Overcurrent protection circuit and method of motor controller

Abstract

The invention relates to an overcurrent protection circuit and method of a motor controller. The overcurrent protection circuit comprises a sampling module, a first detection module and a control module. The sampling module is used for collecting operation current of the motor controller and generating sampling voltage according to the operation current. The first detection module is electrically connected with the sampling module; the first detection module is used for outputting a first level signal under the condition that the sampling voltage meets an overcurrent protection condition; the control module is connected with the first detection module and used for stopping sending the control signal to the motor controller under the condition that the first level signal is received. According to the invention, the sampling voltage generated by the operation current of the motor controller is detected, and the motor controller stops working under the condition that the sampling voltage meets the overcurrent protection condition, so that the motor and the motor controller can be prevented from being damaged due to the overlarge operation current.

Description

Technical Field

[0001] The present disclosure relates to the technical field of motor protection, and in particular to an overcurrent protection circuit and method for a motor controller. Background Art

[0002] With the development of the new energy industry, the demand for motor controllers is increasing. When the motor controller controls the rotation of the motor, the operating current of the motor controller may exceed its load capacity, causing the motor controller to heat up and fail, and then causing damage to the motor and the motor controller. Therefore, how to monitor the operating current of the motor controller in real time during operation to prevent the motor or motor controller from being damaged due to excessive current has become a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0003] In order to solve the above technical problem or at least partially solve the above technical problem, the present disclosure provides an overcurrent protection circuit and method for a motor controller.

[0004] The present disclosure provides an overcurrent protection circuit for a motor controller, comprising: a sampling module, a first detection module and a control module. The sampling module is used to collect the operating current of the motor controller and generate a sampling voltage according to the operating current; the first detection module is electrically connected to the sampling module; the first detection module is used to output a first level signal when the sampling voltage meets the overcurrent protection condition; the control module is connected to the first detection module and is used to stop sending a control signal to the motor controller when the first level signal is received.

[0005] Optionally, the first detection module includes a first switch; the input end of the first switch is electrically connected to the sampling module, the first end of the first switch is electrically connected to the power supply module, the first end of the first switch is also electrically connected to the control module, and the second end of the first switch is grounded; wherein the first switch is used to turn on the first end of the first switch and the second end of the first switch according to whether the sampled voltage meets the overcurrent protection condition.

[0006] Optionally, the first switch includes an NPN transistor, a pull-up resistor and a current limiting resistor; the base of the NPN transistor is electrically connected to the sampling module through the current limiting resistor, the collector of the NPN transistor is electrically connected to the power supply module through the pull-up resistor, the collector of the NPN transistor is also electrically connected to the control module, and the emitter of the NPN transistor is grounded.

[0007] Optionally, the first detection module also includes a first filter capacitor, a second filter capacitor and a filter resistor; the first end of the first filter capacitor is electrically connected to the base of the NPN transistor, the second end of the first filter capacitor is electrically connected to the emitter of the NPN transistor, the collector of the NPN transistor is electrically connected to the control module through the filter resistor, the first end of the second filter capacitor is electrically connected to the collector of the NPN transistor, and the first end of the second filter capacitor is electrically connected to the emitter of the NPN transistor.

[0008] Optionally, the first detection module further includes a voltage-stabilizing capacitor; a first end of the voltage-stabilizing capacitor is electrically connected to the collector of the NPN transistor, and a second end of the capacitor is electrically connected to the emitter of the NPN transistor.

[0009] Optionally, the overcurrent protection circuit also includes a second detection module; the second detection module is electrically connected to the sampling module and the control module respectively; the second detection module is used to control the control module to stop working according to the comparison result between the sampling voltage and the voltage threshold.

[0010] Optionally, the control module includes a power supply unit and a drive unit; the first detection module is electrically connected to the drive unit through the power supply unit; wherein the power supply unit is used to stop supplying power to the drive unit when receiving a first level signal; and the drive unit is used to send a control signal to the motor controller.

[0011] Optionally, the overcurrent protection circuit also includes a recording module; the recording module is electrically connected to the control module, and the recording module is used to record fault information; wherein the fault information is information that the control module stops sending a control signal.

[0012] The present disclosure also provides an overcurrent protection method for a motor controller, which is applicable to the overcurrent protection circuit of any motor controller as described above; the method includes: obtaining a sampled voltage; based on the sampled voltage satisfying the overcurrent protection condition, controlling the control module to stop sending a control signal to the motor controller.

[0013] The present disclosure also provides an overcurrent protection method for a motor controller, which is applicable to the overcurrent protection circuit of any motor controller as described above; the overcurrent protection circuit also includes a second detection module; the second detection module is electrically connected to the sampling module and the control module respectively; the method includes: obtaining a sampling voltage; based on the comparison result of the sampling voltage and the voltage threshold, controlling the control module to stop working.

[0014] The present disclosure provides an overcurrent protection circuit and method for a motor controller, and the overcurrent protection circuit includes a sampling module, a first detection module and a control module. The sampling module is used to sample the operating current of the motor controller and obtain a sampled voltage by calculation. The first detection module detects the sampled voltage in real time. When it is detected that the sampled voltage meets the overcurrent protection condition, the first detection module outputs a first level signal to the control module. The control module determines that an overcurrent fault occurs in the motor controller according to the first level signal received, and stops sending a control signal to the motor controller, so that the motor controller also stops working. The present disclosure collects the operating current in the motor controller through the sampling module, so that the operating current will generate a sampled voltage after passing through the sampling module with a resistance value. After receiving the sampled voltage that meets the overcurrent protection condition, the first detection module outputs a signal to transmit a first level signal. The control module stops the motor controller according to the first level signal received, thereby preventing the motor and the motor controller from working in an overcurrent state and being damaged. In addition, the overcurrent protection circuit of the present disclosure performs overcurrent detection by directly transmitting signals through a hardware circuit, which improves the reaction speed of stopping the motor controller after detecting an overcurrent fault in the motor controller, and further realizes the protection of the motor and the motor controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A schematic diagram of the structure of an overcurrent protection circuit of a motor controller provided in an embodiment of the present disclosure.

[0017] Figure 2 A schematic structural diagram of an overcurrent protection circuit of another motor controller provided in an embodiment of the present disclosure.

[0018] Figure 3 A schematic flow chart of an overcurrent protection method for a motor controller provided in an embodiment of the present disclosure.

[0019] Figure 4 A flowchart of another overcurrent protection method for a motor controller provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] The features and exemplary embodiments of various aspects of the application will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the application. However, it is obvious to those skilled in the art that the application can be implemented when some details in these specific details are not needed. The following description of the embodiments is only to provide a better understanding of the application by illustrating the example of the application.

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The embodiments will be described in detail below in conjunction with the accompanying drawings.

[0022] Figure 1 A schematic diagram of the structure of an overcurrent protection circuit of a motor controller provided by an embodiment of the present disclosure is shown in FIG. Figure 1 As shown, the overcurrent protection circuit includes: a sampling module 100, a first detection module 200 and a control module 300. The sampling module 100 is used to collect the operating current of the motor controller 400 and generate a sampling voltage according to the operating current; the first detection module 200 is electrically connected to the sampling module 100; the first detection module 200 is used to output a first level signal when the sampling voltage meets the overcurrent protection condition; the control module 300 is connected to the first detection module 200, and is used to stop sending a control signal to the motor controller 400 when receiving the first level signal.

[0023] Exemplarily, the motor controller 400 is a three-phase motor controller as an example for introduction. The motor controller 400 includes a first bridge arm, a second bridge arm and a third bridge arm, and the sampling module 100 is electrically connected to the first bridge arm, the second bridge arm and the third bridge arm respectively. The sampling module 100 can be, for example, a first shunt 101, a second shunt 102 and a third shunt 103. The first shunt 101 is used to collect the operating current on the first bridge arm, the second shunt 102 is used to collect the operating current on the second bridge arm, and the third shunt 103 is used to collect the operating current on the third bridge arm. The operating current will form a corresponding sampling voltage after flowing through the shunt. A first detection module 200 is connected to each shunt, and each first detection module 200 receives the sampling voltage on the corresponding shunt. The control module 300 is electrically connected to each first detection module 200, and the control module 300 is also connected to the control end 401 of the motor controller 400. When the sampling voltage on any shunt meets the overcurrent protection condition, the first detection module 200 corresponding to the shunt will output a first level signal to the control module 300, and the control module 300 stops sending control signals to the motor controller 400 according to the received first level signal, and the motor controller 400 stops working.

[0024] Therefore, the present invention collects the operating current of each bridge arm of the motor controller 400 through the sampling module 100, and converts the collected operating current into a sampling voltage. After an overcurrent fault occurs in the operating current on any bridge arm of the motor controller 400, the sampling voltage received by the first detection module 200 corresponding to the bridge arm meets the overcurrent protection condition, and the first detection module 200 outputs a first level signal to the control module 300. The control module 300 stops sending a control signal to the motor controller 400 based on the received first level signal, and the motor controller 400 stops working, thereby preventing the motor and the motor controller 400 from continuing to work in an overcurrent state and being damaged.

[0025] Moreover, the overcurrent protection current provided by the embodiment of the present disclosure implements overcurrent protection through a hardware circuit. When the first detection module 200 receives a sampled voltage that meets the overcurrent protection condition, it will output a first level signal by turning on or off the internal switch device. However, the collected voltage or current needs to be compared with the preset value by software control, and then the corresponding control signal is output. Therefore, there is a problem of software delay. It can be seen that the overcurrent protection method through software control has a slower reaction speed than the overcurrent protection method through hardware circuit. The overcurrent protection circuit of the present disclosure performs overcurrent detection by directly transmitting signals through the hardware circuit, which improves the reaction speed of the overcurrent protection circuit to stop the motor controller from working after an overcurrent operation failure occurs in the motor controller 400, and further realizes the protection of the motor and the motor controller 400.

[0026] It should be noted that the motor controller 400 being a three-phase motor controller is only an example, and the motor controller 400 may also be, for example, a two-phase motor controller, a six-phase motor controller, etc., which is specifically configured according to actual conditions and is not specifically limited here.

[0027] It should be noted that the sampling module 100 being a shunt is only an example, and the sampling module 100 may also be other modules that can convert the operating current in the bridge arm of the motor controller 400 into a sampling voltage, which is not specifically limited here.

[0028] In some embodiments, the first detection module includes a first switch; the input end of the first switch is electrically connected to the sampling module, the first end of the first switch is electrically connected to the power supply module, the first end of the first switch is also electrically connected to the control module, and the second end of the first switch is grounded; wherein the first switch is used to turn on the first end of the first switch and the second end of the first switch according to the sampling voltage satisfying the overcurrent protection condition.

[0029] Specifically, the sampling module collects the running current of the motor controller and converts the collected running current into a sampling voltage. The input end of the first switch is electrically connected to the sampling module, and the sampling voltage collected by the sampling module will be transmitted to the first switch. When the motor controller is in a normal working state, the sampling voltage does not meet the overcurrent protection condition. At this time, the first switch remains disconnected, the control module is directly electrically connected to the power module, and the power module outputs a second level signal, i.e., a high level signal, to the control module. The control module continues to output a control signal to the motor controller according to the received high level signal, and the motor controller maintains normal operation. When the running current of the motor controller is overcurrent, the sampling voltage output by the sampling module to the input end of the first switch meets the overcurrent protection condition. At this time, the first end of the first switch is connected to the second end of the first switch, and the control module is directly grounded. Therefore, the control module receives a first level signal, i.e., a low level signal. The control module stops sending a control signal to the motor controller according to the received first level signal, and the motor controller stops working, thereby preventing the motor and the motor controller from continuing to work in an overcurrent state and being damaged. Furthermore, the overcurrent protection circuit disclosed in the present invention performs overcurrent detection by directly transmitting signals through hardware circuits, thereby improving the reaction speed of the overcurrent protection circuit in stopping the operation of the motor controller after an overcurrent operating fault occurs in the motor controller, thereby further realizing protection for the motor and the motor controller.

[0030] In some embodiments, the first switch includes an NPN transistor, a pull-up resistor and a current limiting resistor; the base of the NPN transistor is electrically connected to the sampling module through the current limiting resistor, the collector of the NPN transistor is electrically connected to the power module through the pull-up resistor, the collector of the NPN transistor is also electrically connected to the control module, and the emitter of the NPN transistor is grounded.

[0031] Specifically, the base of the NPN transistor is electrically connected to the sampling module through a current limiting resistor. The current limiting resistor can prevent the current output to the NPN transistor from being too large, thereby causing damage to the NPN transistor, and plays a role in protecting the NPN transistor. When the motor controller works normally, the sampling voltage received by the base of the NPN transistor is less than the emitter voltage of the NPN transistor, and the NPN transistor is not turned on. The control module is electrically connected to the power module through a pull-up resistor. The power module outputs a second level signal, i.e., a high level signal, to the control module. The control module continues to output a control signal to the motor controller according to the received high level signal, and the motor controller maintains normal operation. When the motor controller is in an overcurrent operation state, the sampling voltage received by the base of the NPN transistor gradually increases until the sampling voltage received by the base of the NPN transistor is greater than the emitter voltage of the NPN transistor, that is, the sampling voltage meets the overcurrent protection condition, at this time, the NPN transistor is turned on, the control module is grounded through the turned-on NPN transistor, the control module receives a first level signal, that is, a low level signal, and the control module stops sending a control signal to the motor controller according to the received first level signal, and the motor controller stops working, thereby preventing the motor and the motor controller from continuing to work in the overcurrent state and being damaged. In addition, the overcurrent protection circuit of the present disclosure performs overcurrent detection by directly transmitting signals through a hardware circuit, which improves the reaction speed of the overcurrent protection circuit stopping the motor controller from working after an overcurrent operation fault occurs in the motor controller, and further realizes the protection of the motor and the motor controller.

[0032] In some embodiments, the first detection module also includes a first filter capacitor, a second filter capacitor and a filter resistor; the first end of the first filter capacitor is electrically connected to the base of the NPN transistor, the second end of the first filter capacitor is electrically connected to the emitter of the NPN transistor, the collector of the NPN transistor is electrically connected to the control module through the filter resistor, the first end of the second filter capacitor is electrically connected to the collector of the NPN transistor, and the first end of the second filter capacitor is electrically connected to the emitter of the NPN transistor.

[0033] Specifically, the first filter capacitor is used to filter out the interference signal in the sampled voltage output by the sampling module to the NPN transistor, thereby ensuring that the base of the NPN transistor can directly receive the accurate sampled voltage, thereby avoiding the problem that the NPN transistor is incorrectly turned on due to the presence of the interference signal, and even causes the motor controller to be incorrectly shut down. When the control module is grounded through the turned-on NPN transistor, if there is an interference signal in the circuit, the signal received by the control module will not be a low-level signal, so the control module will not stop outputting the control signal to the motor controller, and the motor controller will not stop working, which will cause damage to the motor and the motor controller. The present disclosure uses a second filter capacitor and a filter resistor to filter out the interference signal when the control module is grounded through the turned-on NPN transistor, so that the control module receives an accurate and stable low-level signal, avoiding the problem that the control module will not stop the motor controller when an overcurrent operation fault occurs in the motor controller, and further ensuring the operation safety of the motor and the motor controller.

[0034] In some embodiments, the first detection module further includes a voltage-stabilizing capacitor; a first end of the voltage-stabilizing capacitor is electrically connected to the collector of the NPN transistor, and a second end of the capacitor is electrically connected to the emitter of the NPN transistor.

[0035] Specifically, the power module is electrically connected to the collector of the NPN transistor, and the power module is used to provide voltage for the collector of the NPN transistor and the emitter of the NPN transistor. Since the conduction condition of the NPN transistor is that the base voltage of the NPN transistor is greater than the emitter voltage of the NPN transistor, if the voltage provided by the power module is unstable due to the presence of interference signals in the circuit, it may happen that the base voltage of the NPN transistor should be greater than the emitter voltage of the NPN transistor, so that the NPN transistor is turned on, but the base voltage of the NPN transistor is less than the emitter voltage of the NPN transistor, and the NPN transistor is not turned on. When the base voltage of the NPN transistor should be less than the emitter voltage of the NPN transistor, so that the NPN transistor is not turned on, the base voltage of the NPN transistor is greater than the emitter voltage of the NPN transistor, so that the NPN transistor is turned on. This will result in the motor controller continuing to work when it is necessary to stop the motor controller. The problem that the motor controller stops working when it is necessary to work. The present disclosure filters out interference signals in the circuit by arranging a voltage-stabilizing capacitor between the collector and the emitter of the NPN transistor, so that the voltage in the circuit is stable, thereby ensuring that the NPN transistor can be turned on and off normally according to demand, so that the working state of the motor controller can be normally controlled, thereby further ensuring the safe operation of the motor and the motor controller.

[0036] In some embodiments, Figure 2 A schematic diagram of the structure of an overcurrent protection circuit of another motor controller provided in an embodiment of the present disclosure is shown in FIG. Figure 2 As shown, the first detection module includes: an NPN transistor Q1, a current limiting resistor R1, a pull-up resistor R2, a filter resistor R3, a first filter capacitor C1, a second filter capacitor C2 and a voltage stabilizing capacitor C3.

[0037] The base of the NPN transistor Q1 is electrically connected to the sampling module 100 through the current limiting resistor R1, the power module 500 is electrically connected to the collector of the NPN transistor Q1 through the pull-up resistor R2, the collector of the NPN transistor Q1 is electrically connected to the control module 300 through the filter resistor R3, the emitter of the NPN transistor Q1 is grounded, the base of the NPN transistor Q1 is electrically connected to the emitter of the NPN transistor Q1 through the first filter capacitor C1, the collector of the NPN transistor Q1 is electrically connected to the emitter of the NPN transistor Q1 through the second filter capacitor C2, and the power module 500 is electrically connected to the emitter of the NPN transistor Q1 through the voltage stabilizing capacitor C3.

[0038] Specifically, the base of the NPN transistor Q1 is electrically connected to the sampling module 100 through the current limiting resistor R1. The current limiting resistor R1 can prevent the current output to the NPN transistor Q1 from being too large, thereby causing the NPN transistor Q1 to be damaged, and plays a role in protecting the NPN transistor Q1. When the motor controller works normally, the sampling voltage received by the base of the NPN transistor Q1 from the sampling module 100 is less than the emitter voltage of the NPN transistor Q1, and the NPN transistor Q1 is not turned on. The control module 300 is electrically connected to the power module through the pull-up resistor R2, and the power module 500 outputs a second level signal, i.e., a high level signal, to the control module 300. The control module 300 continues to output a control signal to the motor controller according to the received high level signal, and the motor controller maintains normal operation. When the motor controller is in an overcurrent operation state, the sampling voltage received by the base of the NPN transistor Q1 gradually increases until the sampling voltage received by the base of the NPN transistor Q1 is greater than the emitter voltage of the NPN transistor Q1, that is, the sampling voltage meets the overcurrent protection condition, at this time, the NPN transistor Q1 is turned on, the control module 300 is grounded through the turned-on NPN transistor Q1, and the control module 300 receives a first level signal, that is, a low level signal. The control module 300 stops sending a control signal to the motor controller according to the received first level signal, and the motor controller stops working, thereby preventing the motor and the motor controller from continuing to work in the overcurrent state and being damaged. In addition, the overcurrent protection circuit of the present disclosure performs overcurrent detection by directly transmitting signals through a hardware circuit, which improves the reaction speed of the overcurrent protection circuit stopping the motor controller from working after an overcurrent operation fault occurs in the motor controller, and further realizes the protection of the motor and the motor controller.

[0039] The first filter capacitor C1 is used to filter out the interference signal in the sampled voltage output by the sampling module 100 to the NPN transistor Q1, thereby ensuring that the base of the NPN transistor Q1 can directly receive the accurate sampled voltage. The second filter capacitor C2 and the filter resistor R3 are used to filter out the interference signal when the control module 300 is grounded through the turned-on NPN transistor Q1, so that the control module 300 receives an accurate and stable low-level signal. The voltage-stabilizing capacitor C3 is used to filter out the interference signal in the circuit, so that the voltage in the circuit is stable, thereby ensuring that the NPN transistor Q1 can be turned on and off normally according to demand, so that the working state of the motor controller can be normally controlled, thereby further ensuring the safe operation of the motor and the motor controller.

[0040] In some embodiments, the overcurrent protection circuit further includes a second detection module; the second detection module is electrically connected to the sampling module and the control module respectively; the second detection module is used to control the control module to stop working according to the comparison result between the sampling voltage and the voltage threshold.

[0041] Specifically, when the motor is blocked or overloaded, the motor controller will also produce an overcurrent fault, but in this type of overcurrent fault, the overcurrent of the motor controller is small, so the sampled voltage received by the first detection module cannot meet the overcurrent protection condition of the first detection module. Therefore, the present disclosure is provided with a second detection module, and the second detection module is used to detect overcurrent faults with weaker overcurrent conditions. The second detection module compares the received sampled voltage with the voltage threshold. When the sampled voltage is greater than the voltage threshold, the second detection module determines that the motor controller has an overcurrent operation fault. And because the first detection module implements overcurrent protection by directly transmitting signals through hardware circuits, the first detection module has a faster detection speed for overcurrent faults than the second detection module. Therefore, when an overcurrent fault with a larger overcurrent occurs, the first detection module will output the first level signal faster to cause the control module to stop the operation of the motor controller. For overcurrent faults with smaller overcurrents, the first detection module cannot perform detection, but the second detection module can complete the detection. Therefore, it can be determined whether it is the first detection module or the second detection module that performs overcurrent protection on the motor controller, and then the cause of the overcurrent fault in the motor controller can be determined. On the basis of further ensuring the safe operation of the motor and the motor controller, it can also assist maintenance personnel to determine the cause of the fault as soon as possible, thereby facilitating the maintenance of the motor and the motor controller.

[0042] In some embodiments, the control module includes a power supply unit and a drive unit; the first detection module is electrically connected to the drive unit through the power supply unit; wherein the power supply unit is used to stop supplying power to the drive unit when receiving a first level signal; and the drive unit is used to send a control signal to the motor controller.

[0043] Specifically, the power supply unit is used to supply power to the drive unit. When the motor controller is in a normal working state, the sampling voltage does not meet the overcurrent protection condition. At this time, the first detection module does not output the first level signal to the power supply unit. The power supply unit maintains a normal working state and supplies power to the drive unit. The drive unit can normally send a control signal to the motor controller, and the motor controller maintains normal operation. When the operating current of the motor controller is overcurrent, the sampling voltage output by the sampling module to the first detection module meets the overcurrent protection condition. At this time, the first detection module outputs a first level signal to the power supply unit, and the power supply unit stops supplying power to the drive unit according to the first level signal, thereby causing the drive unit to stop sending control signals to the motor controller, and the motor controller stops working, thereby preventing the motor and the motor controller from continuing to work in an overcurrent state and being damaged.

[0044] In some embodiments, the overcurrent protection circuit further includes a recording module; the recording module is electrically connected to the control module, and the recording module is used to record fault information; wherein the fault information is information indicating that the control module stops sending a control signal.

[0045] Specifically, when an overcurrent occurs in the operating current of the motor controller, the sampling voltage output by the sampling module to the first detection module meets the overcurrent protection condition. At this time, the first detection module outputs a first level signal to the control module, and the control module stops sending control signals to the motor controller according to the first level signal. The recording module can record the information that the control module stops sending control signals, thereby recording an overcurrent operating fault in the motor controller.

[0046] Figure 3 A flow chart of an overcurrent protection method for a motor controller provided by an embodiment of the present disclosure is shown as follows: Figure 3 As shown, the overcurrent protection method is applicable to the overcurrent protection circuit of the motor controller described in any of the above embodiments; the overcurrent protection method includes: S610 and S620. S610, obtaining a sampled voltage. S620, based on the sampled voltage satisfying the overcurrent protection condition, controlling the control module to stop sending a control signal to the motor controller.

[0047] Specifically, the first detection module acquires the sampled voltage collected by the sampling module, and outputs a first level signal to the control module according to the sampled voltage meeting the overcurrent protection condition, and the control module stops sending the control signal to the motor controller according to the first level signal received, thereby realizing the control of the control module by the first detection module. When the motor controller is in a normal working state, the sampled voltage acquired by the first detection module does not meet the overcurrent protection condition, and the first detection module does not output the first level signal at this time, and the control module continues to output the control signal to the motor controller, so that the motor controller maintains normal operation. When the running current of the motor controller has an overcurrent condition, the sampled voltage acquired by the first detection module meets the overcurrent protection condition, and the first detection module outputs the first level signal to the control module at this time, and the control module stops sending the control signal to the motor controller, so that the motor controller stops working, thereby preventing the motor and the motor controller from continuing to work in the overcurrent state and being damaged. In addition, the overcurrent protection circuit disclosed in the present invention performs overcurrent detection by directly transmitting signals through a hardware circuit, which improves the reaction speed of the overcurrent protection circuit stopping the motor controller after an overcurrent operation failure occurs in the motor controller, and further realizes the protection of the motor and the motor controller.

[0048] Figure 4 A flow chart of another overcurrent protection method for a motor controller provided in an embodiment of the present disclosure is shown as follows: Figure 4As shown, the overcurrent protection method is applicable to the overcurrent protection circuit of the motor controller described in any of the above embodiments; the overcurrent protection circuit also includes a second detection module; the second detection module is electrically connected to the sampling module and the control module respectively; the overcurrent protection method includes: S710 and S720. S710, obtaining a sampled voltage. S720, based on the comparison result of the sampled voltage and the voltage threshold, controlling the control module to stop working.

[0049] Specifically, when the motor is blocked or overloaded, the motor controller will also generate an overcurrent fault, but in this type of overcurrent fault, the overcurrent of the motor controller is small, so the sampling voltage received by the first detection module cannot meet the overcurrent protection condition of the first detection module, so the present disclosure is provided with a second detection module, and the second detection module is used to detect the overcurrent fault with a weaker overcurrent condition. The second detection module obtains the sampling voltage provided by the sampling module, and compares the obtained sampling voltage with the voltage threshold. When the sampling voltage is greater than the voltage threshold, the second detection module determines that the motor controller has an overcurrent operation fault, and the second detection module controls the control module to stop working, so that the motor controller stops working, thereby preventing the motor and the motor controller from being damaged due to overcurrent operation. And because the first detection module realizes overcurrent protection by directly transmitting signals through a hardware circuit, the detection speed of the first detection module for overcurrent faults is faster than that of the second detection module. Therefore, when an overcurrent fault with a larger overcurrent occurs, the first detection module will output a first level signal faster to stop the control module from working on the motor controller. For overcurrent faults with smaller overcurrents, the first detection module cannot perform detection, but the second detection module can complete the detection. Therefore, it can be determined whether it is the first detection module or the second detection module that performs overcurrent protection on the motor controller, and then the cause of the overcurrent fault in the motor controller can be determined. On the basis of further ensuring the safe operation of the motor and the motor controller, it can also assist maintenance personnel to determine the cause of the fault as soon as possible, thereby facilitating the maintenance of the motor and the motor controller.

[0050] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0051] The above are only specific embodiments of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An overcurrent protection circuit for a motor controller, characterized in that: include: A sampling module, used for collecting the running current of the motor controller and generating a sampling voltage according to the running current; A first detection module, electrically connected to the sampling module; The first detection module is used for outputting a first level signal when the sampled voltage meets the overcurrent protection condition; A control module is connected to the first detection module and is used to stop sending a control signal to the motor controller when receiving the first level signal.

2. The overcurrent protection circuit according to claim 1, characterized in that: The first detection module includes a first switch; an input end of the first switch is electrically connected to the sampling module, a first end of the first switch is electrically connected to the power supply module, a first end of the first switch is also electrically connected to the control module, and a second end of the first switch is grounded; The first switch is used to conduct the first end of the first switch and the second end of the first switch according to the sampling voltage satisfying the overcurrent protection condition.

3. The overcurrent protection circuit according to claim 2, characterized in that: The first switch includes an NPN transistor, a pull-up resistor and a current limiting resistor; The base of the NPN transistor is electrically connected to the sampling module through the current limiting resistor, the collector of the NPN transistor is electrically connected to the power module through the pull-up resistor, the collector of the NPN transistor is also electrically connected to the control module, and the emitter of the NPN transistor is grounded.

4. The overcurrent protection circuit according to claim 3, characterized in that: The first detection module also includes a first filter capacitor, a second filter capacitor and a filter resistor; The first end of the first filter capacitor is electrically connected to the base of the NPN transistor, the second end of the first filter capacitor is electrically connected to the emitter of the NPN transistor, the collector of the NPN transistor is electrically connected to the control module through the filter resistor, the first end of the second filter capacitor is electrically connected to the collector of the NPN transistor, and the first end of the second filter capacitor is electrically connected to the emitter of the NPN transistor.

5. The overcurrent protection circuit according to claim 3, characterized in that: The first detection module also includes a voltage-stabilizing capacitor; a first end of the voltage-stabilizing capacitor is electrically connected to the collector of the NPN transistor, and a second end of the capacitor is electrically connected to the emitter of the NPN transistor.

6. The overcurrent protection circuit according to claim 1, characterized in that: The overcurrent protection circuit also includes a second detection module; the second detection module is electrically connected to the sampling module and the control module respectively; the second detection module is used to control the control module to stop working according to the comparison result between the sampling voltage and the voltage threshold.

7. The overcurrent protection circuit according to claim 1, characterized in that: The control module includes a power supply unit and a driving unit; the first detection module is electrically connected to the driving unit through the power supply unit; The power supply unit is used for stopping supplying power to the driving unit when receiving the first level signal; and the driving unit is used for sending a control signal to the motor controller.

8. The overcurrent protection circuit according to claim 1, characterized in that: It also includes a recording module; the recording module is electrically connected to the control module, and the recording module is used to record fault information; wherein the fault information is information that the control module stops sending a control signal.

9. An overcurrent protection method for a motor controller, characterized in that: An overcurrent protection circuit suitable for a motor controller as claimed in any one of claims 1 to 8; The method comprises: Acquiring the sampled voltage; Based on the sampling voltage satisfying the overcurrent protection condition, the control module is controlled to stop sending the control signal to the motor controller.

10. An overcurrent protection method for a motor controller, characterized in that: An overcurrent protection circuit applicable to a motor controller according to any one of claims 1 to 8; the overcurrent protection circuit further comprises a second detection module; the second detection module is electrically connected to the sampling module and the control module respectively; The method comprises: Acquiring the sampled voltage; Based on the comparison result between the sampled voltage and the voltage threshold, the control module is controlled to stop working.

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