Temperature protection circuit of IGBT (Insulated Gate Bipolar Translator)

Abstract

The invention relates to a temperature protection circuit of an IGBT (Insulated Gate Bipolar Translator), which is used for receiving IGBT temperature information and outputting a fan starting signal or a fan stopping signal. The IGBT temperature protection circuit comprises a plurality of IGBT temperature detection circuits and an IGBT temperature control circuit, and has the beneficial effects that a plurality of groups of temperature sampling circuits are arranged, so that the temperature of the IGBT is accurately controlled, and the IGBT and the circuit thereof are prevented from being damaged due to the temperature problem.

Description

Technical Field

[0001] This invention belongs to the field of IGBTs, and specifically relates to a temperature protection circuit for IGBTs. Background Technology

[0002] In power electronic equipment such as APF, photovoltaic inverters, converters, and SVG, some power components sometimes experience high temperature problems during operation. For power components with high heat generation, such as IGBTs, fast recovery diodes, and rectifier bridges, they are generally only cooled by heat sinks during use. Once these components overheat abnormally, they can easily damage the circuit.

[0003] Chinese patent CN115224663A discloses a temperature protection circuit and electrical appliance. Although it adds a sampling circuit for collecting temperature changes of the device under test and a comparison circuit connected to the sampling circuit for over-temperature detection to the heat sink to prevent the power module of the air conditioner from being damaged by high temperature, it only protects the power module under extreme temperature abnormalities and cannot monitor the temperature of the IGBT power module in real time. For example, it cannot monitor the IGBT power module under over-temperature conditions caused by ambient temperature rise, promptly shut down the IGBT module, and extend its service life. It cannot solve the technical problem of accurately collecting real-time multi-point temperature and protecting IGBTs in power electronic equipment in power transmission and transformation systems such as photovoltaic inverters. Summary of the Invention

[0004] The purpose of this invention is to design a temperature protection circuit for IGBTs.

[0005] The specific technical solution of the present invention is as follows: an IGBT temperature protection circuit, characterized in that the IGBT temperature protection circuit is used to receive IGBT temperature information and output a fan start signal or a fan stop signal; the IGBT temperature protection circuit includes: a plurality of IGBT temperature detection circuits and IGBT temperature control circuits.

[0006] As an improvement, the IGBT temperature detection circuit includes a first temperature detection circuit, a second temperature detection circuit, and a third temperature detection circuit, and the IGBT temperature control circuit includes a processor and an IGBT fan drive circuit.

[0007] As a further improvement, the first temperature detection circuit is used to receive the first temperature information of the IGBT and output a first voltage comparison signal.

[0008] As a further improvement, the first temperature detection circuit includes: resistor R1, thermistor R2, resistor R3, diode D1, resistor R4, resistor R5, resistor R6, resistor R7, resistor R8, a first lower voltage comparator, a first upper voltage comparator, and resistor R9.

[0009] As a further improvement, the second temperature detection circuit is used to receive the second temperature information of the IGBT and output a second voltage comparison signal.

[0010] As a further improvement, the second temperature detection circuit includes: resistor R10, thermistor R11, resistor R12, diode D2, resistor R13, resistor R14, resistor R15, resistor R16, resistor R17, second lower limit voltage comparator, second upper limit voltage comparator, and resistor R18.

[0011] As a further improvement, the third temperature detection circuit is used to receive the third temperature information of the IGBT and output a regulated third voltage comparison signal.

[0012] As a further improvement, the third temperature detection circuit includes a voltage comparison circuit and a voltage regulation circuit.

[0013] As a further improvement, the voltage comparison circuit includes: resistor R19, thermistor R20, resistor R21, diode D3, resistor R22, resistor R23, resistor R24, resistor R25, resistor R26, a third lower limit voltage comparator, a third upper limit voltage comparator, and resistor R27. The voltage comparison circuit is used to receive the IGBT voltage signal and output a third voltage comparison signal.

[0014] As a further improvement, the voltage regulator circuit includes: resistor R28, inverter, resistor R29, resistor R30, capacitor C1, diode D4, and diode D5. The voltage regulator circuit is used to receive the voltage comparison signal and output the regulated third voltage comparison signal.

[0015] As a further improvement, the processor is used to receive the first voltage comparison signal, the second voltage comparison signal and the regulated third voltage comparison signal, and output a fan drive signal.

[0016] As a further improvement, the IGBT fan drive circuit includes: resistor R31, resistor R32, and diode D6. The IGBT fan drive circuit is used to receive fan drive signals and output fan start signals or fan stop signals.

[0017] The beneficial effect of this invention is that it sets up multiple temperature sampling circuits to collect the temperature of multiple sampling points of the IGBT, accurately control the IGBT temperature, and prevent the IGBT and its circuits from being damaged due to temperature problems. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an IGBT temperature protection circuit according to the present invention.

[0019] Figure 2 This is a schematic diagram of the temperature protection circuit of an IGBT according to some specific embodiments of the present invention.

[0020] Figure 3 The circuit diagram shows the first temperature detection circuit of some specific embodiments of the temperature protection circuit for an IGBT of the present invention.

[0021] Figure 4 The circuit diagram shows the second temperature detection circuit of some specific embodiments of the temperature protection circuit for an IGBT of the present invention.

[0022] Figure 5 The circuit diagram shows the third temperature detection circuit of some specific embodiments of the temperature protection circuit for an IGBT of the present invention.

[0023] Figure 6 The diagram shows a circuit diagram of an IGBT fan drive circuit according to some specific embodiments of an IGBT temperature protection circuit of the present invention. Detailed Implementation

[0024] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and examples.

[0025] The specific technical solution of this invention is as follows: Figure 1 As shown, an IGBT temperature protection circuit is used to receive IGBT temperature information and output a fan start signal or a fan stop signal. The IGBT temperature protection circuit includes several IGBT temperature detection circuits and IGBT temperature control circuits.

[0026] In some specific embodiments, such as Figure 2 As shown, the IGBT temperature detection circuit includes a first temperature detection circuit, a second temperature detection circuit, and a third temperature detection circuit, and the IGBT temperature control circuit includes a processor and an IGBT fan drive circuit.

[0027] In some specific embodiments, such as Figure 3 As shown, the first temperature detection circuit is used to receive the first temperature information of the IGBT and output the first voltage comparison signal. The first temperature detection circuit includes: resistor R1, thermistor R2, resistor R3, diode D1, resistor R4, resistor R5, resistor R6, resistor R7, resistor R8, first lower voltage comparator, first upper voltage comparator, and resistor R9.

[0028] In some specific embodiments, such as Figure 4As shown, the second temperature detection circuit is used to receive the second temperature information of the IGBT and output a second voltage comparison signal. The second temperature detection circuit includes: resistor R10, thermistor R11, resistor R12, diode D2, resistor R13, resistor R14, resistor R15, resistor R16, resistor R17, second lower limit voltage comparator, second upper limit voltage comparator, and resistor R18.

[0029] In some specific embodiments, such as Figure 5 As shown, the third temperature detection circuit receives the third temperature information from the IGBT and outputs a regulated third voltage comparison signal. The third temperature detection circuit includes a voltage comparison circuit and a voltage regulation circuit. The voltage comparison circuit includes: resistor R19, thermistor R20, resistor R21, diode D3, resistors R22, R23, R24, R25, R26, a third lower limit voltage comparator, a third upper limit voltage comparator, and resistor R27. This circuit receives the IGBT voltage signal and outputs the third voltage comparison signal. The voltage regulation circuit includes: resistor R28, inverter, resistor R29, resistor R30, capacitor C1, diodes D4 and D5. This circuit receives the voltage comparison signal and outputs the regulated third voltage comparison signal. In these technical solutions, compared to the second temperature detection circuit, the third temperature detection circuit's signal protection and filtering can prevent excessively high or low temperatures from damaging the main processing chip. It also makes the temperature signal smoother, preventing sudden fluctuations that could trigger temperature protection or other protection mechanisms.

[0030] In some specific embodiments, combined with Figure 2 and Figure 6 As shown, the processor receives a first voltage comparison signal, a second voltage comparison signal, and a regulated third voltage comparison signal, and outputs a fan drive signal. The IGBT fan drive circuit includes resistors R31 and R32, and diode D6. The IGBT fan drive circuit receives the fan drive signal and outputs a fan start signal or a fan stop signal. It should be noted that a fan is connected to the IGBT fan drive circuit.

[0031] In a further embodiment, to facilitate thermal management of the IGBT power module, an NTC (Negative Temperature Coefficient) thermistor is embedded inside the IGBT power module to more efficiently measure the internal temperature of the IGBT. Based on the NTC thermistor inside the IGBT power module, a voltage divider circuit converts the IGBT power module temperature into a definite voltage quantity. Due to the characteristics of the NTC thermistor—its resistance decreases as temperature increases—the voltage divider circuit results in a higher voltage after voltage division as the IGBT power module temperature increases, exhibiting an inverse relationship. When a voltage quantity reflecting the IGBT power module temperature in real time is obtained, this voltage signal is sent to a voltage comparator and compared with a set over-temperature threshold voltage value. Once the voltage reflecting the IGBT temperature exceeds the over-temperature threshold voltage, the voltage comparator output voltage will flip, changing from a high level to a low level. This allows the processor to detect the over-temperature situation of the IGBT power module. After the voltage comparator output level shifts, the fan drive circuit is activated, thereby reducing the temperature of the IGBT power module. The voltage readings from the IGBT power module's temperature are sent to the MCU's analog-to-digital converter (ADC) to convert the analog signal into a digital signal, which is then output by the MCU to the display screen or backend platform. This allows for real-time monitoring of the IGBT power module's temperature. When the IGBT power module's temperature reaches a certain level, the MCU controller can promptly output a fan start signal to complete the thermal management of the IGBT power module.

[0032] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A temperature protection circuit of an IGBT, characterized by, The IGBT temperature protection circuit is used for receiving IGBT temperature information, outputting a fan starting signal or a fan stopping signal; the IGBT temperature protection circuit comprises a plurality of IGBT temperature detection circuits and an IGBT temperature control circuit.

2. The temperature protection circuit of an IGBT according to claim 1, wherein The IGBT temperature detection circuit comprises a first temperature detection circuit, a second temperature detection circuit and a third temperature detection circuit, and the IGBT temperature control circuit comprises a processor and an IGBT fan driving circuit.

3. The temperature protection circuit of an IGBT according to claim 2, wherein The first temperature detection circuit is used for receiving IGBT first temperature information and outputting a first voltage comparison signal.

4. The temperature protection circuit for an IGBT according to claim 3, wherein The first temperature detection circuit comprises a resistor R1, a thermistor R2, a resistor R3, a diode D1, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a first lower limit voltage comparator, a first upper limit voltage comparator and a resistor R9.

5. The temperature protection circuit for an IGBT according to claim 2, wherein The second temperature detection circuit is used for receiving IGBT second temperature information and outputting a second voltage comparison signal; preferably, the second temperature detection circuit comprises a resistor R10, a thermistor R11, a resistor R12, a diode D2, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R17, a second lower limit voltage comparator, a second upper limit voltage comparator and a resistor R18.

6. The temperature protection circuit of an IGBT according to claim 5, wherein The third temperature detection circuit is used for receiving the IGBT third temperature information and outputting a third voltage comparison signal after voltage stabilization; preferably, the third temperature detection circuit comprises a voltage comparison circuit and a voltage stabilization circuit.

7. The temperature protection circuit of an IGBT according to claim 6, wherein The voltage comparison circuit comprises a resistor R19, a thermistor R20, a resistor R21, a diode D3, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R26, a third lower limit voltage comparator, a third upper limit voltage comparator and a resistor R27, and is used for receiving an IGBT voltage signal and outputting a third voltage comparison signal.

8. The temperature protection circuit of an IGBT according to claim 7, wherein The voltage stabilization circuit comprises a resistor R28, an inverter, a resistor R29, a resistor R30, a capacitor C1, a diode D4 and a diode D5, and is used for receiving a voltage comparison signal and outputting a third voltage comparison signal after voltage stabilization.

9. The temperature protection circuit of an IGBT according to claim 8, wherein The processor is used for receiving the first voltage comparison signal, the second voltage comparison signal and the third voltage comparison signal after voltage stabilization, and outputting a fan driving signal.

10. The temperature protection circuit for an IGBT according to claim 9, wherein The IGBT fan driving circuit comprises a resistor R31, a resistor R32 and a diode D6, and is used for receiving a fan driving signal and outputting a fan starting signal or a fan stopping signal.

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