Overcurrent protection circuit and motor controller

Abstract

The utility model provides an overcurrent protection circuit and a motor controller. Because the to-be-protected switch tube is an IGBT or a triode, that is, the to-be-protected switch tube has an overcurrent desaturation characteristic, when the to-be-protected switch tube is conducted and overcurrent occurs, the voltage at the two ends of the to-be-protected switch tube rises, so that the first one-way conduction circuit is cut off, and the partial voltage of the second resistor branch is greater than the preset voltage; even if the potential of the in-phase input end of the comparison circuit is greater than that of the inverted input end of the comparison circuit, the first switch module is switched on; the first end of the first switch module receives the turn-off signal of the to-be-protected switch tube, and the second end of the first switch module is connected with the control end of the to-be-protected switch tube, so that the control end of the to-be-protected switch tube can receive the turn-off signal of the control end of the to-be-protected switch tube, the to-be-protected switch tube is turned off, and the to-be-protected switch tube can be prevented from being damaged due to overcurrent; therefore, the overcurrent protection circuit can prevent the IGBT from being damaged due to overcurrent.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, in particular to an overcurrent protection circuit and a motor controller. Background Art

[0002] At present, when the load needs to withstand high voltage and large current during operation, the power conversion circuit that supplies power to the load usually uses IGBT as its own switching tube to ensure the power supply operation of the load.

[0003] However, when the current output by the power conversion circuit is too large, that is, when the IGBT in the power conversion circuit is overcurrent, if the IGBT in the power conversion circuit cannot be shut down in time, the IGBT in the power conversion circuit may be damaged, thereby causing damage to the power conversion circuit, and further may cause damage to the load.

[0004] Therefore, how to prevent the IGBT in the power conversion circuit from being damaged due to overcurrent is a technical problem that needs to be solved urgently. Utility Model Content

[0005] In view of this, the utility model provides an overcurrent protection circuit and a motor controller to prevent the IGBT in the power conversion circuit from being damaged due to overcurrent.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] It can be seen from the above technical scheme that the utility model provides an overcurrent protection circuit. In the overcurrent protection circuit, since the switch tube to be protected is an IGBT or a triode, that is, the switch tube to be protected has an overcurrent desaturation characteristic, when the switch tube to be protected is turned on and an overcurrent occurs, the voltage at both ends of the switch tube to be protected increases, thereby causing the first unidirectional conduction circuit to be cut off, so that the voltage division of the second resistance branch is greater than the preset voltage, that is, the potential of the in-phase input end of the comparison circuit is greater than the potential of its inverting input end, thereby causing the first switch module to be turned on; and since the first end of the first switch module receives the shutdown signal of the switch tube to be protected and the second end is connected to the control end of the switch tube to be protected, the control end of the switch tube to be protected will receive its own shutdown signal at this time, thereby causing the switch tube to be protected to be turned off, thereby preventing the switch tube to be protected from being damaged due to overcurrent; in addition, since the switch tube to be protected is an IGBT, the overcurrent protection circuit can prevent the IGBT from being damaged due to overcurrent. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0009] Figure 1-Figure 15 The figures are schematic diagrams of the structures of fifteen implementation modes of the overcurrent protection circuit provided in the present application. DETAILED DESCRIPTION

[0010] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0011] In this application, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0012] In order to prevent the IGBT in the power conversion circuit from being damaged due to overcurrent, the embodiment of the present application provides an overcurrent protection circuit, the specific structure of which can be seen in Figure 1 , specifically comprising: a first switch module 100, a comparison circuit 200, a first unidirectional conduction circuit 300, a first resistance branch 400 and a second resistance branch 500; the connection relationship between the components is specifically as follows:

[0013] The first end of the first resistance branch 400 is connected to the first end of the first power supply, and the second end of the first resistance branch 400 is respectively connected to the first end of the second resistance branch 500 and the input end of the first unidirectional conduction circuit 300; the input end of the switch tube Qd to be protected is connected to the output end of the first unidirectional conduction circuit 300, and the output end of the switch tube Qd to be protected and the second end of the second resistance branch 500 are both connected to the second end of the first power supply.

[0014] Optionally, the switch tube Qd to be protected can be an IGBT, a MOS tube, or a triode. In practical applications, this includes but is not limited to these. No specific limitation is made here and it may depend on the specific circumstances. All are within the protection scope of this application.

[0015] Optionally, the switch tube Qd to be protected can be a PNP type tube or an NPN type tube, which is not specifically limited here and can be determined according to the specific circumstances, all of which are within the protection scope of this application.

[0016] The first resistance branch 400 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the first resistance branch 400 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the first resistance branch 400 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 1 As shown, the first resistor branch 400 is represented by a resistor R1.

[0017] The second resistance branch 500 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the second resistance branch 500 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the second resistance branch 500 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 1 As shown, the second resistance branch 500 is represented by a resistor R2.

[0018] The first unidirectional conducting circuit 300 includes at least one unidirectional conducting device. If the number of the unidirectional conducting devices is greater than 1, each unidirectional conducting device is connected in series in the same direction, and the anode of the formed branch serves as the anode of the first unidirectional conducting circuit 300, and the cathode of the formed branch serves as the cathode of the first unidirectional conducting circuit 300; if the number of the unidirectional conducting devices is equal to 1, the anode of the unidirectional conducting device serves as the anode of the first unidirectional conducting circuit 300, and the cathode of the unidirectional conducting device serves as the cathode of the first unidirectional conducting circuit 300.

[0019] Optionally, the unidirectional conducting device may be a diode. In practical applications, including but not limited to this, no specific limitation is made here, and it may be determined according to specific circumstances, and all are within the scope of protection of this application; for example, Figure 1 As shown, the first unidirectional conducting circuit 300 is represented by a diode D1 .

[0020] The non-inverting input terminal of the comparison circuit 200 is connected to the first end of the second resistance branch 500 , the inverting input terminal of the comparison circuit 200 receives the preset voltage Vy, and the output terminal of the comparison circuit 200 is connected to the control terminal of the first switch module 100 .

[0021] Among them, the output voltage of the first power supply is a voltage that makes the divided voltage of the second resistance branch 500 greater than the preset voltage Vy when the first unidirectional conductive circuit 300 is not conducting; in actual applications, the output voltage of the first power supply and the preset voltage Vy are set according to the actual situation of the overcurrent protection circuit. For example, the second end of the first power supply is the high-voltage reference ground GND_HV, and the first end of the first power supply is +16V_HV, that is, the potential of the first end of the first power supply is 16V higher than the high-voltage reference ground GND_HV.

[0022] Optionally, the switch tube in the first switch module 100 can be a MOS tube, an IGBT, or a triode. In practical applications, this includes but is not limited to these. No specific limitation is made here and it may depend on the specific situation. All are within the protection scope of this application.

[0023] Optionally, the switch tube in the first switch module 100 may be a PNP type tube or an NPN type tube, which is not specifically limited here and may be determined according to specific circumstances, and all are within the protection scope of this application.

[0024] If the output signal of the comparison circuit 200 when the potential at its own non-inverting input terminal is greater than the potential at its own inverting input terminal is a high level signal, the switch tube in the first switch module 100 is an NMOS tube.

[0025] In a specific example, if Figure 1 As shown, the switch tube in the first switch module 100 is an NMOS tube, and the first switch module 100 specifically includes: a first switch tube Q1 and two resistance branches; the input end of the first switch tube Q1 serves as the first end of the first switch module 100, the output end of the first switch tube Q1 serves as the second end of the first switch module 100, the control end of the first switch tube Q1 is connected to the control end of the first switch module 100 through the seventeenth resistance branch 110, and the control end of the first switch tube Q1 is also connected to the output end of the first switch tube Q1 through the eighteenth resistance branch 120.

[0026] The seventeenth resistor branch 110 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the seventeenth resistor branch 110 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the seventeenth resistor branch 110 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 1As shown, the seventeenth resistor branch 110 is represented by a resistor R17 .

[0027] The eighteenth resistor branch 120 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the eighteenth resistor branch 120 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the eighteenth resistor branch 120 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 1 As shown, the eighteenth resistor branch 120 is represented by a resistor R18.

[0028] The above is only a specific implementation of the first switch module 100 when the switch tube in the first switch module 100 is an NMOS tube. In practical applications, it includes but is not limited to this, and is not specifically limited here, and all are within the protection scope of this application.

[0029] The first end of the first switch module 100 receives the shutdown signal of the switch tube Qd to be protected, and the second end of the first switch module 100 is connected to the control end of the switch tube Qd to be protected. The conduction signal of the first switch module 100 is the output signal of the comparison circuit 200 when the potential of its own non-inverting input terminal is greater than the potential of its own inverting input terminal.

[0030] If the switch tube Qd to be protected is an NPN type tube, the turn-on signal of the switch tube Qd to be protected is a high level signal, and the turn-off signal of the switch tube Qd to be protected is a low level signal; if the switch tube Qd to be protected is a PNP type tube, the turn-on signal of the switch tube Qd to be protected is a low level signal, and the turn-off signal of the switch tube Qd to be protected is a high level signal.

[0031] It should be noted that the high-level signal and the low-level signal are set according to the actual situation of the switch tube Qd to be protected. For example, if the switch tube Qd to be protected is an NPN-type tube, the shutdown signal of the switch tube Qd to be protected is a low-level signal. Figure 1 As shown, the first end of the first switch module 100 is connected to the low voltage reference ground GND_LV; no specific limitation is made here, and it can be determined according to the specific situation, which is within the protection scope of this application.

[0032] The working principle of the overcurrent protection circuit is as follows:

[0033] When the switch tube Qd to be protected receives its own shutdown signal, the switch tube Qd to be protected is turned off, and the first unidirectional conduction circuit 300 is not turned on, so that the first resistor branch 400 and the second resistor branch 500 divide the voltage; since the divided voltage of the second resistor branch 500 is greater than the preset voltage Vy when the first unidirectional conduction circuit 300 is not turned on, the non-inverting input terminal of the comparison circuit 200 is greater than the inverting input terminal; and since the turn-on signal of the first switch module 100 is the output signal of the comparison circuit 200 when the potential of its own non-inverting input terminal is greater than the potential of its own inverting input terminal, the first switch module 100 is turned on; and since the first end of the first switch module 100 receives the shutdown signal of the switch tube Qd to be protected, the switch tube Qd to be protected still only receives its own shutdown signal, that is, the switch tube Qd to be protected is still in the off state.

[0034] When the switch tube Qd to be protected receives its own turn-on signal, the switch tube Qd to be protected is turned on; if the current flowing through the switch tube Qd to be protected is small, the tube drop of the switch tube Qd to be protected is low, usually only about 1 to 3V, so that the first unidirectional conduction circuit 300 is turned on, that is, the divided voltage of the second resistance branch 500 is low; since the divided voltage of the second resistance branch 500 is less than the preset voltage Vy when the first unidirectional conduction circuit 300 is turned on, the non-inverting input terminal of the comparison circuit 200 is less than the inverting input terminal; and since the turn-on signal of the first switch module 100 is the output signal of the comparison circuit 200 when the potential of its own non-inverting input terminal is greater than the potential of its own inverting input terminal, the first switch module 100 is turned off, so that the switch tube Qd to be protected still only receives its own turn-on signal, that is, the switch tube Qd to be protected is still in the on state.

[0035] When the switch tube Qd to be protected receives its own turn-on signal, the switch tube Qd to be protected is turned on. If the current flowing through the switch tube Qd to be protected is large, that is, overcurrent, the tube drop of the switch tube Qd to be protected becomes larger due to its own overcurrent desaturation characteristic, so that the first unidirectional conduction circuit 300 is not turned on, that is, the divided voltage of the second resistance branch 500 is large; because the divided voltage of the second resistance branch 500 is greater than the preset voltage Vy when the first unidirectional conduction circuit 300 is not turned on, the non-inverting input terminal of the comparison circuit 200 is greater than the inverting input terminal. ; Since the turn-on signal of the first switch module 100 is the output signal of the comparison circuit 200 when the potential of its own non-inverting input terminal is greater than the potential of its own inverting input terminal, the first switch module 100 is turned on; and since the first end of the first switch module 100 receives the turn-off signal of the switch tube Qd to be protected, the switch tube Qd to be protected receives not only its own turn-on signal but also its own turn-off signal, thereby switching the switch tube Qd to be protected from the turn-on state to the turn-off state, that is, the switch tube Qd to be protected is turned off.

[0036] In the overcurrent protection circuit, since the switch tube Qd to be protected is an IGBT or a triode, that is, the switch tube Qd to be protected has an overcurrent desaturation characteristic, when the switch tube Qd to be protected is turned on and an overcurrent occurs, the voltage across the switch tube Qd to be protected increases, thereby turning off the first unidirectional conduction circuit 300, so that the divided voltage of the second resistance branch 500 is greater than the preset voltage Vy, that is, the potential of the non-inverting input end of the comparison circuit 200 is greater than the potential of its inverting input end, thereby turning on the first switch module 100; and since the first end of the first switch module 100 receives the shutdown signal of the switch tube Qd to be protected and the second end is connected to the control end of the switch tube Qd to be protected, the control end of the switch tube Qd to be protected will receive its own shutdown signal at this time, thereby turning off the switch tube Qd to be protected, thereby preventing the switch tube Qd to be protected from being damaged due to overcurrent; in addition, since the switch tube Qd to be protected is an IGBT, the overcurrent protection circuit can prevent the IGBT from being damaged due to overcurrent.

[0037] Another embodiment of the present application provides another implementation of the overcurrent protection circuit, which is suitable for the case where the control end of the switch tube Qd to be protected receives its own turn-on signal / turn-off signal through the first isolation circuit 700; the specific structure of this implementation can be seen in Figure 2 ( Figure 2 Only in Figure 1 Based on the above embodiment, this embodiment further includes: a second isolation circuit 600; the connection relationship between the components is as follows:

[0038] The output end of the comparison circuit 200 is connected to the control end of the first switch module 100 through the second isolation circuit 600; the second end of the first switch module 100 is connected to the control end of the switch tube Qd to be protected through the first isolation circuit 700.

[0039] In this implementation, two isolation circuits are added to achieve isolation between high voltage and low voltage, thereby improving power safety.

[0040] Another embodiment of the present application provides a specific implementation of the second isolation circuit 600. The specific structure of the second isolation circuit 600 can be found in Figure 3 ( Figure 3 Only in Figure 2 The invention is shown on the basis of FIG. 6 , which specifically includes: a photoelectric coupler 610, a second switch module 620, a third resistor branch 630, a fourth resistor branch 640, a fifth resistor branch 650, a sixth resistor branch 660 and a seventh resistor branch 670; the connection relationship between the components is specifically described as follows:

[0041] The third resistor branch 630 , the fourth resistor branch 640 , and the second switch module 620 are connected in series, and two ends of the formed series branch are respectively connected to two poles of the second power supply.

[0042] In a specific example, if Figure 3 As shown, one end of the third resistor branch 630 is connected to the first end of the second power supply, the other end of the third resistor branch 630 is connected to one end of the fourth resistor branch 640, the other end of the fourth resistor branch 640 is connected to the first end of the second switch module 620, and the second end of the second switch module 620 is connected to the second end of the second power supply.

[0043] The above example only shows a series connection mode of the third resistor branch 630, the fourth resistor branch 640, and the second switch module 620. In practical applications, including but not limited to this, no specific limitation is made here, and all are within the protection scope of this application.

[0044] The third resistor branch 630 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the third resistor branch 630 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the third resistor branch 630 respectively; for example, Figure 3 As shown, the third resistance branch 630 is represented by a resistor R3.

[0045] The fourth resistor branch 640 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the fourth resistor branch 640 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the fourth resistor branch 640 respectively; for example, Figure 3 As shown, the fourth resistance branch 640 is represented by a resistor R4.

[0046] Optionally, the switch tube in the second switch module 620 can be a MOS tube, an IGBT, or a triode. In practical applications, this includes but is not limited to these. No specific limitation is made here and it may depend on the specific situation. All are within the protection scope of this application.

[0047] Optionally, the switch tube in the second switch module 620 can be a PNP type tube or an NPN type tube, which is not specifically limited here and can be determined according to specific circumstances, all of which are within the protection scope of this application.

[0048] If the output signal of the comparison circuit 200 when the potential at its own non-inverting input terminal is greater than the potential at its own inverting input terminal is a high level signal, the switch tube in the second switch module 620 is an NMOS tube.

[0049] In a specific example, if Figure 3As shown, the switch tube in the second switch module 620 is an NMOS tube, and the second switch module 620 specifically includes: a second switch tube Q2 and two resistance branches; the input end of the second switch tube Q2 serves as the first end of the second switch module 620, and the output end of the second switch tube Q2 serves as the second end of the second switch module 620, and the control end of the second switch tube Q2 is connected to the control end of the second switch module 620 through the nineteenth resistance branch 621, and the control end of the second switch tube Q2 is also connected to the output end of the second switch tube Q2 through the twentieth resistance branch 622.

[0050] The nineteenth resistor branch 621 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the nineteenth resistor branch 621 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the nineteenth resistor branch 621 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 3 As shown, the nineteenth resistor branch 621 is represented by the resistor R19.

[0051] The twentieth resistor branch 622 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twentieth resistor branch 622 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twentieth resistor branch 622 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 3 As shown, the twentieth resistor branch 622 is represented by a resistor R20.

[0052] The above is only a specific implementation of the second switch module 620 when the switch tube in the second switch module 620 is an NMOS tube. In practical applications, it includes but is not limited to this, and is not specifically limited here, and all are within the protection scope of this application.

[0053] In practical applications, the output voltage of the second power supply is set according to the actual situation of the overcurrent protection circuit. For example, the first end of the second power supply is +16V_HV, that is, the potential of the first end of the second power supply is 16V higher than the high-voltage reference ground GND_HV, and the second end of the second power supply is -7V_HV, that is, the potential of the first end of the second power supply is 7V lower than the high-voltage reference ground GND_HV.

[0054] The control end of the second switch module 620 serves as the input end of the second isolation circuit 600 , and the conduction signal of the second switch module 620 is the output signal of the comparison circuit 200 when the potential of its own non-inverting input end is greater than the potential of its own inverting input end.

[0055] The primary side of the photocoupler 610 is connected in parallel to two ends of the third resistance branch 630 and the fourth resistance branch 640 , which are closer to the second end of the second power supply.

[0056] Taking the third resistor branch 630, the fourth resistor branch 640, and the second switch module 620 shown in the above example as an example, Figure 3 As shown, the primary side of the photocoupler 610 is connected in parallel to two ends of the fourth resistance branch 640 .

[0057] The anode of the secondary side of the photocoupler 610 is connected to the first end of the third power supply through the fifth resistor branch 650, the cathode of the secondary side of the photocoupler 610 is connected to the second end of the third power supply through the sixth resistor branch 660, and the cathode of the secondary side of the photocoupler 610 is also connected to the output end of the second isolation circuit 600 through the seventh resistor branch 670.

[0058] The fifth resistance branch 650 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the fifth resistance branch 650 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the fifth resistance branch 650 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 3 As shown, the fifth resistor branch 650 is represented by a resistor R5.

[0059] The sixth resistor branch 660 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the sixth resistor branch 660 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the sixth resistor branch 660 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 3 As shown, the sixth resistor branch 660 is represented by a resistor R6.

[0060] The seventh resistor branch 670 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the seventh resistor branch 670 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the seventh resistor branch 670 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 3 As shown, the seventh resistor branch 670 is represented by a resistor R7.

[0061] In practical applications, the output voltage of the third power supply is set according to the actual situation of the overcurrent protection circuit. For example, if the output signal of the comparison circuit 200 is a high-level signal when the potential at its own non-inverting input terminal is greater than the potential at its own inverting input terminal, the first end of the third power supply is +5V_LV, that is, the potential of the first end of the third power supply is 5V higher than the low-voltage reference ground, and the second end of the third power supply is the low-voltage reference GND_LV.

[0062] The working principle of the second isolation circuit 600 is specifically described as follows:

[0063] When the potential of the non-inverting input terminal of the comparison circuit 200 is greater than the potential of its own inverting input terminal, the second switch module 620 is turned on, and the branch formed by the third resistor branch 630, the fourth resistor branch 640, and the second switch module 620 forms a path, and the primary side of the optocoupler 610 is energized and turned on, so that the secondary side of the optocoupler 610 is turned on and output to the outside, wherein the output signal of the second isolation circuit 600 is the same as its own input signal.

[0064] It should be noted that, in practical applications, by reasonably setting the output voltage of the second power supply, the output voltage of the third power supply and the resistance of the third resistor branch 630 to the seventh resistor branch 670, the output signal of the second isolation circuit 600 can be made the same as its own input signal.

[0065] The above is only a specific implementation of the second isolation circuit 600. In practical applications, including but not limited to this, no specific limitation is made here, and it can be determined according to specific circumstances, all of which are within the protection scope of this application.

[0066] Another embodiment of the present application provides a specific implementation of the first isolation circuit 700. The specific structure of the first isolation circuit 700 can be found in Figure 4 ( Figure 4 Only in Figure 3 The invention is demonstrated on the basis of FIG. 7 , specifically including: an isolation driving chip 710, a third switch module 720, an eighth resistance branch 730 and a ninth resistance branch 740; the connection relationship between the components is specifically described as follows:

[0067] The eighth resistance branch 730, the ninth resistance branch 740, and the third switch module 720 are connected in series, and two ends of the formed series branch are respectively connected to two poles of the fourth power supply.

[0068] In a specific example, if Figure 4As shown, one end of the eighth resistor branch 730 is connected to the first end of the fourth power supply, the other end of the eighth resistor branch 730 is connected to one end of the ninth resistor branch 740, the other end of the ninth resistor branch 740 is connected to the first end of the third switch module 720, and the second end of the third switch module 720 is connected to the second end of the fourth power supply.

[0069] The above example only shows a series connection method of the eighth resistor branch 730, the ninth resistor branch 740, and the third switch module 720. In practical applications, including but not limited to this, no specific limitation is made here and all are within the protection scope of this application.

[0070] The eighth resistance branch 730 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the eighth resistance branch 730 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the eighth resistance branch 730 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 4 As shown, the eighth resistor branch 730 is represented by a resistor R8.

[0071] The ninth resistor branch 740 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the ninth resistor branch 740 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the ninth resistor branch 740 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 4 As shown, the ninth resistor branch 740 is represented by a resistor R9.

[0072] Optionally, the switch tube in the third switch module 720 can be a MOS tube, an IGBT, or a triode. In practical applications, this includes but is not limited to these. No specific limitation is made here and it may depend on the specific situation. All are within the protection scope of this application.

[0073] Optionally, the switch tube in the third switch module 720 can be a PNP type tube or an NPN type tube, which is not specifically limited here and can be determined according to the specific situation, all of which are within the protection scope of this application.

[0074] If the switch tube Qd to be protected is an NPN tube, the switch tube in the third switch module 720 is an NMOS tube.

[0075] In a specific example, if Figure 4As shown, the switch tube in the third switch module 720 is an NMOS tube, and the third switch module 720 specifically includes: a third switch tube Q3 and two resistance branches; the input end of the third switch tube Q3 serves as the first end of the third switch module 720, the output end of the third switch tube Q3 serves as the second end of the third switch module 720, the control end of the third switch tube Q3 is connected to the control end of the third switch module 720 through the twenty-first resistance branch 721, and the control end of the third switch tube Q3 is also connected to the output end of the third switch tube Q3 through the twenty-second resistance branch 722.

[0076] The twenty-first resistor branch 721 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twenty-first resistor branch 721 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twenty-first resistor branch 721 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 4 As shown, the twenty-first resistor branch 721 is represented by the resistor R21.

[0077] The twenty-second resistor branch 722 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twenty-second resistor branch 722 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twenty-second resistor branch 722 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 4 As shown, the twenty-second resistor branch 722 is represented by a resistor R22.

[0078] The above is only a specific implementation of the third switch module 720 when the switch tube in the third switch module 720 is an NMOS tube. In practical applications, it includes but is not limited to this, and is not specifically limited here, and all are within the protection scope of this application.

[0079] In practical applications, the output voltage of the fourth power supply is set according to the actual situation of the overcurrent protection circuit. For example, the first end of the fourth power supply is +5V_LV, that is, the potential of the first end of the fourth power supply is 5V higher than the low voltage reference ground, and the second end of the fourth second power supply is the low voltage reference GND_LV.

[0080] The control end of the third switch module 720 serves as the input end of the first isolation circuit 700 , and the turn-on signal of the third switch module 720 is the turn-on signal of the switch tube Qd to be protected.

[0081] The primary side of the isolation driver chip 710 is provided with an anode pin ANODE and a cathode pin CATHODE, and the anode pin ANODE and the cathode pin CATHODE are respectively connected to two ends of the resistance branch closer to the second end of the fourth power supply in the two resistance branches.

[0082] Taking the series connection of the eighth resistor branch 730, the ninth resistor branch 740, and the third switch module 720 shown in the above example as an example, Figure 4 As shown, the anode pin ANODE and the cathode pin CATHODE are connected to two ends of the ninth resistance branch 740 respectively.

[0083] The secondary side of the isolation driver chip 710 is provided with a first power supply pin VCC, a second power supply pin VEE, and two output pins Vout. The first power supply pin VCC is connected to the first end of the fifth power supply, and the second power supply pin VEE is connected to the second end of the fifth power supply; the two output pins Vout are connected, and the connection point serves as the output end of the first isolation circuit 700.

[0084] In practical applications, the output voltage of the fifth power supply is set according to the actual situation of the overcurrent protection circuit. For example, if the switch tube Qd to be protected is an NPN type tube, the first end of the fifth power supply is +16V_HV, that is, the potential of the first end of the fifth power supply is 16V higher than the high-voltage reference ground GND_HV, and the second end of the fifth power supply is -7V_HV, that is, the potential of the first end of the fifth power supply is 7V lower than the high-voltage reference ground GND_HV.

[0085] The working principle of the first isolation circuit 700 is specifically described as follows:

[0086] When the third switch module 720 receives the turn-on signal of the switch tube Qd to be protected, the third switch module 720 is turned on, and the branch formed by the eighth resistor branch 730, the ninth resistor branch 740, and the third switch module 720 forms a path, and the primary side of the isolation driver chip 710 is energized and turned on, so that the secondary side of the isolation driver chip 710 is turned on and output to the outside, wherein the output signal of the first isolation circuit 700 is the same as its own input signal.

[0087] It should be noted that, in practical applications, by reasonably setting the output voltage of the fourth power supply, the output voltage of the fifth power supply, and the resistance values ​​of the eighth resistor branch 730 and the ninth resistor branch 740, the output signal of the first isolation circuit 700 can be made the same as its own input signal.

[0088] The above is only a specific implementation of the first isolation circuit 700. In practical applications, including but not limited to this, no specific limitation is made here, and it can be determined according to specific circumstances, all of which are within the protection scope of this application.

[0089] Another embodiment of the present application provides a specific implementation of the comparison circuit 200, and its specific structure is as follows: Figure 5 As shown, it specifically includes: a comparator 210, a tenth resistor branch 220 and an eleventh resistor branch 230; the connection relationship between each device is as follows:

[0090] The non-inverting input terminal of the comparator 210 is connected to the non-inverting input terminal of the comparison circuit 200 through the tenth resistor branch 220 and the eleventh resistor branch 230 in sequence, and the inverting input terminal of the comparator 210 receives the preset voltage Vy; the output terminal of the comparator 210 is connected to the output terminal of the comparison circuit 200.

[0091] It should be noted that the comparator 210 is already a very mature device in the prior art and will not be described in detail here.

[0092] The tenth resistor branch 220 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the tenth resistor branch 220 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the tenth resistor branch 220 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 5 As shown, the tenth resistor branch 220 is represented by a resistor R10.

[0093] The eleventh resistor branch 230 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the eleventh resistor branch 230 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the eleventh resistor branch 230 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 5 As shown, the eleventh resistor branch 230 is represented by a resistor R11.

[0094] In a specific example, if Figure 5 As shown, the preset voltage Vy is generated in the following manner: the cathode of the Zener diode branch 250 is connected to the positive electrode of the eighth power supply through the twenty-third resistor branch 240, the anode of the Zener diode branch 250 is connected to the negative electrode of the eighth power supply, and the cathode of the Zener diode branch 250 is connected to the inverting input terminal of the comparator 210.

[0095] Wherein, the voltage-stabilizing diode branch 250 includes at least one voltage-stabilizing diode. If the number of voltage-stabilizing diodes is greater than 1, each voltage-stabilizing diode is connected in series in the same direction, and the anode of the formed branch serves as the anode of the voltage-stabilizing diode branch 250, and the cathode of the formed branch serves as the cathode of the voltage-stabilizing diode branch 250; if the number of voltage-stabilizing diodes is equal to 1, the anode of the voltage-stabilizing diode serves as the anode of the voltage-stabilizing diode branch 250, and the cathode of the voltage-stabilizing diode serves as the cathode of the voltage-stabilizing diode branch 250; for example, Figure 5 As shown, the Zener diode branch 250 is represented by a Zener diode Z.

[0096] The twenty-third resistor branch 240 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twenty-third resistor branch 240 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twenty-third resistor branch 240 respectively; for example, Figure 5 As shown, the twenty-third resistor branch 240 is represented by a resistor R23.

[0097] In practical applications, the output voltage of the eighth power supply is set according to actual conditions. For example, the positive pole of the eighth power supply is +16V_HV, that is, the positive pole potential of the eighth power supply is 16V higher than the high voltage reference ground GND_HV, and the negative pole of the eighth power supply is the high voltage reference ground GND_HV.

[0098] It should be noted that, in practical applications, by reasonably setting the output voltage of the eighth power supply, the resistance of the twenty-third resistor branch 240 and the corresponding parameters of the Zener diode branch 250, the potential of the cathode of the Zener diode branch 250 can be made equal to the preset voltage Vy.

[0099] The above example only shows one way to generate the preset voltage Vy. In practical applications, including but not limited to this, no specific limitation is made here and it may be determined according to the specific situation and is within the scope of protection of this application.

[0100] This embodiment also provides a specific implementation of the comparison circuit 200, and its specific structure is as follows: Figure 6 As shown, this embodiment, based on the above embodiment, further includes: a second unidirectional conducting circuit 260; the connection relationship between this device and other devices is specifically described as follows:

[0101] The output end of the comparator 210 is also connected to the input end of the second unidirectional conducting circuit 260 . The output end of the second unidirectional conducting circuit 260 is connected to the connection point between the tenth resistor branch 220 and the eleventh resistor branch 230 .

[0102] The second unidirectional conducting circuit 260 includes at least one unidirectional conducting device. If the number of unidirectional conducting devices is greater than 1, each unidirectional conducting device is connected in series in the same direction, and the anode of the formed branch serves as the anode of the second unidirectional conducting circuit 260, and the cathode of the formed branch serves as the cathode of the second unidirectional conducting circuit 260; if the number of unidirectional conducting devices is equal to 1, the anode of the unidirectional conducting device serves as the anode of the second unidirectional conducting circuit 260, and the cathode of the unidirectional conducting device serves as the cathode of the second unidirectional conducting circuit 260.

[0103] Optionally, the unidirectional conducting device may be a diode. In practical applications, including but not limited to this, no specific limitation is made here, and it may be determined according to specific circumstances, and all are within the scope of protection of this application; for example, Figure 1 As shown, the second unidirectional conducting circuit 260 is represented by a diode D2.

[0104] In this embodiment, by adding a second unidirectional conduction circuit 260, the comparison circuit 200 has a latching function, that is, after the output signal of the comparison circuit 200 is a signal output by the comparison circuit 200 when the potential of its own non-inverting input terminal is greater than the potential of its own inverting input terminal, the output signal of the comparison circuit 200 no longer changes, and is always a signal output by the comparison circuit 200 when the potential of its own non-inverting input terminal is greater than the potential of its own inverting input terminal. Therefore, when the switch tube Qd to be protected is overcurrent, the switch tube Qd to be protected is always in the off state, that is, self-locking of the switch tube Qd to be protected is achieved, thereby avoiding the frequent switching of the switch tube Qd to be protected.

[0105] This embodiment also provides another implementation of the comparison circuit 200, whose specific structure is as follows: Figure 7 As shown, this embodiment, based on the previous embodiment, further includes: a reset circuit 270; the connection relationship between this device and other devices is specifically described as follows:

[0106] The control end of the reset circuit 270 receives a reset signal, and the output end of the reset circuit 270 is connected to the output end of the comparator 210; when the reset circuit 270 receives the reset signal, the output signal of the reset circuit 270 is the output signal of the comparator 210 when the potential of its own inverting input end is greater than the potential of its own non-inverting input end.

[0107] When the control end of the reset circuit 270 receives a reset signal, the output signal of the reset circuit 270 is the output signal of the comparator 210 when the potential of its own inverting input end is greater than the potential of its own non-inverting input end. At this time, the output signal of the comparator 210 is opposite to the output signal of the reset circuit 270. Therefore, after the two are superimposed, the output signal of the comparator 210 jumps to the output signal of the comparator 210 when the potential of its own non-inverting input end is greater than the potential of its own inverting input end, thereby resetting the comparator 210.

[0108] This embodiment also provides a specific implementation of the reset circuit 270, and its specific structure is as follows: Figure 8 As shown, it specifically includes: a fourth switch module 271 and a twelfth resistance branch 272 .

[0109] The control end of the fourth switch module 271 serves as the control end of the reset circuit 270 .

[0110] The first end of the fourth switch module 271 is connected to one end of the twelfth resistor branch 272, and the signal received by the other end of the twelfth resistor branch 272 is: the output signal of the comparator 210 when the potential of its own non-inverting input terminal is greater than the potential of its own inverting input terminal; the signal received by the second end of the fourth switch module 271 is: the output signal of the comparator 210 when the potential of its own inverting input terminal is greater than the potential of its own non-inverting input terminal.

[0111] Normally, the comparator 210 outputs its own positive power supply voltage when the potential of its own non-inverting input terminal is greater than the potential of its own inverting input terminal, that is, one end of the twelfth resistor branch 272 receives the positive power supply voltage of the comparator 210; the comparator 210 outputs its own negative power supply voltage when the potential of its own inverting input terminal is greater than the potential of its own non-inverting input terminal, that is, the second end of the fourth switch module 271 receives the negative power supply voltage of the comparator 210; in actual applications, the positive power supply voltage and the negative power supply voltage of the comparator 210 are set according to actual conditions. For example, the positive power supply voltage of the comparator 210 is +16V_HV, that is, one end of the twelfth resistor branch 272 receives +16V_HV, and the negative power supply voltage of the comparator 210 is the potential of the high-voltage reference ground GND_HV, that is, the second end of the fourth switch module 271 is connected to the high-voltage reference ground GND_HV.

[0112] The twelfth resistor branch 272 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twelfth resistor branch 272 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twelfth resistor branch 272 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 8 As shown, the twelfth resistor branch 272 is represented by a resistor R12.

[0113] The first end of the fourth switch module 271 serves as the output end of the reset circuit 270 ; the conduction signal of the fourth switch module 271 is a reset signal.

[0114] Optionally, the switch tube in the fourth switch module 271 can be a MOS tube, an IGBT, or a triode. In practical applications, this includes but is not limited to these. No specific limitations are made here and it may depend on the specific circumstances. All are within the protection scope of this application.

[0115] Optionally, the switch tube in the fourth switch module 271 can be a PNP type tube or an NPN type tube, which is not specifically limited here and can be determined according to specific circumstances, all of which are within the protection scope of this application.

[0116] If the reset signal is a high level signal, the switch tube in the fourth switch module 271 is an NMOS tube.

[0117] In a specific example, if Figure 8 As shown, the switch tube in the fourth switch module 271 is a MOS tube, and the fourth switch module 271 specifically includes: a fourth switch tube Q4 and two resistance branches; the first end of the fourth switch tube Q4 serves as the first end of the fourth switch module 271, the second end of the fourth switch tube Q4 serves as the second end of the fourth switch module 271, the control end of the fourth switch tube Q4 is connected to the control end of the fourth switch module 271 through the twenty-fourth resistance branch 2711, and the control end of the fourth switch tube Q4 is also connected to the second end of the fourth switch tube Q4 through the twenty-fifth resistance branch 2712.

[0118] The twenty-fourth resistor branch 2711 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twenty-fourth resistor branch 2711 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twenty-fourth resistor branch 2711 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 8 As shown, the twenty-fourth resistor branch 2711 is represented by resistor R24.

[0119] The twenty-fifth resistor branch 2712 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twenty-fifth resistor branch 2712 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twenty-fifth resistor branch 2712 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Figure 8 As shown, the twenty-fifth resistor branch 2712 is represented by resistor R25.

[0120] The above is only a specific implementation of the fourth switch module 271 when the switch tube in the fourth switch module 271 is an NMOS tube. In practical applications, it includes but is not limited to this, and is not specifically limited here, and all are within the protection scope of this application.

[0121] The above is only one implementation of the reset circuit 270. In practical applications, including but not limited to this, no specific limitation is made here and it can be determined according to the specific situation, all of which are within the protection scope of this application.

[0122] It should be noted that, in addition to this implementation, the comparator 210 may also be reset by resetting the power supply that supplies power to the comparator 210 .

[0123] The above are only three implementations of the comparison circuit 200. In practical applications, including but not limited to these, no specific limitation is made here, and it can be determined according to the specific situation, all of which are within the protection scope of this application.

[0124] Another embodiment of the present application provides another implementation of the overcurrent protection circuit, and its specific structure is as follows: Fig. 9 As shown, this embodiment, based on the above embodiment, further includes: a switch circuit 800.

[0125] The switch circuit 800 is connected in parallel with the second resistance branch 500; the control end of the switch circuit 800 is connected to the control end of the switch tube Qd to be protected; the turn-off signal of the switch circuit 800 is the turn-on signal of the switch tube Qd to be protected.

[0126] If the overcurrent protection circuit includes both the switch circuit 800 and the first isolation circuit 700, the control end of the switch circuit 800 can be directly connected to the control end of the switch tube Qd to be protected, or it can be indirectly connected to the control end of the switch tube Qd to be protected through the first isolation circuit 700. No specific limitation is made here and it depends on the specific situation.

[0127] This embodiment also provides an implementation of the switch circuit 800, whose specific structure is as follows: Fig.10 As shown, it specifically includes: an inverting circuit 810 and a fifth switch module 820.

[0128] The fifth switch module 820 is connected in parallel with the second resistance branch 500; the control end of the fifth switch module 820 is connected to the control end of the switch tube Qd to be protected through the inversion circuit 810; the turn-on signal of the fifth switch module 820 is the turn-off signal of the switch tube Qd to be protected.

[0129] Optionally, the switch tube in the fifth switch module 820 can be a MOS tube, an IGBT, or a triode. In practical applications, this includes but is not limited to these. No specific limitation is made here and it may depend on the specific situation. All are within the protection scope of this application.

[0130] Optionally, the switch tube in the fifth switch module 820 can be a PNP type tube or an NPN type tube, which is not specifically limited here and can be determined according to the specific situation, all of which are within the protection scope of this application.

[0131] If the switch tube Qd to be protected is an NPN tube, the switch tube in the fourth switch module 271 is an NMOS tube.

[0132] In a specific example, if Fig.10 As shown, the switch tube in the fifth switch module 820 is an NMOS tube, and the fifth switch module 820 specifically includes: a fifth switch tube Q5 and two resistance branches; the input end of the fifth switch tube Q5 serves as the first end of the fifth switch module 820, and the output end of the fifth switch tube Q5 serves as the second end of the fifth switch module 820, and the control end of the fifth switch tube Q5 is connected to the control end of the fifth switch module 820 through the twenty-sixth resistance branch 821, and the control end of the fifth switch tube Q5 is also connected to the output end of the fifth switch tube Q5 through the twenty-seventh resistance branch 822.

[0133] The twenty-sixth resistor branch 821 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twenty-sixth resistor branch 821 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twenty-sixth resistor branch 821 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.10 As shown, the twenty-sixth resistor branch 821 is represented by resistor R26.

[0134] The twenty-seventh resistor branch 822 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twenty-seventh resistor branch 822 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twenty-seventh resistor branch 822 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.10 As shown, the twenty-seventh resistor branch 822 is represented by resistor R27.

[0135] The above is only a specific implementation of the fifth switch module 820 when the switch tube in the fifth switch module 820 is an NMOS tube. In practical applications, it includes but is not limited to this, and is not specifically limited here, and all are within the protection scope of this application.

[0136] This embodiment also provides an implementation of the inversion circuit 810, and its specific structure is as follows: Fig.11 As shown, it specifically includes: a sixth switch module 811 and a thirteenth resistance branch 812.

[0137] The control end of the sixth switch module 811 serves as the input end of the inverting circuit 810; the first end of the sixth switch module 811 is connected to one end of the thirteenth resistor branch, the other end of the thirteenth resistor branch 812 is connected to the positive electrode of the sixth power supply, and the second end of the sixth switch module 811 is connected to the negative electrode of the sixth power supply; the first end of the sixth switch module 811 serves as the output end of the inverting circuit 810; the conduction signal of the sixth switch module 811 is the conduction signal of the switch tube Qd to be protected.

[0138] In practical applications, the output voltage of the sixth power supply is set according to actual conditions. For example, the positive electrode of the sixth power supply is +16V_HV, that is, the positive electrode potential of the sixth power supply is 16V higher than the high voltage reference ground GND_HV, and the negative electrode of the sixth power supply is GND_HV.

[0139] The thirteenth resistor branch 812 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the thirteenth resistor branch 812 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the thirteenth resistor branch 812 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.11 As shown, the thirteenth resistor branch 812 is represented by a resistor R13.

[0140] Optionally, the switch tube in the sixth switch module 811 can be a MOS tube, an IGBT, or a triode. In practical applications, this includes but is not limited to these. No specific limitation is made here and it may depend on the specific situation. All are within the protection scope of this application.

[0141] Optionally, the switch tube in the sixth switch module 811 can be a PNP type tube or an NPN type tube, which is not specifically limited here and can be determined according to the specific situation, all of which are within the protection scope of this application.

[0142] If the switch tube Qd to be protected is an NPN tube, the switch tube in the sixth switch module 811 is an NMOS tube.

[0143] In a specific example, if Fig.11As shown, the switch tube in the sixth switch module 811 is an NMOS tube, and the sixth switch module 811 specifically includes: a sixth switch tube Q6 and two resistance branches; the input end of the sixth switch tube Q6 serves as the first end of the sixth switch module 811, the output end of the sixth switch tube Q6 serves as the second end of the sixth switch module 811, the control end of the sixth switch tube Q6 is connected to the control end of the sixth switch module 811 through the twenty-eighth resistance branch 8111, and the control end of the sixth switch tube Q6 is also connected to the output end of the sixth switch tube Q6 through the twenty-ninth resistance branch 8112.

[0144] The twenty-eighth resistor branch 8111 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twenty-eighth resistor branch 8111 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twenty-eighth resistor branch 8111 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.11 As shown, the twenty-eighth resistor branch 8111 is represented by resistor R28.

[0145] The twenty-ninth resistor branch 8112 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the twenty-ninth resistor branch 8112 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the twenty-ninth resistor branch 8112 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.11 As shown, the twenty-ninth resistor branch 8112 is represented by resistor R29.

[0146] The above is only a specific implementation of the sixth switch module 811 when the switch tube in the sixth switch module 811 is an NMOS tube. In practical applications, it includes but is not limited to this, and is not specifically limited here, and all are within the protection scope of this application.

[0147] When the sixth switch module 811 receives a turn-on signal of the switch tube Qd to be protected, the sixth switch module 811 is turned on, that is, the sixth switch module 811 and the branch where the thirteenth resistor branch 812 is located form a path, so that the inversion circuit 810 outputs a turn-off signal of the switch tube Qd to be protected; when the sixth switch module 811 receives a turn-off signal of the switch tube Qd to be protected, the sixth switch module 811 is turned off, that is, the sixth switch module 811 and the branch where the thirteenth resistor branch 812 is located do not form a path, so that the inversion circuit 810 outputs a turn-on signal of the switch tube Qd to be protected.

[0148] It should be noted that, in actual applications, by reasonably setting the resistance value of the thirteenth resistor branch 812 and the output voltage of the sixth power supply, the inverting circuit can output a shutdown signal of the switch tube to be protected Qd when the sixth switch module 811 receives a turn-on signal of the switch tube to be protected Qd, and output a turn-on signal of the switch tube to be protected Qd when the sixth switch module 811 receives a turn-off signal of the switch tube to be protected Qd.

[0149] The above is only a specific implementation of the inversion circuit 810. In practical applications, including but not limited to this, no specific limitation is made here and all are within the protection scope of this application.

[0150] The above is only a specific implementation of the switch circuit 800. In practical applications, including but not limited to this, no specific limitation is made here and all are within the protection scope of this application.

[0151] Another embodiment of the present application provides another implementation of the overcurrent protection circuit, which is suitable for the case where the control end of the switch tube Qd to be protected receives its own shutdown signal / on signal through the driving circuit; this implementation has the same structure as the above implementation, except that: Fig.12 ( Fig.12 Only in Fig.11 In this embodiment, the second end of the first switch module 100 is connected to the control end of the switch tube Qd to be protected through a driving circuit.

[0152] The driving circuit is used to amplify the driving capability of the turn-on signal of the switch tube Qd to be protected, so as to ensure that the switch tube Qd to be protected can be turned on reliably.

[0153] This embodiment also provides an implementation of a driving circuit, and its specific structure is as follows: Fig.13 As shown, it specifically includes: a fourteenth resistor branch 910, a fifteenth resistor branch 920 and two driving switch tubes.

[0154] The input end of the first driving switch tube Qq1 is connected to the first end of the seventh power supply, the output end of the first driving switch tube Qq1 is connected to the input end of the second driving switch tube Qq2, and the output end of the second driving switch tube Qq2 is connected to the second end of the seventh power supply.

[0155] The control end of the first driving switch tube Qq1 is connected to the control end of the second driving switch tube Qq2, and the connection point is connected to the input end of the driving circuit through the fourteenth resistor branch 910; the control end of the second driving switch tube Qq2 is also connected to the second end of the seventh power supply through the fifteenth resistor branch 920.

[0156] The fourteenth resistor branch 910 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the fourteenth resistor branch 910 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the fourteenth resistor branch 910 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.13 As shown, the fourteenth resistor branch 910 is represented by a resistor R14.

[0157] The fifteenth resistor branch 920 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the fifteenth resistor branch 920 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the fifteenth resistor branch 920 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.13 As shown, the fifteenth resistor branch 920 is represented by resistor R15.

[0158] In practical applications, the output voltage of the seventh power supply is set according to actual conditions. For example, the positive electrode of the seventh power supply is +16V_HV, that is, the positive electrode potential of the seventh power supply is 16V higher than the high-voltage reference ground GND_HV, and the negative electrode of the seventh power supply is -7V_HV, that is, the negative electrode potential of the seventh power supply is 7V lower than the high-voltage reference ground GND_HV.

[0159] The turn-on signal of the first drive switch tube Qq1 is the turn-on signal of the switch tube Qd to be protected; the turn-on signal of the second drive switch tube Qq2 is the turn-off signal of the switch tube Qd to be protected; the first drive switch tube Qq1 and the second drive switch tube Qq2 are both IGBTs or triodes.

[0160] Optionally, the first driving switch tube Qq1 and the second driving switch tube Qq2 may both be NPN type tubes or PNP type tubes, which are not specifically limited here and may be determined according to specific circumstances, and are all within the protection scope of this application.

[0161] The above is only a specific implementation of the driving circuit. In practical applications, including but not limited to this, no specific limitation is made here and it can be determined according to the specific situation, all of which are within the protection scope of this application.

[0162] Another embodiment of the present application provides another implementation of the overcurrent protection circuit, and its specific structure can be found in Fig.14 ( Fig.14 Only in Fig.13 ), this implementation manner further includes, on the basis of the above implementation manner: a sixteenth resistor branch 1000, and / or a first capacitor branch 1100.

[0163] The first end of the second resistance branch 500 is connected to the second end of the first resistance branch 400 through the sixteenth resistance branch 1000 ; the first capacitance branch 1100 is connected in parallel with the second resistance branch 500 .

[0164] The sixteenth resistor branch 1000 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the sixteenth resistor branch 1000 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the sixteenth resistor branch 1000 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.14 As shown, the sixteenth resistor branch 1000 is represented by resistor R16.

[0165] The first capacitor branch 1100 includes at least one resistor. If the number of capacitors is greater than 1, each capacitor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the first capacitor branch 1100 respectively; if the number of capacitors is equal to 1, the two ends of the capacitor serve as the two ends of the first capacitor branch 1100 respectively; in addition, the number of capacitors and the size of the capacitors are set according to actual conditions and are not specifically limited here; for example, Fig.14 As shown, the first capacitor branch 1100 is represented by a capacitor C1.

[0166] It should be noted that the control end of the switch tube Qd to be protected also receives its own on / off signal through the 30th resistor branch 1200. Fig.15 For example, the control end of the switch tube Qd to be protected receives its own on-signal / off-signal through the 30th resistor branch 1200, the drive circuit 900, and the second isolation circuit 700 in sequence; a 31st resistor branch 1300 and / or a second capacitor branch 1400 are connected in parallel between the control end of the switch tube Qd to be protected and the output end of the switch tube Qd to be protected.

[0167] The thirtieth resistor branch 1200 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the thirtieth resistor branch 1200 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the thirtieth resistor branch 1200 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.15 As shown, the thirtieth resistor branch 1200 is represented by resistor R30.

[0168] The thirty-first resistor branch 1300 includes at least one resistor. If the number of resistors is greater than 1, each resistor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the thirty-first resistor branch 1300 respectively; if the number of resistors is equal to 1, the two ends of the resistor serve as the two ends of the thirty-first resistor branch 1300 respectively; in addition, the number of resistors and the size of the resistors are set according to actual conditions and are not specifically limited here; for example, Fig.15 As shown, the thirty-first resistor branch 1300 is represented by resistor R31.

[0169] The second capacitor branch 1400 includes at least one resistor. If the number of capacitors is greater than 1, each capacitor is connected in series and in parallel, and the two ends of the formed branch serve as the two ends of the second capacitor branch 1400 respectively; if the number of capacitors is equal to 1, the two ends of the capacitor serve as the two ends of the second capacitor branch 1400 respectively; in addition, the number of capacitors and the size of the capacitors are set according to actual conditions and are not specifically limited here; for example, Fig.15 As shown, the second capacitor branch 1400 is represented by a capacitor C2.

[0170] Another embodiment of the present application provides a motor controller, which specifically includes: a power conversion circuit and at least one overcurrent protection circuit provided in the above embodiment.

[0171] It should be noted that the connection relationship between the overcurrent protection circuit and the power conversion circuit has been described in detail in the above embodiments and will not be repeated here.

[0172] For the above description of the disclosed embodiments, the features recorded in each embodiment in this specification can be replaced or combined with each other, so that professional and technical personnel in this field can implement or use this application. The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Although the utility model has been disclosed as above with a preferred embodiment, it is not used to limit the utility model. Any technician familiar with the field can make many possible changes and modifications to the technical solution of the utility model by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the utility model, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the utility model without departing from the content of the technical solution of the utility model still falls within the scope of protection of the technical solution of the utility model.

Claims

1. An overcurrent protection circuit, characterized in that: include: A first switch module, a comparison circuit, a first unidirectional conduction circuit, a first resistance branch and a second resistance branch; wherein: The first end of the first resistance branch is connected to the first end of the first power supply, and the second end of the first resistance branch is connected to the first end of the second resistance branch and the input end of the first unidirectional conduction circuit respectively; The input end of the switch to be protected is connected to the output end of the first unidirectional conducting circuit, and the output end of the switch to be protected and the second end of the second resistance branch are both connected to the second end of the first power supply; The non-inverting input terminal of the comparison circuit is connected to the first end of the second resistance branch, the inverting input terminal of the comparison circuit receives a preset voltage, and the output terminal of the comparison circuit is connected to the control terminal of the first switch module; The output voltage of the first power supply is a voltage that makes the divided voltage of the second resistance branch greater than the preset voltage when the first unidirectional conduction circuit is not conducting; The first end of the first switch module receives the shutdown signal of the switch tube to be protected, the second end of the first switch module is connected to the control end of the switch tube to be protected, and the conduction signal of the first switch module is the output signal of the comparison circuit when the potential of its own non-inverting input end is greater than the potential of its own inverting input end.

2. The overcurrent protection circuit according to claim 1, characterized in that: If the control end of the switch tube to be protected receives its own on signal / off signal through the first isolation circuit, the overcurrent protection circuit further includes: a second isolation circuit; wherein: The output end of the comparison circuit is connected to the control end of the first switch module through the second isolation circuit; The second end of the first switch module is connected to the control end of the switch tube to be protected through the first isolation circuit.

3. The overcurrent protection circuit according to claim 2, characterized in that: The second isolation circuit includes: a photoelectric coupler, a second switch module, a third resistor branch, a fourth resistor branch, a fifth resistor branch, a sixth resistor branch and a seventh resistor branch; wherein: The third resistor branch, the fourth resistor branch, and the second switch module are connected in series, and two ends of the series branch formed are respectively connected to two poles of the second power supply; The control end of the second switch module serves as the input end of the second isolation circuit, and the conduction signal of the second switch module is the output signal of the comparison circuit when the potential of its own non-inverting input end is greater than the potential of its own inverting input end; The primary side of the photoelectric coupler is connected in parallel to two ends of the resistance branch closer to the second end of the second power supply in the third resistance branch and the fourth resistance branch; The anode of the secondary side of the photoelectric coupler is connected to the first end of the third power supply through the fifth resistor branch, the cathode of the secondary side of the photoelectric coupler is connected to the second end of the third power supply through the sixth resistor branch, and the cathode of the secondary side of the photoelectric coupler is also connected to the output end of the second isolation circuit through the seventh resistor branch.

4. The overcurrent protection circuit according to claim 2, characterized in that: The first isolation circuit includes: an isolation driving chip, a third switch module, an eighth resistance branch and a ninth resistance branch; wherein: The eighth resistor branch, the ninth resistor branch, and the third switch module are connected in series, and two ends of the series branch formed are respectively connected to two poles of the fourth power supply; The control end of the third switch module serves as the input end of the first isolation circuit, and the conduction signal of the third switch module is the conduction signal of the switch tube to be protected; The primary side of the isolation driving chip is provided with an anode pin and a cathode pin, and the anode pin and the cathode pin are respectively connected to two ends of the resistance branch closer to the second end of the fourth power supply in the two resistance branches; The secondary side of the isolation driver chip is provided with a first power supply pin, a second power supply pin, and two output pins, the first power supply pin is connected to the first end of the fifth power supply, and the second power supply pin is connected to the second end of the fifth power supply; the two output pins are connected, and the connection point serves as the output end of the first isolation circuit.

5. The overcurrent protection circuit according to any one of claims 1 to 4, characterized in that: The comparison circuit comprises: a comparator, a tenth resistor branch and an eleventh resistor branch; wherein: The non-inverting input terminal of the comparator is connected to the non-inverting input terminal of the comparison circuit through the tenth resistor branch and the eleventh resistor branch in sequence, and the inverting input terminal of the comparator receives the preset voltage; The output end of the comparator is connected to the output end of the comparison circuit.

6. The overcurrent protection circuit according to claim 5, characterized in that: The comparison circuit further includes: a second unidirectional conduction circuit; wherein: The output end of the comparator is also connected to the input end of the second one-way conducting circuit, and the output end of the second one-way conducting circuit is connected to: a connection point between the tenth resistance branch and the eleventh resistance branch.

7. The overcurrent protection circuit according to claim 6, characterized in that: The comparison circuit further includes a reset circuit; wherein: The control end of the reset circuit receives a reset signal, and the output end of the reset circuit is connected to the output end of the comparator; When the reset circuit receives the reset signal, the output signal of the reset circuit is the output signal of the comparator when the potential of its inverting input terminal is greater than the potential of its non-inverting input terminal.

8. The overcurrent protection circuit according to claim 7, characterized in that: The reset circuit comprises: a fourth switch module and a twelfth resistance branch; wherein: The control end of the fourth switch module serves as the control end of the reset circuit; The first end of the fourth switch module is connected to one end of the twelfth resistor branch, the signal received by the other end of the twelfth resistor branch is: the output signal of the comparator when the potential of its own non-inverting input terminal is greater than the potential of its own inverting input terminal, and the signal received by the second end of the fourth switch module is: the output signal of the comparator when the potential of its own inverting input terminal is greater than the potential of its own non-inverting input terminal; The first end of the fourth switch module serves as the output end of the reset circuit; The conduction signal of the fourth switch module is the reset signal.

9. The overcurrent protection circuit according to any one of claims 1 to 4, characterized in that: Also includes: A switching circuit; wherein: The switch circuit is connected in parallel with the second resistance branch; The control end of the switch circuit is connected to the control end of the switch tube to be protected; The turn-off signal of the switch circuit is the turn-on signal of the switch tube to be protected.

10. The overcurrent protection circuit according to claim 9, characterized in that: The switch circuit comprises: an inversion circuit and a fifth switch module; wherein: The fifth switch module is connected in parallel with the second resistance branch; The control end of the fifth switch module is connected to the control end of the switch tube to be protected through the inversion circuit; The on-signal of the fifth switch module is the off-signal of the switch tube to be protected.

11. The overcurrent protection circuit according to claim 10, characterized in that: The inversion circuit comprises: a sixth switch module and a thirteenth resistor branch; wherein: The control end of the sixth switch module serves as the input end of the inversion circuit; The first end of the sixth switch module is connected to one end of the thirteenth resistor branch, the other end of the thirteenth resistor branch is connected to the positive electrode of the sixth power supply, and the second end of the sixth switch module is connected to the negative electrode of the sixth power supply; The first end of the sixth switch module serves as the output end of the inverting circuit; The conduction signal of the sixth switch module is the conduction signal of the switch tube to be protected.

12. The overcurrent protection circuit according to any one of claims 1 to 4, characterized in that: If the control end of the switch tube to be protected receives its own shut-down signal / on signal through the driving circuit, the second end of the first switch module is connected to the control end of the switch tube to be protected through the driving circuit.

13. The overcurrent protection circuit according to claim 12, characterized in that: The driving circuit comprises: a fourteenth resistor branch, a fifteenth resistor branch, a first driving switch tube and a second driving switch tube; wherein: The input end of the first driving switch tube is connected to the first end of the seventh power supply, the output end of the first driving switch tube is connected to the input end of the second driving switch tube, and the output end of the second driving switch tube is connected to the second end of the seventh power supply; The control end of the first driving switch tube is connected to the control end of the second driving switch tube, and the connection point is connected to the input end of the driving circuit through the fourteenth resistor branch; The control end of the second driving switch tube is also connected to the second end of the seventh power supply through the fifteenth resistor branch; The conduction signal of the first driving switch tube is the conduction signal of the switch tube to be protected; The turn-on signal of the second driving switch tube is the turn-off signal of the switch tube to be protected; The switch tube in the first driving switch tube and the switch tube in the second driving switch tube are both IGBTs or triodes.

14. The overcurrent protection circuit according to any one of claims 1 to 4, characterized in that: Also includes: a sixteenth resistor branch, and / or a first capacitor branch; wherein: The first end of the second resistance branch is connected to the second end of the first resistance branch through the sixteenth resistance branch; The first capacitor branch is connected in parallel with the second resistor branch.

15. A motor controller, characterized in that: include: A power conversion circuit and at least one overcurrent protection circuit as claimed in any one of claims 1 to 14.

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