An automatic heat dissipation device based on an IGBT internal NTC controller

Abstract

The utility model discloses a kind of controller automatic heat sink based on IGBT internal NTC, it is related to electronic equipment heat dissipation technical field.The device includes IGBT module, temperature acquisition module, control unit, heat dissipation execution mechanism and protection module;IGBT module built-in NTC thermistor, temperature acquisition module is connected with NTC to collect temperature signal, control unit receives temperature signal and exports control instruction to heat dissipation execution mechanism, protection module triggers protection mechanism according to temperature threshold value.The utility model monitors IGBT substrate temperature in real time by NTC, combines thermal model to compensate junction temperature deviation, realizes the automatic regulation and accurate protection of heat dissipation, improves the stability and life of IGBT work.

Description

Technical Field

[0001] This utility model relates to the field of heat dissipation technology for electronic devices, and in particular to an automatic heat dissipation device for a controller based on the internal NTC of an IGBT. Background Technology

[0002] IGBTs (Insulated Gate Bipolar Transistors) are core components of power electronic devices, generating a significant amount of heat during operation. Insufficient heat dissipation can lead to excessively high junction temperatures, resulting in performance degradation or even damage. Existing cooling systems often employ fixed-speed fans or water cooling systems, which cannot dynamically adjust the cooling power based on the actual IGBT temperature, leading to high energy consumption and low heat dissipation efficiency.

[0003] In the existing technology, the scheme of measuring IGBT temperature by NTC thermistor has been adopted, but it has the following shortcomings: the NTC response lags behind the junction temperature, resulting in temperature monitoring deviation; the measurement circuit is susceptible to noise interference, affecting the temperature acquisition accuracy; the heat dissipation control strategy is simple and lacks graded adjustment and precise protection mechanisms, making it difficult to adapt to complex operating conditions. Utility Model Content

[0004] To address the problems of existing IGBT heat dissipation devices being unable to be dynamically adjusted, having large temperature monitoring deviations, and lacking perfect protection mechanisms, this utility model provides an automatic heat dissipation device for the controller based on the internal NTC of the IGBT, so as to achieve accurate temperature measurement, dynamic heat dissipation, and reliable protection.

[0005] To achieve the above objectives, this utility model provides an automatic heat dissipation device for a controller based on the internal NTC of an IGBT, comprising:

[0006] The IGBT module has at least one built-in NTC thermistor, which is embedded in the ceramic substrate of the IGBT module.

[0007] The temperature acquisition module is electrically connected to the NTC thermistor and is used to acquire the resistance signal of the NTC thermistor and convert it into a voltage signal.

[0008] The control unit is electrically connected to the temperature acquisition module, receives the voltage signal and calculates the temperature value, and outputs control commands.

[0009] A heat dissipation actuator is electrically connected to the control unit and adjusts the heat dissipation power according to the control command.

[0010] The protection module is electrically connected to both the temperature acquisition module and the IGBT module. When the temperature exceeds a preset threshold, the protection action is triggered.

[0011] As a further improvement to the technical solution of this utility model, the temperature acquisition module includes:

[0012] The voltage divider circuit is composed of the NTC thermistor and the reference resistor connected in series and connected to a DC power supply;

[0013] The filter circuit, consisting of a capacitor connected in parallel with the reference resistor, is used to filter out noise.

[0014] An operational amplifier, connected to the output of the voltage divider circuit, linearly amplifies the voltage signal.

[0015] As a further improvement to the technical solution of this utility model, the control unit includes a microcontroller and a storage unit. The microcontroller has a built-in ADC module to collect voltage signals, and the storage unit stores the coefficients of the Steinhart-Hart equation and a temperature-heat dissipation power mapping table.

[0016] As a further improvement to the technical solution of this utility model, the heat dissipation actuator is a cooling fan or a water pump, and the control unit adjusts its speed or flow rate through a PWM signal.

[0017] As a further improvement to the technical solution of this utility model, the protection module includes:

[0018] The hardware comparator shuts off the IGBT module's drive signal when the temperature exceeds a first threshold.

[0019] The software derating unit reduces the output current or switching frequency of the IGBT module when the temperature exceeds the second threshold (below the first threshold).

[0020] As a further improvement to the technical solution of this utility model, the filter circuit includes a combination of a 1nF capacitor and a 10nF capacitor, which are used to suppress high-frequency noise and low-frequency interference, respectively.

[0021] As a further improvement to the technical solution of this utility model, the IGBT module has 2-3 built-in NTC thermistors arranged redundantly to monitor the temperature of different areas inside the module.

[0022] As a further improvement to the technical solution of this utility model, the microcontroller adopts GD32F450 and calculates the junction temperature using the thermal model formula Tj=Tc+Rth_jc・Ploss, where Tc is the substrate temperature, Rth_jc is the thermal resistance from the junction to the substrate, and Ploss is the IGBT loss.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] Precise temperature measurement: By combining the built-in design of the NTC with the Steinhart-Hart equation, the accuracy of temperature measurement is improved; the thermal model is used to compensate for the hysteresis of the NTC response to the junction temperature, so as to accurately obtain the junction temperature state of the IGBT.

[0025] Dynamic heat dissipation: Based on real-time temperature-based hierarchical PWM control, the heat dissipation power is adaptively adjusted, reducing energy consumption while ensuring heat dissipation effect and adapting to different operating conditions.

[0026] Reliable protection: Dual hardware and software protection mechanisms provide rapid response in case of overheating, preventing IGBT damage and improving equipment safety.

[0027] Strong anti-interference: The filter circuit effectively suppresses noise, and the redundant NTC arrangement reduces the impact of uneven temperature distribution, thus improving system stability. Attached Figure Description

[0028] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0029] Figure 1 is a structural block diagram of this utility model;

[0030] Figure 2 shows the circuit diagram of the temperature acquisition module;

[0031] Figure 3 is a flowchart of the heat dissipation control of the control unit;

[0032] Figure 4 shows the detailed circuit diagram for NTC measurement;

[0033] Figure 5 shows the temperature-voltage relationship curve (T-[C] and VTEMP correspondence);

[0034] Figure 6 shows the IGBT NTC measurement circuit diagram;

[0035] Figure 7 shows the DC transfer result curves (output voltage values ​​at different temperatures). Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0037] It should be noted that all directional indicators (such as up, down, left, right, front, back, upper end, lower end, top, bottom, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0038] In this utility model, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0039] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this utility model.

[0040] The present invention will be further described in detail below with reference to the accompanying drawings.

[0041] Reference Figure 1-7 An automatic heat dissipation device for a controller based on an internal NTC of an IGBT includes: an IGBT module with at least one built-in NTC thermistor, wherein the NTC thermistor is embedded on the ceramic substrate of the IGBT module;

[0042] The temperature acquisition module is electrically connected to the NTC thermistor and is used to acquire the resistance signal of the NTC thermistor and convert it into a voltage signal.

[0043] The control unit is electrically connected to the temperature acquisition module, receives the voltage signal and calculates the temperature value, and outputs control commands.

[0044] A heat dissipation actuator is electrically connected to the control unit and adjusts the heat dissipation power according to the control command.

[0045] The protection module is electrically connected to both the temperature acquisition module and the IGBT module. When the temperature exceeds a preset threshold, the protection action is triggered.

[0046] Specifically, in this embodiment, the temperature acquisition module includes:

[0047] The voltage divider circuit is composed of the NTC thermistor and the reference resistor connected in series and connected to a DC power supply;

[0048] The filter circuit, consisting of a capacitor connected in parallel with the reference resistor, is used to filter out noise.

[0049] An operational amplifier, connected to the output of the voltage divider circuit, linearly amplifies the voltage signal.

[0050] Specifically, in this embodiment, the control unit includes a microcontroller and a storage unit. The microcontroller has a built-in ADC module to collect voltage signals, and the storage unit stores the coefficients of the Steinhart-Hart equation and a temperature-heat dissipation power mapping table.

[0051] Specifically, in this embodiment, the heat dissipation actuator is a cooling fan or a water pump, and the control unit adjusts its speed or flow rate through a PWM signal.

[0052] Specifically, in this embodiment, the protection module includes:

[0053] The hardware comparator shuts off the IGBT module's drive signal when the temperature exceeds a first threshold.

[0054] The software derating unit reduces the output current or switching frequency of the IGBT module when the temperature exceeds the second threshold (below the first threshold).

[0055] Specifically, in this embodiment, the filtering circuit includes a combination of a 1nF capacitor and a 10nF capacitor, which are used to suppress high-frequency noise and low-frequency interference, respectively.

[0056] Specifically, in this embodiment, the IGBT module has 2-3 built-in NTC thermistors arranged redundantly to monitor the temperature of different areas inside the module.

[0057] Specifically, in this embodiment, the microcontroller uses a GD32F450 and calculates the junction temperature using the thermal model formula Tj=Tc+Rth_jc・Ploss, where Tc is the substrate temperature, Rth_jc is the thermal resistance from the junction to the substrate, and Ploss is the IGBT loss.

[0058] Specifically, the present invention provides an automatic heat dissipation device for a controller based on the internal NTC of an IGBT, which includes an IGBT module, a temperature acquisition module, a control unit, a heat dissipation actuator, and a protection module.

[0059] IGBT module: It incorporates at least one NTC thermistor, embedded in the ceramic substrate (DBC) near the chip edge or substrate center, to sense the substrate temperature (Tc). The NTC exhibits a negative temperature coefficient (e.g., 10kΩ at 25°C, decreasing to 1kΩ at 150°C), and due to thermal response delay, a thermal model is needed to compensate for the 5-20°C temperature difference between the junction temperature (Tj) and the substrate temperature (Tc). For high-end modules, 2-3 NTCs can be redundantly arranged to address the issue of uneven temperature distribution within the module.

[0060] Temperature acquisition module: includes voltage divider circuit, filter circuit and operational amplifier.

[0061] The voltage divider circuit consists of an NTC and a reference resistor connected in series, and is connected to a 3.3V or 5V DC power supply. The circuit includes +5V and ±12V power supply interfaces, resistors R1 (22kΩ), R2 (22kΩ), and R3 (39kΩ), etc. The NTC and the voltage divider resistor network work together to convert the resistance change into a voltage signal. The filter circuit uses 1nF (such as C2) and 10nF (such as C3) capacitors connected in parallel to suppress high-frequency and low-frequency noise, respectively. The operational amplifier linearly amplifies the voltage signal to improve the acquisition accuracy.

[0062] Control Unit: Employs a GD32F450 microcontroller, which acquires amplified voltage signals via an ADC module. Temperature calculation is as follows: First, the NTC resistance is calculated using the formula R_NTC = Rref * (Vcc / V_NTC - 1). Then, it is converted to temperature using the Steinhart-Hart equation (1 / T = A + B・ln (R_NTC) + C・[ln (R_NTC)]³, where A / B / C are NTC manufacturer coefficients) or a lookup table. Simultaneously, the control unit estimates the junction temperature using the thermal model formula Tj = Tc + Rth_jc・Ploss, where Ploss is the sum of the IGBT's conduction and switching losses, and Rth_jc is taken from the module datasheet. A temperature-heat dissipation power mapping table is pre-stored in the storage unit, and the control unit outputs a PWM signal based on the real-time temperature.

[0063] Cooling mechanism: A cooling fan or water pump is used, and the control unit adjusts its speed or flow rate via a PWM signal. For example: when Tc < 40℃, the fan is off (natural cooling); when 45℃ < Tc < 80℃, the fan runs at 50% speed; when Tc > 80℃, the fan runs at 100% speed and issues an over-temperature warning.

[0064] Protection module: It includes a hardware comparator and a software derating unit. When Tc exceeds the threshold (such as 110 °C), the hardware comparator triggers the shutdown of the IGBT drive signal; when the temperature approaches the limit value (such as Tc > 90 °C), the software derating unit reduces the output current or switching frequency to reduce the IGBT loss and achieve power derating.

[0065] Embodiment:

[0066] As shown in Figure 1, the automatic cooling device of this embodiment includes: an IGBT module (with 2 NTCs built-in), a temperature acquisition module, a GD32F450 control unit, a cooling fan, and a protection module.

[0067] IGBT module: A high-end module that supports 2 NTCs. The NTCs are respectively located on the ceramic substrates on both sides of the chip and are used to monitor the substrate temperature distribution.

[0068] Temperature acquisition module: Referring to the circuit in Figure 6 , the NTC is connected in series with a 10 kΩ reference resistor to access a 3.3 V power supply. The voltage division point is filtered by 1 nF and 10 nF capacitors and then input to the operational amplifier U38 for amplification. The amplified signal is transmitted to the ADC pin of the GD32F450. The temperature-voltage relationship curve in the "NTC Measurement Circuit Diagram.pdf" shows that within the range of -50 °C to 150 °C, the output voltage changes non-linearly with temperature, verifying the negative temperature coefficient characteristic of the NTC and providing a hardware basis for temperature conversion.

[0069] Control unit: After the GD32F450 single-chip microcomputer collects the voltage signal, it first calculates the NTC resistance and then converts it to the substrate temperature Tc through the Steinhart-Hart equation. Figure 7 The DC transfer result curve diagram of shows that: when Temp = 25 °C, Vout = 0.071 V; when Temp = 50 °C, Vout = 3.231 V, verifying the corresponding relationship between temperature and voltage. The control unit combines the Rth_jc parameter and estimates the junction temperature through Tj = Tc + Rth_jc・Ploss, and outputs a PWM signal according to the Tc value.

[0070] Cooling control: As shown in Figure 3, when Tc ≤ 40 °C, the fan is turned off; when 40 °C < Tc ≤ 80 °C, the fan speed increases linearly with temperature; when Tc > 80 °C, the fan runs at full speed and gives an alarm.

[0071] Protection mechanism: When Tc > 110 °C, the hardware comparator shuts down the IGBT drive signal; when Tc > 90 °C, the software reduces the output current or switching frequency to achieve power derating.

[0072] This embodiment achieves accurate temperature monitoring and automatic heat dissipation of IGBTs through the above design, and is applicable to inverter controllers such as MFDC / MFAC / NICP, thereby improving the reliability and energy efficiency of the equipment.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] Precise temperature measurement: By combining the built-in design of the NTC with the Steinhart-Hart equation, the accuracy of temperature measurement is improved; the thermal model is used to compensate for the hysteresis of the NTC response to the junction temperature, so as to accurately obtain the junction temperature state of the IGBT.

[0075] Dynamic heat dissipation: Based on real-time temperature-based hierarchical PWM control, the heat dissipation power is adaptively adjusted, reducing energy consumption while ensuring heat dissipation effect and adapting to different operating conditions.

[0076] Reliable protection: Dual hardware and software protection mechanisms provide rapid response in case of overheating, preventing IGBT damage and improving equipment safety.

[0077] Strong anti-interference: The filter circuit effectively suppresses noise, and the redundant NTC arrangement reduces the impact of uneven temperature distribution, thus improving system stability.

[0078] The technical solutions provided by the embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of this utility model. The description of the above embodiments is only for helping to understand the principles of the embodiments of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. An automatic heat dissipation device for a controller based on the internal NTC of an IGBT, characterized in that, include: The IGBT module has at least one built-in NTC thermistor, which is embedded in the ceramic substrate of the IGBT module. The temperature acquisition module is electrically connected to the NTC thermistor and is used to acquire the resistance signal of the NTC thermistor and convert it into a voltage signal. The control unit is electrically connected to the temperature acquisition module, receives the voltage signal and calculates the temperature value, and outputs control commands. A heat dissipation actuator is electrically connected to the control unit and adjusts the heat dissipation power according to the control command. The protection module is electrically connected to both the temperature acquisition module and the IGBT module. When the temperature exceeds a preset threshold, the protection action is triggered.

2. The automatic heat dissipation device for the controller based on the internal NTC of the IGBT according to claim 1, characterized in that: The temperature acquisition module includes: The voltage divider circuit is composed of the NTC thermistor and the reference resistor connected in series and connected to a DC power supply; The filter circuit, consisting of a capacitor connected in parallel with the reference resistor, is used to filter out noise. An operational amplifier, connected to the output of the voltage divider circuit, linearly amplifies the voltage signal.

3. The automatic heat dissipation device for the controller based on the internal NTC of the IGBT according to claim 1, characterized in that: The control unit includes a microcontroller and a storage unit. The microcontroller has a built-in ADC module to collect voltage signals, and the storage unit stores the coefficients of the Steinhart-Hart equation and a temperature-heat dissipation power mapping table.

4. The automatic heat dissipation device for the controller based on the internal NTC of the IGBT according to claim 1, characterized in that: The heat dissipation actuator is a cooling fan or a water pump, and the control unit adjusts its speed or flow rate via a PWM signal.

5. The automatic heat dissipation device for the controller based on the internal NTC of the IGBT according to claim 1, characterized in that: The protection module includes: The hardware comparator shuts off the IGBT module's drive signal when the temperature exceeds a first threshold. The software derating unit reduces the output current or switching frequency of the IGBT module when the temperature exceeds the second threshold.

6. The automatic heat dissipation device for the controller based on the internal NTC of the IGBT according to claim 2, characterized in that: The filtering circuit includes a combination of 1nF and 10nF capacitors, which are used to suppress high-frequency noise and low-frequency interference, respectively.

7. The automatic heat dissipation device for the controller based on the internal NTC of the IGBT according to claim 1, characterized in that: The IGBT module has 2-3 built-in NTC thermistors, which are redundantly arranged to monitor the temperature of different areas inside the module.

8. The automatic heat dissipation device for the controller based on the internal NTC of the IGBT according to claim 3, characterized in that: The microcontroller used is GD32F450. The junction temperature is calculated using the thermal model formula Tj=Tc+Rth_jc・Ploss, where Tc is the substrate temperature, Rth_jc is the thermal resistance from the junction to the substrate, and Ploss is the IGBT loss.

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