Over-temperature protection circuit and air conditioner

Abstract

The embodiment of the utility model provides an over-temperature protection circuit and an air conditioner, and the over-temperature protection circuit comprises a first comparison circuit which is connected with a compressor intelligent power module, is connected with a first reference voltage, and is used for comparing a voltage corresponding to a first temperature signal outputted by the compressor intelligent power module with the first reference voltage, and outputting a first comparison signal; the second comparison circuit is connected with the fan intelligent power module, is connected with a second reference voltage and is used for comparing a voltage corresponding to a second temperature signal output by the fan intelligent power module with the second reference voltage and outputting a second comparison signal; and the control circuit is connected with the first comparison circuit and the second comparison circuit, is connected to the power factor correction circuit, and is used for controlling the power factor correction circuit to stop working when the first comparison signal is the first level and / or the second comparison signal is the first level. Over-temperature protection of the power factor correction circuit can be realized, and devices and occupied space are saved.

Description

Technical Field

[0001] This application belongs to the field of air conditioner technology, and particularly relates to an over-temperature protection circuit and an air conditioner. Background Technology

[0002] To achieve frequency conversion, the electronic control board of an air conditioner's outdoor unit uses several high-power devices, such as an Intelligent Power Module (IPM) for compressor inversion, a fan intelligent power module for fan inversion, and insulated-gate bipolar transistors (IGBTs), fast recovery diodes (FRDs), and rectifier bridges for power factor correction (PFC) circuits. Integrated modules combine the necessary components of the air conditioner's outdoor unit to improve development efficiency, production efficiency, and reliability.

[0003] Integrating these power modules can cause all the high-current components within a single module to heat up simultaneously, potentially leading to device failure. However, existing integrated power modules lack over-temperature protection for the power factor correction circuitry. Utility Model Content

[0004] This application provides an over-temperature protection circuit and an air conditioner, which can realize over-temperature protection for the power factor correction circuit and improve the safety and stability of the power integrated module.

[0005] In a first aspect, embodiments of this application provide an over-temperature protection circuit applied in a power integrated module, the power integrated module including a compressor intelligent power module, a fan intelligent power module, and a power factor correction circuit; the over-temperature protection circuit includes:

[0006] The first comparison circuit has a first input terminal for connecting to the temperature signal output terminal of the compressor intelligent power module, and a second input terminal for connecting to a first reference voltage. The first comparison circuit is used to compare the voltage corresponding to the first temperature signal output by the compressor intelligent power module with the first reference voltage and output a first comparison signal.

[0007] The second comparison circuit has a first input terminal for connecting to the temperature signal output terminal of the intelligent power module of the wind turbine, and a second input terminal for connecting to a second reference voltage. The second comparison circuit is used to compare the voltage corresponding to the second temperature signal output by the intelligent power module of the wind turbine with the second reference voltage, and output a second comparison signal.

[0008] The control circuit has a first input terminal connected to the output terminal of the first comparison circuit, a second input terminal connected to the output terminal of the second comparison circuit, and an output terminal used to connect to the controlled terminal of the power factor correction circuit. The control circuit is used to control the power factor correction circuit to stop working when the first comparison signal is at a first level and / or when the second comparison signal is at a first level.

[0009] Optionally, the control circuit includes:

[0010] The first switching circuit has its controlled terminal connected to the output terminal of the first comparison circuit, and its input terminal connected to the controlled terminal of the power factor correction circuit.

[0011] The second switching circuit is connected in series between the output terminal of the first switching circuit and ground, and its controlled terminal is connected to the output terminal of the second comparison circuit.

[0012] The first switching circuit and the second switching circuit are used to jointly pull the controlled terminal of the power factor correction circuit low to ground when the first comparison signal is at a first level and the second comparison signal is at a first level.

[0013] Optionally, the first switching circuit includes a first switching transistor, the controlled terminal of which is connected to the output terminal of the first comparison circuit, and the input terminal of which is used to connect to the controlled terminal of the power factor correction circuit.

[0014] The second switching circuit includes a second switching transistor, whose controlled terminal is connected to the output terminal of the second comparator circuit, whose input terminal is connected to the output terminal of the first switching transistor, and whose output terminal is grounded.

[0015] Optionally, the control circuit further includes:

[0016] The third switching circuit has its controlled terminal connected to the output terminal of the first comparison circuit, its input terminal connected to the controlled terminal of the power factor correction circuit, and its output terminal grounded.

[0017] The fourth switching circuit has its controlled terminal connected to the output terminal of the second comparison circuit, its input terminal connected to the controlled terminal of the power factor correction circuit, and its output terminal grounded.

[0018] The third and fourth switching circuits are used to pull the controlled terminal of the power factor correction circuit low to ground when the first comparison signal is at a first level and / or the second comparison signal is at a first level.

[0019] Optionally, the third switching circuit includes a third switching transistor, whose controlled terminal is connected to the output terminal of the first comparison circuit, whose input terminal is used to connect to the controlled terminal of the power factor correction circuit, and whose output terminal is grounded.

[0020] The fourth switching circuit includes a fourth switching transistor, whose controlled terminal is connected to the output terminal of the second comparator circuit, whose input terminal is connected to the controlled terminal of the power factor correction circuit, and whose output terminal is grounded.

[0021] Optionally, the first comparison circuit includes:

[0022] The first comparator has its non-inverting input connected to the temperature signal output of the compressor's intelligent power module, its inverting input connected to the first reference voltage, and its output connected to the control circuit.

[0023] Optionally, the second comparator circuit includes:

[0024] The second comparator has its non-inverting input connected to the temperature signal output of the intelligent power module of the fan, its inverting input connected to the second reference voltage, and its output connected to the control circuit.

[0025] Optionally, the over-temperature protection circuit further includes:

[0026] The reference voltage generating circuit has an input terminal connected to a first power supply, a first output terminal connected to the second input terminal of the first comparator circuit, and a second output terminal connected to the second input terminal of the second comparator circuit. The reference voltage generating circuit is used to convert the voltage of the first power supply and output the first reference voltage through the first output terminal and the second reference voltage through the second output terminal.

[0027] Optionally, the reference voltage generation circuit includes:

[0028] The first voltage divider circuit has its input terminal connected to the first power supply and its output terminal being the first output terminal of the reference voltage generating circuit. The first voltage divider circuit is used to divide the connected first power supply into the first reference voltage and output it.

[0029] The second voltage divider circuit has its input terminal connected to the first power supply and its output terminal being the second output terminal of the reference voltage generating circuit. The second voltage divider circuit is used to divide the connected first power supply into the second reference voltage and output it.

[0030] Secondly, embodiments of this application also provide an air conditioner, comprising:

[0031] The power integration module includes a compressor intelligent power module, a fan intelligent power module, and a power factor correction circuit;

[0032] The over-temperature protection circuit described in any of the above embodiments has its first input terminal connected to the compressor intelligent power module, its second input terminal connected to the fan intelligent power module, and its output terminal connected to the power factor correction circuit.

[0033] In the over-temperature protection circuit and air conditioner of this application embodiment, an over-temperature protection circuit is used, and the temperature detection function of the compressor intelligent power module and the temperature detection function of the fan intelligent power module are used to realize the over-temperature protection of the power factor correction circuit. There is no need to set a separate temperature sensor in the power factor correction circuit, which saves components and space, and can improve the reliability and safety of the power integrated module. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.

[0036] Figure 1 This is a structural block diagram of the over-temperature protection circuit provided in an embodiment of this application.

[0037] Figure 2 A circuit diagram of an over-temperature protection circuit provided in an embodiment of this application.

[0038] Figure 3 A voltage-temperature relationship diagram for a power integrated device provided in an embodiment of this application.

[0039] Figure 4 Another circuit diagram of the over-temperature protection circuit provided in the embodiments of this application.

[0040] Figure 5 Another circuit diagram of the over-temperature protection circuit provided in the embodiments of this application. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0042] With the rapid development of the electronics industry, miniaturization, integration, and unification of components are the future direction of electronics development, and this is also true for air conditioners. Inverter air conditioners are among the most commonly used appliances. The outdoor unit's inverter-driven control board uses several high-power devices to achieve inverter operation. These high-current devices include compressor IPMs for compressor inversion, fan IPMs for fan inversion, and IGBTs, FRDs, and rectifier bridges for PFC circuits. Integrated modules combine these components required by the outdoor unit, offering numerous benefits such as improved development efficiency, production efficiency, reliability control, and reduced space requirements. However, integrating these power modules presents a significant challenge: temperature rise. With various high-current components generating heat together within a single module, heat accumulates more quickly and is difficult to dissipate, leading to a higher component failure rate. Therefore, timely over-temperature protection of the module is crucial.

[0043] In current technology, integrated power devices are rarely used in air conditioners. Moreover, only the compressor IPM and fan IPM sections of the integrated module have integrated temperature detection and over-temperature protection circuits and functions. However, the IGBT, FRD, and rectifier bridge sections lack temperature detection and over-temperature protection functions due to difficulties in implementation, cost, and reliability considerations. Typically, the IGBT generates the most heat and has the highest temperature among these power devices. The integrated module can output the temperatures of the compressor IPM and fan IPM sections, and the CPU can read these temperatures and then indirectly implement protection through software programs. However, software-based protection is not timely or accurate, and it requires the AD port (digital-to-analog converter) resources of two CPUs (central processing units). Although these components are integrated into a large module, temperature monitoring has a strong hysteresis characteristic. If the IGBT overheats abnormally and does not shut down in time, the entire module may overheat and be damaged.

[0044] Based on the above problems, this application provides an over-temperature protection circuit and an air conditioner, which will be described below with reference to the accompanying drawings.

[0045] Please see Figure 1 , Figure 1 This is a structural block diagram of an over-temperature protection circuit provided in an embodiment of this application. Exemplarily, the over-temperature protection circuit 100 is applied in a power integrated module, which includes a compressor intelligent power module, a fan intelligent power module, and a power factor correction circuit. The power integrated module can be a device within an air conditioner; in some embodiments, it can also be applied to a device with a refrigeration system, such as a refrigerator.

[0046] For example, the over-temperature protection circuit 100 includes a first comparison circuit 110, a second comparison circuit 120, and a control circuit 130.

[0047] The first input terminal of the first comparison circuit 110 is connected to the temperature signal output terminal of the compressor intelligent power module, and the second input terminal of the first comparison circuit 110 is connected to the first reference voltage. The compressor intelligent power module has temperature detection and over-temperature protection functions and circuits. Therefore, the first comparison circuit 110 is used to compare the voltage corresponding to the first temperature signal output by the compressor intelligent power module with the first reference voltage and output a first comparison signal. The first temperature signal can be a voltage signal, and the first reference voltage corresponds to the protection temperature of the compressor intelligent power module. After processing by the first comparison circuit 110, such as performing a voltage comparison, the output first comparison signal can be a level signal. The level signal can be a first level and a second level; for example, the first level is greater than the second level. The first level can be, for example, a high level, and the second level can be, for example, a low level.

[0048] For ease of understanding, the first comparison circuit 110 is connected to a connection port YVOT, indicating that it is used to connect to the compressor intelligent power module, and should not be construed as a limitation on the first comparison circuit 110.

[0049] The first input terminal of the second comparison circuit 120 is used to connect to the temperature signal output terminal of the intelligent power module of the fan, and the second input terminal of the second comparison circuit 120 is used to connect to the second reference voltage. The intelligent power module of the fan has temperature detection and over-temperature protection functions and circuits. Therefore, the second comparison circuit 120 is used to compare the voltage corresponding to the second temperature signal output by the intelligent power module of the fan with the second reference voltage, and output a second comparison signal. Similarly, the second temperature signal can be a voltage signal, and the second reference voltage corresponds to the protection temperature of the intelligent power module of the fan. After processing by the second comparison circuit 120, such as performing voltage comparison, the output second comparison signal can be a level signal. The level signal can be a first level and a second level; for example, the first level is greater than the second level, the first level can be a high level, and the second level can be a low level.

[0050] For ease of understanding, the second comparator circuit 120 is connected to a connection port FVOT, indicating that it is used for connection with the wind turbine intelligent power module, and should not be construed as a limitation on the second comparator circuit 120.

[0051] The first input terminal of the control circuit 130 is connected to the output terminal of the first comparison circuit 110, and the second input terminal of the control circuit 130 is connected to the output terminal of the second comparison circuit 120. The output terminal of the control circuit 130 is used to connect to the controlled terminal of the power factor correction circuit. The control circuit 130 is used to adjust the operating state of the power factor correction circuit according to the first comparison signal and the second comparison signal. For example, the control circuit 130 can be used to control the power factor correction circuit to stop working when the first comparison signal is at a first level and / or the second comparison signal is at a first level. That is to say, the temperature of the power factor correction circuit is characterized by the temperature of the compressor intelligent power module and / or the fan intelligent power module. When the compressor intelligent power module is overheated and / or the fan intelligent power module is overheated, the control circuit 130 adjusts the operating state of the power factor correction circuit to stop working to prevent more serious accidents caused by continuous heating.

[0052] For ease of understanding, the control circuit 130 is connected to a connection port PFC_PWM, indicating that it is used to connect to the power factor correction circuit.

[0053] In the over-temperature protection circuit 100 provided in this application embodiment, the over-temperature protection circuit is used, and the temperature detection function of the compressor intelligent power module and the fan intelligent power module are utilized to realize the over-temperature protection of the power factor correction circuit. There is no need to set a separate temperature sensor in the power factor correction circuit, which saves components and space, and can improve the reliability and safety of the power integrated module.

[0054] Please see Figure 2 , Figure 2 This is a circuit diagram of an over-temperature protection circuit provided in an embodiment of this application. The first and second reference voltages can be implemented using a reference voltage generation circuit. Exemplarily, the over-temperature protection circuit 100 further includes a reference voltage generation circuit. The input terminal of the reference voltage generation circuit is connected to a first power supply, such as a DC power supply with a voltage such as 3.3V. The first output terminal of the reference voltage generation circuit is connected to the second input terminal of a first comparator circuit 110, and the second output terminal of the reference voltage generation circuit is connected to the second input terminal of a second comparator circuit 120. The reference voltage generation circuit converts the voltage of the first power supply and outputs a first reference voltage through its first output terminal and a second reference voltage through its second output terminal.

[0055] For example, the reference voltage generation circuit may include a first reference voltage generation branch 112 and a second reference voltage generation branch 122. The input terminal of the first reference voltage generation branch 112 is connected to a first power supply, and the first reference voltage generation branch 112 is used to process the first power supply voltage and output a first reference voltage. The input terminal of the second reference voltage generation branch 122 is connected to the first power supply, and the second reference voltage generation branch 122 is used to process the first power supply voltage and output a second reference voltage.

[0056] In some embodiments, the first reference voltage generation branch 112 may be a component of the first comparison circuit 110. Exemplarily, the first comparison circuit 110 includes the first reference voltage generation branch 112 and a first comparator IC1A. The non-inverting input of the first comparator IC1A is connected to the temperature signal output of the compressor intelligent power module, the inverting input of the first comparator IC1A is connected to the first reference voltage, and the output of the first comparator IC1A is connected to the control circuit 130. The first comparator IC1A is used to compare the first reference voltage with the voltage corresponding to the first temperature signal output by the compressor intelligent power module and output a first comparison signal.

[0057] The first comparator circuit 110 further includes a fifth resistor R5 and a first capacitor C1. One end of the fifth resistor R5 is connected to the temperature signal output terminal of the compressor intelligent power module, such as a connection port YVOT, and the other end of the fifth resistor R5 is connected to the non-inverting input terminal of the first comparator IC1A. One end of the first capacitor C1 is connected to the other end of the fifth resistor R5, and the other end of the first capacitor C1 is grounded (GND). It can be understood that the fifth resistor R5 and the first capacitor C1 form a filter circuit to filter out noise in the first temperature signal output by the compressor intelligent power module.

[0058] The first comparator circuit 110 also includes a sixth resistor R6 and a seventh resistor R7. One end of the sixth resistor R6 is connected to the other end of the fifth resistor R5, and the other end of the sixth resistor R6 is grounded (GND). One end of the seventh resistor R7 is connected to the output terminal of the first comparator IC1A, and the other end of the seventh resistor R7 is grounded (GND). The setting of the seventh resistor R7 can limit the output current of the first comparator IC1A, thereby protecting the comparator and other circuits from excessive current.

[0059] The first comparator IC1A also has a power supply branch. For example, one end of the first comparator IC1A is connected to a power supply such as a 3.3V power supply and grounded to GND through the second capacitor C2. The other end of the first comparator IC1A is grounded to GND.

[0060] For example, the first reference voltage generation branch 112 includes a first voltage divider circuit. The input terminal of the first voltage divider circuit is connected to a first power supply, such as 3.3V. The voltage division point of the first voltage divider circuit is connected to the inverting input terminal of the first comparator IC1A, and the ground terminal of the first voltage divider circuit is grounded. The first voltage divider circuit is used to divide the input first power supply into a first reference voltage and output it. The first voltage divider circuit includes a first resistor R1 and a second resistor R2. One end of the first resistor R1 is connected to the power supply; the other end of the first resistor R1 is connected to the inverting input terminal of the first comparator IC1A. One end of the second resistor R2 is connected to the inverting input terminal of the first comparator IC1A, and the other end of the second resistor R2 is grounded (GND).

[0061] For example, the first reference voltage generation branch 112 also includes a third capacitor C3. One end of the third capacitor C3 is connected to the inverting input of the first comparator IC1A, and the other end of the third capacitor C3 is grounded to GND. It can be understood that the third capacitor C3 serves as a filter.

[0062] For example, the working process and principle of the first comparator circuit 110 are as follows: When the air conditioner is running normally, the first temperature signal of the compressor intelligent power module is output when the YVOT connection port is connected to the YVOT connection port. The first temperature signal passes through the fifth resistor R5 and the first capacitor C1 and enters the non-inverting input terminal of the first comparator IC1A. The first temperature signal is a voltage signal, and the voltage level corresponds to the temperature level of the compressor intelligent power module. The 3.3V power supply voltage is divided by the first resistor R1 and the second resistor R2, and serves as the first reference voltage. This voltage is then filtered by the third capacitor C3 and enters the inverting input terminal of the first comparator IC1A. The magnitude of the first reference voltage can be adjusted by changing the resistance values ​​of the first resistor R1 and the second resistor R2 based on test results. The first comparator IC1A outputs a first comparison signal by comparing the voltage magnitude corresponding to the first reference voltage and the first temperature signal. That is, the temperature of the compressor intelligent power module is compared with the set protection temperature. For example, if the first temperature signal is lower than the set protection temperature, the first comparator IC1A outputs the first comparison signal at a second level, such as a low level; if the first temperature signal is greater than or equal to the set protection temperature, the first comparator IC1A outputs the first comparison signal at a first level, such as a high level.

[0063] For example, if the temperature protection threshold of the power integrated module is set to 105℃, and the IGBT in the power factor correction circuit is typically about 5℃ hotter than the compressor's intelligent power module, then the temperature protection threshold of the compressor's intelligent power module would be around 100℃. Figure 3 , Figure 3This diagram illustrates the voltage-temperature relationship of the power integrated module provided in this embodiment. The voltage of the intelligent power module corresponding to the compressor is approximately 3V at 100℃. Therefore, the resistance of the first resistor R1 can be set to 1KΩ, and the resistance of the second resistor R2 can be set to 10KΩ.

[0064] In some embodiments, the second reference voltage generation branch 122 may be a component of the second comparator circuit 120. Exemplarily, the second comparator circuit 120 includes the second reference voltage generation branch 122 and a second comparator IC1B. The non-inverting input of the second comparator IC1B is connected to the temperature signal output of the wind turbine intelligent power module, the inverting input of the second comparator IC1B is connected to the second reference voltage, and the output of the second comparator IC1B is connected to the control circuit 130. The second comparator IC1B is used to compare the second reference voltage with the voltage corresponding to the second temperature signal output by the wind turbine intelligent power module and output a second comparison signal.

[0065] The second comparator circuit 120 further includes an eighth resistor R8 and a fourth capacitor C4. One end of the eighth resistor R8 is connected to the temperature signal output terminal of the wind turbine intelligent power module, such as a connection port FVOT, and the other end of the eighth resistor R8 is connected to the non-inverting input terminal of the second comparator IC1B. One end of the fourth capacitor C4 is connected to the other end of the eighth resistor R8, and the other end of the fourth capacitor C4 is grounded (GND). It can be understood that the eighth resistor R8 and the fourth capacitor C4 form a filter circuit to filter out noise in the second temperature signal output by the wind turbine intelligent power module.

[0066] The second comparator circuit 120 also includes a ninth resistor R9 and a tenth resistor R10. One end of the ninth resistor R9 is connected to the other end of the eighth resistor R8, and the other end of the ninth resistor R9 is grounded (GND). One end of the tenth resistor R10 is connected to the output terminal of the second comparator IC1B, and the other end of the tenth resistor R10 is grounded (GND). The setting of the tenth resistor R10 can limit the output current of the second comparator IC1B, thereby protecting the comparator and other circuits from excessive current.

[0067] For example, the second reference voltage generation branch 122 includes a second voltage divider circuit. The input terminal of the second voltage divider circuit is connected to a first power supply, such as 3.3V. The voltage division point of the second voltage divider circuit is connected to the inverting input terminal of the second comparator IC1B. The ground terminal of the second voltage divider circuit is grounded. The second voltage divider circuit is used to divide the input first power supply into a second reference voltage and output it. The second voltage divider circuit includes a third resistor R3 and a fourth resistor R4. One end of the third resistor R3 is connected to the power supply, such as 3.3V; the other end of the third resistor R3 is connected to the inverting input terminal of the second comparator IC1B. One end of the fourth resistor R4 is connected to the inverting input terminal of the second comparator IC1B, and the other end of the fourth resistor R4 is grounded (GND).

[0068] For example, the second reference voltage generation branch 122 also includes a fifth capacitor C5. One end of the fifth capacitor C5 is connected to the inverting input of the second comparator IC1B, and the other end of the fifth capacitor C5 is grounded to GND. It can be understood that the fifth capacitor C5 serves a filtering function.

[0069] For example, the working process and principle of the second comparator circuit 120 are as follows: When the air conditioner is running normally, the second temperature signal of the fan intelligent power module is output when the connection port FVOT is connected to the fan intelligent power module. The second temperature signal passes through the eighth resistor R8 and the fourth capacitor C4 and enters the non-inverting input terminal of the second comparator IC1B. The second temperature signal is a voltage signal, and the voltage level corresponds to the temperature level of the fan intelligent power module. The 3.3V power supply voltage is divided by the third resistor R3 and the fourth resistor R4, and used as the second reference voltage. It is then filtered by the fifth capacitor C5 and enters the inverting input terminal of the second comparator IC1B. The magnitude of the second reference voltage can be adjusted by changing the resistance values ​​of the third resistor R3 and the fourth resistor R4 according to the test results. The second comparator IC1B outputs a second comparison signal by comparing the voltage magnitudes corresponding to the second reference voltage and the second temperature signal. That is, it compares the temperature of the intelligent power module of the fan with the set protection temperature. For example, if the second temperature signal is lower than the set protection temperature, the second comparator IC1B outputs a second comparison signal at a second level, such as a low level; if the second temperature signal is greater than or equal to the set protection temperature, the second comparator IC1B outputs a second comparison signal at a first level, such as a high level.

[0070] The values ​​of the third resistor R3 and the fourth resistor R4 can be determined with reference to the first resistor R1 and the second resistor R2, and will not be elaborated here.

[0071] It should be noted that when the relative positions of the power factor correction circuit and the compressor intelligent power module and the fan intelligent power module are different, the control circuit 130 can have at least two types.

[0072] In the first scenario, when the power factor correction circuit composed of IGBTs and FRDs in the power integrated module is located between the compressor intelligent power module and the fan intelligent power module, the temperature detection functions of both the compressor intelligent power module and the fan intelligent power module can be used simultaneously to protect the power factor correction circuit.

[0073] like Figure 4 As shown, Figure 4 This is another circuit diagram of the over-temperature protection circuit provided in this application embodiment. Exemplarily, the control circuit 130 includes a first switching circuit and a second switching circuit. The controlled terminal of the first switching circuit is connected to the output terminal of the first comparison circuit 110, and the input terminal of the first switching circuit is used to connect to the controlled terminal of the power factor correction circuit. The second switching circuit is connected in series between the output terminal of the first switching circuit and ground, and the controlled terminal of the second switching circuit is connected to the output terminal of the second comparison circuit 120. The first and second switching circuits are used to jointly pull the controlled terminal of the power factor correction circuit low to ground when the first comparison signal is at a first level and the second comparison signal is at a first level.

[0074] For example, the first switching circuit includes a first switching transistor Q1, and the second switching circuit includes a second switching transistor Q2.

[0075] The controlled terminal of the first switching transistor Q1 is connected to the output terminal of the first comparator circuit 110, and the input terminal of the first switching transistor Q1 is used to connect to the controlled terminal of the power factor correction circuit. For example, the first switching transistor Q1 can be a transistor, then the controlled terminal, input terminal and output terminal of the first switching transistor Q1 correspond to the base, collector and emitter of the transistor, respectively.

[0076] The controlled terminal of the second switch Q2 is connected to the output terminal of the second comparator circuit 120, the input terminal of the second switch Q2 is connected to the output terminal of the first switch Q1, and the output terminal of the second switch Q2 is grounded to GND. For example, the second switch Q2 can be a transistor, then the controlled terminal, input terminal, and output terminal of the second switch Q2 correspond to the base, collector, and emitter of the transistor, respectively.

[0077] The first switch Q1 is used to turn on when the first comparison signal is at a first level, such as a high level, and the second switch Q2 is used to turn on when the second comparison signal is at a first level, such as a high level, so that the power factor correction circuit stops working.

[0078] It is understandable that the first switch Q1 and the second switch Q2 are connected in series. When both the first switch Q1 and the second switch Q2 receive a first level such as a high level to conduct, the power factor correction circuit can receive a low level signal and stop working. This means that the temperature of the power factor correction circuit is too high at this time. In order to achieve over-temperature protection, the working state of the power factor correction circuit is adjusted to stop working to prevent over-temperature from causing more serious accidents.

[0079] In other words, when at least one of the first switch Q1 and the second switch Q2 is not conducting, the gate drive signal of the IGBT in the power factor correction circuit is not affected by PFC_PWM, and the IGBT continues to work. When both the first switch Q1 and the second switch Q2 are conducting, the gate drive signal of the IGBT in the power factor correction circuit is pulled low by PFC_PWM, the IGBT stops working, and the air conditioner shuts down for protection.

[0080] In the second scenario, when the power factor correction circuit composed of IGBTs and FRDs in the power integration module is not located between the compressor intelligent power module and the fan intelligent power module, but is located next to the power integration module, the power factor correction circuit is protected by one of the temperature detection functions of the compressor intelligent power module and the fan intelligent power module. That is, protection is activated when the temperature of one of the modules exceeds the set value.

[0081] like Figure 5 , Figure 5 Another circuit diagram of the over-temperature protection circuit provided in this application embodiment is shown. Exemplarily, the control circuit 130 includes a third switching circuit and a fourth switching circuit. The controlled terminal of the third switching circuit is connected to the output terminal of the first comparison circuit 110, the input terminal of the third switching circuit is used to connect to the controlled terminal of the power factor correction circuit, and the output terminal of the third switching circuit is grounded. The controlled terminal of the fourth switching circuit is connected to the output terminal of the second comparison circuit 120, the input terminal of the fourth switching circuit is used to connect to the controlled terminal of the power factor correction circuit, and the output terminal of the fourth switching circuit is grounded. The third and fourth switching circuits are used to pull the controlled terminal of the power factor correction circuit low to ground when the first comparison signal is at a first level and / or the second comparison signal is at a first level.

[0082] For example, the third switching circuit includes a third switching transistor Q3 and a fourth switching transistor Q4.

[0083] The controlled terminal of the third switch Q3 is connected to the output terminal of the first comparator circuit 110, the input terminal of the third switch Q3 is used to connect to the controlled terminal of the power factor correction circuit, and the output terminal of the third switch Q3 is grounded to GND. For example, the third switch Q3 can be a transistor, then the controlled terminal, input terminal and output terminal of the third switch Q3 correspond to the base, collector and emitter of the transistor, respectively.

[0084] The controlled terminal of the fourth switch Q4 is connected to the output terminal of the second comparator circuit 120, the input terminal of the fourth switch Q4 is used to connect to the controlled terminal of the power factor correction circuit, and the output terminal of the fourth switch Q4 is grounded to GND. For example, the fourth switch Q4 can be a transistor, then the controlled terminal, input terminal, and output terminal of the fourth switch Q4 correspond to the base, collector, and emitter of the transistor, respectively.

[0085] The third switch Q3 is used to stop the power factor correction circuit from working when the first comparison signal is at a first level, such as a high level, and / or the fourth switch Q4 is used to stop the power factor correction circuit from working when the second comparison signal is at a first level, such as a high level.

[0086] It is understandable that the third switch Q3 and the fourth switch Q4 are connected in parallel. When at least one of the third switch Q3 and the fourth switch Q4 receives a first level such as a high level and is turned on, the power factor correction circuit can receive a low level signal and stop working. This means that the power factor correction circuit is too hot at this time. In order to achieve over-temperature protection, the working state of the power factor correction circuit is adjusted to stop working to prevent over-temperature from causing more serious accidents.

[0087] In other words, when at least one of the third switch Q3 and the fourth switch Q4 is turned on, the gate drive signal of the IGBT in the power factor correction circuit is pulled low by PFC_PWM, the IGBT stops working, and the air conditioner shuts down for protection.

[0088] This over-temperature protection circuit 100 is mainly used for over-temperature protection of the power integrated module in an air conditioner. Optionally, it can also provide temperature protection for the power factor correction circuit, such as the IGBT. Since it's difficult to embed a temperature sensor inside an IGBT that handles high currents, this application utilizes the VTS outputs of the two IPM sections within the power integrated module to achieve indirect hardware-level protection for the IGBT. In the integrated modules used in the air conditioning industry, existing technologies do not provide temperature protection for the IGBT, even though the IGBT is the device that generates the most heat. Existing technologies only protect the IPM section of the integrated module. This is neither accurate nor fast for the entire module. This application achieves temperature protection for the IGBT through an external circuit, namely the over-temperature protection circuit 100. Temperature protection is also provided for the compressor IPM, fan IPM, and PFC section of the entire power integrated module, significantly improving the reliability of the device. Furthermore, software protection is unnecessary, thus saving the two AD port resources for chip VTS reading.

[0089] This application also provides an air conditioner, which includes a power integration module and the aforementioned over-temperature protection circuit. The power integration module includes a compressor intelligent power module, a fan intelligent power module, and a power factor correction circuit. The first input terminal of the over-temperature protection circuit is connected to the compressor intelligent power module, the second input terminal of the over-temperature protection circuit is connected to the fan intelligent power module, and the output terminal of the over-temperature protection circuit is connected to the power factor correction circuit. The structure and working principle of the over-temperature protection circuit are as described in the above embodiments. Since this air conditioner adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.

[0090] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0091] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0092] The over-temperature protection circuit and air conditioner provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. 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 ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An over-temperature protection circuit, applied to a power integrated module, the power integrated module comprising a compressor intelligent power module, a fan intelligent power module, and a power factor correction circuit; characterized in that, The over-temperature protection circuit includes: The first comparison circuit has a first input terminal for connecting to the temperature signal output terminal of the compressor intelligent power module, and a second input terminal for connecting to a first reference voltage. The first comparison circuit is used to compare the voltage corresponding to the first temperature signal output by the compressor intelligent power module with the first reference voltage and output a first comparison signal. The second comparison circuit has a first input terminal for connecting to the temperature signal output terminal of the intelligent power module of the wind turbine, and a second input terminal for connecting to a second reference voltage. The second comparison circuit is used to compare the voltage corresponding to the second temperature signal output by the intelligent power module of the wind turbine with the second reference voltage and output a second comparison signal. The control circuit has a first input terminal connected to the output terminal of the first comparison circuit, a second input terminal connected to the output terminal of the second comparison circuit, and an output terminal used to connect to the controlled terminal of the power factor correction circuit. The control circuit is used to control the power factor correction circuit to stop working when the first comparison signal is at a first level and / or when the second comparison signal is at a first level.

2. The over-temperature protection circuit according to claim 1, characterized in that, The control circuit includes: The first switching circuit has its controlled terminal connected to the output terminal of the first comparison circuit, and its input terminal connected to the controlled terminal of the power factor correction circuit. The second switching circuit is connected in series between the output terminal of the first switching circuit and ground, and its controlled terminal is connected to the output terminal of the second comparison circuit. The first switching circuit and the second switching circuit are used to jointly pull the controlled terminal of the power factor correction circuit low to ground when the first comparison signal is at a first level and the second comparison signal is at a first level.

3. The over-temperature protection circuit according to claim 2, characterized in that, The first switching circuit includes a first switching transistor, the controlled terminal of which is connected to the output terminal of the first comparator circuit, and the input terminal of which is used to connect to the controlled terminal of the power factor correction circuit. The second switching circuit includes a second switching transistor, whose controlled terminal is connected to the output terminal of the second comparator circuit, whose input terminal is connected to the output terminal of the first switching transistor, and whose output terminal is grounded.

4. The over-temperature protection circuit according to claim 1, characterized in that, The control circuit also includes: The third switching circuit has its controlled terminal connected to the output terminal of the first comparison circuit, its input terminal connected to the controlled terminal of the power factor correction circuit, and its output terminal grounded. The fourth switching circuit has its controlled terminal connected to the output terminal of the second comparison circuit, its input terminal connected to the controlled terminal of the power factor correction circuit, and its output terminal grounded. The third and fourth switching circuits are used to pull the controlled terminal of the power factor correction circuit low to ground when the first comparison signal is at a first level and / or the second comparison signal is at a first level.

5. The over-temperature protection circuit according to claim 4, characterized in that, The third switching circuit includes a third switching transistor, whose controlled terminal is connected to the output terminal of the first comparison circuit, whose input terminal is used to connect to the controlled terminal of the power factor correction circuit, and whose output terminal is grounded. The fourth switching circuit includes a fourth switching transistor, whose controlled terminal is connected to the output terminal of the second comparator circuit, whose input terminal is connected to the controlled terminal of the power factor correction circuit, and whose output terminal is grounded.

6. The over-temperature protection circuit according to claim 1, characterized in that, The first comparator circuit includes: The first comparator has its non-inverting input connected to the temperature signal output of the compressor's intelligent power module, its inverting input connected to the first reference voltage, and its output connected to the control circuit.

7. The over-temperature protection circuit according to claim 1 or 6, characterized in that, The second comparator circuit includes: The second comparator has its non-inverting input connected to the temperature signal output of the intelligent power module of the fan, its inverting input connected to the second reference voltage, and its output connected to the control circuit.

8. The over-temperature protection circuit according to claim 1, characterized in that, The over-temperature protection circuit also includes: The reference voltage generating circuit has an input terminal connected to a first power supply, a first output terminal connected to the second input terminal of the first comparator circuit, and a second output terminal connected to the second input terminal of the second comparator circuit. The reference voltage generating circuit is used to convert the voltage of the first power supply and output the first reference voltage through the first output terminal and the second reference voltage through the second output terminal.

9. The over-temperature protection circuit according to claim 8, characterized in that, The reference voltage generating circuit includes: The first voltage divider circuit has its input terminal connected to the first power supply and its output terminal being the first output terminal of the reference voltage generating circuit. The first voltage divider circuit is used to divide the connected first power supply into the first reference voltage and output it. The second voltage divider circuit has its input terminal connected to the first power supply and its output terminal being the second output terminal of the reference voltage generating circuit. The second voltage divider circuit is used to divide the connected first power supply into the second reference voltage and output it.

10. An air conditioner, characterized in that, include: The power integration module includes a compressor intelligent power module, a fan intelligent power module, and a power factor correction circuit; The over-temperature protection circuit as described in any one of claims 1 to 9 has its first input terminal connected to the compressor intelligent power module, its second input terminal connected to the fan intelligent power module, and its output terminal connected to the power factor correction circuit.

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