Overcurrent protection circuit

Abstract

The utility model provides an overcurrent protection circuit, which comprises an integrated operational amplifier module, a first input end of the integrated operational amplifier module is used for inputting a target voltage signal, an output end of the integrated operational amplifier module outputs a target output signal to a controller, and the target voltage signal is used for representing the actual current of a motor; the first end of the integrated operational amplifier peripheral circuit is electrically connected with the second input end of the integrated operational amplifier module, and the integrated operational amplifier peripheral circuit is used for controlling the voltage input to the second input end of the integrated operational amplifier module; the magnitude of the voltage is the voltage at which the level of the output end of the comparator is flipped. According to different connection modes of motor windings, the overcurrent protection circuit controls enabling and failure of a divider resistor through a triode, changes threshold voltage of an inverted input end of a comparator, or changes amplification times of an operational amplifier through the triode, and achieves selection of different hardware overcurrent protection values.

Description

Technical Field

[0001] This application relates to the technical field of motor control, and more particularly, to an overcurrent protection circuit. Background Art

[0002] Since the connection mode of the stator winding of the traditional compressor motor is fixed, the demagnetization current of the motor is determined. Therefore, the hardware overcurrent protection value of the hardware overcurrent protection circuit in the compressor drive board is a fixed value. However, for a switched-winding motor, the connection mode of the motor winding can be switched between star connection and delta connection, and the corresponding demagnetization currents for different winding connection modes are different. Therefore, it is difficult to give full play to the advantages of the switched-winding motor by using a fixed hardware overcurrent protection value for overcurrent protection of different winding connection states. That is, the prior art cannot adjust the hardware overcurrent protection value according to the connection mode of the motor winding. Summary of the Utility Model

[0003] The main purpose of this application is to provide an overcurrent protection circuit to at least solve the problem that the prior art cannot adjust the hardware overcurrent protection value according to the connection mode of the motor winding.

[0004] To achieve the above object, according to one aspect of this application, there is provided an overcurrent protection circuit, including: an integrated operational amplifier module having a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal of the integrated operational amplifier module is used to input a target voltage signal, the output terminal of the integrated operational amplifier module is used to output a target output signal to a controller, and the target voltage signal is used to represent the actual current of the motor; an integrated operational amplifier peripheral circuit, the first end of which is electrically connected to the second input terminal of the integrated operational amplifier module, and the integrated operational amplifier peripheral circuit is used to control the magnitude of the voltage input to the second input terminal of the integrated operational amplifier module, and this voltage magnitude is the voltage at which the level of the comparator output terminal flips.

[0005] Optionally, the integrated operational amplifier peripheral circuit includes: a first voltage division module having a control terminal, a first end, and a second end, wherein the control terminal of the first voltage division module is used to input a first control signal, the first end of the first voltage division module is electrically connected to the positive power supply, and the first control signal is used to control the resistance magnitude of the first voltage division module; a second voltage division module having a first end and a second end, wherein the first end of the second voltage division module is respectively electrically connected to the second end of the first voltage division module and the second input terminal of the integrated operational amplifier module, and the second end of the second voltage division module is grounded.

[0006] Optionally, the first voltage dividing module includes: a first resistor module having a first end and a second end, the first end of the first resistor module being electrically connected to the positive power supply terminal; a second resistor module having a first end and a second end, the first end of the second resistor module being electrically connected to the second end of the first resistor module, and the second end of the second resistor module being electrically connected to the first end of the second voltage dividing module; a first switching device having a control terminal, a first end and a second end, the control terminal of the first switching device being configured to receive the first control signal, the first end of the first switching device being electrically connected to the first end of the first resistor module, and the second end of the first switching device being electrically connected to both the first end of the first resistor module and the second end of the second resistor module.

[0007] Optionally, the first voltage dividing module includes: a first voltage dividing sub-module having a control terminal, a first end and a second end, the control terminal of the first voltage dividing sub-module being configured to receive a second control signal, the first end of the first voltage dividing sub-module being electrically connected to the positive power supply terminal, and the second end of the first voltage dividing sub-module being electrically connected to the first end of the second voltage dividing module; a second voltage dividing sub-module having a control terminal, a first end and a second end, the control terminal of the second voltage dividing sub-module being configured to receive a third control signal, the first end of the second voltage dividing sub-module being electrically connected to the positive power supply terminal, and the second end of the second voltage dividing sub-module being electrically connected to both the second end of the first voltage dividing sub-module and the first end of the second voltage dividing module.

[0008] Optionally, the first voltage dividing sub-module includes a second switching device and a third resistor module, the control terminal of the second switching device being configured to receive the second control signal, the first end of the second switching device being electrically connected to the positive power supply terminal; the first end of the third resistor module being electrically connected to the second end of the second switching device, and the second end of the third resistor module being electrically connected to the first end of the second voltage dividing module; the second voltage dividing sub-module includes a third switching device and a fourth resistor module, the control terminal of the third switching device being configured to receive the third control signal, the first end of the third switching device being electrically connected to the positive power supply terminal; the first end of the fourth resistor module being electrically connected to the second end of the third switching device, and the second end of the fourth resistor module being electrically connected to both the second end of the first voltage dividing module and the first end of the second voltage dividing module.

[0009] Optionally, the second switching device is a PNP transistor and the third switching device is an NPN transistor.

[0010] Optionally, the second voltage dividing module includes: a fifth resistor module having a first end and a second end, the first end of the fifth resistor module being electrically connected to both the second end of the first voltage dividing module and the second input terminal of the integrated operational amplifier module, and the second end of the fifth resistor module being grounded.

[0011] Optionally, the integrated operational amplifier peripheral circuit includes: a sixth resistor module having a first end and a second end, the first end of the sixth resistor module being grounded, and the second end of the sixth resistor module being electrically connected to the second input terminal of the integrated operational amplifier module; a seventh resistor module having a first end and a second end, the first end of the seventh resistor module being electrically connected to the second end of the sixth resistor module and the second input terminal of the integrated operational amplifier module respectively; an eighth resistor module having a first end and a second end, the first end of the eighth resistor module being electrically connected to the second end of the seventh resistor module, and the second end of the eighth resistor module being electrically connected to the output terminal of the integrated operational amplifier module; a fourth switching device having a control terminal, a first end and a second end, the control terminal of the fourth switching device being configured to input a fourth control signal, the first end of the fourth switching device being electrically connected to the second end of the seventh resistor module and the first end of the eighth resistor module respectively, and the second end of the fourth switching device being electrically connected to the second end of the eighth resistor module.

[0012] Optionally, the overcurrent protection circuit further includes: a ninth resistor module having a first end and a second end, the first end of the ninth resistor module being configured to input a reference voltage signal, and the second end of the ninth resistor module being electrically connected to the first input terminal of the integrated operational amplifier module; a tenth resistor module having a first end and a second end, the first end of the tenth resistor module being configured to input the target voltage signal, and the second end of the tenth resistor module being electrically connected to the second end of the ninth resistor module and the first input terminal of the integrated operational amplifier module respectively.

[0013] Optionally, the integrated operational amplifier module includes: a comparator having a first input terminal, a second input terminal, a first end, a second end and an output terminal, the first input terminal of the comparator being configured to input the target voltage signal, the second input terminal of the comparator being electrically connected to the first end of the integrated operational amplifier peripheral circuit, the first end of the comparator being electrically connected to the positive power supply, the second end of the comparator being grounded, and the output terminal of the comparator being configured to output the target output signal.

[0014] Applying the technical solution of the present application, the above overcurrent protection circuit includes: an integrated operational amplifier module, having a first input terminal, a second input terminal, and an output terminal. The first input terminal of the integrated operational amplifier module is used to input a target voltage signal, and the output terminal of the integrated operational amplifier module is used to output a target output signal to the controller. The target voltage signal is used to characterize the actual current of the motor; an integrated operational amplifier peripheral circuit, the first end of the integrated operational amplifier peripheral circuit is electrically connected to the second input terminal of the integrated operational amplifier module, and the integrated operational amplifier peripheral circuit is used to control the magnitude of the voltage input to the second input terminal of the integrated operational amplifier module, and this voltage magnitude is the voltage at which the level of the comparator output terminal flips. For different connection methods of the motor windings, this overcurrent protection circuit controls the enabling and disabling of the voltage-dividing resistor through a triode, changes the threshold voltage of the inverting input terminal of the comparator, or changes the amplification factor of the amplifier through a triode, so as to realize the selection of different hardware overcurrent protection values, and solves the problem that the prior art cannot adjust the hardware overcurrent protection value according to the connection method of the motor windings. Description of the Drawings

[0015] The schematic diagrams of the drawings forming a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0016] Figure 1 Shows a schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the present application;

[0017] Figure 2 Shows a schematic structural diagram of another overcurrent protection circuit provided in an embodiment of the present application;

[0018] Figure 3 Shows a schematic structural diagram of another overcurrent protection circuit provided in an embodiment of the present application;

[0019] Figure 4 Shows a schematic structural diagram of another overcurrent protection circuit provided in an embodiment of the present application;

[0020] Figure 5 Shows a schematic structural diagram of another overcurrent protection circuit provided in an embodiment of the present application;

[0021] Figure 6 Shows a schematic structural diagram of another overcurrent protection circuit provided in an embodiment of the present application;

[0022] Figure 7 Shows a schematic structural diagram of another overcurrent protection circuit provided in an embodiment of the present application;

[0023] Figure 8 The schematic structural diagram of another overcurrent protection circuit provided in the embodiments of the present application is shown;

[0024] Figure 9 The schematic structural diagram of another overcurrent protection circuit provided in the embodiments of the present application is shown.

[0025] Among them, the above-mentioned drawings include the following reference numerals:

[0026] 10. Integrated operational amplifier module; 20. Peripheral circuit of the integrated operational amplifier; 201. Sixth resistor module; 202. Seventh resistor module; 203. Eighth resistor module; 204. Fourth switching device; 21. First voltage dividing module; 211. First resistor module; 212. Second resistor module; 213. First switching device; 22. Second voltage dividing module; 221. Fifth resistor module; 23. First voltage dividing sub-module; 231. Second switching device; 232. Third resistor module; 24. Second voltage dividing sub-module; 241. Third switching device; 242. Fourth resistor module; 30. Controller; 40. Ninth resistor module; 50. Tenth resistor module. Detailed implementation manners

[0027] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further descriptions of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0028] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used herein, unless otherwise clearly specified in the context, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "comprise" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0029] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element can be directly on the other element, or there can also be an intermediate element. Moreover, in the specification and the claims, when an element is described as being "connected" to another element, the element can be "directly connected" to the other element, or "connected" to the other element through a third element.

[0030] As introduced in the background art, in the prior art, the overcurrent protection value of the hardware cannot be adjusted according to the connection mode of the motor windings. To solve the problem that the overcurrent protection value of the hardware cannot be adjusted according to the connection mode of the motor windings in the prior art, the embodiments of the present application provide an overcurrent protection circuit.

[0031] In this embodiment, an overcurrent protection circuit is provided. As Figure 1 shown, it includes: an integrated operational amplifier module 10, which has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the integrated operational amplifier module 10 is used to input a target voltage signal, and the output terminal of the integrated operational amplifier module 10 is used to output a target output signal to the controller 30. The target voltage signal is used to represent the actual current of the motor; an integrated operational amplifier peripheral circuit 20. The first end of the integrated operational amplifier peripheral circuit 20 is electrically connected to the second input terminal of the integrated operational amplifier module 10. The integrated operational amplifier peripheral circuit 20 is used to control the magnitude of the threshold voltage input to the second input terminal of the integrated operational amplifier module 10, or the integrated operational amplifier peripheral circuit 20 is used to control the voltage magnitude of the target output signal.

[0032] The above overcurrent protection circuit of the present application includes: an integrated operational amplifier module, which has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the integrated operational amplifier module is used to input a target voltage signal, and the output terminal of the integrated operational amplifier module is used to output a target output signal to the controller. The target voltage signal is used to represent the actual current of the motor; an integrated operational amplifier peripheral circuit. The first end of the integrated operational amplifier peripheral circuit is electrically connected to the second input terminal of the integrated operational amplifier module. The integrated operational amplifier peripheral circuit is used to control the voltage magnitude input to the second input terminal of the integrated operational amplifier module, and this voltage magnitude is the voltage at which the level of the comparator output terminal flips. For different connection methods of the motor windings, this overcurrent protection circuit controls the enabling and disabling of the voltage-dividing resistor through a triode, changes the threshold voltage of the inverting input terminal of the comparator, or changes the amplification factor of the amplifier through a triode, so as to realize the selection of different hardware overcurrent protection values, and solves the problem that the prior art cannot adjust the hardware overcurrent protection value according to the connection method of the motor windings.

[0033] Among them, there is a mapping relationship between the target voltage signal and the actual current of the motor, that is, the corresponding actual current of the motor can be directly calculated by obtaining the target voltage signal.

[0034] When the peripheral circuit of the integrated operational amplifier is used to control the magnitude of the threshold voltage input to the second input terminal of the integrated operational amplifier module, the integrated operational amplifier module compares the magnitude of the target voltage signal with the threshold voltage input to the second input terminal of the integrated operational amplifier module and obtains a comparison signal, which is the target output signal. The target output signal is a signal characterizing whether the motor is overcurrent. In some examples, when the target voltage signal is greater than the threshold voltage input to the second input terminal of the integrated operational amplifier module, the target output signal is a high level 1, determining that the motor is overcurrent. When the target voltage signal is less than or equal to the threshold voltage input to the second input terminal of the integrated operational amplifier module, the target output signal is a low level 0, determining that the motor is not overcurrent.

[0035] In some examples, since the pins of the controller have voltage limitations and the target voltage signal does not conform to the voltage range recognizable by the controller, the peripheral circuit of the integrated operational amplifier can amplify or reduce the target voltage signal that does not conform to the voltage range recognizable by the controller into a target output signal recognizable by the controller. At this time, there is also a corresponding mapping relationship between the target output signal and the actual current of the motor. The controller can obtain the actual current of the motor through the target output signal, thereby determining whether the motor is overcurrent.

[0036] In some examples, as Figure 2 shown, the above-mentioned peripheral circuit of the integrated operational amplifier includes: a first voltage dividing module 21, having a control terminal, a first terminal, and a second terminal. The control terminal of the first voltage dividing module 21 is used to input a first control signal. The first terminal of the first voltage dividing module 21 is electrically connected to the positive power supply. The first control signal is used to control the resistance magnitude of the first voltage dividing module 21; a second voltage dividing module 22, having a first terminal and a second terminal. The first terminal of the second voltage dividing module 22 is respectively electrically connected to the second terminal of the first voltage dividing module 21 and the second input terminal of the integrated operational amplifier module 10. The second terminal of the second voltage dividing module 22 is grounded.

[0037] Specifically, the first voltage dividing module and the second voltage dividing module are used for voltage division. By adjusting the resistance values of the first voltage dividing module and the second voltage dividing module, the voltage at the second input terminal of the integrated operational amplifier module can be adjusted, thereby controlling the magnitude of the threshold voltage input to the second input terminal of the integrated operational amplifier module. The control terminal of the first voltage dividing module is connected to the IO interface of the controller and is used to receive the first control signal to control the magnitude of the voltage division of the first voltage dividing module.

[0038] Among them, for different connection methods of the motor windings, the resistance value of the first voltage dividing module is adjusted to change the threshold voltage at the second input terminal of the integrated operational amplifier module, thereby realizing the selection of different hardware overcurrent protection values.

[0039] In some examples, such as Figure 3 shown, the first voltage dividing module 21 includes: a first resistor module 211 having a first end and a second end, the first end of the first resistor module 211 being electrically connected to the positive power supply; a second resistor module 212 having a first end and a second end, the first end of the second resistor module 212 being electrically connected to the second end of the first resistor module 211, and the second end of the second resistor module 212 being electrically connected to the first end of the second voltage dividing module 22; a first switching device 213 having a control end, a first end, and a second end, the control end of the first switching device 213 being configured to input the first control signal, the first end of the first switching device 213 being electrically connected to the first end of the first resistor module 211, and the second end of the first switching device 213 being electrically connected to both the first end of the first resistor module 211 and the second end of the second resistor module 212.

[0040] Specifically, both the first resistor module and the second resistor module are composed of one or more resistors connected in series or in parallel, and the first switching device is a switching device having a control end (for example: transistor, MOS transistor, etc.).

[0041] As Figure 4 shown, the first resistor module is a voltage dividing resistor R1, the second resistor module is a voltage dividing resistor R2, the first switching device is Q1, the second voltage dividing module is a voltage dividing resistor R3, and the integrated operational amplifier module is a comparator U1A. In this example, the first switching device is a PNP transistor. In this example, the triode Q1 is connected in parallel with the voltage dividing resistor R1, and the enabling and disabling of the voltage dividing resistor R1 are controlled by the triode Q1, thereby controlling the threshold voltage. When the motor is connected in delta, the IO pin outputs a low level, controlling the triode Q1 to conduct, and the voltage dividing resistor R1 fails, so that the threshold voltage remains at the first reference voltage, corresponding to the first overcurrent protection value; when the motor is connected in star, the IO port outputs a high level, controlling the triode Q1 to cut off, and the voltage dividing resistor R1 is enabled, so that the threshold voltage remains at the second reference voltage, corresponding to the second overcurrent protection value.

[0042] Among them, since the demagnetization current of the motor when connected in star is less than the demagnetization current when connected in delta, and the hardware overcurrent protection value should be less than the demagnetization current value. The first reference voltage corresponds to the reference voltage of the comparator in the delta connection (triangle connection) state, and the hardware overcurrent protection value at this time is the first overcurrent protection value; the second reference voltage corresponds to the reference voltage of the comparator in the star connection (star connection) state, and the hardware overcurrent protection value at this time is the second overcurrent protection value.

[0043] As Figure 4As shown in the figure, when the motor is connected in delta, the IO pin outputs a low level, controlling the triode Q1 to conduct, and the voltage-dividing resistor R1 fails, so that the threshold voltage is maintained at the first reference voltage, corresponding to the first overcurrent protection value. The first reference voltage is V1 = VCC × R3 / (R2 + R3) = 2.2V; when the motor is connected in star, the IO port outputs a high level, controlling the triode Q1 to cut off, and the voltage-dividing resistor R1 is enabled, so that the threshold voltage is maintained at the second reference voltage, corresponding to the second overcurrent protection value. The second reference voltage is V2 = VCC × R3 / (R1 + R2 + R3) = 1.65V, where VCC is the voltage of the positive power supply terminal.

[0044] In some examples, the demagnetization current of the motor in the star connection state is 15A, and the demagnetization current in the delta connection state is 29A (the difference in numerical values is determined by the motor data); assume that the hardware overcurrent protection value in the star connection state is 12A, and the hardware overcurrent protection value in the delta connection state is 26A.

[0045] In some examples, as Figure 5 shown, the above-mentioned first voltage-dividing module 21 includes: a first voltage-dividing sub-module 23, having a control terminal, a first terminal, and a second terminal. The control terminal of the first voltage-dividing sub-module 23 is used to input a second control signal. The first terminal of the first voltage-dividing sub-module 23 is electrically connected to the positive power supply terminal, and the second terminal of the first voltage-dividing sub-module 23 is electrically connected to the first terminal of the second voltage-dividing module 22; a second voltage-dividing sub-module 24, having a control terminal, a first terminal, and a second terminal. The control terminal of the second voltage-dividing sub-module 24 is used to input a third control signal. The first terminal of the second voltage-dividing sub-module 24 is electrically connected to the positive power supply terminal, and the second terminal of the second voltage-dividing sub-module 24 is electrically connected to the second terminal of the first voltage-dividing sub-module 23 and the first terminal of the second voltage-dividing module 22 respectively.

[0046] Specifically, the first voltage-dividing sub-module and the second voltage-dividing sub-module are used for voltage division. By adjusting the resistance values of the first voltage-dividing sub-module and the second voltage-dividing sub-module, the voltage at the second input terminal of the integrated operational amplifier module can be adjusted, thereby controlling the magnitude of the threshold voltage input to the second input terminal of the integrated operational amplifier module. The control terminal of the first voltage-dividing sub-module is connected to the IO1 interface of the controller and is used to receive the second control signal to control the magnitude of the voltage division of the first voltage-dividing sub-module. The control terminal of the second voltage-dividing sub-module is connected to the IO2 interface of the controller and is used to receive the third control signal to control the magnitude of the voltage division of the second voltage-dividing sub-module.

[0047] Among them, for different connection methods of the motor windings, the first voltage-dividing sub-module or the second voltage-dividing sub-module is selected to be connected to change the threshold voltage at the second input terminal of the integrated operational amplifier module, so as to realize the selection of different hardware overcurrent protection values. The resistance values of the first voltage-dividing sub-module and the second voltage-dividing sub-module are different.

[0048] In some examples, such as Figure 6 shown, the first voltage dividing sub-module 23 includes a second switching device 231 and a third resistor module 232. The control terminal of the second switching device is used to input the second control signal, and the first terminal of the second switching device is electrically connected to the positive electrode of the power supply; the first terminal of the third resistor module 232 is electrically connected to the second terminal of the second switching device 231, and the second terminal of the third resistor module 232 is electrically connected to the first terminal of the second voltage dividing module 22; the second voltage dividing sub-module 24 includes a third switching device 241 and a fourth resistor module 242. The control terminal of the third switching device is used to input the third control signal, and the first terminal of the third switching device is electrically connected to the positive electrode of the power supply; the first terminal of the fourth resistor module 242 is electrically connected to the second terminal of the third switching device 241, and the second terminal of the fourth resistor module 242 is electrically connected to the second terminal of the first voltage dividing module 21 and the first terminal of the second voltage dividing module 22 respectively.

[0049] Specifically, both the third resistor module and the fourth resistor module are composed of one or more resistors connected in series or in parallel. The second switching device and the third switching device are switching devices with control terminals (for example: transistors, MOS transistors, etc.).

[0050] Such as Figure 7 shown, the third resistor module is a voltage dividing resistor R4, the fourth resistor module is a voltage dividing resistor R5, the second switching device is Q2, the third switching device is Q3, the second voltage dividing module is a voltage dividing resistor R6, and the integrated operational amplifier module is a comparator U2A. In this example, the second switching device is a PNP transistor, the third switching device is an NPN transistor, and the model of the comparator is OPA4374AID. In this example, the triode Q2 and the voltage dividing resistor R4 are connected in series, and the triode Q3 and the voltage dividing resistor R5 are connected in series. The enabling and disabling of the voltage dividing resistor R4 are controlled by the triode Q2, and the enabling and disabling of the voltage dividing resistor R5 are controlled by the triode Q3, thereby controlling the threshold voltage. When the motor is star-connected, the IO1 pin outputs a low level, controlling the second switching device Q2 to conduct, the IO2 pin outputs a high level, the third switching device Q3 is cut off, and the voltage dividing resistor R6 connected in series with the second switching device is enabled, cooperating with the low-end voltage dividing resistor for voltage division, so that the threshold voltage is maintained at the third reference voltage, corresponding to the third over-current protection value; when the motor is delta-connected, the IO1 pin outputs a high level, controlling the second switching device Q2 to cut off, the IO2 pin outputs a low level, the third switching device Q3 conducts, and the voltage dividing resistor R7 connected in series with the third switching device Q3 is enabled, so that the threshold voltage is maintained at the fourth reference voltage, corresponding to the fourth over-current protection value.

[0051] In some examples, such as Figure 7As shown, the second switching device 231 is a PNP transistor Q2, and the third switching device 241 is an NPN transistor Q3.

[0052] Specifically, the first, second, and third switching devices can be NPN transistors, PNP transistors, MOS transistors, etc.

[0053] In some examples, such as Figure 3 and Figure 6 As shown, the second voltage dividing module 22 includes: a fifth resistor module 221 having a first end and a second end. The first end of the fifth resistor module 221 is electrically connected to the second end of the first voltage dividing module 21 and the second input terminal of the integrated operational amplifier module 10, and the second end of the fifth resistor module 221 is grounded.

[0054] Specifically, the fifth resistor module is composed of one or more resistors connected in series or in parallel, and is used for voltage division of the positive power supply.

[0055] In some examples, such as Figure 8 As shown, the integrated operational amplifier peripheral circuit 20 includes: a sixth resistor module 201 having a first end and a second end. The first end of the sixth resistor module 201 is grounded, and the second end of the sixth resistor module 201 is electrically connected to the second input terminal of the integrated operational amplifier module 10; a seventh resistor module 202 having a first end and a second end. The first end of the seventh resistor module 202 is electrically connected to the second end of the sixth resistor module 201 and the second input terminal of the integrated operational amplifier module 10; an eighth resistor module 203 having a first end and a second end. The first end of the eighth resistor module 203 is electrically connected to the second end of the seventh resistor module 202, and the second end of the eighth resistor module 203 is electrically connected to the output terminal of the integrated operational amplifier module 10; a fourth switching device 204 having a control terminal, a first end, and a second end. The control terminal of the fourth switching device 204 is used to input a fourth control signal. The first end of the fourth switching device 204 is electrically connected to the second end of the seventh resistor module 202 and the first end of the eighth resistor module 203, and the second end of the fourth switching device 204 is electrically connected to the second end of the eighth resistor module 203.

[0056] Specifically, the sixth, seventh, and eighth resistor modules are each composed of one or more resistors connected in series or in parallel, and the fourth switching device is a switching device with a control terminal (e.g., a transistor, a MOS transistor, etc.).

[0057] Such as Figure 9As shown, the sixth resistor module is the voltage-dividing resistor R7, the seventh resistor module is the feedback resistor R8, the eighth resistor module is the feedback resistor R9, the fourth switching device is Q4, and the integrated operational amplifier module is the comparator U1B. In this embodiment, the fourth switching device is a PNP transistor. In this embodiment, when the motor is star-connected, the IO pin outputs a high level, controlling the triode Q4 to cut off, enabling the feedback resistor R9, and keeping the amplification factor at the first amplification factor. At this time, the collected current value is equal to the actual current value of the motor. When the motor is delta-connected, the IO pin outputs a low level, controlling the triode Q4 to conduct, disabling the feedback resistor R9, and keeping the amplification factor at the second amplification factor. At this time, the collected current value is 1 / 1.732 of the actual current value, achieving current protection without changing the threshold voltage of the comparator.

[0058] In some embodiments, such as Figure 8 As shown, the above overcurrent protection circuit further includes: a ninth resistor module 40 having a first end and a second end. The first end of the ninth resistor module 40 is used to input a reference voltage signal, and the second end of the ninth resistor module 40 is electrically connected to the first input terminal of the integrated operational amplifier module 10; a tenth resistor module 50 having a first end and a second end. The first end of the tenth resistor module 50 is used to input the target voltage signal, and the second end of the tenth resistor module 50 is electrically connected to the second end of the ninth resistor module 40 and the first input terminal of the integrated operational amplifier module 10 respectively.

[0059] Specifically, both the ninth resistor module and the tenth resistor module are composed of one or more resistors connected in series or in parallel.

[0060] Such as Figure 9 As shown, the ninth resistor module is the resistor R10, and the tenth resistor module is the resistor R11.

[0061] In some embodiments, the above integrated operational amplifier module includes: a comparator having a first input terminal, a second input terminal, a first end, a second end, and an output terminal. The first input terminal of the comparator is used to input the target voltage signal, the second input terminal of the comparator is electrically connected to the first end of the peripheral circuit of the integrated operational amplifier, the first end of the comparator is electrically connected to the positive power supply, the second end of the comparator is grounded, and the output terminal of the comparator is used to output the target output signal.

[0062] Specifically, when the peripheral circuit of the integrated operational amplifier is used to control the magnitude of the threshold voltage input to the second input terminal of the integrated operational amplifier module, the comparator is used to compare the magnitude of the threshold voltage input to the second input terminal of the integrated operational amplifier module with the target voltage signal and output the comparison result to the controller.

[0063] As can be seen from the above description, the above embodiments of the present application achieve the following technical effects:

[0064] The above overcurrent protection circuit of the present application includes: an integrated operational amplifier module having a first input terminal, a second input terminal, and an output terminal. The first input terminal of the integrated operational amplifier module is used to input a target voltage signal, and the output terminal of the integrated operational amplifier module is used to output a target output signal to the controller. The target voltage signal is used to represent the actual current of the motor; an integrated operational amplifier peripheral circuit. The first end of the integrated operational amplifier peripheral circuit is electrically connected to the second input terminal of the integrated operational amplifier module. The integrated operational amplifier peripheral circuit is used to control the magnitude of the voltage input to the second input terminal of the integrated operational amplifier module, and this voltage magnitude is the voltage at which the level of the comparator output terminal flips. For different connection modes of the motor windings, this overcurrent protection circuit enables or disables the voltage-dividing resistor through a triode, changes the threshold voltage of the inverting input terminal of the comparator, or changes the amplification factor of the amplifier through a triode, thereby realizing the selection of different hardware overcurrent protection values, and solving the problem that the prior art cannot adjust the hardware overcurrent protection value according to the connection mode of the motor windings.

[0065] The foregoing is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. An overcurrent protection circuit, characterized in that: include: An integrated operational amplifier module, comprising a first input terminal, a second input terminal and an output terminal, wherein the first input terminal of the integrated operational amplifier module is used to input a target voltage signal, and the output terminal of the integrated operational amplifier module is used to output a target output signal to a controller, wherein the target voltage signal is used to characterize an actual current of the motor; An integrated operational amplifier peripheral circuit, wherein the first end of the integrated operational amplifier peripheral circuit is electrically connected to the second input end of the integrated operational amplifier module, and the integrated operational amplifier peripheral circuit is used to control the magnitude of the voltage input to the second input end of the integrated operational amplifier module, wherein the voltage is the voltage at which the level of the output end of the integrated operational amplifier module is flipped, and the integrated operational amplifier peripheral circuit is also used to control the magnitude of the voltage of the target output signal.

2. The overcurrent protection circuit according to claim 1, characterized in that: The integrated operational amplifier peripheral circuit comprises: A first voltage divider module has a control end, a first end, and a second end, wherein the control end of the first voltage divider module is used to input a first control signal, the first end of the first voltage divider module is electrically connected to the positive electrode of the power supply, and the first control signal is used to control the resistance of the first voltage divider module; The second voltage divider module has a first end and a second end. The first end of the second voltage divider module is electrically connected to the second end of the first voltage divider module and the second input end of the integrated operational amplifier module respectively, and the second end of the second voltage divider module is grounded.

3. The overcurrent protection circuit according to claim 2, characterized in that: The first voltage dividing module comprises: A first resistance module, having a first end and a second end, wherein the first end of the first resistance module is electrically connected to the positive electrode of the power supply; A second resistance module having a first end and a second end, the first end of the second resistance module being electrically connected to the second end of the first resistance module, and the second end of the second resistance module being electrically connected to the first end of the second voltage divider module; The first switch device has a control end, a first end, and a second end. The control end of the first switch device is used to input the first control signal. The first end of the first switch device is electrically connected to the first end of the first resistor module. The second end of the first switch device is electrically connected to the first end of the first resistor module and the second end of the second resistor module, respectively.

4. The overcurrent protection circuit according to claim 2, characterized in that: The first voltage dividing module comprises: A first voltage divider submodule, comprising a control end, a first end, and a second end, wherein the control end of the first voltage divider submodule is used to input a second control signal, the first end of the first voltage divider submodule is electrically connected to the positive electrode of the power supply, and the second end of the first voltage divider submodule is electrically connected to the first end of the second voltage divider module; The second voltage divider submodule has a control end, a first end and a second end. The control end of the second voltage divider submodule is used to input a third control signal. The first end of the second voltage divider submodule is electrically connected to the positive pole of the power supply. The second end of the second voltage divider submodule is electrically connected to the second end of the first voltage divider submodule and the first end of the second voltage divider module respectively.

5. The overcurrent protection circuit according to claim 4, characterized in that: The first voltage-dividing submodule includes a second switch device and a third resistor module, the control end of the second switch device is used to input the second control signal, the first end of the second switch device is electrically connected to the positive electrode of the power supply; the first end of the third resistor module is electrically connected to the second end of the second switch device, and the second end of the third resistor module is electrically connected to the first end of the second voltage-dividing module; The second voltage divider submodule includes a third switching device and a fourth resistance module, the control end of the third switching device is used to input the third control signal, and the first end of the third switching device is electrically connected to the positive electrode of the power supply; the first end of the fourth resistance module is electrically connected to the second end of the third switching device, and the second end of the fourth resistance module is electrically connected to the second end of the first voltage divider module and the first end of the second voltage divider module respectively.

6. The overcurrent protection circuit according to claim 5, characterized in that: The second switch device is a PNP transistor, and the third switch device is an NPN transistor.

7. The overcurrent protection circuit according to claim 2, characterized in that: The second voltage dividing module comprises: The fifth resistor module has a first end and a second end. The first end of the fifth resistor module is electrically connected to the second end of the first voltage divider module and the second input end of the integrated operational amplifier module respectively, and the second end of the fifth resistor module is grounded.

8. The overcurrent protection circuit according to claim 1, characterized in that: The integrated operational amplifier peripheral circuit comprises: a sixth resistance module, having a first end and a second end, the first end of the sixth resistance module being grounded, and the second end of the sixth resistance module being electrically connected to the second input end of the integrated operational amplifier module; a seventh resistor module, having a first end and a second end, wherein the first end of the seventh resistor module is electrically connected to the second end of the sixth resistor module and the second input end of the integrated operational amplifier module respectively; an eighth resistance module, having a first end and a second end, the first end of the eighth resistance module being electrically connected to the second end of the seventh resistance module, and the second end of the eighth resistance module being electrically connected to the output end of the integrated operational amplifier module; A fourth switching device has a control end, a first end and a second end. The control end of the fourth switching device is used to input a fourth control signal. The first end of the fourth switching device is electrically connected to the second end of the seventh resistor module and the first end of the eighth resistor module, respectively. The second end of the fourth switching device is electrically connected to the second end of the eighth resistor module.

9. The overcurrent protection circuit according to claim 1, characterized in that: The overcurrent protection circuit also includes: a ninth resistance module, having a first end and a second end, wherein the first end of the ninth resistance module is used to input a reference voltage signal, and the second end of the ninth resistance module is electrically connected to the first input end of the integrated operational amplifier module; The tenth resistor module has a first end and a second end, the first end of the tenth resistor module is used to input the target voltage signal, and the second end of the tenth resistor module is electrically connected to the second end of the ninth resistor module and the first input end of the integrated operational amplifier module respectively.

10. The overcurrent protection circuit according to claim 1, characterized in that: The integrated operational amplifier module comprises: A comparator having a first input terminal, a second input terminal, a first terminal, a second terminal and an output terminal, wherein the first input terminal of the comparator is used to input the target voltage signal, the second input terminal of the comparator is electrically connected to the first terminal of the integrated operational amplifier peripheral circuit, the first terminal of the comparator is electrically connected to the positive pole of the power supply, the second terminal of the comparator is grounded, and the output terminal of the comparator is used to output the target output signal.

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