that the MOS tube M1 is always turned on later than the IGBT device to be tested, and avoids the high voltage of the collector of the IGBT device to be tested directly inputting into the positive input terminal of the operational amplifier U1, which may cause damage to the circuit.

[0045] Optionally, the drive signal V G It can be connected to the gate terminal of the IGBT device to be tested. At the same time, the drive signal V GIt is also possible to connect the MOS tube M1 through a delay circuit composed of a delay resistor R0 and a delay capacitor C0. The advantage of this is that it ensures that the turn-on time of the MOS tube M1 is always later than the IGBT device to be tested, and can avoid the high voltage of the collector being directly added to the positive input terminal of the operational amplifier when the IGBT device to be tested is not turned on, thereby preventing the circuit from being damaged.

[0046] When there is no driving signal V G When the IGBT device under test is turned off, there will be a return current after the IGBT device under test is turned off, causing circuit damage. To avoid the above situation, refer to Figure 1 , wherein, as an example, the circuit includes: an anti-reverse diode D1.

[0047] The positive terminal of the anti-reverse diode D1 is connected to the source terminal of the MOS tube M1, and the negative terminal of the anti-reverse diode D1 is connected to the output terminal of the operational amplifier U1.

[0048] During monitoring, when there is a driving signal V G The IGBT device to be tested is driven to be turned on, so that the MOS tube M1 is turned on. At this time, the voltage between the drain and source ends of the MOS tube M1 is the on-state voltage V of the IGBT device to be tested. ce_on , on-state voltage V ce_on After passing through the anti-reverse diode D1, it is amplified by the operational amplifier U1. The anti-reverse diode D1 can prevent reverse current when the IGBT device to be tested is turned off.

[0049] If there is a large current and a large voltage, it is easy to cause the operational amplifier U1 to be damaged, increase the risk of use, and reduce the service life of the circuit. To avoid the above situation, refer to Figure 1 , where, as an example, the circuit includes: a noise reduction capacitor C1, a voltage divider resistor R1 and a shunt resistor R ds .

[0050] The first end of the noise reduction capacitor C1 is connected to the cathode end of the anti-reverse diode D1, and the second end of the noise reduction capacitor C1 is connected to the second end of the second measuring resistor R2.

[0051] The first end of the voltage-dividing resistor R1 is connected to the positive terminal of the anti-reverse diode D1 , and the second end of the voltage-dividing resistor R1 is connected to the second end of the second measuring resistor R2 .

[0052] The shunt resistor R ds The first end of the shunt resistor R ds The second end of is connected to the second end of the second measuring resistor R2.

[0053] Noise reduction capacitor C1 can be used to filter out the noise at the positive input of operational amplifier U1, and shunt resistor R ds Can be used to shunt current, shunt resistor R ds The resistance value can be small and is used to measure the current flowing through the IGBT device under test.

[0054] When the MOS tube M1 is turned on, the on-resistance of the MOS tube M1 is several hundred ohms to several thousand ohms. The voltage-dividing resistor R1 is used for voltage division. The voltage across it can be regarded as the voltage of the positive input terminal of the operational amplifier U1. When its resistance is large enough, the voltage of the positive input terminal of the operational amplifier U1 is the on-voltage drop V of the IGBT device to be tested. ce_on .

[0055] In actual use, the on-state voltage drop V ce_on Through MOS tube M1, anti-reverse diode D1 is connected to the positive input terminal of operational amplifier U1. ce_o n is generally a very small value, usually around 2V. During the aging monitoring process, its rise is only tens to hundreds of millivolts. The operating conditions of the IGBT device to be tested are high voltage and high current. In this case, the on-state voltage drop V ce_on It is very susceptible to electromagnetic interference, which can cause V ce_on To solve this problem, the V ce_on Before connecting to the positive input terminal of the operational amplifier U1, add the noise reduction capacitor C1 to filter the signal. At the same time, use the same-direction amplification function of the operational amplifier U1 to collect the conduction voltage drop V ce_on Amplification is performed to improve the accuracy of monitoring. According to the "virtual short and virtual break" of the operational amplifier U1, the output voltage of the operational amplifier U1 is V0 = (1 + R f / R2)V ce_on , by selecting a suitable first measuring resistor R f and the second measuring resistor R2, can achieve V ce_on amplification effect.

[0056] In one embodiment, if the voltage at the output end of the operational amplifier U1 is too large, the subsequent circuit may be damaged. In order to protect the subsequent circuit, refer to Figure 1 , wherein, as an example, the circuit includes: a protection capacitor C f and protection diode Z1.

[0057] The first end of the second measuring resistor R2 is connected to the first end of the protection capacitor and the negative terminal of the protection diode Z1 respectively;

[0058] The second end of the second measuring resistor R2 is connected to the second end of the protection capacitor and the positive terminal of the protection diode Z1 respectively.

[0059] Protection capacitor C f It can be a filter capacitor with a smaller capacitance value, and the protection diode Z1 can be a Zener diode for protection. Its working principle is that when the output value of the operational amplifier U1 is too large, the protection diode Z1 can limit the voltage to a lower range to prevent overvoltage from damaging the subsequent circuit.

[0060] In this embodiment, the embodiment of the present invention provides a monitoring circuit for the health status of a power device, and its beneficial effects are: the present invention can add an operational amplifier on the basis of the IGBT device to be tested, and directly amplify the on-state voltage drop of the IGBT device to be tested by adjusting the operational amplifier gain of the operational amplifier. Not only is the structure simple, the cost of the monitoring circuit can be reduced, but also the voltage is directly amplified by the operational amplifier gain for measurement, which can improve the problems of insufficient accuracy and poor anti-interference ability, thereby improving detection accuracy and reducing measurement errors.

[0061] Reference Figure 2 , showing a flow chart of a method for monitoring the health status of a power device provided by an embodiment of the present invention.

[0062] The method may be applicable to the power device health status monitoring circuit as described in the above embodiment, wherein, as an example, the power device health status monitoring method may include:

[0063] S11 . After transmitting a driving signal to the gate terminal of the IGBT device to be measured, detecting the voltage at the connection terminal of the first measuring resistor and the second measuring resistor to obtain a measured voltage value.

[0064] S12. Calculate the on-state voltage drop value of the IGBT device to be tested using the measured voltage value.

[0065] S13, determining the health status of the IGBT device to be tested according to the difference between the on-state voltage drop value and a preset voltage value, wherein the preset voltage value is the voltage value of the positive input terminal of the operational amplifier when the IGBT device to be tested is working normally.

[0066] Specifically, a driving signal V may be transmitted to the gate terminal of the IGBT device to be tested. G , when there is a driving signal V GWhen the IGBT device to be tested is turned on immediately, due to the existence of the delay circuit, the MOS tube M1 will not be turned on immediately, but will be turned on after a time t=R0C0. This ensures that the MOS tube M1 is always turned on later than the IGBT device to be tested, and avoids the high voltage of the IGBT device to be tested directly input into the positive input terminal of the operational amplifier U1, which may cause damage to the circuit.

[0067] After the MOS tube M1 is turned on, the voltage between the drain terminal and the source terminal of the MOS tube M1 is the on-state voltage V of the IGBT device to be tested. ce_on After the same direction amplification, the output value of the operational amplifier U1 is V0 = (1 + R f / R2)V ce_on , by selecting the first measuring resistor R f and the value of the second measuring resistor R2 can more accurately measure the on-state voltage drop V of the IGBT device to be tested ce_on .

[0068] Specifically, the on-state voltage drop V ce_on The calculation can be shown as follows:

[0069] V0=(1+R f / R2)V ce_on ;

[0070] exist Figure 1 According to the “virtual short”, V i =V - Because of the "virtual disconnection", there is no current input or output at the reverse input terminal, and the first measuring resistor R f The current of the second measuring resistor R2 is equal to that of the second measuring resistor R2. Let this current be I. According to Ohm's law, I=V out / (R f +R2), V i Equal to the divided voltage on resistor R2, that is, V i =I*R2, from the above formulas we can get: V out =Vi*(R f +R2) / R2. The first measuring resistor R f The parameter selection and measurement process of the second measuring resistor R2 are shown in the following table. Assuming that a certain type of IGBT device to be tested is working normally, its on-state voltage drop V ce_on =2V.

[0071]

[0072] According to the measurements in the table above, by choosing a suitable first measuring resistor R fThe resistance value of the second measuring resistor R2 can amplify the originally small difference by 10 times, which can be more conducive to monitoring and judging the aging status of the IGBT. At the same time, due to the addition of the operational amplifier U1, the measurement of the amplified difference is less susceptible to interference than before.

[0073] According to the above description, it can be known that when obtaining the first measured resistance R f After obtaining the measured voltage value of the connection terminal of the second measuring resistor R2, the on-state voltage drop value of the IGBT device to be measured can be calculated using the measured voltage value according to the above formula.

[0074] Then, the difference between the on-state voltage drop value and the preset voltage value is calculated, and then the health status of the IGBT device to be tested is determined based on the numerical value of the difference, wherein the preset voltage value is the voltage value at the positive input terminal of the operational amplifier when the IGBT device to be tested is working normally, for example, 2V.

[0075] In one operation mode, after a long period of operation, the IGBT device under test will generate stress due to the inconsistent thermal expansion between the chip and the packaging material, which will eventually lead to thermal fatigue and crack formation. Or due to repeated power cycles, the chip connection and packaging of the IGBT device under test will generate mechanical stress, which will lead to failure. It is generally believed that the on-state voltage drop V ce_on If it rises by about 30%, it can be considered that the device has failed. Specifically, the health status can be shown in the following table.

[0076]

[0077]

[0078] Assuming that the difference between the on-state voltage drop value and the preset voltage value is 0.5V, 0.5 / 2=0.25, that is, the rise value is 20%-30%, it can be judged that the health state of the IGBT device to be tested is severely aged. For another example, if the difference between the on-state voltage drop value and the preset voltage value is 0.2V, 0.2 / 2=0.1, that is, the rise value is 5%-10%, it can be judged that the health state of the IGBT device to be tested is generally aged.

[0079] In addition, it should be noted that when there is no driving signal V G Or the driving signal V GWhen the voltage is smaller, the IGBT device to be tested will be turned off. At this time, due to the existence of the delay circuit, the MOS tube M1 will not be turned off immediately, but will continue to be turned on for a duration of t=R0C0. In this process, the positive input terminal of the operational amplifier U1 is directly connected to the IGBT device to be tested. This voltage is a high voltage, but due to the short time and the existence of the Zener diode, it will not have much impact on the circuit. After that, the MOS tube M1 is also turned off, and the collector voltage of the IGBT device to be tested is shared by the MOS tube M1. The appropriate MOS tube M1 can be selected according to the operating voltage of the IGBT device to be tested.

[0080] The above power device health status monitoring circuit is not only simple in structure and low in cost, but also has higher monitoring accuracy for the on-state voltage drop and stronger anti-interference ability due to the use of operational amplifiers. In the design of the circuit, both practicality and safety are taken into account, and high-precision monitoring can be achieved. During use, the MOS tube M1 can be replaced according to actual needs, and the first measuring resistor R f , a second measuring resistor R2 and a protection diode Z1.

[0081] In this embodiment, an embodiment of the present invention provides a method for monitoring the health status of a power device, and its beneficial effects are: the present invention can transmit a driving signal to the gate terminal of the IGBT device to be tested, so that the device connected to the IGBT device to be tested is turned on, and the on-state voltage drop value of the IGBT device to be tested is calculated; the health status of the IGBT device to be tested is determined according to the difference between the on-state voltage drop value and the preset voltage value, so as to reduce the error in monitoring the on-state voltage drop, improve the accuracy of the on-state voltage drop, and accurately determine the health status of the IGBT device according to the numerical value of the accurately monitored on-state voltage drop, thereby improving the monitoring accuracy of the health status.

[0082] The embodiment of the present invention also provides a device for monitoring the health status of a power device, see Figure 3 , showing a schematic structural diagram of a device for monitoring the health status of a power device provided by an embodiment of the present invention.

[0083] The device is applicable to the monitoring circuit of the health status of the power device as described in the above embodiment, wherein, as an example, the monitoring device of the health status of the power device may include:

[0084] The voltage measurement module 310 is used to detect the voltage at the connection end of the first measurement resistor and the second measurement resistor after transmitting the driving signal to the gate end of the IGBT device to be measured, so as to obtain a measurement voltage value;

[0085] A voltage calculation module 320 is used to calculate the on-state voltage drop value of the IGBT device to be tested using the measured voltage value;

[0086] The detection status module 330 is used to determine the health status of the IGBT device under test according to the difference between the on-state voltage drop value and a preset voltage value. The preset voltage value is the voltage value of the positive input terminal of the operational amplifier when the IGBT device under test works normally.

[0087] Those skilled in the art can clearly understand that, for the sake of convenience and brevity of description, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0088] Furthermore, an embodiment of the present application also provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method for monitoring the health status of a power device as described in the above embodiment is implemented.

[0089] Furthermore, an embodiment of the present application also provides a computer-readable storage medium, which stores a computer-executable program, and the computer-executable program is used to enable a computer to execute the method for monitoring the health status of a power device as described in the above embodiment.

[0090] It should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. When an element such as a layer, region or substrate is referred to as being "on" or "above" another element, it can be directly on the other element, or there can also be an intermediate element. On the contrary, when an element is referred to as "directly on" or "above" another element, there is no intermediate element. It should also be understood that when an element is referred to as being "under" or "below" another element, it can be directly under or below the other element, or there can also be an intermediate element. On the contrary, when an element is referred to as being "directly under" or "below" another element, there is no intermediate element. Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0091] Those skilled in the art will appreciate that the embodiments of the present application may also provide computer program products. Therefore, the present application may adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application may adopt the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program codes.

[0092] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), apparatuses, and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks 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 generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. 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.

[0093] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate 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 A function specified in one or more boxes.

[0094] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0095] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A power device health status monitoring circuit, characterized in that: The circuit comprises: a first measuring resistor, a second measuring resistor, an IGBT device to be measured, a MOS tube and an operational amplifier; Among them, the collector terminal of the IGBT device to be tested is connected to the drain terminal of the MOS tube, the source terminal of the MOS tube is connected to the positive input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the first end of the first measuring resistor, the second end of the first measuring resistor is respectively connected to the negative input terminal of the operational amplifier and the first end of the second measuring resistor, and the second end of the second measuring resistor is respectively connected to the gate terminal of the MOS tube and the emitter terminal of the IGBT device to be tested.

2. The power device health status monitoring circuit according to claim 1, characterized in that: The circuit comprises: a delay resistor and a delay capacitor; The first end of the delay resistor is connected to the gate terminal of the IGBT device to be tested, the second end of the delay resistor is respectively connected to the emitter terminal of the IGBT device to be tested and the first end of the delay capacitor, and the second end of the delay capacitor is connected to the second end of the second measuring resistor.

3. The power device health status monitoring circuit according to claim 1, characterized in that: The circuit comprises: an anti-reverse diode; The positive terminal of the anti-reverse diode is connected to the source terminal of the MOS tube, and the negative terminal of the anti-reverse diode is connected to the output terminal of the operational amplifier.

4. The power device health status monitoring circuit according to claim 3, characterized in that: The circuit includes: a noise reduction capacitor; The first end of the noise reduction capacitor is connected to the cathode end of the anti-reverse diode, and the second end of the noise reduction capacitor is connected to the second end of the second measuring resistor.

5. The power device health status monitoring circuit according to claim 3, characterized in that: The circuit comprises: a voltage dividing resistor; The first end of the voltage-dividing resistor is connected to the positive terminal of the anti-reverse diode, and the second end of the voltage-dividing resistor is connected to the second end of the second measuring resistor.

6. The power device health status monitoring circuit according to claim 1, characterized in that: The circuit comprises: a shunt resistor; The first end of the shunt resistor is connected to the emitter terminal of the IGBT device to be measured, and the second end of the shunt resistor is connected to the second end of the second measuring resistor.

7. The power device health status monitoring circuit according to any one of claims 1 to 6, characterized in that: The circuit comprises: a protection capacitor and a protection diode; The first end of the second measuring resistor is connected to the first end of the protection capacitor and the negative terminal of the protection diode respectively; The second end of the second measuring resistor is connected to the second end of the protection capacitor and the positive terminal of the protection diode respectively.

8. A method for monitoring the health status of a power device, characterized in that: The method is applicable to the power device health status monitoring circuit according to any one of claims 1 to 7, and the method comprises: After transmitting a driving signal to the gate terminal of the IGBT device to be tested, detecting a voltage at a connection terminal of the first measuring resistor and the second measuring resistor to obtain a measured voltage value; Calculating the on-state voltage drop value of the IGBT device to be tested by using the measured voltage value; The health state of the IGBT device to be tested is determined according to the difference between the on-state voltage drop value and a preset voltage value, wherein the preset voltage value is the voltage value of the positive input terminal of the operational amplifier when the IGBT device to be tested is working normally.

9. A device for monitoring the health status of a power device, characterized in that: The device is applicable to the power device health status monitoring circuit according to any one of claims 1 to 7, and the device comprises: A voltage measurement module is used to detect the voltage at the connection end of the first measurement resistor and the second measurement resistor after transmitting a driving signal to the gate end of the IGBT device to be measured, so as to obtain a measurement voltage value; A voltage calculation module is used to calculate the on-state voltage drop value of the IGBT device to be tested using the measured voltage value; The detection status module is used to determine the health status of the IGBT device to be tested according to the difference between the on-state voltage drop value and a preset voltage value. The preset voltage value is the voltage value of the positive input terminal of the operational amplifier when the IGBT device to be tested is working normally.

10. An electronic device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for monitoring the health status of a power device as claimed in claim 8 when executing the computer program.

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