A short circuit protection circuit for a power conversion device

Abstract

The invention relates to the technical field of power supply circuit protection, and discloses a short-circuit protection circuit of a power conversion device, comprising a short-circuit protection unit, wherein the short-circuit protection unit comprises a first operational amplifier, a first triode, a fourth field effect transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a seventh resistor, a first connector, a second connector, and a third connector; one end of the first resistor is connected to a source of the fourth field effect transistor and an end of the first connector, a drain of the fourth field effect transistor is connected to the second connector, a base of the first triode is connected to the other end of the first resistor and one end of the second resistor, a collector of the first triode is connected to one end of the third resistor and a non-inverting end of the first operational amplifier, the other end of the third resistor and one end of the seventh resistor are connected to a power supply, an inverting end of the first operational amplifier is connected to one end of the fourth resistor and the other end of the seventh resistor, and an output end of the first operational amplifier is connected to one end of the fifth resistor and an end of the third connector.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply circuit protection, and in particular to a short-circuit protection circuit of a power conversion device. Background Art

[0002] The short-circuit protection circuit can protect the load and the protection circuit in the event of a short circuit to prevent the load from being impacted by the short-circuit current. However, the existing short-circuit protection circuit is unable to cut off the power supply signal when the power supply end signal is in a short-circuit state to prevent the load from being impacted by the short-circuit current, and at the same time, automatically establish dynamic protection for the load based on the power supply signal amplitude when the power supply end signal is in a non-short-circuit state to prevent damage to the load when the power supply end voltage changes transiently. Summary of the invention

[0003] In view of the above technical problems, the object of the present invention is to provide a short-circuit protection circuit of a power conversion device, comprising a short-circuit protection unit, wherein the short-circuit protection unit comprises a first operational amplifier U1, a first transistor Q1, a fourth field effect transistor Q4, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a seventh resistor R7, a first connector P1, a second connector P2, and a third connector P3;

[0004] One end of the first resistor R1 is connected to the source of the fourth field effect transistor Q4 and the end of the first connector P1, the drain of the fourth field effect transistor Q4 is connected to the second connector P2, the base of the first transistor Q1 is connected to the other end of the first resistor R1 and one end of the second resistor R2, the collector of the first transistor Q1 is connected to one end of the third resistor R3 and the in-phase end of the first operational amplifier U1, the other end of the third resistor R3 and one end of the seventh resistor R7 are connected to the power supply, the inverting end of the first operational amplifier U1 is connected to one end of the fourth resistor R4 and the other end of the seventh resistor R7, the output end of the first operational amplifier U1 is connected to one end of the fifth resistor R5 and the end of the third connector P3, the other end of the second resistor R2, the other end of the fourth resistor R4, the other end of the fifth resistor R5, the emitter of the first transistor Q1 and the ground end are connected.

[0005] Further, a dynamic protection unit is included, which includes a second operational amplifier U2, a fourth operational amplifier U4, a sixth operational amplifier U6, a sixth resistor R6, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, and a first capacitor C1;

[0006] The in-phase end of the second operational amplifier U2 is connected to one end of the twelfth resistor R12, one end of the seventeenth resistor R17, and one end of the first connector P1, the inverting end of the second operational amplifier U2 is connected to one end of the sixteenth resistor R16, the output end of the second operational amplifier U2 is connected to the other end of the sixteenth resistor R16, one end of the nineteenth resistor R19, and one end of the first capacitor C1, the in-phase end of the fourth operational amplifier U4 is connected to the other end of the twelfth resistor R12 and one end of the thirteenth resistor R13, the inverting end of the fourth operational amplifier U4 is connected to one end of the sixth resistor R6 and one end of the eleventh resistor R11, and the output end of the fourth operational amplifier U4 is connected to the other end of the sixth resistor R6, The in-phase end of the sixth operational amplifier U6 is connected to the other end of the seventeenth resistor R17 and one end of the eighteenth resistor R18, the inverting end of the sixth operational amplifier U6 is connected to one end of the nineteenth resistor R19 and one end of the twentieth resistor R20, the output end of the sixth operational amplifier U6 is connected to the other end of the nineteenth resistor R19, one end of the fifteenth resistor R15 is connected to the power supply, the other end of the fifteenth resistor R15 is connected to the other end of the thirteenth resistor R13, one end of the fourteenth resistor R14, and the other end of the twentieth resistor R20, the other end of the eleventh resistor R11, the other end of the fourteenth resistor R14, the other end of the eighteenth resistor R18, the other end of the first capacitor C1 and the ground end are connected.

[0007] Further, the dynamic protection unit also includes a third operational amplifier U3, a fifth operational amplifier U5, a tenth resistor R10, a twenty-third resistor R23, a first diode D1, and a second diode D2;

[0008] The in-phase end of the third operational amplifier U3 is connected to the output end of the second operational amplifier U2, the inverting end of the third operational amplifier U3 is connected to the output end of the fourth operational amplifier U4, the output end of the third operational amplifier U3 is connected to one end of the tenth resistor R10 and the anode of the first diode D1, the cathode of the first diode D1 is connected to the cathode of the second diode D2, the in-phase end of the fifth operational amplifier U5 is connected to the output end of the sixth operational amplifier U6, the inverting end of the fifth operational amplifier U5 is connected to the output end of the second operational amplifier U2, the output end of the fifth operational amplifier U5 is connected to one end of the twenty-third resistor R23 and the anode of the second diode D2, and the other end of the tenth resistor R10, the other end of the twenty-third resistor R23 and the ground are connected.

[0009] Further, the dynamic protection unit also includes a seventh operational amplifier U7, an eighth operational amplifier U8, a ninth operational amplifier U9, a twenty-first resistor R21, a twenty-second resistor R22, a twenty-fourth resistor R24, a twenty-sixth resistor R26, a twenty-seventh resistor R27, and a second capacitor C2;

[0010] The in-phase end of the seventh operational amplifier U7 is connected to one end of the twenty-seventh resistor R27 and one end of the second capacitor C2, the inverting end of the seventh operational amplifier U7 is connected to one end of the twenty-first resistor R21 and one end of the twenty-second resistor R22, the output end of the seventh operational amplifier U7 is connected to the other end of the twenty-second resistor R22 and the in-phase end of the ninth operational amplifier U9, the in-phase end of the eighth operational amplifier U8 is connected to one end of the twenty-fourth resistor R24 ​​and the cathode of the first diode D1, the inverting end of the eighth operational amplifier U8 is connected to the inverting end of the ninth operational amplifier U9 and one end of the fourteenth resistor R14, the output end of the eighth operational amplifier U8 is connected to one end of the twenty-sixth resistor R26 and the other end of the second capacitor C2, the output end of the ninth operational amplifier U9 is connected to the gate of the fourth field effect transistor Q4, and the other end of the twenty-first resistor R21, the other end of the twenty-fourth resistor R24, the other end of the twenty-sixth resistor R26 are connected to the ground end.

[0011] Furthermore, the short-circuit protection unit also includes a third field effect transistor Q3 and a fourth connector P4;

[0012] The drain of the third field effect transistor Q3 is connected to the end of the third connector P3, the gate of the third field effect transistor Q3 is connected to the end of the fourth connector P4, and the source of the third field effect transistor Q3 is connected to the ground end.

[0013] Furthermore, the short circuit protection unit further includes an eighth resistor R8;

[0014] One end of the eighth resistor R8 is connected to the gate of the third field effect transistor Q3, and the other end of the eighth resistor R8 is connected to the ground.

[0015] Furthermore, the short circuit protection unit further includes a twenty-eighth resistor R28;

[0016] One end of the 28th resistor R28 is connected to the gate of the fourth field effect transistor Q4, and the other end of the 28th resistor R28 is connected to the ground.

[0017] Furthermore, the fourteenth resistor R14 is an adjustable resistor.

[0018] The beneficial effects of the present invention compared with the prior art are:

[0019] The present invention can cut off the power supply signal when the power supply end signal is in a short-circuit state to prevent the protection circuit and the load from being impacted by the short-circuit current. When the power supply end signal is in a non-short-circuit state, dynamic protection is automatically established for the load based on the power supply signal amplitude to prevent damage to the load when the power supply end voltage changes transiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the prior art and the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A schematic diagram of the circuit structure provided by the present invention. DETAILED DESCRIPTION

[0022] In order to make the objects and advantages of the present invention more clearly understood, the present invention is specifically described below in conjunction with embodiments. It should be understood that the following text is only used to describe one or several specific implementations of the present invention, and does not strictly limit the scope of protection specifically requested by the present invention.

[0023] The present invention discloses a short-circuit protection circuit of a power conversion device, comprising a short-circuit protection unit, wherein the short-circuit protection unit comprises a first operational amplifier U1, a first transistor Q1, a fourth field effect transistor Q4, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a seventh resistor R7, a first connector P1, a second connector P2, and a third connector P3;

[0024] One end of the first resistor R1 is connected to the source of the fourth field effect transistor Q4 and the end of the first connector P1, the drain of the fourth field effect transistor Q4 is connected to the second connector P2, the base of the first transistor Q1 is connected to the other end of the first resistor R1 and one end of the second resistor R2, the collector of the first transistor Q1 is connected to one end of the third resistor R3 and the in-phase end of the first operational amplifier U1, the other end of the third resistor R3 and one end of the seventh resistor R7 are connected to the power supply, the inverting end of the first operational amplifier U1 is connected to one end of the fourth resistor R4 and the other end of the seventh resistor R7, the output end of the first operational amplifier U1 is connected to one end of the fifth resistor R5 and the end of the third connector P3, the other end of the second resistor R2, the other end of the fourth resistor R4, the other end of the fifth resistor R5, the emitter of the first transistor Q1 and the ground end are connected.

[0025] Specifically, it also includes a dynamic protection unit, which includes a second operational amplifier U2, a fourth operational amplifier U4, a sixth operational amplifier U6, a sixth resistor R6, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, and a first capacitor C1;

[0026] The in-phase end of the second operational amplifier U2 is connected to one end of the twelfth resistor R12, one end of the seventeenth resistor R17, and one end of the first connector P1, the inverting end of the second operational amplifier U2 is connected to one end of the sixteenth resistor R16, the output end of the second operational amplifier U2 is connected to the other end of the sixteenth resistor R16, one end of the nineteenth resistor R19, and one end of the first capacitor C1, the in-phase end of the fourth operational amplifier U4 is connected to the other end of the twelfth resistor R12 and one end of the thirteenth resistor R13, the inverting end of the fourth operational amplifier U4 is connected to one end of the sixth resistor R6 and one end of the eleventh resistor R11, and the output end of the fourth operational amplifier U4 is connected to the other end of the sixth resistor R6, The in-phase end of the sixth operational amplifier U6 is connected to the other end of the seventeenth resistor R17 and one end of the eighteenth resistor R18, the inverting end of the sixth operational amplifier U6 is connected to one end of the nineteenth resistor R19 and one end of the twentieth resistor R20, the output end of the sixth operational amplifier U6 is connected to the other end of the nineteenth resistor R19, one end of the fifteenth resistor R15 is connected to the power supply, the other end of the fifteenth resistor R15 is connected to the other end of the thirteenth resistor R13, one end of the fourteenth resistor R14, and the other end of the twentieth resistor R20, the other end of the eleventh resistor R11, the other end of the fourteenth resistor R14, the other end of the eighteenth resistor R18, the other end of the first capacitor C1 and the ground end are connected.

[0027] Specifically, the dynamic protection unit further includes a third operational amplifier U3, a fifth operational amplifier U5, a tenth resistor R10, a twenty-third resistor R23, a first diode D1, and a second diode D2;

[0028] The in-phase end of the third operational amplifier U3 is connected to the output end of the second operational amplifier U2, the inverting end of the third operational amplifier U3 is connected to the output end of the fourth operational amplifier U4, the output end of the third operational amplifier U3 is connected to one end of the tenth resistor R10 and the anode of the first diode D1, the cathode of the first diode D1 is connected to the cathode of the second diode D2, the in-phase end of the fifth operational amplifier U5 is connected to the output end of the sixth operational amplifier U6, the inverting end of the fifth operational amplifier U5 is connected to the output end of the second operational amplifier U2, the output end of the fifth operational amplifier U5 is connected to one end of the twenty-third resistor R23 and the anode of the second diode D2, and the other end of the tenth resistor R10, the other end of the twenty-third resistor R23 and the ground are connected.

[0029] Specifically, the dynamic protection unit further includes a seventh operational amplifier U7, an eighth operational amplifier U8, a ninth operational amplifier U9, a twenty-first resistor R21, a twenty-second resistor R22, a twenty-fourth resistor R24, a twenty-sixth resistor R26, a twenty-seventh resistor R27, and a second capacitor C2;

[0030] The in-phase end of the seventh operational amplifier U7 is connected to one end of the twenty-seventh resistor R27 and one end of the second capacitor C2, the inverting end of the seventh operational amplifier U7 is connected to one end of the twenty-first resistor R21 and one end of the twenty-second resistor R22, the output end of the seventh operational amplifier U7 is connected to the other end of the twenty-second resistor R22 and the in-phase end of the ninth operational amplifier U9, the in-phase end of the eighth operational amplifier U8 is connected to one end of the twenty-fourth resistor R24 ​​and the cathode of the first diode D1, the inverting end of the eighth operational amplifier U8 is connected to the inverting end of the ninth operational amplifier U9 and one end of the fourteenth resistor R14, the output end of the eighth operational amplifier U8 is connected to one end of the twenty-sixth resistor R26 and the other end of the second capacitor C2, the output end of the ninth operational amplifier U9 is connected to the gate of the fourth field effect transistor Q4, and the other end of the twenty-first resistor R21, the other end of the twenty-fourth resistor R24, the other end of the twenty-sixth resistor R26 are connected to the ground end.

[0031] Specifically, the short-circuit protection unit further includes a third field effect transistor Q3 and a fourth connector P4;

[0032] The drain of the third field effect transistor Q3 is connected to the end of the third connector P3, the gate of the third field effect transistor Q3 is connected to the end of the fourth connector P4, and the source of the third field effect transistor Q3 is connected to the ground end.

[0033] Specifically, the short circuit protection unit further includes an eighth resistor R8;

[0034] One end of the eighth resistor R8 is connected to the gate of the third field effect transistor Q3, and the other end of the eighth resistor R8 is connected to the ground.

[0035] Specifically, the short circuit protection unit further includes a twenty-eighth resistor R28;

[0036] One end of the 28th resistor R28 is connected to the gate of the fourth field effect transistor Q4, and the other end of the 28th resistor R28 is connected to the ground.

[0037] Specifically, the fourteenth resistor R14 is an adjustable resistor.

[0038] The principle of the present invention is as follows: the power supply signal is transmitted to the load through the first connector P1, the source of the fourth field effect transistor Q4, the drain of the fourth field effect transistor Q4, and the second connector P2 to supply power to the load. At the same time, the power supply signal is transmitted to the ground terminal through the first resistor R1 and the second resistor R2. The signal at the end of the second resistor R2 is transmitted to the ground terminal through the base of the first transistor Q1 and the emitter of the first transistor Q1. The base of the first transistor Q1 and the emitter of the first transistor Q1 are forward biased, and the first transistor Q1 is turned on. The power supply signal is transmitted to the ground terminal through the third resistor R3, the collector of the first transistor Q1, and the emitter of the first transistor Q1. The power supply signal is transmitted to the ground terminal through the seventh resistor R7 and the fourth resistor R4. The collector end signal of the first transistor Q1 is fed back to the in-phase end of the first operational amplifier U1, and the end signal of the fourth resistor R4 is fed back to the inverting end of the first operational amplifier U1. When the signal at the power supply end is short-circuited, the first transistor Q1 is turned off, and the first transistor Q1 is turned off. The collector terminal voltage of a transistor Q1 rises, and the first operational amplifier U1 outputs. The signal at the output terminal of the first operational amplifier U1 reaches the ground terminal through the fifth resistor R5. The signal at the fifth resistor R5 is a power-off signal. The signal at the fifth resistor R5 is fed back to the power supply unit through the third connector P3. After obtaining the signal, the power supply unit disconnects the signal supply at the first connector P1 terminal, thereby cutting off the power supply signal when the power supply terminal signal is in a short-circuit state to prevent the protection circuit and the load from being impacted by the short-circuit current. The reset signal is provided by the operator, and the signal is fed back to the gate of the third field effect tube Q3 through the fourth connector P4. The voltage difference between the gate of the third field effect tube Q3 and the source of the third field effect tube Q3 is higher than the conduction threshold, and the third field effect tube Q3 is turned on. The signal at the third connector P3 reaches the ground terminal through the drain of the third field effect tube Q3 and the source of the third field effect tube Q3, and the first connector P1 terminal obtains the power supply signal supply.

[0039] Considering that when the power supply signal is in a non-short-circuit state, the power supply signal transiently changes and may cause damage to the load, the signal at the first connector P1 end is fed back to the in-phase end of the second operational amplifier U2, and the output end of the second operational amplifier U2 is negatively feedback connected to the inverting end of the second operational amplifier U2 through the sixteenth resistor R16. The second operational amplifier U2 follows the output signal amplitude of the first connector P1 end while preventing interference from the lower circuit signal. At the same time, the output end signal of the second operational amplifier U2 is fed back to the first capacitor C1. When the signal at the first connector P1 end transiently changes, the first capacitor C1 lags behind the signal amplitude followed by the output end of the second operational amplifier U2, the power supply signal passes through the fifteenth resistor R15 and the fourteenth resistor R14 to the ground end, the signal at the fourteenth resistor R14 end is the protection amplitude, the signal at the first connector P1 end passes through the seventeenth resistor R17 and the eighteenth resistor R18 to the ground end, the signal at the eighteenth resistor R18 end is fed back to the in-phase end of the sixth operational amplifier U6, the signal at the fourteenth resistor R14 end is fed back to the inverting end of the sixth operational amplifier U6 through the twentieth resistor R20, and the output end of the sixth operational amplifier U6 is fed back to the inverting end through the nineteenth resistor R19 and The inverting end of the sixth operational amplifier U6 forms a negative feedback connection so that the output signal of the sixth operational amplifier U6 is lower than the signal at the first connector P1, so as to establish a lower threshold value of the dynamic protection range for the load based on the power supply signal amplitude in a non-short circuit state. The signal at the end of the fourteenth resistor R14 is fed back to the in-phase end of the fourth operational amplifier U4 via the thirteenth resistor R13, and the signal at the end of the first connector P1 is fed back to the in-phase end of the fourth operational amplifier U4 via the twelfth resistor R12. The output signal of the fourth operational amplifier U4 is fed back to the ground end via the sixth resistor R6 and the eleventh resistor R11, and the signal at the end of the eleventh resistor R11 is fed back to the inverting end of the fourth operational amplifier U4. The output signal of the fourth operational amplifier U4 is higher than the signal at the end of the first connector P1, so as to establish an upper threshold value of the dynamic protection range for the load based on the power supply signal amplitude in a non-short circuit state. In this way, dynamic protection is established through the protection signals output from the output ends of the fourth operational amplifier U4 and the sixth operational amplifier U6. The larger the protection range, the lower the protection sensitivity. The protection sensitivity is changed by adjusting the resistance value of the fourteenth resistor R14, and the protection sensitivity is adjusted by setting the resistance value of the fourteenth resistor R14 as needed.

[0040] The output signal of the sixth operational amplifier U6 is fed back to the non-inverting terminal of the fifth operational amplifier U5, the output signal of the second operational amplifier U2 is fed back to the inverting terminal of the fifth operational amplifier U5 and the non-inverting terminal of the third operational amplifier U3, the output signal of the fourth operational amplifier U4 is fed back to the inverting terminal of the third operational amplifier U3, when the power supply signal transiently changes to the point where its signal amplitude rises, the first capacitor C1 lags the output signal of the second operational amplifier U2 to make the third operational amplifier U3 output, when the power supply signal transiently changes to the point where its signal amplitude drops, the first capacitor C1 lags the output signal of the second operational amplifier U2 to make the third operational amplifier U3 output. The signal makes the fifth operational amplifier U5 output, the output signal of the third operational amplifier U3 is connected to the ground through the twenty-third resistor R23, and the output signal of the fifth operational amplifier U5 is connected to the ground through the tenth resistor R10. The output signals of the third operational amplifier U3 and the fifth operational amplifier U5 are power supply disconnection signals for the load. When the third operational amplifier U3 and the fifth operational amplifier U5 output, the power supply to the load is disconnected, so that dynamic protection is automatically established for the load based on the power supply signal amplitude when the power supply end signal is in a non-short-circuit state to prevent damage to the load when the power supply end voltage changes transiently.

[0041] Taking into account that when the power supply signal changes transiently, the rise / fall of the signal will cause the output signal of the second operational amplifier U2 that lags behind the first capacitor C1 to overlap with the upper / lower threshold for establishing the dynamic protection range, resulting in a protection gap. The signal at the end of the twenty-third resistor R23 is fed back to the in-phase end of the eighth operational amplifier U8 via the second diode D2, the signal at the end of the tenth resistor R10 is fed back to the in-phase end of the eighth operational amplifier U8 via the first diode D1, the signal at the end of the fourteenth resistor R14 is synchronously fed back to the inverting end of the eighth operational amplifier U8, and the twenty-fourth resistor R24 ​​is the eighth operational amplifier. The third operational amplifier U3 or the fifth operational amplifier U5 outputs, the eighth operational amplifier U8 outputs, the output terminal signal of the eighth operational amplifier U8 is connected to the ground terminal through the twenty-sixth resistor R26, and the signal at the twenty-sixth resistor R26 is fed back to the second capacitor C2. When the eighth operational amplifier U8 outputs or is cut off, the charge between the two plates of the second capacitor C2 moves, and at the same time, the signal at the twenty-seventh resistor R27 is fed back to the seventh operational amplifier U7 in phase, and the output terminal signal of the seventh operational amplifier U7 is connected to the twenty-second resistor R22 and the twenty-first resistor R 21 to the ground terminal, the signal at the end of the twenty-first resistor R21 is fed back to the inverting end of the seventh operational amplifier U7, when the charge of the two plates of the second capacitor C2 moves, the seventh operational amplifier U7 outputs, the signal at the end of the fourteenth resistor R14 is fed back to the inverting end of the ninth operational amplifier U9, the signal at the output end of the seventh operational amplifier U7 is fed back to the non-inverting end of the ninth operational amplifier U9, when the seventh operational amplifier U7 outputs, the ninth operational amplifier U9 outputs, the signal at the output end of the ninth operational amplifier U9 is fed back to the gate of the fourth field effect transistor Q4, the gate of the fourth field effect transistor Q4 and the fourth field effect transistor Q 4 The voltage difference between the source and the source is higher than the conduction threshold, the fourth field effect transistor Q4 is cut off, and the second connector P2 loses signal supply. The twenty-eighth resistor R28 is used to discharge the parasitic capacitance of the gate of the fourth field effect transistor Q4, so that when the power supply signal changes transiently, whether it is in a rising / falling state, the output of the ninth operational amplifier U9 is cut off to cut off the power supply signal to the load, and the protection gap caused by the overlap of the output signal of the second operational amplifier U2 and the output signal of the sixth operational amplifier U6 / the output signal of the fourth operational amplifier U4 when the power supply voltage transiently rises / falls during the dynamic protection period is removed.

[0042] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A short-circuit protection circuit for a power conversion device, characterized in that: A short circuit protection unit is included, and the short circuit protection unit includes a first operational amplifier, a first triode, a fourth field effect transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a seventh resistor, a first connector, a second connector, and a third connector; One end of the first resistor is connected to the source of the fourth field effect transistor and the first connector end, the drain of the fourth field effect transistor is connected to the second connector, the base of the first transistor is connected to the other end of the first resistor and one end of the second resistor, the collector of the first transistor is connected to one end of the third resistor and the in-phase end of the first operational amplifier, the other end of the third resistor and one end of the seventh resistor are connected to the power supply, the inverting end of the first operational amplifier is connected to one end of the fourth resistor and the other end of the seventh resistor, the output end of the first operational amplifier is connected to one end of the fifth resistor and the third connector end, and the other end of the second resistor, the other end of the fourth resistor, the other end of the fifth resistor, the emitter of the first transistor and the ground end are connected; Also included is a dynamic protection unit, the dynamic protection unit including a second operational amplifier, a fourth operational amplifier, a sixth operational amplifier, a sixth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, and a first capacitor; The non-inverting end of the second operational amplifier is connected to one end of the twelfth resistor, one end of the seventeenth resistor, and the first connector end, the inverting end of the second operational amplifier is connected to one end of the sixteenth resistor, the output end of the second operational amplifier is connected to the other end of the sixteenth resistor and one end of the first capacitor, the non-inverting end of the fourth operational amplifier is connected to the other end of the twelfth resistor and one end of the thirteenth resistor, the inverting end of the fourth operational amplifier is connected to one end of the sixth resistor and one end of the eleventh resistor, the output end of the fourth operational amplifier is connected to the other end of the sixth resistor, the non-inverting end of the sixth operational amplifier is connected to the other end of the seventeenth resistor and one end of the eighteenth resistor, the inverting end of the sixth operational amplifier is connected to one end of the nineteenth resistor and one end of the twentieth resistor, the output end of the sixth operational amplifier is connected to the other end of the nineteenth resistor, one end of the fifteenth resistor is connected to the power supply, the other end of the fifteenth resistor is connected to the other end of the thirteenth resistor, one end of the fourteenth resistor, and the other end of the twentieth resistor, the other end of the eleventh resistor, the other end of the fourteenth resistor, the other end of the eighteenth resistor, the other end of the first capacitor, and the ground end are connected; The dynamic protection unit further includes a third operational amplifier, a fifth operational amplifier, a tenth resistor, a twenty-third resistor, a first diode, and a second diode; The non-inverting end of the third operational amplifier is connected to the output end of the second operational amplifier, the inverting end of the third operational amplifier is connected to the output end of the fourth operational amplifier, the output end of the third operational amplifier is connected to one end of the tenth resistor and the anode of the first diode, the cathode of the first diode is connected to the cathode of the second diode, the non-inverting end of the fifth operational amplifier is connected to the output end of the sixth operational amplifier, the inverting end of the fifth operational amplifier is connected to the output end of the second operational amplifier, the output end of the fifth operational amplifier is connected to one end of the twenty-third resistor and the anode of the second diode, and the other end of the tenth resistor, the other end of the twenty-third resistor and the ground are connected.

2. The short-circuit protection circuit of the power conversion device according to claim 1, characterized in that: The dynamic protection unit also includes a seventh operational amplifier, an eighth operational amplifier, a ninth operational amplifier, a twenty-first resistor, a twenty-second resistor, a twenty-fourth resistor, a twenty-sixth resistor, a twenty-seventh resistor, and a second capacitor.

3. The short-circuit protection circuit of the power conversion device according to claim 2, characterized in that: The non-inverting end of the seventh operational amplifier is connected to one end of the twenty-seventh resistor and one end of the second capacitor, the inverting end of the seventh operational amplifier is connected to one end of the twenty-first resistor and one end of the twenty-second resistor, the output end of the seventh operational amplifier is connected to the other end of the twenty-second resistor and the non-inverting end of the ninth operational amplifier, the non-inverting end of the eighth operational amplifier is connected to one end of the twenty-fourth resistor and the cathode of the first diode, the inverting end of the eighth operational amplifier is connected to the inverting end of the ninth operational amplifier and one end of the fourteenth resistor, the output end of the eighth operational amplifier is connected to one end of the twenty-sixth resistor and the other end of the second capacitor, the output end of the ninth operational amplifier is connected to the gate of the fourth field effect transistor, and the other end of the twenty-first resistor, the other end of the twenty-fourth resistor, the other end of the twenty-sixth resistor and the ground end are connected.

4. The short-circuit protection circuit of the power conversion device according to claim 1, characterized in that: The short circuit protection unit also includes a third field effect tube and a fourth connector; The drain of the third field effect tube is connected to the third connector end, the gate of the third field effect tube is connected to the fourth connector end, and the source of the third field effect tube is connected to the ground end.

5. The short-circuit protection circuit of the power conversion device according to claim 4, characterized in that: The short circuit protection unit further includes an eighth resistor; One end of the eighth resistor is connected to the gate of the third field effect transistor, and the other end of the eighth resistor is connected to the ground.

6. The short-circuit protection circuit of the power conversion device according to claim 1, characterized in that: The short circuit protection unit further includes a twenty-eighth resistor; One end of the 28th resistor is connected to the gate of the fourth field effect transistor, and the other end of the 28th resistor is connected to the ground end; the 14th resistor is an adjustable resistor.

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