IGBT overcurrent detection protection circuit, compressor and air conditioning device

Abstract

The present invention relates to an IGBT overcurrent detection protection circuit, a compressor and an air conditioning device. By setting a switch module between the output end of the IGBT inverter module and the load, and by controlling the control module to stop outputting the PWM signal when the output current of the IGBT inverter module is greater than the threshold current, the main control chip is controlled to disconnect from the load by turning off the IGBT and cutting off the load circuit when the IGBT inverter module is short-circuited or a large current mutation occurs, the IGBT module is protected by double protection by turning off the IGBT and cutting off the load circuit, thereby improving the timeliness and effectiveness of the IGBT overcurrent detection protection, and being able to solve the problem of protection delay in the prior art of using software to detect IGBT current for overcurrent protection. Furthermore, the technical solution provided by the present invention integrates overcurrent detection and IGBT protection, uses hardware to build a protection circuit, has a high circuit integration, and is used in conjunction with software to detect IGBT current for overcurrent protection, which is safer and more reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit design, and in particular to an IGBT overcurrent detection protection circuit, a compressor and an air conditioning device. Background Art

[0002] With the continuous development of industrial technology, IGBT is being used more and more widely, especially in the field of motor control. In the process of using IGBT, overcurrent protection of the motor and the overcurrent protection of the IGBT itself are particularly important. If the motor protection is not timely, it may cause motor demagnetization or winding burnout; if the IGBT itself is not protected in time, it may cause the IGBT to burn out, which is dangerous.

[0003] At present, most of the methods used are software detection of the current flowing through the IGBT. When the current reaches a certain value, corresponding protection measures will appear. However, due to the delay in software processing, some protection will not be timely, which may cause certain dangers. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide an IGBT overcurrent detection protection circuit, a compressor and an air conditioning device to solve the problem of protection delay in the prior art that software is used to detect IGBT current for overcurrent protection.

[0005] According to a first aspect of an embodiment of the present invention, there is provided an IGBT overcurrent detection protection circuit, comprising:

[0006] A switch module is arranged between the output end of the IGBT inverter module and the load; the IGBT inverter module is connected to the main control chip through the first drive circuit, and the main control chip is used to generate a PWM signal;

[0007] The control module is connected to the switch module and the main control chip, and is used to control the main control chip to stop outputting the PWM signal and control the switch module to disconnect from the load when the output current of the IGBT inverter module is greater than the threshold current.

[0008] Preferably, the switch module comprises:

[0009] At least one P-type IGBT module;

[0010] If there are multiple P-type IGBT modules, the multiple P-type IGBT modules are connected in parallel;

[0011] The drain of the switch module is connected to the output end of the IGBT inverter module, the source is grounded, and the gate is connected to the control module through a second drive circuit.

[0012] Preferably, the control module comprises:

[0013] A common-phase amplifier, whose non-phase input end is connected to the drain of the switch module, whose inverting input end is connected to the source of the switch module through a first resistor, whose output end is connected to the source of the switch module through a second resistor, and is also connected to the main control chip;

[0014] A comparator, wherein the non-inverting input terminal of the comparator is externally connected to a reference voltage source, and the inverting input terminal of the comparator is connected to the output terminal of the in-phase amplifier; the reference voltage output by the reference voltage source is positively correlated with the threshold current;

[0015] A first multivibrator, whose input end is connected to the output end of the comparator and whose output end is connected to the second driving circuit;

[0016] The second multivibrator has an input end connected to the output end of the comparator, and an output end connected to the main control chip.

[0017] Preferably, the comparator is used to output a low level signal when the input voltage is greater than the reference voltage output by the reference voltage source; and output a high level signal when the input voltage is less than the reference voltage output by the reference voltage source;

[0018] The first multivibrator is used for outputting a low-level signal lasting for a first time period when the comparator outputs a low level, so as to control the switch module to disconnect from the load;

[0019] The second multivibrator is used for outputting a low level signal lasting for a second time period when the comparator outputs a low level, so as to control the main control chip to stop outputting the PWM signal.

[0020] Preferably, the first duration ≤ the second duration.

[0021] Preferably, the load includes at least one of the following items:

[0022] Motors, compressors, fans.

[0023] According to a second aspect of an embodiment of the present invention, there is provided a compressor driving circuit, comprising:

[0024] The above-mentioned IGBT over-current detection protection circuit.

[0025] According to a third aspect of an embodiment of the present invention, there is provided a compressor, comprising:

[0026] The compressor driving circuit mentioned above.

[0027] According to a fourth aspect of an embodiment of the present invention, there is provided an air conditioning device, comprising:

[0028] The compressor described above.

[0029] Preferably, the air conditioning device comprises:

[0030] Air conditioning, and / or, fresh air blower.

[0031] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0032] By arranging a switch module between the output end of the IGBT inverter module and the load, and by controlling the control module to stop outputting the PWM signal when the output current of the IGBT inverter module is greater than the threshold current, and controlling the switch module to disconnect from the load, when a short circuit or a large current mutation occurs in the IGBT inverter module, the IGBT is turned off and the load circuit is cut off, thereby achieving dual protection of the IGBT module, improving the timeliness and effectiveness of the IGBT overcurrent detection protection, and being able to solve the problem of protection delay in the prior art of using software to detect the IGBT current for overcurrent protection.

[0033] Furthermore, the technical solution provided by the present invention integrates overcurrent detection with IGBT protection, and uses hardware to build a protection circuit with high circuit integration. It is used in combination with software to detect IGBT current for overcurrent protection, which is safer and more reliable.

[0034] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0036] Figure 1 is a schematic block diagram of an IGBT overcurrent detection protection circuit according to an exemplary embodiment;

[0037] Figure 2 The diagram is a circuit schematic diagram of an IGBT overcurrent detection protection circuit according to an exemplary embodiment. DETAILED DESCRIPTION

[0038] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0039] Embodiment 1

[0040] Figure 1 is a schematic block diagram of an IGBT overcurrent detection protection circuit according to an exemplary embodiment. Figure 1 As shown, the circuit comprises:

[0041] The switch module 101 is arranged between the output terminal of the IGBT inverter module and the load; the IGBT inverter module is connected to the main control chip through the first drive circuit, and the main control chip is used to generate a PWM signal;

[0042] The control module 102 is connected to the switch module 101 and the main control chip, and is used to control the main control chip to stop outputting the PWM signal and control the switch module 101 to disconnect from the load when the output current of the IGBT inverter module is greater than the threshold current.

[0043] Preferably, the load includes at least one of the following items:

[0044] Motors, compressors, fans.

[0045] It can be understood that the technical solution provided in this embodiment is applicable to scenarios including but not limited to: a compressor drive circuit, a motor drive circuit, and a fan drive circuit.

[0046] See also Figure 2 , IGBT inverter module such as Figure 2 In specific practice, the switch module 101 includes:

[0047] At least one P-type IGBT module Q7 (the number of P-type IGBT modules is selected according to the output current of the IGBT inverter module. For example, if the output current of the IGBT inverter module is small, a P-type IGBT module can be selected. If the output current of the IGBT inverter module is large, multiple P-type IGBT modules can be selected and connected in parallel);

[0048] If there are multiple P-type IGBT modules Q7, the multiple P-type IGBT modules Q7 are connected in parallel;

[0049] The drain of the switch module 101 is connected to the output end of the IGBT inverter module, the source is grounded, and the gate is connected to the control module 102 through the second drive circuit 1011 .

[0050] Preferably, the control module 102 includes:

[0051] A common-mode amplifier Q8, whose non-inverting input terminal is connected to the drain of the switch module 101, whose inverting input terminal is connected to the source of the switch module 101 through a first resistor R1, whose output terminal is connected to the source of the switch module 101 through a second resistor R2, and is also connected to the main control chip;

[0052] A comparator Q9, whose non-inverting input terminal is externally connected to a reference voltage source, and whose inverting input terminal is connected to the output terminal of the in-phase amplifier; the reference voltage output by the reference voltage source is positively correlated with the threshold current;

[0053] A first multivibrator 1021, whose input end is connected to the output end of the comparator Q9, and whose output end is connected to the second driving circuit 1011;

[0054] The second multivibrator 1022 has its input end connected to the output end of the comparator Q9, and its output end connected to the main control chip.

[0055] It can be understood that the comparator Q9 outputs a low level signal when the input voltage is greater than the reference voltage output by the reference voltage source; and outputs a high level signal when the input voltage is less than the reference voltage output by the reference voltage source.

[0056] The first multivibrator 1021, when the comparator Q9 outputs a low level signal, outputs a low level signal lasting for a first duration T1, so as to control the switch module 101 to disconnect from the load;

[0057] When the comparator Q9 outputs a low level signal, the second multivibrator 1022 outputs a low level signal lasting for a second time duration T2 to control the main control chip to stop outputting the PWM signal.

[0058] In specific practice, it can be understood that the first multivibrator 1021 and the second multivibrator 1022 are used to generate a rectangular wave, and the duty cycle of the generated rectangular wave can be adjusted to control the duration of the output low-level signal. The first duration T1 and the second duration T2 can be determined according to actual conditions and application scenarios as needed. Preferably, the first duration T1 ≤ the second duration T2.

[0059] For ease of understanding, now combined Figure 2 The circuit schematic diagram shown in the figure explains in detail the working principle of the IGBT overcurrent detection protection circuit provided by this embodiment, which is as follows:

[0060] See also Figure 2When the IGBT inverter module works normally, the P-type IGBT module Q7 works in the on state. Since there is an internal resistance when Q7 is turned on, the voltage across it can be collected to convert the current flowing through Q7 (that is, the total three-phase current output by the IGBT inverter module) when it is turned on. The voltage signal collected by Q7 is sent to the main control chip after passing through the in-phase amplifier Q8 for software current protection; at the same time, the voltage signal is also sent to the comparator Q9 and compared with the reference voltage V output by the reference voltage source. ref Make comparisons.

[0061] When the IGBT inverter module does not have a short circuit or a large current mutation, the comparator Q9 outputs a constant high level, the first multivibrator 1021 and the second multivibrator 1022 will not be triggered, and the IGBT inverter module works normally.

[0062] When the IGBT inverter module is short-circuited or has a large current mutation, as the current increases rapidly, the input voltage of the comparator Q9 is greater than the reference voltage V ref When the comparator Q9 outputs a signal level from a high level to a low level, the first multivibrator 1021 and the second multivibrator 1022 will process and generate low level signals with durations of T1 and T2, respectively.

[0063] The low-level signal with a duration of T1 acts on the P-type IGBT module Q7, and the P-type IGBT module Q7 will be disconnected for T1, at which time the entire load circuit will be cut off to prevent the large current from burning the load device; the low-level signal with a duration of T2 acts on the main control chip, and the main control chip will stop outputting PWM signals within T2 to ensure that all IGBT inverter modules are disconnected. This dual protection structure design can make the IGBT inverter module safer and more reliable.

[0064] It can be understood that the technical solution provided in this embodiment is to set a switch module between the output end of the IGBT inverter module and the load, and control the main control chip to stop outputting the PWM signal and control the switch module to disconnect the connection with the load when the output current of the IGBT inverter module is greater than the threshold current, so that when a short circuit or a large current mutation occurs in the IGBT inverter module, the IGBT is turned off and the load circuit is cut off, thereby achieving dual protection of the IGBT module, improving the timeliness and effectiveness of the IGBT overcurrent detection protection, and being able to solve the problem of protection delay in the prior art of using software to detect the IGBT current for overcurrent protection.

[0065] Furthermore, the technical solution provided in this embodiment integrates overcurrent detection and IGBT protection, and uses hardware to build a protection circuit with high circuit integration. It is used in combination with software to detect IGBT current for overcurrent protection, which is safer and more reliable.

[0066] Embodiment 2

[0067] According to an exemplary embodiment, a compressor driving circuit is shown, comprising:

[0068] The above-mentioned IGBT over-current detection protection circuit.

[0069] It can be understood that the technical solution provided by this embodiment, since the compressor drive circuit includes the IGBT overcurrent detection protection circuit described in the above-mentioned embodiment 1, and the IGBT overcurrent detection protection circuit sets a switch module between the output end of the IGBT inverter module and the load, and controls the main control chip to stop outputting the PWM signal and controls the switch module to disconnect the connection with the load when the output current of the IGBT inverter module is greater than the threshold current through the control module, so that when a short circuit or a large current mutation occurs in the IGBT inverter module, the IGBT is turned off and the load circuit is cut off, thereby achieving dual protection of the IGBT module, improving the timeliness and effectiveness of the IGBT overcurrent detection protection, and being able to solve the problem of protection delay in the prior art of using software to detect the IGBT current for overcurrent protection.

[0070] Furthermore, the technical solution provided in this embodiment integrates overcurrent detection and IGBT protection, and uses hardware to build a protection circuit with high circuit integration. It is used in combination with software to detect IGBT current for overcurrent protection, which is safer and more reliable.

[0071] Embodiment 3

[0072] A compressor according to an exemplary embodiment includes:

[0073] The compressor driving circuit mentioned above.

[0074] It can be understood that the technical solution provided by this embodiment, since the compressor includes the IGBT overcurrent detection protection circuit described in the above-mentioned embodiment 1, and the IGBT overcurrent detection protection circuit sets a switch module between the output end of the IGBT inverter module and the load, and controls the main control chip to stop outputting the PWM signal and controls the switch module to disconnect the connection with the load when the output current of the IGBT inverter module is greater than the threshold current through the control module, so that when a short circuit or a large current mutation occurs in the IGBT inverter module, the IGBT is turned off and the load circuit is cut off, thereby achieving dual protection of the IGBT module, improving the timeliness and effectiveness of the IGBT overcurrent detection protection, and being able to solve the problem of protection delay in the prior art of using software to detect IGBT current for overcurrent protection.

[0075] Furthermore, the technical solution provided in this embodiment integrates overcurrent detection and IGBT protection, and uses hardware to build a protection circuit with high circuit integration. It is used in combination with software to detect IGBT current for overcurrent protection, which is safer and more reliable.

[0076] Embodiment 4

[0077] According to an exemplary embodiment, an air conditioning device is shown, comprising:

[0078] The compressor described above.

[0079] Preferably, the air conditioning device comprises:

[0080] Air conditioning, and / or fresh air blower.

[0081] It can be understood that the technical solution provided by this embodiment, since the air conditioning device includes the IGBT overcurrent detection protection circuit described in the above-mentioned embodiment 1, and the IGBT overcurrent detection protection circuit is configured by setting a switch module between the output end of the IGBT inverter module and the load, and controlling the main control chip to stop outputting the PWM signal and controlling the switch module to disconnect the load when the output current of the IGBT inverter module is greater than the threshold current through the control module, so that when a short circuit or a large current mutation occurs in the IGBT inverter module, the IGBT is turned off and the load circuit is cut off, thereby achieving dual protection of the IGBT module, improving the timeliness and effectiveness of the IGBT overcurrent detection protection, and being able to solve the problem of protection delay in the prior art of using software to detect the IGBT current for overcurrent protection.

[0082] Furthermore, the technical solution provided in this embodiment integrates overcurrent detection and IGBT protection, and uses hardware to build a protection circuit with high circuit integration. It is used in combination with software to detect IGBT current for overcurrent protection, which is safer and more reliable.

[0083] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0084] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0085] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0086] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0087] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0088] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0089] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0091] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An IGBT overcurrent detection protection circuit, It is characterized in that include: The switch module is arranged between the output end of the IGBT inverter module and the load; The IGBT inverter module is connected to the main control chip through a first drive circuit, and the main control chip is used to generate a PWM signal; The switch module comprises: at least one P-type IGBT module; The control module is connected to the switch module and the main control chip, and is used to control the main control chip to stop outputting the PWM signal and control the switch module to disconnect from the load when the output current of the IGBT inverter module is greater than the threshold current.

2. The circuit according to claim 1, It is characterized in that If there are multiple P-type IGBT modules, the multiple P-type IGBT modules are connected in parallel; The drain of the switch module is connected to the output end of the IGBT inverter module, the source is grounded, and the gate is connected to the control module through a second drive circuit.

3. The circuit according to claim 2, It is characterized in that The control module comprises: A common-phase amplifier, whose non-phase input end is connected to the drain of the switch module, whose inverting input end is connected to the source of the switch module through a first resistor, whose output end is connected to the source of the switch module through a second resistor, and is also connected to the main control chip; A comparator, wherein the non-inverting input terminal of the comparator is externally connected to a reference voltage source, and the inverting input terminal of the comparator is connected to the output terminal of the in-phase amplifier; the reference voltage output by the reference voltage source is positively correlated with the threshold current; A first multivibrator, whose input end is connected to the output end of the comparator and whose output end is connected to the second driving circuit; The second multivibrator has an input end connected to the output end of the comparator, and an output end connected to the main control chip.

4. The circuit according to claim 3, It is characterized in that The comparator is used to output a low level signal when the input voltage is greater than the reference voltage output by the reference voltage source; and output a high level signal when the input voltage is less than the reference voltage output by the reference voltage source; The first multivibrator is used for outputting a low-level signal lasting for a first time length when the comparator outputs a low-level signal, so as to control the switch module to disconnect from the load; The second multivibrator is used for outputting a low-level signal lasting for a second time period when the comparator outputs a low-level signal, so as to control the main control chip to stop outputting the PWM signal.

5. The circuit according to claim 4, It is characterized in that The first duration ≤ the second duration.

6. The circuit according to any one of claims 1 to 5, It is characterized in that The load includes at least one of the following: Motors, compressors, fans.

7. A compressor drive circuit, It is characterized in that include: An IGBT overcurrent detection protection circuit as claimed in any one of claims 1 to 6.

8. A compressor, It is characterized in that include: The compressor driving circuit as claimed in claim 7.

9. An air conditioning device, It is characterized in that include: The compressor as claimed in claim 8.

10. The air conditioning device according to claim 9, It is characterized in that include: Air conditioning, and / or, fresh air blower.

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