High voltage protection method, device, circuit and electric equipment

Abstract

The present invention is applicable to the field of electronic circuit technology, and provides a high-voltage protection method, device, circuit, and electric equipment. The method includes detecting the voltage of the power supply terminal currently used for power supply when the MCU is powered on; judging whether the voltage of the power supply terminal is greater than the target voltage; if so, controlling the motor to brake until the detected voltage of the power supply terminal is less than the target voltage. The present invention determines whether the power supply of the current power supply terminal is the alternating current generated when the motor is running by detecting the voltage of the power supply terminal when the power is powered on. When it is determined that the power supply of the current power supply terminal is the alternating current generated when the motor is running, the motor running speed is reduced by braking control so that the voltage of the alternating current generated when the motor is running can be reduced, thereby solving the problem of existing electric equipment being damaged by high voltage.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic circuits, and in particular relates to a high voltage protection method, device, circuit and electric equipment. Background Art

[0002] With the development of science and technology, more and more electric devices with motors are used by users. The motors used in these electric devices include walking motors, which can be used to realize the walking function of the electric devices.

[0003] The motor shaft gear and the tire shaft gear in the existing normal travel motor are disengaged, and the controller will not generate high voltage when dragging the whole machine. However, some customers use low-cost motors to save costs, and the motor shaft gear and the tire shaft gear in their low-cost motors cannot be disengaged.

[0004] At this time, in electric equipment with a travel motor, such as a snowplow, when the user pushes the electric equipment to travel without connecting the battery pack, the tire rotating shaft gear drives the motor shaft gear to rotate, so that the travel motor will generate AC power. At the same time, the AC power generated is related to the speed of the travel motor. When the speed is faster, the voltage generated on the phase line of the travel motor is higher. When the speed is greater than 7KM / H, high voltage (up to 200V or more) will be generated on the phase line of the travel motor. If there is no protection on the control board, it is easy to cause high voltage breakdown and damage the MOS tube and subsequent devices. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a high voltage protection method, aiming to solve the problem that the existing electric equipment is damaged by high voltage.

[0006] The embodiment of the present invention is implemented as follows: a high voltage protection method, the method comprising:

[0007] When the MCU is powered on, the voltage of the power supply terminal currently used for power supply is detected;

[0008] Determine whether the voltage at the power supply end is greater than the target voltage;

[0009] If so, the motor is controlled to brake until the detected power supply terminal voltage is less than the target voltage.

[0010] Furthermore, the step of controlling the motor to brake until the detected power supply terminal voltage is less than the target voltage includes:

[0011] Determining in real time the duty cycle of braking control of the motor according to the currently detected power supply terminal voltage and the target voltage;

[0012] The motor is controlled to brake according to the duty cycle determined in real time.

[0013] Furthermore, before the step of controlling the motor to brake until the detected power supply terminal voltage is less than the target voltage, the method further includes:

[0014] Controls communication between the lock and the power supply terminal for power supply.

[0015] Another embodiment of the present invention further provides a high voltage protection device, the device comprising:

[0016] The voltage detection unit is used to detect the voltage of the power supply terminal currently used for power supply when the MCU is powered on;

[0017] A voltage judgment unit, used to judge whether the voltage at the power supply end is greater than the target voltage;

[0018] The brake control unit is used to control the motor to brake until the detected power supply terminal voltage is less than the target voltage when the voltage judgment unit judges that the power supply terminal voltage is greater than the target voltage.

[0019] Furthermore, the brake control unit comprises:

[0020] A duty cycle determination module, used to determine in real time the duty cycle of the brake control of the motor according to the currently detected power supply terminal voltage and the target voltage;

[0021] The brake control module is used to control the motor to brake according to the duty cycle determined in real time.

[0022] Furthermore, the device also includes:

[0023] The power lock unit is used to control the connection between the lock and the power supply terminal for power supply.

[0024] Another embodiment of the present invention further provides a high voltage protection circuit, the circuit comprising a switching module, a power module, a high voltage identification module, a controller, a driving module, and a voltage detection module;

[0025] The on-off module is respectively connected to the power supply end, the power supply module, and the high-voltage identification module, and is used to control the on-off state between the power supply end and the power supply module according to the control of the high-voltage identification module;

[0026] The power supply module is connected to the on-off module, the controller, the drive module, and the voltage detection module respectively, and is used to convert the power provided by the power supply end into the working power required for the normal operation of the controller, the drive module, and the voltage detection module when the on-off module is turned on;

[0027] The high-voltage identification module is connected to the power supply terminal and the on-off module respectively, and is used to control the on-off module to conduct the power supply terminal and the power supply module when it is identified that the voltage of the power supply terminal is a high voltage higher than the first voltage threshold;

[0028] The controller is connected to the power supply module, the driving module and the voltage detection module respectively, and is used to output a control signal to the driving module when the voltage detected by the voltage detection module at the power supply end connected to it is greater than the target voltage, so that the driving module drives the motor connected to it to brake until the voltage detected by the voltage detection module is less than the target voltage.

[0029] Furthermore, the circuit further comprises:

[0030] A control module connected to the on-off module and the controller respectively, the control module is used to control the on-off module accordingly according to the control of the controller, so as to control the on-off state between the power supply terminal and the power supply module.

[0031] Furthermore, the circuit further comprises:

[0032] A power switch module is respectively connected to the power supply end and the on-off module, and the power switch module is used to control the on-off module to control the on-off state between the power supply end and the power module.

[0033] Furthermore, the on-off module includes a first field effect transistor, a first resistor, and a first capacitor;

[0034] The first end of the first field effect transistor is respectively connected to the power supply end, one end of the first resistor, and one end of the first capacitor, the second end of the first field effect transistor is respectively connected to the high voltage identification module, the other end of the first resistor and the other end of the second capacitor, and the third end of the first field effect transistor is connected to the power supply module.

[0035] Furthermore, the power module includes:

[0036] A first step-down unit connected to the on-off module and configured to step down the voltage at the power supply end and stabilize the voltage to a first voltage when the on-off module is turned on; and

[0037] A second step-down unit connected to the first step-down unit, used for stepping down the first voltage and stabilizing the first voltage to a second voltage.

[0038] Furthermore, the high voltage identification module includes a first voltage stabilizing diode and a second resistor;

[0039] The anode of the first voltage stabilizing diode is connected to one end of the second resistor, the cathode of the first voltage stabilizing diode is connected to the on-off module, and the other end of the second resistor is grounded.

[0040] Furthermore, the driving module includes a gate driving unit connected to the power module and the controller respectively, an upper bridge arm and a lower bridge arm connected to each of the three-phase ends of the motor correspondingly, and a sampling unit;

[0041] Each of the upper bridge arms is also respectively connected to a power supply terminal and a first output terminal of a corresponding gate driving unit;

[0042] Each of the lower bridge arms is also connected to the second output end of the corresponding gate driving unit and the first end of the sampling unit respectively;

[0043] Each of the three-phase ends of the motor is also respectively connected to the third output end of the corresponding gate driving unit.

[0044] Furthermore, the voltage detection module includes a third resistor, a fourth resistor, a fifth resistor, a second capacitor and a first diode;

[0045] One end of the third resistor is connected to one end of the on-off module and the power module, the other end of the third resistor is respectively connected to one end of the fourth resistor and one end of the fifth resistor, the other end of the fourth resistor and one end of the second capacitor are grounded, the other end of the fifth resistor is respectively connected to the positive electrode of the first diode, the other end of the second capacitor and the controller, and the negative electrode of the first diode is connected to the power module.

[0046] Furthermore, the control module includes a sixth resistor, a seventh resistor, a first transistor, an eighth resistor and a ninth resistor;

[0047] One end of the sixth resistor is connected to one end connected to the on-off module and the high-voltage identification module, the other end of the sixth resistor is connected to one end of the seventh resistor, the other end of the seventh resistor is connected to the first end of the first transistor, the second end of the first transistor is respectively connected to one end of the eighth resistor and one end of the ninth resistor, the third end of the first transistor and the other end of the eighth resistor are grounded, and the other end of the ninth resistor is connected to the controller.

[0048] Another embodiment of the present invention further provides a household appliance, wherein the electric appliance includes the high-voltage protection circuit described above.

[0049] The high-voltage protection method provided by the embodiment of the present invention detects the voltage at the power supply end when power is on, and determines whether the power supplied by the current power supply end is the alternating current generated when the motor is running according to the voltage at the power supply end. When the voltage at the power supply end is greater than the target voltage, it is determined that the power supplied by the current power supply end is the alternating current generated when the motor is driven. Therefore, the motor running speed is reduced through braking control accordingly, so that the voltage of the alternating current generated when the motor is running can be reduced, thereby avoiding the problem that the voltage of the alternating current generated by the motor running too fast is too high and causes damage to the device, thereby solving the problem of existing electric equipment being damaged by high voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a module schematic diagram of a high voltage protection circuit provided by an embodiment of the present invention;

[0051] Figure 2 is a module schematic diagram of a high voltage protection circuit provided by another embodiment of the present invention;

[0052] Figure 3 is a circuit diagram of a controller in a high voltage protection circuit provided by another embodiment of the present invention;

[0053] Figure 4 It is a circuit diagram of a switch module, a high voltage identification module, a voltage detection module, a control module, and a power switch module in a high voltage protection circuit provided by another embodiment of the present invention;

[0054] Figure 5 is a circuit diagram of a power module in a high voltage protection circuit provided by another embodiment of the present invention;

[0055] Figure 6 is a circuit diagram of a driving module in a high voltage protection circuit provided by another embodiment of the present invention;

[0056] Figure 7 is a flow chart of a high voltage protection method provided by an embodiment of the present invention;

[0057] Figure 8 is a flow chart of a high voltage protection method provided by another embodiment of the present invention;

[0058] Fig. 9 is a schematic diagram of a module of a high voltage protection device provided by an embodiment of the present invention;

[0059] Fig.10 It is a module schematic diagram of a high voltage protection device provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0061] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0062] The present invention determines whether the power supplied by the current power supply end is the alternating current generated when the motor is running by detecting the voltage at the power supply end when power is turned on. When it is determined that the power supplied by the current power supply end is the alternating current generated when the motor is running, the motor running speed is reduced through brake control so that the voltage of the alternating current generated when the motor is running can be reduced, thereby solving the problem of existing electric equipment being damaged by high voltage.

[0063] Embodiment 1

[0064] See also Figure 1 , is a module schematic diagram of a high-voltage protection circuit provided in a first embodiment of the invention. For ease of description, only the parts related to the embodiment of the invention are shown. The high-voltage protection circuit provided in the embodiment of the invention includes:

[0065] A switching module 20, a power module 30, a high voltage identification module 40, a controller 50, a driving module 60, and a voltage detection module 70;

[0066] The on-off module 20 is respectively connected to the power supply terminal 10, the power supply module 30, and the high-voltage identification module 40, and is used to control the on-off state between the power supply terminal 10 and the power supply module 30 according to the control of the high-voltage identification module 40;

[0067] The power supply module 30 is respectively connected to the on-off module 20, the controller 50, the drive module 60, and the voltage detection module 70, and is used to convert the power provided by the power supply end 10 into the working power required for the normal operation of the controller 50, the drive module 60, and the voltage detection module 70 when the on-off module 20 is turned on;

[0068] The high voltage identification module 40 is connected to the power supply terminal 10 and the on-off module 20 respectively, and is used to control the on-off module 20 to conduct the power supply terminal 10 and the power supply module 30 when it is identified that the voltage of the power supply terminal 10 is a high voltage higher than the first voltage threshold;

[0069] Among them, the controller 50 is respectively connected to the power module 30, the driving module 60 and the voltage detection module 70, and is used to output a control signal to the driving module 60 when the voltage of the power supply terminal 10 connected to it detected by the voltage detection module 70 is greater than the target voltage, so that the driving module 60 drives the motor 80 connected to it to brake until the voltage detected by the voltage detection module 70 is less than the target voltage.

[0070] Furthermore, the driving module 60 is respectively connected to the power supply terminal 10, the power supply module 30, the controller 50, and the motor 80, and is used to drive the operating state of the motor 80 accordingly according to the control of the controller 50, and to generate alternating current to the power supply terminal 10 when the motor 80 runs without the control of the controller 50.

[0071] In one embodiment of the invention, the high-voltage protection device is applied to an electric device using a walking motor, wherein, in this embodiment, the walking motor used in the electric device is a low-cost motor, and its motor shaft gear and the tire rotating shaft gear cannot be disengaged. Therefore, when the electric device is pushed by the user to walk in a non-working environment, its tire rotating shaft gear drives the motor shaft gear to rotate, thereby causing the walking motor to rotate and generate alternating current.

[0072] Furthermore, the power source used in the electric device is usually a lithium battery pack. For example, in the present embodiment, the power supply voltage provided by the lithium battery pack is 50V-84V. When the electric device is in use, the lithium battery pack is connected to the power supply terminal 10. It can be understood that in other embodiments of the invention, the power supply may also adopt other power supply devices, and the voltage range provided by the lithium battery pack may also be other. When selecting, it only needs to not exceed the maximum voltage that the electric device can bear. It is set according to actual use requirements and is not limited here.

[0073] Furthermore, since the walking motor generates alternating current when it is pushed to walk, and the alternating current flows to the power supply terminal 10 through the driving module 60, the power provided by the power supply terminal 10 can be powered by a connected lithium battery pack or other power source, or it can be the alternating current generated when the walking motor is running.

[0074] Furthermore, in one embodiment of the invention, the on-off module 20 is a switch-type device that controls the on-off state between the power supply terminal 10 and the power supply module 30. In this embodiment, the on-off module 20 is controlled by the high-voltage identification module 40. When the high-voltage identification module 40 outputs a control signal to the on-off module 20, the on-off module 20 controls the conduction between the power supply terminal 10 and the power supply module 30.

[0075] Further, in one embodiment of the invention, the power module 30 converts the power provided by the power supply terminal 10 into the working power required for the normal operation of the subsequent devices. For example, in this embodiment, it can step down the power supply voltage to 12V to provide the working power for the drive module 60; it can stabilize the converted 12V voltage to 3.3V to provide the working power for the controller 50 and the voltage detection module 70. It can be understood that in other embodiments of the invention, the voltage converted by the power module 30 can also be other values, which are set according to the working power required by the controller 50, the drive module 60 and the voltage detection module 70 actually used, and are not limited here.

[0076] Furthermore, in one embodiment of the invention, the high-voltage identification module 40 is used to identify the voltage of the power supply terminal 10. When the voltage of the power supply terminal 10 is greater than the first voltage threshold, the corresponding control on-off module 20 is used to conduct the power supply terminal 10 with the power module 30. It should be noted that the first voltage threshold is greater than the power supply voltage when the power supply terminal 10 is normally powered, and is less than the maximum voltage that the electric device can bear. For example, the maximum load voltage that the electric device protected by the invention can bear is 110V. When the voltage of the power supply terminal 10 is greater than 110V, it will cause damage to the MOS tube and subsequent devices in the control board of the electric device; and when the power supply adopts a lithium battery pack, the voltage range of the lithium battery pack is 50V-84V; therefore, in this embodiment, the first voltage threshold is greater than 84V and less than 110V. In this embodiment, it is specifically set to 91V. At this time, its high-voltage identification module 40 can identify whether the voltage of the power supply terminal 10 is greater than 91V. When it is identified that it is greater than 91V, it can be determined that it is not only powered by a lithium battery pack, but may be powered by the high-voltage alternating current generated by the running of the walking motor 80, or a high-voltage power supply combined with a lithium battery pack. At the same time, in this embodiment, the first voltage threshold is set to 91V, and there is a certain voltage margin between it and the maximum voltage 110V that the electric device can bear. It can make high-voltage protection when it is identified that the alternating current generated by the running of the walking motor 80 is greater than 91V, so as to avoid the first voltage threshold and the maximum load voltage being too close, and the AC voltage generated by the motor 80 increasing too fast, causing a direct breakthrough of the maximum load voltage that the electric device can bear, and causing high-voltage damage to the components in the electric device. Among them, it can be understood that in other embodiments of the invention, the first voltage threshold identified by its high-voltage identification module 40 can be set according to the actual use environment, and is not limited here.

[0077] Furthermore, in one embodiment of the invention, the controller 50 is used to control the power supply terminal 10 to be connected to the power supply module 30 when the on-off module 20 controls the power supply terminal 10 to be connected, so that when the power supply module 30 performs power conversion and voltage stabilization and performs power-on operation, obtain the voltage of the power supply terminal 10 detected by the voltage detection module 70 connected thereto, and determine whether the voltage obtained is greater than the target voltage. When it is determined that the voltage obtained is greater than the target voltage, a control signal is output to the drive module 60 connected thereto, so that the drive module 60 drives the motor 80 to brake. At the same time, the controller 50 also obtains the voltage detected by the voltage detection module 70 in real time. Among them, in this embodiment, when the controller 50 is powered on, it has normal power supply provided by power sources such as lithium battery packs, and also has AC power supply generated by the operation of the walking motor 80. Therefore, in order to avoid the damage to the electric equipment caused by excessive AC voltage generated by the operation of the walking motor 80, the controller 50 detects the voltage of the power supply terminal 10 through the voltage detection module 70 connected thereto. In this embodiment, the target voltage can be set to be not less than the maximum voltage of the lithium battery pack, for example, the target voltage is set to the first voltage threshold 91V. When its voltage is greater than the target voltage, it is determined that there is AC power supply generated by the operation of the walking motor 80. At this time, the damage to the electric tool caused by the high voltage generated when the user pushes the walking motor 80 to walk at high speed is avoided. The controller 50 controls the driving module 60 to brake the control motor 80. After the motor 80 is braked, its speed gradually slows down. The slower the speed of the walking motor 80, the smaller the AC voltage it generates. Therefore, the high voltage damage that the electric equipment may suffer can be avoided. It can be understood that in other embodiments of the invention, the target voltage corresponding to the controller 50 can be set according to the actual use environment, which is not limited here. In this embodiment, the controller 50 can be a single-chip microcomputer, DSP (Digital Signal Processing) or other controller 50 with the function of controlling and processing signals, which is set according to the actual use requirements of the user, which is not limited here.

[0078] Furthermore, in one embodiment of the invention, the motor 80 is a low-cost walking motor, and the motor shaft gear and the tire rotating shaft gear cannot be disengaged. Therefore, when the electric device is pushed by the user to walk in a non-working environment, the tire rotating shaft gear drives the motor shaft gear to rotate, thereby causing the motor 80 to rotate and generate AC power. Furthermore, the motor 80 can be a three-phase brushless motor or a two-phase brushed motor, which is set according to the actual use needs of the user and is not limited here.

[0079] Among them, the electric device using the high-voltage protection circuit is in a non-working state, and when the user pushes the electric device to walk in a non-working environment, the tire rotating shaft gear drives the motor 80 shaft gear to rotate, so that the walking motor 80 rotates to generate alternating current. Among them, the user pushes the electric device to make the walking motor 80 rotate faster, and the higher the alternating current it generates. Therefore, when the voltage of the alternating current connected to the power supply terminal 10 is higher than the first voltage threshold, its high-voltage identification module 40 correspondingly controls the on-off module 20, so that the power supply terminal 10 is connected to the power supply module 30. At this time, the power supply module 30 works to convert the high voltage electricity of the power supply terminal 10 and provide it to the controller 50, the drive module 60 and the voltage detection module 70. The voltage detection module 70 detects the voltage of the power supply terminal 10 connected to it and outputs it to the controller. The controller 50 obtains the voltage detected by the voltage detection module 70, and when it is determined that the voltage is greater than the target voltage, in order to prevent the user from continuing to push the electric device too fast and causing the generated AC voltage to be greater than the maximum load voltage that the electric device can bear, causing damage to the control board in the electric device, the controller 50 outputs a control signal to the drive module 60, so that the drive module 60 controls the motor 80 to brake. At this time, when the motor 80 slows down after braking, the voltage of the corresponding AC power generated begins to decrease. When it decreases to less than the first voltage threshold, the corresponding high-voltage identification module 40 disconnects the power supply terminal 10 from the on-off module 20. At this time, the power module 30 loses power, and the controller 50, the drive module 60, and the voltage detection module 70 stop working. At this time, the electric device moves slowly until it stops. If the user continues to push the electric device, the corresponding steps refer to the above steps, which will not be repeated here.

[0080] In this embodiment, the high-voltage identification module is set up to identify high-voltage AC power higher than the normal power supply. When the high-voltage identification module identifies the high voltage, the on-off module is controlled to be turned on, so that the power at the power supply end can be transmitted to the subsequent device, so that the controller, the drive module and the voltage detection module can start working. The voltage detection module is set up to detect the voltage at the power supply end. The controller is set up to determine whether the current power supply is normal power supply or AC power generated when the motor is running according to the voltage detected by the voltage detection module. When the controller obtains that the voltage detected by the voltage detection module is greater than the target voltage, it is determined that the power supply end is the AC power generated by the motor, and the drive module is controlled to brake the motor until the voltage at the power supply end is less than the target voltage. At this time, after the motor is braked, the speed is reduced, and the voltage of the AC power generated accordingly is also reduced accordingly, so that the problem of excessive voltage of the AC power generated due to excessive running of the motor to damage the device can be avoided, and the problem of existing electric equipment being damaged by high voltage is solved.

[0081] Embodiment 2

[0082] See also Figure 2 , is a schematic diagram of a module of a high voltage protection circuit provided by the second embodiment of the invention. The structure of the second embodiment is substantially the same as that of the first embodiment, except that, in the present embodiment, the high voltage protection circuit further includes:

[0083] A control module 90 connected to the on-off module 20 and the controller 50 respectively, the control module 90 is used to control the on-off module 20 accordingly according to the control of the controller 50, so as to control the on-off state between the power supply terminal 10 and the power supply module 30; and

[0084] The power switch module 100 is connected to the power terminal 10 and the on-off module 20 respectively. The power switch module 100 is used to control the on-off module 20 to control the on-off state between the power terminal 10 and the power module 30 .

[0085] Furthermore, in one embodiment of the invention, the power module 30 includes:

[0086] A first voltage reduction unit 31 connected to the on-off module 20 and configured to reduce the voltage of the power supply terminal 10 and stabilize the voltage to a first voltage when the on-off module 20 is turned on; and

[0087] A second step-down unit 32 connected to the first step-down unit 31 is used to step down the first voltage and stabilize the first voltage to a second voltage.

[0088] For specific implementation, see Figure 3-Figure 6 As shown, in one embodiment of the invention, Figure 4 As shown, the on-off module 20 includes a first field effect transistor Q1, a first resistor R1, and a first capacitor C1;

[0089] The first end of the first field effect transistor Q1 is respectively connected to the power supply terminal 10, one end of the first resistor R1, and one end of the first capacitor C1, the second end of the first field effect transistor Q1 is respectively connected to the high voltage identification module 40, the other end of the first resistor R1, the other end of the first capacitor C1, and the control module 90, and the third end of the first field effect transistor Q1 is connected to the power module 30. In this embodiment, the first field effect transistor Q1 is an NMOS transistor, the first end of the first field effect transistor Q1 is a source, the second end is a gate, and the third end is a drain.

[0090] Furthermore, in one embodiment of the invention, the high voltage identification module 40 includes a first voltage stabilizing diode Z1 and a second resistor R2;

[0091] The positive electrode of the first voltage zener diode Z1 is connected to one end of the second resistor R2, the negative electrode of the first voltage zener diode Z1 is connected to the on-off module 20, and the other end of the second resistor R2 is grounded. In this embodiment, the negative electrode of the first voltage zener diode Z1 is connected to the gate of the first field effect transistor Q1 in the on-off module 20, and the first voltage zener diode Z1 specifically adopts the SMAJ4763A / 91V voltage zener diode model, and its stable voltage is 91V. When the voltage exceeds 91V, the first voltage zener diode Z1 breaks down and conducts. It can be understood that in other embodiments of the invention, the model and voltage stabilization value of the first voltage zener diode Z1 can be set to other according to actual use conditions, and are not limited here.

[0092] Further, in one embodiment of the invention, the voltage detection module 70 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, a second capacitor C2 and a first diode D1;

[0093] Among them, one end of the third resistor R3 is connected to one end VBUS connected to the on-off module 20 and the power module 30, the other end of the third resistor R3 is respectively connected to one end of the fourth resistor R4 and one end of the fifth resistor R5, the other end of the fourth resistor R4 is grounded to one end of the second capacitor C2, the other end of the fifth resistor R5 is respectively connected to the positive electrode of the first diode D1, the other end of the second capacitor C2 and the Vbus_AD3 pin in the controller 50, and the cathode of the first diode D1 is connected to the power module 30. Specifically, the first diode D1 adopts a high-speed switching diode, the specific model is 1N4148, and the cathode of the first diode D1 is connected to the second buck unit 32 in the power module 30.

[0094] Further, in one embodiment of the invention, the control module 90 includes a sixth resistor R6, a seventh resistor R7, a first transistor Q2, an eighth resistor R8 and a ninth resistor R9;

[0095] Among them, one end of the sixth resistor R6 is connected to one end (i.e., the gate of the first field effect transistor Q1) connected to the on-off module 20 and the high-voltage identification module 40, the other end of the sixth resistor R6 is connected to one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected to the first end of the first transistor Q2, the second end of the first transistor Q2 is respectively connected to one end of the eighth resistor R8 and one end of the ninth resistor R9, the third end of the first transistor Q2 and the other end of the eighth resistor R8 are grounded, and the other end of the ninth resistor R9 is connected to the MCU_PRON pin in the controller 50. Among them, in this embodiment, the first transistor Q2 is an NPN transistor, and the first end of the first transistor Q2 is a collector, the second end is a base, and the third end is an emitter.

[0096] Further, in one embodiment of the invention, the power switch module 100 includes a second voltage zener diode Z2, a tenth resistor R10, a third voltage zener diode Z3, an eleventh resistor R11, and a power switch KEY_SW;

[0097] Among them, the cathode of the second voltage zener diode Z2 is connected to the power supply terminal 10, the anode of the second voltage zener diode Z2 is respectively connected to the gate of the first field effect transistor Q1 in the on-off module 20 and one end of the tenth resistor R10, the other end of the tenth resistor R10 is connected to the anode of the third voltage zener diode Z3, the cathode of the third voltage zener diode Z3 is connected to one end of the eleventh resistor R11, the other end of the eleventh resistor R11 is connected to one end of the power switch KEY_SW, and the other end of the power switch KEY_SW is grounded.

[0098] Further, in one embodiment of the invention, Figure 5 As shown, the first step-down unit 31 in the power module 30 includes: a twelfth resistor R12, a fourth voltage-stabilizing diode Z4, a first electrolytic capacitor EC1, a third capacitor C3, a second field effect transistor Q3, a thirteenth resistor R13, a fourth capacitor C4, a fourteenth resistor R14, a fifteenth resistor R15, a second diode D2, a sixteenth resistor R16, a fifth capacitor C5, a first inductor L1, a seventeenth resistor R17, a sixth capacitor C6, an eighteenth resistor R18, a second electrolytic capacitor EC2, a seventh capacitor C7, an eighth capacitor C8, and a nineteenth resistor R1 9, the 20th resistor R20, the 21st resistor R21, the voltage regulator U1, the 9th capacitor C9, the optocoupler U2, the 10th capacitor C10, the 22nd resistor R22, the 23rd resistor R23, the 11th capacitor C11, the 12th capacitor C12, the 24th resistor R24, the 25th resistor R25, the power chip U3, the 13th capacitor C13, the 26th resistor R26, the 27th resistor R27, the 14th capacitor C14, the third electrolytic capacitor EC3, the 28th resistor R28, the 29th resistor R29, and the third diode D3.

[0099] Among them, one end of the twelfth resistor R12 is connected to one end VBUS (that is, the drain of the first field effect transistor Q1) connected to the on-off module 20; the other end of the twelfth resistor R12 is respectively connected to the cathode of the fourth voltage-stabilizing diode Z4, the anode of the first electrolytic capacitor EC1, one end of the third capacitor C3, the drain of the second field effect transistor Q3, one end of the twenty-sixth resistor R26, and one end of the twenty-seventh resistor R27; the anode of the fourth voltage-stabilizing diode Z4, the cathode of the first electrolytic capacitor EC1, and the other end of the third capacitor C3 are all grounded; the gate of the second field effect transistor Q3 is respectively connected to one end of the thirteenth resistor R13, one end of the fourth capacitor C4, and one end of the fourteenth resistor R14; the source of the second field effect transistor Q3 is respectively connected to the other end of the fourth capacitor C4, the fourteenth resistor The other end of R14, one end of the fifteenth resistor R15 and one end of the twenty-third resistor R23 are connected; the other end of the thirteenth resistor R13 is connected to the GATE pin of the power chip U3; the other end of the fifteenth resistor R15 is respectively connected to the cathode of the second diode D2, one end of the sixteenth resistor R16, and one end of the first inductor L1; the anode of the second diode D2 is grounded; the other end of the sixteenth resistor R16 is connected to one end of the fifth capacitor C5; the other end of the fifth capacitor C5 is grounded; the other end of the first inductor L1 is respectively connected to one end of the seventeenth resistor R17, one end of the eighteenth resistor R18, the anode of the second electrolytic capacitor EC2, one end of the seventh capacitor C7, one end of the eighth capacitor C8, one end of the nineteenth resistor R19, one end of the twentieth resistor R20, and the third diode D3 The positive electrode of the seventeenth resistor R17 is connected; the other end of the seventeenth resistor R17 is connected to one end of the sixth capacitor C6; the other end of the sixth capacitor C6, the other end of the eighteenth resistor R18, the negative electrode of the second electrolytic capacitor EC2, the other end of the seventh capacitor C7, and the other end of the eighth capacitor C8 are all grounded; the other end of the nineteenth resistor R19 is respectively connected to one end of the twenty-first resistor R21 and the reference electrode G of the voltage-stabilizing source U1; the other end of the twentieth resistor R20 is connected to the anode pin 1 of the optical coupler U2; the other end of the twenty-first resistor R21 and the anode of the voltage-stabilizing source U1 are grounded; the cathode of the voltage-stabilizing source U1 is connected to the cathode pin 2 of the optical coupler U2 and one end of the ninth capacitor C9; the other end of the ninth capacitor C9 is grounded; the emission pin 3 of the optical coupler U2 is respectively connected to one end of the tenth capacitor C10, the twenty-second resistor R22 and the The first end, the first end, the second end, the eleventh capacitor C11, the first end, the twelfth capacitor C12, the first end, the thirteenth capacitor C13, the first end, the fourteenth capacitor C14, the negative electrode of the third electrolytic capacitor EC3, the GND pin of the power chip U3, and the fifteenth resistor R15 are connected to the first inductor L1; the collector pin 4 of the optocoupler U2 is respectively connected to the other end of the tenth capacitor C10 and the COMP pin of the power chip U3; the VFB pin of the power chip U3 is connected to the other end of the twenty-second resistor R22; the SENSE pin of the power chip U3 is respectively connected to the other end of the twenty-third resistor R23 and one end of the twenty-fourth resistor R24; the RT / CT pin of the power chip U3 is respectively connected to the other end of the twelfth capacitor C12 and one end of the twenty-fifth resistor R25;The VREF pin of the power chip U3 is respectively connected to the other end of the twelfth resistor, the other end of the twenty-fifth resistor R25, and the other end of the thirteenth capacitor C13; the VI pin of the power chip U3 is respectively connected to the other end of the fourteenth capacitor C14, the other end of the twenty-sixth resistor, the other end of the twenty-seventh resistor R27, one end of the twenty-eighth resistor R28, one end of the twenty-ninth resistor, and the positive electrode of the third electrolytic capacitor EC3; the other end of the twenty-eighth resistor R28 and the other end of the twenty-ninth resistor are connected to the cathode of the third diode D3. Among them, one end of the first inductor L1 connected to the nineteenth resistor R19, the twentieth resistor R20 and the third diode D3 is the output end of the first buck unit 31, which finally bucks any voltage input from the power supply terminal 10 to the first voltage for output. In this embodiment, the first voltage is 12V, which can be used to provide power for the driving module 60. It can be understood that in other embodiments of the invention, the first buck unit 31 can also adopt other circuit structures and buck to other voltages. It is set according to actual use requirements and is not limited here. ;

[0100] Further, in one embodiment of the invention, Figure 5 As shown, the second step-down unit 32 in the power module 30 includes: a 30th resistor R30, a 31st resistor R31, a 15th capacitor C15, a regulator U4, a 16th capacitor C16, and a 17th capacitor C17.

[0101] Among them, one end of the 30th resistor R30 and one end of the 31st resistor R31 are connected to the output end of the first step-down unit 31, the other end of the 30th resistor R30 and the other end of the 31st resistor R31 are connected to the input end I of the voltage regulator U4 and one end of the fifteenth capacitor C15, the ground terminal G of the voltage regulator U4 is respectively connected to the other end of the fifteenth capacitor C15, one end of the sixteenth capacitor C16, and one end of the seventeenth capacitor C17, and the output end O of the voltage regulator U4 is respectively connected to the other end of the sixteenth capacitor C16 and the other end of the seventeenth capacitor C17, wherein the output end O of the voltage regulator U4 is the output end of the second step-down unit 32, which outputs the second voltage from the output end of the first step-down unit 31. In this embodiment, the second voltage is 3.3V, which can be used to provide working power for the controller 50 and the voltage detection module 70. It can be understood that in other embodiments of the invention, the second step-down unit 32 can also adopt other circuit structures and stabilize to other voltage sizes. It is set according to actual usage requirements and is not limited here.

[0102] Further, in one embodiment of the invention, Figure 6As shown, the driving module 60 includes a gate driving unit 61 respectively connected to the power module 30 and the controller 50, an upper bridge arm 62 and a lower bridge arm 63 corresponding to each end of the three-phase end of the motor 80, and a sampling unit 64; wherein, in this embodiment, the motor 80 uses a three-phase brushless motor, and therefore, correspondingly in this embodiment, the driving module 60 is a module used to drive the three-phase brushless motor, and it can be understood that in other embodiments of the present invention, when the motor 80 uses a two-phase brushed motor, the driving module 60 is a module used to drive the two-phase brushed motor.

[0103] Each upper bridge arm 62 is also connected to the power supply terminal 10 and the first output terminal of the corresponding gate driving unit 61 respectively;

[0104] Each lower bridge arm 63 is also connected to the second output terminal of the corresponding gate driving unit 61 and the first terminal of the sampling unit 64 respectively;

[0105] Each of the three-phase terminals of the motor 80 is also connected to the third output terminal of the corresponding gate driving unit 61 .

[0106] When implementing it, Figure 6 As shown, the number of the gate driving unit 61, the upper bridge arm 62, and the lower bridge arm 63 are all three, wherein the gate driving unit 61, the upper bridge arm 62, and the lower bridge arm 63 on one phase terminal Drive A among the three-phase terminals are taken as an example.

[0107] The gate driving unit 61 includes a half-bridge driving chip U5, a thirty-second resistor R32, a thirty-third resistor R33, an eighteenth capacitor C18, a fourth diode D4, and a fourth electrolytic capacitor EC4. Among them, the VCC pin of the half-bridge driver chip U5 is connected to one end of the eighteenth capacitor C18, the positive electrode of the fourth diode D4, and the output end of the first buck unit 31, the other end of the eighteenth capacitor C18 is grounded, the HIN pin of the half-bridge driver chip U5 is connected to one end of the thirty-second resistor R32, the other end of the thirty-second resistor R32 is connected to the AH3 pin of the controller 50, the LIN pin of the half-bridge driver chip U5 is connected to one end of the thirty-third resistor R33, the other end of the thirty-third resistor R33 is connected to the AL3 pin of the controller 50, the COM pin of the half-bridge driver chip U5 is grounded, the VB pin of the half-bridge driver chip U5 is respectively connected to the negative electrode of the fourth diode D4 and the positive electrode of the fourth electrolytic capacitor EC4, the VS pin (third output end) of the half-bridge driver chip U5 is respectively connected to the negative electrode of the fourth electrolytic capacitor EC4, and one phase end Drive of the three-phase ends of the motor 80 A is connected, the HO pin (first output end) of the half-bridge driver chip U5 is connected to the upper bridge arm 62, and the LO pin (second output end) of the half-bridge driver chip U5 is connected to the lower bridge arm 63.

[0108] The upper bridge arm 62 includes an upper bridge driving MOS tube Q4, a thirty-fourth resistor R34, a thirty-fifth resistor R35, a fifth diode D5, a nineteenth capacitor C19, a thirty-sixth resistor R36, a fifth Zener diode Z5, a sixth Zener diode Z6, a twentieth capacitor C20, and a twenty-first capacitor C21. Among them, one end of the thirty-fourth resistor R34 is connected to the HO pin of the half-bridge driver chip U5; the other end of the thirty-fourth resistor R34 is connected to the cathode of the fifth diode D5 and one end of the thirty-fifth resistor R35; the anode of the fifth diode D5 and the other end of the thirty-fifth resistor R35 are connected to one end of the nineteenth capacitor C19, one end of the thirty-sixth resistor R36, the cathode of the fifth voltage-stabilizing diode Z5, and the gate of the upper bridge driver MOS tube Q4; the anode of the fifth voltage-stabilizing diode Z5 is connected to the anode of the sixth voltage-stabilizing diode Z6; the other end of the nineteenth capacitor C19, the other end of the thirty-sixth resistor R36, the cathode of the sixth voltage-stabilizing diode Z6, and the source of the upper bridge driver MOS tube Q4 are connected to the VS pin of the half-bridge driver chip U5 and one of the three-phase ends of the motor 80. A is connected; the drain of the upper bridge driving MOS tube Q4 is connected to one end of the twentieth capacitor C20, one end of the twenty-first capacitor C21, and the power supply terminal 10; the other end of the twentieth capacitor C20 and the other end of the twenty-first capacitor C21 are connected to one end of the sampling unit 64.

[0109] The lower bridge arm 63 includes a lower bridge driving MOS transistor Q5, a thirty-seventh resistor R37, a thirty-eighth resistor R38, a sixth diode D6, a twenty-second capacitor C22, a thirty-ninth resistor R39, and a fortieth resistor R40. Among them, one end of the thirty-seventh resistor R37 is connected to the LO pin of the half-bridge driving chip U5; the other end of the thirty-seventh resistor R37 is connected to one end of the thirty-eighth resistor R38 and the cathode of the sixth diode D6; the other end of the thirty-eighth resistor R38 and the anode of the sixth diode D6 are connected to one end of the twenty-second capacitor C22, one end of the thirty-ninth resistor R39, and the gate of the lower bridge driving MOS transistor Q5; the drain of the lower bridge driving MOS transistor Q5 is connected to one end of the fortieth resistor R40, the VS pin of the half-bridge driving chip U5, and one phase end Drive A of the three-phase ends of the motor 80, and the other end of the twenty-second capacitor C22, the other end of the thirty-ninth resistor R39, the other end of the fortieth resistor R40, and the source of the lower bridge driving MOS transistor Q5 are connected to one end of the sampling unit 64.

[0110] Correspondingly, the gate drive unit 61, the upper bridge arm 62, and the lower bridge arm 63 in the other two phase ends (Drive B, Drive C) of the three-phase end refer to the above description, and the numbers of the components in the gate drive unit 61, the upper bridge arm 62, and the lower bridge arm 63 are as follows: Figure 6 The above is not repeated here.

[0111] Furthermore, the sampling unit 64 includes a sampling resistor R59, one end of which is connected to the source of the lower bridge driving MOS tube Q5 in each of the three-phase ends, and the other end of which is grounded.

[0112] Further, the circuit diagram of the controller 50 is shown in FIG. Figure 3 As shown, no further description is given here.

[0113] In normal use, such as Figure 4 As shown, the power supply terminal 10 is connected to the positive electrode Bat+ of the lithium battery pack, and the negative electrode Bat- of the lithium battery pack is grounded. When the user needs to start the electric device using the high-voltage protection circuit, the user starts the power switch KEY_SW in the power switch module 100, that is, the power switch KEY_SW is closed and turned on. At this time, the power provided by the lithium battery pack is grounded through the first resistor R1, the tenth resistor R10, the third voltage stabilizing diode Z3, the eleventh resistor R11, and the power switch KEY_SW. At this time, after the voltage is divided at both ends of the first resistor R1, the on-state voltage between the source and the gate of the on-off module 20 is turned on, so that the on-off module 20 is turned on. Therefore, the power supply of the lithium battery pack provided by the power supply terminal 10 is provided to the power module 30 to generate a 12V working voltage of the driving module 60, and a 3.3V working voltage of the controller 50 and the voltage detection module 70. At this time, the controller 50 starts working after being powered on, and it can control the working state of the driving module 60 accordingly. At the same time, its voltage detection module 70 starts working after being powered on to obtain the voltage of the power supply terminal 10. It should be pointed out at this time that the voltage detection point detected by its voltage detection module 70 is located at the end VBUS connected to the on-off module 20 and the power supply module 30, which is used to reduce power consumption and avoid the power consumption problem caused by the power supply detection module 70 detecting the voltage of the power supply terminal 10 in real time when the voltage detection point is set at the power supply terminal 10. At this time, when the on-off module 20 is turned on to make the power supply module 30 work, its voltage detection module 70 detects the voltage of the power supply terminal 10. At this time, since the voltage detected by the voltage detection module 70 is the working range voltage of the lithium battery pack, it is less than the target voltage. At this time, the controller 50 can correspondingly determine that it is currently in the lithium battery pack power supply state. The controller 50 is used to determine whether the current operation is normal due to power supply from the lithium battery pack or abnormal operation due to the high-voltage alternating current generated by the motor 80 based on the voltage at the power supply terminal 10 detected by the voltage detection module 70. The high-voltage alternating current generated by the motor 80 may damage the control board, so high-voltage protection is required.

[0114] When the power supply terminal 10 is not connected to the lithium battery pack, the electric device using the high-voltage protection circuit is in an inoperative state, and when the user pushes the electric device to walk at this time, the walking motor 80 runs to generate AC power to the power supply terminal 10. When the voltage of the power supply terminal 10 is higher than the first voltage threshold, that is, the user pushes the electric device too fast and the generated voltage is greater than 91V, the first voltage regulator diode Z1 in the high-voltage identification module 40 breaks down and turns on, so the current of the power supply terminal 10 passes through the first resistor R1, the first voltage regulator diode Z1, and the second resistor R2 and then grounded. At this time, after the voltage is divided at both ends of the first resistor R1, there is a conduction voltage between the source and the gate of the on-off module 20 to make it turn on, so that the on-off module 20 is turned on, and accordingly, the power supply module 30 works and converts the AC power into 12V and 3.3V power supply. After the controller 50 and the voltage detection module 70 are powered on, the controller 50 obtains When the voltage detected by the voltage detection module 70 is greater than the target voltage, the controller 50 sends a control signal to the control module 90, that is, the controller 50 outputs a high level to the control module 90 from the MCU_PRON pin. At this time, the base level of the corresponding first transistor Q2 is high, and it realizes the conduction condition, so the first transistor Q2 is turned on. At this time, the power supply of the power supply terminal 10 is grounded after passing through the first resistor R1, the sixth resistor R6, the seventh resistor R7, and the first transistor Q2. Therefore, the control module 90 takes over the control of the on-off module 20. At this time, even when the voltage of the power supply terminal 10 is less than the first voltage threshold, it can still control the on-off module 20 to be turned on, which avoids the problem that when the power supply terminal 10 is protected from high voltage, whenever the voltage of the power supply terminal 10 is less than the first voltage threshold, the first voltage regulator diode Z1 in the high-voltage identification module 40 is not turned on, which causes the on-off module 20 to be disconnected and affects the subsequent work of the controller 50.

[0115] Furthermore, when the controller 50 obtains that the voltage detected by the voltage detection module 70 is greater than the target voltage, it sends a control signal to the drive module 60 so that the drive module 60 controls the motor 80 to brake. At this time, when the braking speed of the motor 80 is reduced, the voltage of the AC power generated by it is also reduced accordingly. At this time, high-voltage protection can be achieved to avoid the problem of high voltage causing damage to the electric device due to the user pushing the electric device to make the motor 80 rotate too fast. At the same time, since there is a certain voltage margin between the first voltage threshold setting and the maximum load voltage that the control board in the electric device can bear, when the high-voltage identification module 40 drives the on-off module 20 to turn on, its controller 50 controls the braking to avoid direct damage to the electric device due to the AC voltage rising too fast due to the fast rotation speed of the motor 80, and the voltage difference between the first voltage threshold and the maximum load voltage is small.

[0116] Furthermore, due to the setting of the control module 90, the controller 50 can drive the control module 90 to lock the conduction of the on-off module 20. Therefore, even if the voltage of the AC power generated by its motor 80 is less than the first voltage threshold during braking, its on-off module 20 is still in the on state. At this time, its control module 90 can output a control signal to the drive module 60 so that the drive module 60 controls the motor 80 to brake until it stops. At this time, the motor 80 no longer generates AC power, and the on-off module 20 disconnects the connection between the power supply terminal 10 and the power supply module 30, and the controller 50, the drive module 60, and the voltage detection module 70 lose power and stop working.

[0117] Further, when the power supply terminal 10 is connected to a lithium battery pack but the power switch module 100 is not turned on, the electric device using the high-voltage protection circuit is in an inoperative state. When the user pushes the electric device to walk without this, the control process refers to the above description. At this time, in the process of the controller 50 controlling the drive module 60 to brake the motor 80, when the brake is performed to the voltage detected by the acquired voltage detection module 70 to maintain a stable state, it is determined that the power supply terminal 10 is connected to a lithium battery pack. At this time, the controller 50 outputs a control signal to the control module 90, that is, the controller 50 outputs a low level through the MCU_PRON pin, so that the control module 90 controls the on-off module 20 to disconnect the connection between the power supply terminal 10 and the power module 30. At this time, the controller 50, the drive module 60 and the voltage detection module 70 are powered off and stop working, thereby avoiding the power consumption problem caused by the controller 50 and other devices still being in a working state after the motor 80 stops running due to the fact that the lithium battery pack is connected to the power supply terminal 10 and the controller 50 locks the connection between the power supply terminal 10 and the power module 30 due to the drive control module 90.

[0118] In this embodiment, due to the power switch module provided, when the power supply end is connected to a lithium battery pack, the switch state of the electric device can be controlled; due to the high-voltage identification module provided, when a high voltage higher than the first voltage threshold is identified, the on-off module is controlled to be turned on, so that the power at the power supply end can be transmitted to the subsequent device, so that the controller, the drive module and the voltage detection module start working; due to the voltage detection module provided, the voltage at the power supply end can be detected; due to the controller provided, it can be determined whether the current power supply is normal power supply or AC power generated when the motor is running according to the voltage detected by the voltage detection module; when the controller obtains that the voltage detected by the voltage detection module is greater than the target voltage, the drive module is controlled to brake the motor until the voltage at the power supply end is less than the target voltage; at the same time, due to the control module provided, when the controller obtains that the voltage at the power supply end is greater than the target voltage, the connected state of the on-off module can be locked and controlled, so as to avoid the on-off module controlled by the high-voltage identification module from being disconnected when the voltage at the power supply end is less than the first voltage threshold due to braking; at this time, the controller can control the drive module until the motor stops by braking, thereby solving the problem of the existing electric device being damaged by high voltage.

[0119] Embodiment 3

[0120] See also Figure 7 , is a flow chart of a high voltage protection method provided by a third embodiment of the present invention. For ease of description, only the part related to the embodiment of the present invention is shown. The high voltage protection method includes:

[0121] Step S10, when the MCU is powered on, detecting the voltage of the power supply terminal currently used for power supply;

[0122] Among them, in an embodiment of the present invention, the high-voltage protection method is applied to a controller in an electric device with a travel motor, and the high-voltage protection method realizes the function of eliminating and protecting the high voltage electricity generated when the motor is running by adopting the high-voltage protection circuit described in any one of the above-mentioned embodiments one or two.

[0123] Specifically, as described in the aforementioned circuit embodiment, the motor equipped in the electric device used in the present method is a low-cost walking motor, and its motor shaft gear and the tire rotating shaft gear cannot be disengaged. Therefore, when the electric device is pushed by the user to walk in a non-working environment, its tire rotating shaft gear drives the motor shaft gear to rotate, thereby causing the motor to rotate and generate alternating current.

[0124] At this time, the power supply end used for power supply can be powered by a power source such as a connected lithium battery pack, or it can be the alternating current generated when the walking motor is running. Therefore, in order to avoid damage to the electric device caused by excessive voltage of the alternating current generated by the running of the walking motor, at this time, as described in the circuit in the aforementioned circuit embodiment, when the on-off module is turned on so that the power supply end used for power supply is connected to the power module, its power module starts to work so as to convert the voltage of the power supply end into the voltage required for the normal operation of each device, and drive each device to start working, that is, when the MCU is powered on to work, wherein, in this embodiment, the MCU is the controller in the above-mentioned embodiment one or embodiment two, and any MCU or controller appearing in this embodiment has the same meaning, at this time, its MCU starts to obtain the voltage of the power supply end detected by the voltage detection module, so as to determine whether the power provided by the current power supply end is powered by a power source such as a lithium battery pack or the alternating current generated when the walking motor is rotating according to the voltage of the power supply end.

[0125] Step S20, determining whether the voltage at the power supply terminal is greater than the target voltage;

[0126] When it is determined that the power supply terminal voltage is greater than the target voltage, step S30 is executed.

[0127] When the controller obtains the power supply terminal voltage detected by the voltage detection module, it compares the power supply terminal voltage with the target voltage. It should be noted that the target voltage is greater than the maximum voltage of the lithium battery pack and other power sources within the normal working range. For example, as described in the above embodiment, the target voltage is greater than 84V.

[0128] At this time, when the real-time detected power supply voltage is greater than 84V, the controller can determine that the current on-off module is conducting because the alternating current generated by the running of the walking motor makes the power supply voltage greater than the first voltage threshold, which is then controlled by the high-voltage identification module. Therefore, the controller needs to perform high-voltage protection accordingly to prevent the AC voltage generated by the running of the walking motor from being greater than the maximum voltage that the electric device can bear, causing damage to the control board in the electric device.

[0129] At this time, when the real-time detected power supply voltage is less than 84V, the controller can determine that the current on-off module is turned on by the user by starting the power switch in the power switch module as shown in the second embodiment. Therefore, the electric device is powered by a normal lithium battery pack or other power source, which will not cause damage to the control panel, so its controller does not take any high-voltage protection measures, and operates accordingly according to the user's control. For example, when the user controls the electric device to work, its controller controls the corresponding work accordingly, and the electric device works normally at this time.

[0130] Step S30, controlling the motor to brake until the detected power supply terminal voltage is less than the target voltage;

[0131] Among them, when the controller obtains that the voltage at the power supply end is greater than the target voltage, it correspondingly determines that the current power supply end is the alternating current generated when the walking motor is running. At this time, in order to avoid damage to the electric equipment caused by the excessive voltage of the alternating current generated by the walking motor, it starts to perform high-voltage protection. Specifically, since the power supply at the power supply end is the alternating current generated when the walking motor is running, the faster the walking motor runs, the higher the voltage of the corresponding alternating current is. Therefore, in order to reduce the alternating current, its controller outputs a control signal to the drive module, so that the drive module drives the motor to brake. After the motor brakes, its speed slows down, thereby reducing the voltage of the generated alternating current, and finally gradually decreases to less than the target voltage, thereby achieving high-voltage protection.

[0132] Among them, in the embodiment of the present invention, the method of controlling the motor brake to the power supply terminal voltage less than the target voltage includes two methods: software braking and hardware braking. Among them, the software braking has a better braking effect in the form of a duty cycle, but it can also be directly software braking without a duty cycle. Among them, the hardware brake determines in real time to brake the motor according to the current detected power supply terminal voltage and the target voltage, such as by triggering a mechanical device to brake the motor. The method embodiment of the present invention selects corresponding hardware to support according to different braking methods. In this embodiment, it is mainly a software braking method. It can be understood that in other embodiments of the present invention, it can also provide existing circuit hardware corresponding to the hardware braking method to achieve hardware braking, which will not be repeated here.

[0133] In this embodiment, the voltage at the power supply end is detected during power-on operation, and it is determined whether the power supplied by the current power supply end is the alternating current generated when the motor is running according to the voltage at the power supply end. When the voltage at the power supply end is greater than the target voltage, it is determined that the power supplied by the current power supply end is the alternating current generated when the motor is driven. Therefore, the motor speed is reduced through brake control accordingly, so that the voltage of the alternating current generated when the motor is running can be reduced, thereby avoiding the problem of the motor running too fast and causing the voltage of the alternating current to be too high to cause damage to the device, thereby solving the problem of existing electric equipment being damaged by high voltage.

[0134] Embodiment 4

[0135] See also Figure 8 , is a flow chart of a high voltage protection construction method provided by the fourth embodiment of the present invention. For the sake of convenience, only the part related to the embodiment of the present invention is shown. The high voltage protection method includes:

[0136] Step S11, when the MCU is powered on, the voltage of the power supply terminal currently used for power supply is detected.

[0137] Step S21, determining whether the power supply terminal voltage is greater than the target voltage.

[0138] Among them, in the embodiment of the present invention, it detects the power supply terminal voltage currently used for power supply, and there are multiple ways to determine whether the power supply terminal voltage is greater than the target voltage, including detecting the voltage by software through the controller using the AD / DA method as described in the above-mentioned embodiments 1 and 2 of the present invention, and when it is detected that the AD value of the power supply terminal voltage exceeds the set range, it is determined that it is greater than the target voltage; or it also includes directly comparing the power supply terminal voltage with the reference voltage through a pure hardware comparator, so as to determine the magnitude relationship between the power supply terminal voltage and the target voltage. Among them, in this embodiment, the circuit used is mainly determined by the first method, that is, obtaining the AD value of the power supply terminal voltage to determine its magnitude. It can be understood that in other embodiments of the present invention, other circuit structures can also be used to achieve the magnitude relationship between the power supply terminal voltage and the target voltage determined by the second or third method described in this embodiment. It is set according to actual use and is not limited here.

[0139] Step S31, controlling the connection between the lock and the power supply terminal for power supply;

[0140] Among them, as shown in the aforementioned embodiment 2, when its controller obtains that the voltage at the power supply end detected by the voltage detection module is greater than the target voltage, it outputs a control signal to the control module so that the control module takes over the control of the on-off module. At this time, even when the voltage at the power supply end is less than the first voltage threshold, it can still control the on-off module to be turned on, that is, it locks the connection between the power supply end and the power supply module, which avoids high-voltage protection of the power supply end. Whenever the voltage at the power supply end is less than the first voltage threshold, its high-voltage identification module controls the on-off module to disconnect the connection between the power supply end and the power supply module, which causes the on-off module to be disconnected and affects the subsequent work of the controller.

[0141] Step S41, determining in real time the duty cycle of the motor brake control according to the currently detected power supply terminal voltage and the target voltage;

[0142] Among them, after the controller obtains that the power supply end voltage detected by the voltage detection module is greater than the target voltage, it needs to control the drive module to brake the motor to reduce the voltage at the power supply end. At this time, the larger the power supply end voltage is, the more likely it is to exceed the maximum load voltage that the electric equipment can bear, and it needs to perform rapid voltage reduction processing. Therefore, the greater the braking force required, the controller determines the corresponding duty cycle of the braking control of the motor according to the voltage difference between the current detected power supply end voltage and the target voltage. At this time, since the power supply end voltage gradually decreases during the braking process, the controller determines the current duty cycle of reducing the braking control in real time according to the power supply end voltage detected by the voltage detection module obtained in real time.

[0143] Step S51, controlling the motor to brake according to the duty cycle determined in real time.

[0144] Among them, the controller outputs a corresponding control signal to the driving module in real time according to the duty cycle determined in real time, and the driving module controls the brakes of the motor with a corresponding braking force according to the duty cycle in the control signal output by the controller to reduce the voltage at the power supply end.

[0145] Among them, when the power supply end is not connected to the lithium battery pack, due to the connection between the power supply end and the power module locked by the control module, even if the voltage of the AC power generated by its motor during braking is less than the first voltage threshold, its on-off module is still in the on state. At this time, its control module can output a control signal to the drive module to enable the drive module to control the motor to brake. When the voltage at the power supply end is less than the target voltage, it can also control the braking until it stops. At this time, the motor no longer generates AC power, and the on-off module disconnects the connection between the power supply end and the power module, and the controller, drive module, and voltage detection module lose power and stop working.

[0146] Among them, when the power supply end is connected to a lithium battery pack but the power switch module is not turned on, in the process of the controller controlling the drive module to brake the motor, when the voltage detected by the voltage detection module is less than the target voltage and maintains a stable state, the controller determines that the power supply end is connected to a lithium battery pack. At this time, the controller outputs a control signal to the control module so that the control module controls the on-off module to disconnect the connection between the power supply end and the power module. At this time, the controller, the drive module and the voltage detection module lose power and stop working, thereby avoiding the power consumption problem caused by the controller and other devices being still in a working state after the motor stops running due to the lithium battery pack being connected to the power supply end and the controller locking the connection between the power supply end and the power module due to the drive control module.

[0147] In this embodiment, when it is determined by detecting the voltage at the power supply end that the power supply is the alternating current generated when the motor is running, the duty cycle of the corresponding braking control of the motor is determined according to the power supply end voltage and the target voltage, and the motor is controlled to brake according to the duty cycle, so that fast braking can be achieved when the power supply end voltage is too large, and slow braking can be achieved when the power supply end voltage is small.

[0148] Embodiment 5

[0149] See also Fig. 9 , is a schematic diagram of a module of a high voltage protection device provided in a fifth embodiment of the present invention. For the sake of convenience, only the part related to the embodiment of the present invention is shown. The high voltage protection device includes:

[0150] The voltage detection unit 11 is used to detect the voltage of the power supply terminal currently used for power supply when the MCU is powered on;

[0151] A voltage determination unit 21 is used to determine whether the voltage at the power supply end is greater than a target voltage;

[0152] The brake control unit 31 is used to control the motor to brake until the detected power supply terminal voltage is less than the target voltage when the voltage judgment unit 21 judges that the power supply terminal voltage is greater than the target voltage.

[0153] The high-voltage protection device provided in the embodiment of the present invention has the same implementation principle and technical effects as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0154] Embodiment 6

[0155] See also Fig.10 , is a schematic diagram of a module of a high voltage protection device provided by the sixth embodiment of the present invention. For the sake of convenience, only the parts related to the embodiment of the present invention are shown. Its implementation principle and technical effects are roughly the same as those of the fifth embodiment. For the sake of brief description, for the parts not mentioned in the embodiment of the present invention, reference can be made to the corresponding contents in the fifth embodiment.

[0156] The difference is that, in one embodiment of the present invention, the device further comprises:

[0157] The power locking unit 41 is used to control the connection between the lock and the power supply terminal for power supply.

[0158] Furthermore, the brake control unit 31 includes:

[0159] The duty ratio determination module 311 is used to determine the duty ratio of the brake control of the motor in real time according to the currently detected power supply terminal voltage and the target voltage;

[0160] The brake control module 312 is used to control the motor to brake according to the duty cycle determined in real time.

[0161] The high-voltage protection device provided in the embodiment of the present invention has the same implementation principle and technical effects as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0162] Embodiment 7

[0163] The seventh embodiment of the present invention further provides an electric device, comprising the high voltage protection circuit as described in the first or second embodiment above.

[0164] The electric equipment provided in this embodiment can identify high-voltage alternating current that is higher than the normal power supply due to the high-voltage identification module. When the high-voltage identification module identifies the high voltage, the on-off module is controlled to be turned on, so that the electricity at the power supply end can be transmitted to the subsequent device, so that the controller, the drive module and the voltage detection module can start working. The voltage detection module is set to detect the voltage at the power supply end. The controller is set to determine whether the current power supply is normal power supply or alternating current generated by the motor operation according to the voltage detected by the voltage detection module. When the controller obtains that the voltage detected by the voltage detection module is greater than the target voltage, it is determined that the power supply end is the alternating current generated by the motor operation, and the drive module is controlled to brake the motor until the voltage at the power supply end is less than the target voltage. At this time, after the motor is braked, the voltage of the alternating current generated by it is reduced due to the speed reduction, which solves the problem of existing electric equipment being damaged by high voltage.

[0165] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high voltage protection circuit, characterized in that: The circuit includes a switch module, a power module, a high-voltage identification module, a controller, a drive module, and a voltage detection module; the high-voltage protection circuit is applied to an electric device using a walking motor, the electric device has an external power supply, and when the electric device is pushed to walk, the walking motor generates alternating current, and the alternating current flows to the power supply terminal of the electric device through the drive module; The on-off module is respectively connected to the power supply end, the power supply module, and the high-voltage identification module, and is used to control the on-off state between the power supply end and the power supply module according to the control of the high-voltage identification module; The power supply module is connected to the on-off module, the controller, the drive module, and the voltage detection module respectively, and is used to convert the power provided by the power supply end into the working power required for the normal operation of the controller, the drive module, and the voltage detection module when the on-off module is turned on; The high-voltage identification module is connected to the power supply terminal and the on-off module respectively, and is used to control the on-off module to conduct the power supply terminal and the power supply module when it is identified that the voltage of the power supply terminal is a high voltage higher than the first voltage threshold; The first voltage threshold is greater than the power supply voltage when the power supply end is normally powered, and the first voltage threshold is less than the maximum voltage that the electric device can bear. When the voltage at the power supply end is greater than the first voltage threshold, the high-voltage alternating current generated when the walking motor is running and the external power supply jointly power the electric device; The controller is connected to the power supply module, the driving module and the voltage detection module respectively, and is used to output a control signal to the driving module when the voltage detected by the voltage detection module at the power supply end connected to it is greater than the target voltage, so that the driving module drives the motor connected to it to brake until the voltage detected by the voltage detection module is less than the target voltage, and the target voltage is not less than the maximum voltage of the external power supply.

2. The high voltage protection circuit according to claim 1, characterized in that: The circuit further comprises: A control module connected to the on-off module and the controller respectively, the control module is used to control the on-off module accordingly according to the control of the controller, so as to control the on-off state between the power supply terminal and the power supply module.

3. The high voltage protection circuit according to claim 1, characterized in that: The circuit further comprises: A power switch module is connected to the power supply end and the on-off module respectively, and the power switch module is used to control the on-off module to control the on-off state between the power supply end and the power module.

4. The high voltage protection circuit according to claim 1, characterized in that: The on-off module includes a first field effect transistor, a first resistor, and a first capacitor; The first end of the first field effect transistor is respectively connected to the power supply end, one end of the first resistor, and one end of the first capacitor, the second end of the first field effect transistor is respectively connected to the high voltage identification module, the other end of the first resistor and the other end of the first capacitor, and the third end of the first field effect transistor is connected to the power supply module.

5. The high voltage protection circuit according to claim 1, characterized in that: The power module comprises: A first voltage reduction unit connected to the on-off module and configured to reduce the voltage at the power supply end and stabilize the voltage to a first voltage when the on-off module is turned on; and A second step-down unit connected to the first step-down unit, used for stepping down the first voltage and stabilizing the first voltage to a second voltage.

6. The high voltage protection circuit according to claim 1, characterized in that: The high voltage identification module includes a first voltage stabilizing diode and a second resistor; The anode of the first voltage stabilizing diode is connected to one end of the second resistor, the cathode of the first voltage stabilizing diode is connected to the on-off module, and the other end of the second resistor is grounded.

7. The high voltage protection circuit according to claim 1, characterized in that: The driving module includes a gate driving unit connected to the power module and the controller respectively, an upper bridge arm and a lower bridge arm connected to each of the three-phase ends of the motor correspondingly, and a sampling unit; Each of the upper bridge arms is also respectively connected to a power supply terminal and a first output terminal of a corresponding gate driving unit; Each of the lower bridge arms is also connected to the second output end of the corresponding gate driving unit and the first end of the sampling unit respectively; Each of the three-phase ends of the motor is also respectively connected to the third output end of the corresponding gate driving unit.

8. The high voltage protection circuit according to claim 1, characterized in that: The voltage detection module includes a third resistor, a fourth resistor, a fifth resistor, a second capacitor and a first diode; One end of the third resistor is connected to one end of the on-off module and the power module, the other end of the third resistor is respectively connected to one end of the fourth resistor and one end of the fifth resistor, the other end of the fourth resistor and one end of the second capacitor are grounded, the other end of the fifth resistor is respectively connected to the positive electrode of the first diode, the other end of the second capacitor and the controller, and the negative electrode of the first diode is connected to the power module.

9. The high voltage protection circuit according to claim 2, characterized in that: The control module includes a sixth resistor, a seventh resistor, a first triode, an eighth resistor and a ninth resistor; One end of the sixth resistor is connected to one end connected to the on-off module and the high-voltage identification module, the other end of the sixth resistor is connected to one end of the seventh resistor, the other end of the seventh resistor is connected to the first end of the first transistor, the second end of the first transistor is respectively connected to one end of the eighth resistor and one end of the ninth resistor, the third end of the first transistor and the other end of the eighth resistor are grounded, and the other end of the ninth resistor is connected to the controller.

10. An electric device, characterized in that: The electric device comprises the high voltage protection circuit according to any one of claims 1 to 9.

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