Temperature detection method, device and circuit of insulated gate bipolar transistor

Abstract

The invention provides a temperature detection method, device and circuit of an insulated gate bipolar transistor, which can be applied to the technical field of power electronics. The temperature detection method is applied to a temperature detection circuit, and the temperature detection circuit is located on a driving board. Determining the power-on start of the driving board and the start of the power factor correction circuit, and judging whether the IGBT is in a turn-off state or not; when the IGBT is in a turn-off state, the voltage of the negative temperature coefficient thermistor is collected. And obtaining the temperature of the IGBT based on the voltage of the negative temperature coefficient thermistor, and if the temperature of the IGBT is greater than a preset reference temperature, executing frequency limiting and reducing operation on the driving board. When the IGBT is in the off state, temperature detection is carried out, and the detection error can be reduced. Temperature detection is carried out by utilizing the characteristic that the resistance value of the negative temperature coefficient thermistor is reduced along with the rise of the temperature, so that the accuracy of IGBT temperature detection is improved, the situation that protection is not carried out when the temperature is too high or mistaken protection is carried out when the temperature is insufficient is avoided, and frequency limiting and reducing protection is reliably carried out on the driving board.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a temperature detection method, device, and circuit for an insulated gate bipolar transistor. Background Art

[0002] Driver boards with power factor correction (PFC) circuits primarily use air cooling and liquid cooling. For example, using air cooling to dissipate heat from the PFC circuit's key power components can lead to excessive temperatures as ambient temperature, driver board power levels rise, or fan damage occurs. This can necessitate power reduction or shutdown to prevent damage.

[0003] The main power components of a PFC circuit include a rectifier bridge, insulated-gate bipolar transistors (IGBTs), and intelligent power modules (IPMs). The IPM, located in the downstream stage, has internal temperature sensing capabilities, directly outputting the temperature to the main chip for downstream protection. However, discrete PFC circuits, such as the rectifier bridge and IGBTs located in the upstream stage, lack temperature sensing capabilities. Therefore, it is crucial to implement a circuit that accurately senses the IGBT temperature for protection, as it is the hottest part of the circuit.

[0004] Currently, a temperature sampling circuit using a negative temperature coefficient (NTC) thermistor is typically placed near the IGBT emitter pin, but at a distance. This circuit uses spatial heat radiation to simulate and estimate the IGBT temperature during IGBT operation. However, this method provides low IGBT temperature measurement accuracy and is ineffective in protecting the driver board. Summary of the Invention

[0005] In view of this, the present application provides a temperature detection method, device and circuit for an insulated gate bipolar transistor, which can improve the accuracy of IGBT temperature detection and reliably perform frequency limiting and reducing protection on the driver board.

[0006] To solve the above problems, the technical solutions provided by this application are as follows:

[0007] In a first aspect, the present application provides a temperature detection method for an insulated gate bipolar transistor, the temperature detection method being applied to a temperature detection circuit, the temperature detection circuit being located on a driver board, the temperature detection circuit comprising a power factor correction circuit, a negative temperature coefficient thermistor, a differential circuit, and a main chip, the insulated gate bipolar transistor being disposed in the power factor correction circuit; the output end of the main chip being connected to the gate of the insulated gate bipolar transistor, the input end of the main chip being connected to the second end of the differential circuit; the emitter of the insulated gate bipolar transistor being connected to the first end of the negative temperature coefficient thermistor; and the second end of the negative temperature coefficient thermistor being connected to the first end of the differential circuit;

[0008] The temperature detection method comprises:

[0009] In response to determining that the driving board is powered on and the power factor correction circuit is started, determining whether the insulated gate bipolar transistor is in an off state;

[0010] When the insulated gate bipolar transistor is in an off state, collecting the voltage of the negative temperature coefficient thermistor;

[0011] obtaining a temperature of the insulated gate bipolar transistor based on a voltage of the negative temperature coefficient thermistor;

[0012] If the temperature of the insulated gate bipolar transistor is greater than a preset reference temperature, a frequency limiting and reducing operation is performed on the driving board.

[0013] In one possible implementation, when the insulated gate bipolar transistor is in an off state, collecting the voltage of the negative temperature coefficient thermistor includes:

[0014] Presetting a dead time during a time period in which the insulated gate bipolar transistor is in an off state;

[0015] After the dead time is reached, the voltage of the negative temperature coefficient thermistor is collected.

[0016] In one possible implementation, obtaining the temperature of the insulated gate bipolar transistor based on the voltage of the negative temperature coefficient thermistor includes:

[0017] determining a resistance value of the negative temperature coefficient thermistor based on a voltage of the negative temperature coefficient thermistor;

[0018] According to the corresponding relationship between the temperature and the resistance value of the negative temperature coefficient thermistor, the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is determined, and the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is the temperature of the insulated gate bipolar transistor.

[0019] In one possible implementation, the temperature detection method further includes:

[0020] If the temperature of the insulated gate bipolar transistor is not greater than the preset reference temperature, a normal operation signal is sent to the driving board.

[0021] In a second aspect, the present application provides a temperature detection device for an insulated gate bipolar transistor, the temperature detection device being applied to a temperature detection circuit, the temperature detection circuit being located on a driver board, the temperature detection circuit comprising a power factor correction circuit, a negative temperature coefficient thermistor, a differential circuit, and a main chip, the insulated gate bipolar transistor being disposed in the power factor correction circuit; the output end of the main chip being connected to the gate of the insulated gate bipolar transistor, the input end of the main chip being connected to the second end of the differential circuit; the emitter of the insulated gate bipolar transistor being connected to the first end of the negative temperature coefficient thermistor; and the second end of the negative temperature coefficient thermistor being connected to the first end of the differential circuit;

[0022] The temperature detection device includes a judgment module, a collection module, an acquisition module and a frequency reduction module:

[0023] The judging module is configured to judge whether the insulated gate bipolar transistor is in an off state in response to determining that the driving board is powered on and the power factor correction circuit is started;

[0024] The acquisition module is used to collect the voltage of the negative temperature coefficient thermistor when the insulated gate bipolar transistor is in an off state;

[0025] The acquisition module is configured to obtain the temperature of the insulated gate bipolar transistor based on the voltage of the negative temperature coefficient thermistor;

[0026] The frequency limiting and reducing module is used to perform a frequency limiting and reducing operation on the driving board if the temperature of the insulated gate bipolar transistor is greater than a preset reference temperature.

[0027] In one possible implementation, the acquisition module is specifically configured to:

[0028] A dead time is pre-set within a time period in which the insulated gate bipolar transistor is in an off state; and after the dead time is reached, the voltage of the negative temperature coefficient thermistor is collected.

[0029] In one possible implementation, the acquisition module is specifically configured to:

[0030] The resistance value of the negative temperature coefficient thermistor is determined based on the voltage of the negative temperature coefficient thermistor; the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is determined according to the corresponding relationship between the temperature and the resistance value of the negative temperature coefficient thermistor, and the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is the temperature of the insulated gate bipolar transistor.

[0031] In one possible implementation, the temperature detection device further includes a signal sending module:

[0032] The signal sending module is configured to send a normal operation signal to the driving board if the temperature of the insulated gate bipolar transistor is not greater than the preset reference temperature.

[0033] In a third aspect, the present application provides a temperature detection circuit for an insulated gate bipolar transistor, the temperature detection circuit being located on a driver board and comprising a power factor correction circuit, a negative temperature coefficient thermistor, a differential circuit, and a main chip; the power factor correction circuit comprising a voltage input terminal and an insulated gate bipolar transistor;

[0034] The voltage input terminal is connected to the collector and emitter of the insulated gate bipolar transistor;

[0035] The output terminal of the master chip is connected to the gate of the insulated gate bipolar transistor, and the input terminal of the master chip is connected to the second terminal of the differential circuit;

[0036] The emitter of the insulated gate bipolar transistor is connected to the first end of the negative temperature coefficient thermistor;

[0037] The second end of the negative temperature coefficient thermistor is connected to the first end of the differential circuit;

[0038] The main chip is used to send a control signal to the insulated gate bipolar transistor after the driving board is powered on;

[0039] The insulated gate bipolar transistor is configured to output a first signal according to the control signal and the voltage inputted from the voltage input terminal;

[0040] The differential circuit is used to perform a differential operation on the first signal passing through the negative temperature coefficient thermistor to obtain a second signal, and input the second signal to the main chip;

[0041] The main chip is further used to determine whether the insulated gate bipolar transistor is in an off state based on the second signal; when the insulated gate bipolar transistor is in the off state, collect the voltage of the negative temperature coefficient thermistor; obtain the temperature of the insulated gate bipolar transistor based on the voltage of the negative temperature coefficient thermistor; if the temperature of the insulated gate bipolar transistor is greater than a preset reference temperature, send a frequency reduction signal to the driver board.

[0042] In one possible implementation, the power factor correction circuit further includes a fast recovery diode;

[0043] The first end of the fast recovery diode is connected to the collector of the insulated gate bipolar transistor;

[0044] The second end of the fast recovery diode is connected to the emitter of the insulated gate bipolar transistor;

[0045] The fast recovery diode is used to protect the insulated gate bipolar transistor during the operation of the power factor correction circuit.

[0046] It can be seen that this application has the following beneficial effects:

[0047] The present application provides a temperature detection method, device, and circuit for an insulated gate bipolar transistor (IGBT). The temperature detection method is applied to a temperature detection circuit located on a driver board. The temperature detection circuit includes a power factor correction circuit, a negative temperature coefficient (NTC) thermistor (NTC), a differential circuit, and a main chip. The IGBT is located in the power factor correction circuit. The output terminal of the main chip is connected to the gate of the IGBT, and the input terminal of the main chip is connected to the second terminal of the differential circuit. The emitter of the IGBT is connected to the first terminal of the NTC thermistor (NTC), and the second terminal of the NTC thermistor is connected to the first terminal of the differential circuit. The temperature detection method first determines whether the IGBT is in the off state in response to determining that the driver board is powered on and the power factor correction circuit is activated. When the IGBT is determined to be in the off state, the voltage of the NTC thermistor is collected. The temperature of the IGBT is then obtained based on the voltage of the NTC thermistor. If the temperature of the IGBT is greater than a preset reference temperature, a frequency reduction operation is performed on the driver board. In this way, temperature detection is performed when the IGBT is in the off state, which can reduce detection errors. Temperature detection utilizes the characteristic of negative temperature coefficient thermistors (NTCs) that their resistance decreases as temperature increases, thereby improving the accuracy of IGBT temperature detection. This avoids failure to protect due to overtemperature or erroneous protection due to insufficient temperature, and reliably implements frequency reduction protection for the driver board.

[0048] The embodiments of the present application also provide devices and circuits corresponding to the above methods, which have the same beneficial effects as the above methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A schematic structural diagram of a temperature detection circuit for an insulated gate bipolar transistor provided in an embodiment of the present application;

[0050] Figure 2 A schematic flow chart of a temperature detection method for an insulated gate bipolar transistor provided in an embodiment of the present application;

[0051] Figure 3 A schematic structural diagram of a temperature detection device for an insulated gate bipolar transistor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0053] In this application, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0054] To facilitate understanding of the technical solutions provided in the embodiments of the present application, a temperature detection method, device, and circuit for an insulated gate bipolar transistor provided in the embodiments of the present application are described below with reference to the accompanying drawings.

[0055] See also Figure 1 , Figure 1 A schematic structural diagram of a temperature detection circuit for an insulated gate bipolar transistor provided in an embodiment of the present application.

[0056] In the embodiments of this application, the driver board is equipped with an insulated gate bipolar transistor temperature detection circuit. A driver board is a board-level circuit product used to process and convert signals to drive other devices or components. Driver boards can be divided into various types depending on the application scenario. Driver boards can integrate multiple circuits, improving operational efficiency and stability, reducing the error rate of electronic components, and thus enhancing the reliability of electronic equipment.

[0057] The temperature detection circuit includes a power factor correction (PFC) circuit 1 , a negative temperature coefficient (NTC) thermistor 2 , a differential circuit 3 and a main chip MCU 4 , wherein the PFC circuit 1 may include a voltage input terminal and an insulated gate bipolar transistor (IGBT).

[0058] The voltage input terminal of the PFC circuit 1 is connected to the collector and emitter of the IGBT, the output terminal of the main chip MCU (Microcontroller Unit) 4 is connected to the gate of the IGBT, the emitter of the IGBT is also connected to the first end of the NTC thermistor 2, the second end of the NTC thermistor 2 is connected to the first end of the differential circuit 3, and the second end of the differential circuit 3 is connected to the input terminal of the main chip MCU4.

[0059] See also Figure 1 The PFC circuit 1 may include an inductor, an IGBT, a fast recovery diode (FRD), an electrolytic capacitor, and a DC bus. The IGBT is one of the components that generates the most heat. The first end of the FRD is connected to the collector of the IGBT, the second end of the inductor, and the first end of the electrolytic capacitor. The second end of the FRD is connected to the emitter of the IGBT and the second end of the electrolytic capacitor via the DC bus. During the temperature detection process, this effectively prevents the PFC circuit 1 from burning out due to the large amount of energy released when the inductor suddenly loses power.

[0060] After the driver board is powered on and PFC circuit 1 is started, the main chip MCU4 sends a control signal to the IGBT, turning the IGBT on and off by controlling the gate voltage of the IGBT. Specifically, the temperature detection circuit also includes an IGBT driver circuit. The main chip MCU4 outputs the control signal to the IGBT driver circuit, which converts the control signal into a gate voltage suitable for the IGBT.

[0061] When the gate voltage applied to the IGBT is a positive voltage, the IGBT is turned on; when the gate voltage of the IGBT is 0V or a negative voltage, the IGBT is turned off. The IGBT outputs a first signal under the influence of the voltage input terminal and the control signal.

[0062] The differential circuit 3 includes a voltage follower differential amplifier, and the first signal is transmitted to the differential circuit 3 via the NTC thermistor 2. In the embodiment of the present application, the voltage follower differential amplifier is used to implement a voltage follower function.

[0063] Using NTC thermistor 2 as the output terminal of the IGBT allows it to be directly connected to the emitter of the IGBT. During wiring, a large number of NTC thermistors can be placed directly on the copper foil of the IGBT emitter. In other words, the copper foil of the IGBT emitter is directly connected to the NTC thermistor 2, and heat is transferred through the copper foil with good thermal conductivity rather than through space heat radiation.

[0064] The IGBT's heat sink is connected to the IGBT's collector. During PFC circuit 1 operation, the IGBT is constantly on and off, so the temperature of the IGBT's emitter is close to that of the IGBT's collector. Consequently, the temperature of the IGBT's emitter is close to that of the IGBT's heat sink. The IGBT's emitter is typically connected to a reference ground, allowing the NTC thermistor 2 to be directly placed there. The IGBT emitter temperature obtained in the present embodiment can reflect the IGBT's temperature.

[0065] The first signal is differentially connected to a voltage follower differential amplifier to form a second signal. The voltage follower differential amplifier isolates the first signal output by the IGBT from the main chip MCU4, thereby preventing the energy of the IGBT conduction period from damaging the chip.

[0066] After receiving the second signal transmitted by the differential circuit 3, the main chip MCU4 can determine whether the IGBT is on or off based on the second signal. If it is determined that the IGBT is in the off state, temperature detection is performed; if it is determined that the IGBT is in the on state, temperature detection is not performed. When the IGBT is in the on state, a large current flows through it, and the energy passing through the IGBT is large, which will cause ground line fluctuations and affect the accuracy of temperature detection. Therefore, the embodiment of the present application performs temperature detection when the IGBT is in the off state to reduce the error in temperature detection and improve the accuracy of temperature detection.

[0067] In the PFC circuit 1, the carrier frequency of the IGBT control signal is relatively high, and the temperature condition of the IGBT can be fed back in time, thereby avoiding the possibility of untimely temperature detection.

[0068] When the IGBT is off, the main chip MCU4 collects the voltage of NTC thermistor 2 and uses this voltage to determine the IGBT temperature. If the IGBT temperature exceeds a preset reference temperature, a frequency reduction signal is sent to the driver board. Taking advantage of the fact that the resistance of NTC thermistor 2 decreases as temperature rises, temperature detection is performed based on the different collected voltages.

[0069] In summary, the temperature detection circuit of the present embodiment can detect the temperature of the IGBT. When the IGBT temperature exceeds the reference temperature, the driver board performs a frequency reduction operation. By reducing the overall operating power of the driver board, the temperature of the IGBT and other devices is reduced, keeping the device temperature within a safe range.

[0070] This embodiment provides a temperature detection method for an insulated gate bipolar transistor (IGBT). This temperature detection method is applied to the temperature detection circuit provided in the previous embodiment. The temperature detection circuit is located on a driver board and includes a PFC circuit 1, an NTC thermistor 2, a differential circuit 3, and a main chip 4. An IGBT is provided in the PFC circuit 1.

[0071] In one possible implementation, the PFC circuit 1 includes a fast recovery diode.

[0072] In practical applications, there is a freewheeling problem. The PFC circuit 1 also includes at least one fast recovery diode, which can prevent the IGBT from burning out when a large amount of electrical energy is released when the inductor of the PFC circuit 1 is suddenly powered off during the temperature detection process.

[0073] See also Figure 2 , Figure 2 A flow chart of a temperature detection method for an insulated gate bipolar transistor provided in an embodiment of the present application is provided. The method specifically includes S201-S204.

[0074] S201: In response to determining that the driving board is powered on and started and the power factor correction circuit is started, determine whether the insulated gate bipolar transistor is in an off state.

[0075] After the driver board is powered on and the PFC circuit 1 is powered on and started, it is determined whether the IGBT is in the on state or the off state. Whether the IGBT is in the off state is a criterion for determining whether temperature detection can be performed.

[0076] When the IGBT is in the on state, the energy passing through the IGBT is large, which will cause ground line fluctuations and affect the accuracy of temperature detection. Therefore, temperature detection is not performed when the IGBT is in the on state. Performing temperature detection when the IGBT is in the off state can reduce the error in temperature detection and improve the accuracy of temperature detection.

[0077] S202: When the insulated gate bipolar transistor is in an off state, collecting the voltage of the negative temperature coefficient thermistor.

[0078] When the IGBT is in the off state, temperature detection is performed, that is, the voltage of the NTC thermistor 2 is collected. The temperature of the IGBT is determined based on the characteristic that the resistance of the thermistor decreases as the temperature increases.

[0079] In one possible implementation, when the insulated gate bipolar transistor is in an off state, collecting the voltage of the negative temperature coefficient thermistor includes: presetting a dead time within the time period when the insulated gate bipolar transistor is in the off state; and collecting the voltage of the negative temperature coefficient thermistor after the dead time is reached.

[0080] During the period when the IGBT is in the off state, a dead time is preset. After the dead time, the voltage of NTC thermistor 2 is collected to determine the temperature of the IGBT. Setting the dead time can protect the circuit and load. The specific value of the dead time is not limited in this embodiment of the application and should be determined according to actual needs.

[0081] S203: Obtaining the temperature of the insulated gate bipolar transistor based on the voltage of the negative temperature coefficient thermistor.

[0082] The resistance value of the NTC thermistor 2 decreases as the temperature increases. The resistance value of the NTC thermistor 2 can be determined based on the collected voltage of the NTC thermistor 2 .

[0083] In one possible implementation, obtaining the temperature of the insulated gate bipolar transistor based on the voltage of the negative temperature coefficient thermistor includes: determining the resistance value of the negative NTC thermistor based on the voltage of the NTC thermistor 2; and determining the temperature corresponding to the resistance value of the NTC thermistor according to a correspondence between the temperature and the resistance value of the NTC thermistor, wherein the temperature corresponding to the resistance value of the determined NTC thermistor is the temperature of the IGBT.

[0084] The relationship between the resistance and temperature of an NTC thermistor is nonlinear, typically following a beta (β) curve. Beta represents the rate at which resistance changes with temperature and is a parameter used to describe the relationship between temperature and resistance of an NTC thermistor. Different NTC thermistors have different beta values.

[0085] The temperature value corresponding to the resistance value of the NTC thermistor 2 can be determined based on a data sheet provided by the electronic device manufacturer. The data sheet includes parameters such as the resistance value and beta value of the NTC thermistor at different temperatures.

[0086] The relationship between the resistance value and temperature of an NTC thermistor is also affected by other factors and can be determined based on the actual application scenario and requirements. To improve the accuracy of temperature detection, calibration and testing can also be performed. The specific calibration and testing methods are not limited here and can be selected based on actual needs.

[0087] S204: If the temperature of the insulated gate bipolar transistor is greater than a preset reference temperature, performing a frequency reduction operation on the driving board.

[0088] Frequency reduction refers to limiting the operating frequency of the processor or other key components to control temperature, which can extend the life of the device. In the embodiment of the present application, when the temperature of the IGBT is higher than the preset reference temperature, the driver board needs to perform frequency reduction.

[0089] The NTC thermistor 2 includes a temperature detection reference resistor and a temperature detection NTC resistor, and the temperature measured by the temperature detection reference resistor is used as a preset reference temperature.

[0090] The IGBT temperature is compared with a preset reference temperature. If the IGBT temperature is higher than the preset reference temperature, the driver board is subjected to a frequency reduction operation. If the IGBT temperature is not higher than the preset reference temperature, a normal operation signal is sent to the driver board, and the driver board does not perform the frequency reduction operation.

[0091] In one possible implementation, after the driver board performs a frequency reduction operation, the temperature detection method may further include: detecting the temperature of the IGBT in real time, and stopping the frequency reduction operation on the driver board if the temperature of the IGBT drops to a preset temperature limit. This embodiment of the present application does not limit the preset reference temperature and the preset temperature limit.

[0092] It should be noted that the aforementioned embodiments of this application can be applied to any driver board with a PFC circuit that requires temperature-based frequency limiting and reduction protection. The driver board can be applied to any device that requires generalization. For example, it can be applied to scenarios where liquid cooling is used to dissipate heat from the main power components of the PFC circuit.

[0093] Based on steps S201-S204, the method for detecting the temperature of an IGBT is applied to a temperature detection circuit located on a driver board. In response to determining that the driver board has been powered on and the power factor correction circuit has been activated, a determination is made as to whether the IGBT is in the off state. When the IGBT is determined to be in the off state, a voltage of a negative temperature coefficient thermistor is acquired. The temperature of the IGBT is then determined based on the voltage of the negative temperature coefficient thermistor. If the temperature of the IGBT is greater than a preset reference temperature, a frequency reduction operation is performed on the driver board. Thus, performing temperature detection when the IGBT is in the off state can reduce detection errors. Temperature detection utilizes the characteristic of the negative temperature coefficient thermistor, whose resistance decreases with increasing temperature, to improve the accuracy of IGBT temperature detection, avoid situations where protection is not provided due to excessively high temperatures or erroneous protection due to insufficient temperatures, and reliably implement frequency reduction protection on the driver board.

[0094] The above embodiment of the present application provides a temperature detection method based on the above-mentioned insulated gate bipolar transistor. Next, a temperature detection device for an insulated gate bipolar transistor also provided in the embodiment of the present application is described. The device is applied to the temperature detection circuit of the insulated gate bipolar transistor described in the above embodiment, and performs the above-mentioned Figure 2 Next, the function of the temperature detection device of the insulated gate bipolar transistor is described. The structural diagram of the temperature detection device of the insulated gate bipolar transistor is shown in FIG. Figure 3 As shown, it includes a judgment module 301 , a collection module 302 , an acquisition module 303 and a frequency reduction module 304 .

[0095] The judging module 301 is configured to judge whether the insulated gate bipolar transistor is in an off state in response to determining that the driving board is powered on and the power factor correction circuit is started;

[0096] The acquisition module 302 is configured to acquire the voltage of the negative temperature coefficient thermistor when the insulated gate bipolar transistor is in an off state;

[0097] The acquisition module 303 is configured to obtain the temperature of the insulated gate bipolar transistor based on the voltage of the negative temperature coefficient thermistor;

[0098] The frequency reduction module 304 is configured to perform a frequency reduction operation on the driving board if the temperature of the insulated gate bipolar transistor is greater than a preset reference temperature.

[0099] In one possible implementation, the acquisition module 302 is specifically configured to:

[0100] A dead time is pre-set within a time period in which the insulated gate bipolar transistor is in an off state; and after the dead time is reached, the voltage of the negative temperature coefficient thermistor is collected.

[0101] In one possible implementation, the acquisition module 303 is specifically configured to:

[0102] The resistance value of the negative temperature coefficient thermistor is determined based on the voltage of the negative temperature coefficient thermistor; the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is determined according to the corresponding relationship between the temperature and the resistance value of the negative temperature coefficient thermistor, and the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is the temperature of the insulated gate bipolar transistor.

[0103] In one possible implementation, the temperature detection device further includes a signal sending module:

[0104] The signal sending module is configured to send a normal operation signal to the driving board if the temperature of the insulated gate bipolar transistor is not greater than the preset reference temperature.

[0105] An embodiment of the present application provides a temperature detection device for an insulated gate bipolar transistor (IGBT), which is applied to an IGBT temperature detection circuit. The IGBT temperature detection device includes a judgment module, a collection module, an acquisition module, and a frequency reduction module. The judgment module is configured to determine whether the IGBT is in the off state in response to determining that the driver board is powered on and the power factor correction circuit is activated. The collection module is configured to collect the voltage of the negative temperature coefficient thermistor (NTC) when the IGBT is in the off state. The acquisition module is configured to obtain the temperature of the IGBT based on the voltage of the NTC thermistor. The frequency reduction module is configured to perform frequency reduction on the driver board if the temperature of the IGBT is greater than a preset reference temperature. This minimizes detection errors by performing temperature detection when the IGBT is in the off state. Temperature detection utilizes the characteristic of the NTC thermistor that its resistance decreases as temperature increases, thereby improving the accuracy of IGBT temperature detection and avoiding situations where protection is not provided due to excessively high temperatures or erroneous protection due to insufficient temperatures, thereby reliably implementing frequency reduction protection on the driver board.

[0106] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the device or device embodiment, since it is basically similar to the method embodiment, the description is relatively simple. For the relevant parts, refer to the partial description of the method embodiment. The device and device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without expending creative work.

[0107] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0108] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A temperature detection method for an insulated gate bipolar transistor, characterized in that: The temperature detection method is applied to a temperature detection circuit, the temperature detection circuit being located on a driver board, the temperature detection circuit comprising a power factor correction circuit, a negative temperature coefficient thermistor, a differential circuit, and a main chip, the insulated gate bipolar transistor being provided in the power factor correction circuit; the output end of the main chip being connected to the gate of the insulated gate bipolar transistor, the input end of the main chip being connected to the second end of the differential circuit; the emitter of the insulated gate bipolar transistor being connected to the first end of the negative temperature coefficient thermistor; and the second end of the negative temperature coefficient thermistor being connected to the first end of the differential circuit; The temperature detection method comprises: In response to determining that the driving board is powered on and the power factor correction circuit is started, determining whether the insulated gate bipolar transistor is in an off state; When the insulated gate bipolar transistor is in an off state, collecting the voltage of the negative temperature coefficient thermistor; obtaining a temperature of the insulated gate bipolar transistor based on a voltage of the negative temperature coefficient thermistor; If the temperature of the insulated gate bipolar transistor is greater than a preset reference temperature, a frequency limiting and reducing operation is performed on the driving board.

2. The temperature detection method according to claim 1, wherein: When the insulated gate bipolar transistor is in an off state, collecting the voltage of the negative temperature coefficient thermistor, comprising: Presetting a dead time during a time period in which the insulated gate bipolar transistor is in an off state; After the dead time is reached, the voltage of the negative temperature coefficient thermistor is collected.

3. The temperature detection method according to claim 1, wherein: The obtaining the temperature of the insulated gate bipolar transistor based on the voltage of the negative temperature coefficient thermistor comprises: determining a resistance value of the negative temperature coefficient thermistor based on a voltage of the negative temperature coefficient thermistor; According to the corresponding relationship between the temperature and the resistance value of the negative temperature coefficient thermistor, the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is determined, and the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is the temperature of the insulated gate bipolar transistor.

4. The temperature detection method according to claim 1, wherein: The temperature detection method further includes: If the temperature of the insulated gate bipolar transistor is not greater than the preset reference temperature, a normal operation signal is sent to the driving board.

5. A temperature detection device for an insulated gate bipolar transistor, characterized in that: The temperature detection device is applied to a temperature detection circuit, which is located on a driving board. The temperature detection circuit includes a power factor correction circuit, a negative temperature coefficient thermistor, a differential circuit, and a main chip. The insulated gate bipolar transistor is provided in the power factor correction circuit; the output end of the main chip is connected to the gate of the insulated gate bipolar transistor, and the input end of the main chip is connected to the second end of the differential circuit; the emitter of the insulated gate bipolar transistor is connected to the first end of the negative temperature coefficient thermistor; and the second end of the negative temperature coefficient thermistor is connected to the first end of the differential circuit; The temperature detection device includes a judgment module, a collection module, an acquisition module and a frequency reduction module: The judging module is configured to judge whether the insulated gate bipolar transistor is in an off state in response to determining that the driving board is powered on and the power factor correction circuit is started; The acquisition module is configured to acquire the voltage of the negative temperature coefficient thermistor when the insulated gate bipolar transistor is in an off state; The acquisition module is configured to obtain the temperature of the insulated gate bipolar transistor based on the voltage of the negative temperature coefficient thermistor; The frequency reduction module is configured to perform a frequency reduction operation on the driving board if the temperature of the insulated gate bipolar transistor is greater than a preset reference temperature.

6. The temperature detection device according to claim 5, characterized in that: The acquisition module is specifically used for: A dead time is pre-set within a time period in which the insulated gate bipolar transistor is in an off state; and after the dead time is reached, the voltage of the negative temperature coefficient thermistor is collected.

7. The temperature detection device according to claim 5, characterized in that: The acquisition module is specifically used for: The resistance value of the negative temperature coefficient thermistor is determined based on the voltage of the negative temperature coefficient thermistor; the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is determined according to the corresponding relationship between the temperature and the resistance value of the negative temperature coefficient thermistor, and the temperature corresponding to the resistance value of the negative temperature coefficient thermistor is the temperature of the insulated gate bipolar transistor.

8. The temperature detection device according to claim 5, characterized in that: The temperature detection device also includes a signal sending module: The signal sending module is configured to send a normal operation signal to the driving board if the temperature of the insulated gate bipolar transistor is not greater than the preset reference temperature.

9. A temperature detection circuit for an insulated gate bipolar transistor, characterized in that: The temperature detection circuit is located on the driver board, and includes a power factor correction circuit, a negative temperature coefficient thermistor, a differential circuit, and a main chip; the power factor correction circuit includes a voltage input terminal and an insulated gate bipolar transistor; The voltage input terminal is connected to the collector and emitter of the insulated gate bipolar transistor; The output end of the master chip is connected to the gate of the insulated gate bipolar transistor, and the input end of the master chip is connected to the second end of the differential circuit; The emitter of the insulated gate bipolar transistor is connected to the first end of the negative temperature coefficient thermistor; The second end of the negative temperature coefficient thermistor is connected to the first end of the differential circuit; The main chip is used to send a control signal to the insulated gate bipolar transistor after the driving board is powered on; The insulated gate bipolar transistor is configured to output a first signal according to the control signal and the voltage inputted from the voltage input terminal; The differential circuit is used to perform a differential operation on the first signal passing through the negative temperature coefficient thermistor to obtain a second signal, and input the second signal to the main chip; The main chip is further used to determine whether the insulated gate bipolar transistor is in an off state based on the second signal; when the insulated gate bipolar transistor is in the off state, collect the voltage of the negative temperature coefficient thermistor; obtain the temperature of the insulated gate bipolar transistor based on the voltage of the negative temperature coefficient thermistor; if the temperature of the insulated gate bipolar transistor is greater than a preset reference temperature, send a frequency reduction signal to the driver board.

10. The temperature detection circuit according to claim 9, wherein: The power factor correction circuit also includes a fast recovery diode; The first end of the fast recovery diode is connected to the collector of the insulated gate bipolar transistor; The second end of the fast recovery diode is connected to the emitter of the insulated gate bipolar transistor; The fast recovery diode is used to protect the insulated gate bipolar transistor during the operation of the power factor correction circuit.

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