Bail release circuit and motor drive device

Abstract

The application relates to the technical field of motor brake locking, and discloses a brake locking unlocking circuit and a motor driving device; in the embodiment of the application, when the motor is in a brake locking and three-phase winding short-circuit locked-rotor state, a direct supply loop of a driving power supply to the motor is cut off, and a power supply loop of the driving power supply to a step-down conversion module is turned on; the power supply voltage of the driving power supply is stepped down through the step-down conversion module, the output voltage of the step-down conversion module is controlled to make the locked-rotor current value meet a preset brake locking attraction condition, and then the output voltage of the step-down conversion module is controlled to be stabilized to a preset step-down interval; compared with directly unlocking the brake locking by using the power supply voltage of the driving power supply, the preset step-down interval is smaller than the power supply voltage of the driving power supply, and the locked-rotor steady-state current is greatly reduced; under the premise of guaranteeing that the brake locking unlocking torque is equivalent to the brake locking unlocking torque corresponding to the driving power supply, the temperature rise of the motor winding is inhibited to support continuous safe power-on operation for a long time.

Description

Technical Field

[0001] This application relates to the field of motor brake technology, and more particularly to brake unlocking circuits and motor drive devices. Background Technology

[0002] During the operation of motor-driven equipment, factors such as sudden power outages, program anomalies, and hardware failures can easily cause the drive motor to experience mechanical brake jamming. Taking a rail-mounted inspection robot as an example, if its walking motor brake jams, the robot will be locked on the track and unable to move. If it cannot be unlocked in time, it will seriously affect the operation and maintenance efficiency and may even lead to the scrapping of the robot.

[0003] The current method for unlocking the brake involves short-circuiting the three-phase windings of the motor and applying a standard voltage (such as 24V). The electromagnetic torque generated by the motor's stalled rotor counteracts the mechanical braking force of the brake, thus releasing it. While this three-phase short-circuit unlocking method is common in the industry, it has significant drawbacks: under standard voltage, the motor is in a stalled state with three phases shorted, resulting in a high steady-state stall current and continuous heat accumulation in the motor windings, leading to an extremely high temperature rise rate. For example, under 24V standard voltage, the stall steady-state current is approximately 28A, and a measured temperature rise of approximately 85K in 60 seconds. If the motor is operated for an extended period, the winding temperature will rapidly exceed the insulation limit (e.g., 120℃), causing winding breakdown and ultimately, equipment burnout.

[0004] Therefore, there is an urgent need for a brake release solution that can suppress the temperature rise of the motor windings to support safe operation for a long time, while ensuring that the release torque is equivalent to the original standard voltage conditions. Summary of the Invention

[0005] This application provides a brake unlocking circuit and a motor drive device, which can suppress the temperature rise of the motor windings to support continuous and safe power-on operation over a long period of time, while ensuring that the unlocking torque is equivalent to the unlocking torque corresponding to the drive power supply.

[0006] This application provides a brake unlocking circuit, including: a step-down converter module, a voltage regulation control module, and a current sampling module; The input terminal of the buck converter module is connected to the drive power supply via the main control module, and the output terminal of the buck converter module is connected to one end of the voltage regulation control module; the buck converter module is used to step down the power supply voltage of the drive power supply. The other end of the voltage regulation control module is connected to one end of the current sampling module, and the other end of the current sampling module is connected to the three-phase windings of the motor; the current sampling module is used to sample the winding current of the motor and feed it back to the voltage regulation control module. When the motor is in a state of brake jamming and three-phase winding short-circuited and locked, the main control module cuts off the direct power supply circuit from the drive power supply to the motor and connects the power supply circuit from the drive power supply to the step-down converter module. The voltage regulation control module is used to control the output voltage of the buck converter module to stabilize the output voltage of the buck converter module to a preset buck range after the stall current value is satisfied by the preset brake engagement condition, based on the stall current value fed back by the current sampling module; wherein, the release torque generated by the motor stall within the preset buck range is equivalent to the release torque corresponding to the power supply voltage of the drive power supply.

[0007] Furthermore, the stall current value satisfies the preset brake engagement condition as follows: the electromagnetic torque established based on the stall current value within a preset time period is sufficient to complete brake engagement; wherein, the preset time period is less than a preset time threshold.

[0008] Furthermore, the voltage regulation control module is specifically used to control the output voltage of the buck converter module to stabilize the stall current value to the stall steady-state current value, so that the output voltage of the buck converter module is stabilized to a preset buck range; wherein, the stall steady-state current value is less than the stall current value that satisfies the preset release brake condition.

[0009] Furthermore, when the driving power supply is 24V, the preset step-down range is 7V±0.5V.

[0010] Furthermore, the voltage regulation control module is specifically used to control the output voltage of the buck converter module to stabilize the stall current value to the stall steady-state current value, wherein the stall steady-state current value is less than 7A.

[0011] Furthermore, it also includes: a temperature detection module; The temperature detection module is used to detect the winding temperature of the motor, determine and output the temperature rise information of the motor winding within a preset time period based on the winding temperature of the motor.

[0012] Furthermore, the voltage regulation control module is also used to provide a warning when the output voltage of the buck converter module is less than 6.5V, indicating insufficient release torque of the output motor; and to provide a warning when the output voltage of the buck converter module is greater than 7.5V, indicating that the temperature rise of the output motor winding exceeds the safety threshold.

[0013] Furthermore, the step-down conversion module is an isolated DC step-down circuit.

[0014] Furthermore, it also includes: a motor status detection module; The motor status detection module is used to detect the operating status of the motor; The motor status detection module is connected to the main control module. When the motor's operating status is determined to be normal, the motor status detection module triggers the main control module to close the direct power supply circuit from the drive power supply to the motor.

[0015] This application embodiment also provides a motor drive device, including a drive power supply, a motor, a main control module, and the aforementioned brake unlocking circuit; The drive power supply is connected to the input terminal of the main control module; The first output terminal of the main control module is connected to the motor; The second output terminal of the main control module is connected to the motor via the brake unlocking circuit.

[0016] As can be seen from the above technical solutions, the embodiments of this application have the following advantages: In this embodiment, the brake unlocking circuit includes: a step-down conversion module, a voltage regulation control module, and a current sampling module; the input terminal of the step-down conversion module is connected to the drive power supply via the main control module, and the output terminal of the step-down conversion module is connected to one end of the voltage regulation control module; the step-down conversion module is used to step down the power supply voltage of the drive power supply; the other end of the voltage regulation control module is connected to one end of the current sampling module, and the other end of the current sampling module is connected to the three-phase windings of the motor; the current sampling module is used to sample the winding current of the motor and feed it back to the voltage regulation control module; when the current is released... When the motor is in a locked state with the brake engaged and the three-phase windings short-circuited, the main control module cuts off the direct power supply circuit from the drive power supply to the motor and connects the power supply circuit from the drive power supply to the step-down converter module. The voltage regulation control module is used to control the output voltage of the step-down converter module based on the locked current value fed back by the current sampling module, so that after the locked current value meets the preset brake engagement condition, the output voltage of the step-down converter module is stabilized to a preset step-down range. The release torque generated by the motor lock-up within the preset step-down range is equivalent to the release torque corresponding to the power supply voltage of the drive power supply.

[0017] As can be seen, when the motor is in a locked state with the brake engaged and the three-phase windings short-circuited, the direct power supply circuit from the drive power supply to the motor is cut off, and the power supply circuit from the drive power supply to the step-down converter module is connected. The step-down converter module reduces the power supply voltage of the drive power supply, and the output voltage of the step-down converter module is controlled so that the locked current value meets the preset brake engagement condition. Then, the output voltage of the step-down converter module is stabilized to the preset step-down range. Compared with using the power supply voltage of the drive power supply to directly unlock the brake, this preset step-down range is smaller than the power supply voltage of the drive power supply, which significantly reduces the locked steady-state current and can effectively suppress the temperature rise of the motor windings. It can be seen that this brake unlocking circuit can suppress the temperature rise of the motor windings to support continuous and safe power-on operation for a long time, while ensuring that the unlocking torque is equivalent to the unlocking torque corresponding to the drive power supply. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a system block diagram of a brake unlocking circuit disclosed in an embodiment of this application; Figure 2 This is a system block diagram of another brake unlocking circuit disclosed in an embodiment of this application; Figure 3 This is a current waveform diagram of a different unlocking scheme disclosed in an embodiment of this application; Figure 4 This is a waveform diagram of motor winding temperature for a different unlocking scheme disclosed in an embodiment of this application; Figure 5 This is a structural block diagram of a motor drive device disclosed in an embodiment of this application. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0021] In the description of the embodiments of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0022] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0023] The motor brake, also known as the electromagnetic holding brake, is a type of mechanical brake that can easily become stuck in the drive motor during the operation of motor-driven equipment due to factors such as sudden power outages, program abnormalities, and hardware failures. Taking a rail-mounted inspection robot as an example, if its walking motor brake gets stuck, the robot is locked on the track and cannot move. If it cannot be unlocked in time, it will seriously affect maintenance efficiency and may even lead to the robot being scrapped.

[0024] Existing motor brake unlocking methods involve short-circuiting the three-phase windings of the motor and applying the standard voltage of the equipment. The electromagnetic torque generated by the motor's stalled rotor counteracts the mechanical braking force of the brake, thus releasing it. This three-phase short-circuit unlocking method is a common industry technology, but it has insurmountable drawbacks: under standard voltage, the motor is in a three-phase short-circuit stalled state, resulting in a high steady-state stall current in the circuit, continuous heat accumulation in the motor windings, and an extremely high temperature rise rate. If the motor operates for an extended period, the motor winding temperature will rapidly exceed the insulation limit (e.g., 120°C), leading to winding breakdown and equipment burnout. Therefore, this application provides a brake unlocking circuit that, while ensuring the unlocking torque is equivalent to the unlocking torque corresponding to the drive power supply, suppresses the temperature rise of the motor windings to support continuous and safe operation over extended periods. This brake unlocking circuit is as follows: Figure 1 As shown, the details are as follows: In this embodiment, the brake unlocking circuit 100 includes: a step-down conversion module 101, a voltage regulation control module 102, and a current sampling module 103.

[0025] The input terminal of the buck converter module 101 is connected to the drive power supply 200 via the main control module 400. The power supply voltage of the drive power supply can be 24V, 35V, etc., and is not specifically limited here. The output terminal of the buck converter module 101 is connected to one end of the voltage regulation control module 102; the buck converter module 101 is used to step down the power supply voltage of the drive power supply 200. It can be understood that the buck converter module 101 includes a switching transistor (such as a MOSFET or transistor), an inductor, and a capacitor. By controlling the high-frequency switching of the switching transistor, and in conjunction with the inductor and capacitor for energy storage and release, precise voltage reduction regulation of the output voltage is achieved. In one feasible embodiment, the buck converter module 101 can be an isolated DC-DC buck circuit.

[0026] The other end of the voltage regulation control module 102 is connected to one end of the current sampling module 103, and the other end of the current sampling module 103 is connected to the three-phase windings of the motor 300. It is understood that the motor can be a servo motor, stepper motor, asynchronous motor, or synchronous motor, etc., and no specific limitation is made here. In one feasible implementation, the motor is the walking motor of the rail-mounted inspection robot.

[0027] The current sampling module 103 is used to sample the winding current of the motor 300 and feed it back to the voltage regulation control module 102. The current sampling module 103 can be implemented by a sampling resistor or a shunt. For example, according to Ohm's law, when current flows through a sampling resistor with a known resistance value, a voltage drop will be generated. By measuring this voltage drop, the actual current magnitude can be calculated, and the current signal can be fed back to the voltage regulation control module 102.

[0028] When the motor 300 is in a brake-locked state and the three-phase windings are short-circuited and stalled, the main control module 400 cuts off the direct supply circuit from the drive power supply 200 to the motor 300 and connects the power supply circuit from the drive power supply 200 to the step-down converter module 101. It can be understood that the main control module 400 is mainly used for fault detection and switching control of the motor 300. The main control module 400 may include a multiplexer and a control chip. The control chip selects the corresponding switch of the multiplexer based on the state of the motor 300. When the motor 300 is in a normal state, the brake unlocking circuit 100 of this embodiment is in a bypass standby state, and the main control module 400 connects the direct supply circuit from the drive power supply 200 to the motor 300, and the motor 300 is driven by the drive power supply 200. When the motor 300 is in a state of brake jamming and three-phase winding short-circuit and stalled, if a fault signal of brake jamming and three-phase winding short-circuit and stalled is detected, the main control module 400 cuts off the direct supply circuit from the drive power supply 200 to the motor 300 and connects the power supply circuit from the drive power supply 200 to the step-down conversion module 101, that is, activates the step-down unlocking circuit 100 to work.

[0029] The voltage regulation control module 102 can be a voltage regulator or a voltage regulation module (VRM), and the specific type is not limited here. The voltage regulation control module 102 is used to control the output voltage of the buck converter module 101 to stabilize it within a preset buck range after the stall current value meets the preset brake engagement condition, based on the stall current value fed back by the current sampling module 103. Within this preset buck range, the release torque generated by the stalled motor 300 is equivalent to the release torque corresponding to the power supply voltage of the drive power supply 200.

[0030] Specifically, the voltage regulation control module 102 can control the output voltage of the buck converter module 101 based on the locked-rotor current value fed back by the current sampling module 103, using a PWM closed-loop current control strategy. For example, the voltage regulation control module 102 can control the output voltage of the buck converter module 101 by controlling the switching frequency of the switching transistor. The corresponding control strategy is as follows: first, reduce the output voltage of the buck converter module 101 so that the locked-rotor current value meets the preset brake engagement condition; wherein, the locked-rotor current value is less than the locked-rotor current value for brake unlocking via the drive power supply 200.

[0031] It is understood that the stall current value satisfies the preset brake engagement condition as follows: the electromagnetic torque established based on the stall current value within a preset time period is sufficient to engage the brake; wherein, the preset time period is less than a preset time threshold; this preset time threshold is relatively short, and can be 0.1ms or 0.2ms, the specific value is not limited here. That is, when the stall current value satisfies the preset brake engagement condition, the electromagnetic torque rapidly established based on the stall current can offset the braking force, the mechanical brake unlocks, and the brake engagement is completed.

[0032] The voltage regulation control module 102 reduces the output voltage of the buck converter module 101 so that the locked rotor current value meets the preset brake engagement condition. Then, it stabilizes the output voltage of the buck converter module 101 to a preset buck range, keeping the locked rotor current value low to maintain the brake release state. Specifically, the voltage regulation control module 102 controls the output voltage of the buck converter module 101 to stabilize the locked rotor current value to a locked rotor steady-state current value, thereby stabilizing the output voltage of the buck converter module 101 to a preset buck range. The locked rotor steady-state current value is less than the locked rotor current value corresponding to meeting the preset brake release condition. It can be understood that the locked rotor current meeting the preset brake engagement condition is a peak current used to engage the brake, with a short holding time, such as 410ms or 420ms. The locked rotor steady-state current value is a holding current, which is less than the locked rotor steady-state current value used for brake release via the drive power supply 200, and can be 0.3A or 0.5A, with no specific limitation here.

[0033] In this embodiment, the locked rotor current for brake unlocking is innovatively divided into two stages: a peak current stage (used to engage the brake) and a holding current stage (held at low temperature rise). The corresponding step-down unlocking mode of the step-down unlocking circuit is as follows: the voltage regulator control module 102 first controls the output voltage of the step-down conversion module 101 to be reduced until the locked rotor current is the peak current, quickly establishing electromagnetic torque to engage the brake; then the voltage regulator control module 102 controls the output voltage of the step-down conversion module 101 to continue to reduce the voltage until the locked rotor current stabilizes at the locked rotor steady-state current value. At this time, the output voltage of the step-down conversion module 101 stabilizes within the preset step-down range.

[0034] As can be seen, when the motor is in a locked state with the brake engaged and the three-phase windings short-circuited, the direct power supply circuit from the drive power supply to the motor is cut off, and the power supply circuit from the drive power supply to the step-down converter module is connected. The step-down converter module reduces the power supply voltage of the drive power supply, and the output voltage of the step-down converter module is controlled so that the locked current value meets the preset brake engagement condition. Then, the output voltage of the step-down converter module is stabilized to the preset step-down range. Compared with directly unlocking the brake using the power supply voltage of the drive power supply, this preset step-down range is smaller than the power supply voltage of the drive power supply, which significantly reduces the locked steady-state current and effectively suppresses the temperature rise of the motor windings. Therefore, this brake unlocking circuit can suppress the temperature rise of the motor windings to support continuous and safe power-on operation for a long time, while ensuring that the unlocking torque is equivalent to the unlocking torque corresponding to the drive power supply. In addition, in this embodiment, the brake unlocking circuit designed for the special fault condition of three-phase short-circuited locked motor uses PWM closed-loop current control and does not modify the general three-phase short-circuit unlocking structure, which can effectively improve the adaptability of the brake unlocking circuit.

[0035] Furthermore, in order to intuitively highlight the beneficial effects of the step-down unlocking circuit in the embodiments of this application, the embodiments of this application use the most commonly used 24V standard voltage as an example for explanation.

[0036] Using a rail-mounted inspection robot as the implementation platform, the robot uses a 24V drive power supply to power its walking motor. The step-down unlocking circuit is integrated into the main control power board of the device and connects to the robot's internal and external components through a terminal interface. The step-down unlocking circuit in this embodiment adopts a modular circuit design, resulting in a small PCBA size that does not require modification of the original mechanical structure and has strong versatility.

[0037] When the motor is in normal operation, the step-down unlocking circuit is in bypass standby mode, and the walking motor is driven normally by the original 24V circuit for inspection operations. When the equipment encounters a sudden power outage or software / hardware failure, the motor's mechanical brake seizes the rail, and the three-phase windings short-circuit and stall. The main control module identifies the fault signal, cuts off the 24V direct supply circuit, and activates the step-down unlocking circuit.

[0038] The voltage regulation control module uses a PWM closed-loop circuit to control the output voltage of the buck converter module, so that the stall current value quickly establishes electromagnetic torque with peak current to achieve brake engagement, and then automatically switches to the stall steady-state current value, and the output voltage stabilizes to the preset buck range.

[0039] In this embodiment, when the drive power supply is 24V, the preset voltage reduction range is 7V±0.5V. The release torque under the 7V±0.5V condition is equivalent to that under the 24V condition, ensuring reliable brake release. It is understood that when directly using a 24V drive power supply for brake unlocking, the corresponding minimum release voltage is 23V; the preset voltage reduction range of 7V±0.5V is far lower than the nominal release voltage (23V), making such a significant voltage reduction difficult to attempt under normal circumstances.

[0040] In this embodiment, the preset step-down range is the only feasible range under four constraints: torque threshold, current threshold, temperature rise threshold, and maximum operating time. When the output voltage of the step-down converter module is less than 6.5V, the motor's release torque is insufficient, and the voltage regulation control module outputs a warning that the motor's release torque is insufficient. When the output voltage of the step-down converter module is greater than 7.5V, the temperature rise of the output motor winding exceeds the safety threshold, and the voltage regulation control module outputs a warning that the temperature rise of the motor winding exceeds the safety threshold. Precise parameter design of the preset step-down range is achieved through multiple constraints.

[0041] In this embodiment, the voltage regulation control module is specifically used to control the output voltage of the buck converter module to stabilize the locked-rotor current value to a locked-rotor steady-state current value, wherein the locked-rotor steady-state current value is less than 7A. The measured current difference between 24V direct unlocking and 7V±0.5V unlocking is as follows: Figure 3 As shown, the locked-rotor steady-state current corresponding to direct unlocking at 24V is approximately 28A; the peak locked-rotor current corresponding to unlocking at 7V±0.5V is approximately 1.5A, while the steady-state current remains at approximately 0.25A (a reduction of approximately 99%). It can be understood that 7A is approximately 25% of the peak locked-rotor current of 28A corresponding to direct unlocking at 24V, representing the corresponding safety upper limit. The measured locked-rotor steady-state current of 7V±0.5V unlocking (approximately 0.25A) is significantly lower than both the locked-rotor steady-state current of direct unlocking at 24V and the safety upper limit, effectively reducing the locked-rotor steady-state current and significantly improving safety performance.

[0042] In this embodiment, the brake unlocking circuit further includes a temperature detection module. This temperature detection module can be a thermocouple sensor, a thermistor, or an infrared thermometer, etc., and is not specifically limited here. This temperature detection module is used to detect the winding temperature of the motor, and based on the winding temperature, determines and outputs the temperature rise information of the motor winding within a preset time period. It is understood that this temperature detection module can, based on the detected motor winding temperature, statistically analyze the temperature rise within the preset time period and output the temperature rise information of the motor winding. The preset time period can be 24 hours or 30 hours, and is not specifically limited here.

[0043] The difference in measured temperature rise between 24V direct unlocking and 7V±0.5V unlocking is as follows: Figure 4 As shown, the temperature will rise above 100°C within 24 hours of direct 24V unlocking operation, and above 120°C (motor insulation limit) after 7 days of operation. However, with 7V±0.5V unlocking, the highest temperature during 24 hours of continuous operation is 39°C (temperature rise of approximately 12K), and the temperature shows no significant change after 7 days of continuous operation. This means that the 7-day continuous operating temperature of 39°C is far below the motor insulation limit (approximately 120°C) and the industrial safety threshold (40°C). Therefore, under the premise of equivalent unlocking torque, the step-down unlocking circuit in this embodiment significantly suppresses the temperature rise.

[0044] The actual measured data of the brake unlocking circuit of this embodiment in a real rail-mounted inspection robot are shown in Table 1 below:

[0045] Table 1 As can be seen from the above measured data, by designing a preset voltage reduction range of 7V±0.5V, which is much lower than the nominal release voltage (23V), the stall steady-state current is reduced to about 0.2~0.3A while maintaining the equivalent unlocking torque. The winding temperature is about 39℃ (temperature rise of about 12K) after 7 days of continuous operation. This achieves a significant reduction in stall steady-state current and motor winding temperature rise while maintaining the equivalent torque.

[0046] Furthermore, such as Figure 2 As shown in this embodiment, the brake unlocking circuit further includes a motor status detection module 104. This motor status detection module 104 can be a current transformer, frequency converter, or servo driver, etc., and is not specifically limited here. The motor status detection module 104 is used to detect the operating status of the motor 300. The motor status detection module 104 is connected to the main control module 400. When it is determined that the operating status of the motor 300 is normal, the motor status detection module 104 triggers the main control module 400 to close the direct power supply circuit from the drive power supply 200 to the motor 300.

[0047] The motor status detection module 105 can detect the operating signal of motor 300. When the operating signal of motor 300 is normal, it is determined that the fault of motor 300 has been eliminated, that is, the fault state of motor 300 being disengaged from the brake jam and the three-phase windings being short-circuited and locked. At this time, a reset is required to restore the motor to normal rotation. Based on the operating signal of motor 300 collected by motor status detection module 104, the original 24V power supply mode can be automatically restored, and the equipment can resume normal inspection operations.

[0048] As can be seen, the step-down unlocking circuit in this embodiment adopts a closed-loop control design. By incorporating a current sampling module and a motor status detection module, when the motor is in a fault state of brake jamming and three-phase winding short-circuiting and stalled rotation, it automatically switches to step-down mode, cuts off the direct power supply circuit of the drive power supply, and activates the brake unlocking circuit to control the output voltage of the step-down conversion module to stabilize to the preset step-down range. When the motor emerges from the fault state, it automatically resets the motor's operating condition, that is, it closes the direct power supply circuit of the drive power supply and resets to direct power supply by the drive power supply. Therefore, in this embodiment, the automatic switching to step-down mode during faults and automatic reset upon recovery of operating conditions require no human intervention and demonstrate a high degree of automation.

[0049] This application also provides a motor drive device, such as... Figure 5 As shown, the device includes a drive power supply 200, a motor 300, a main control module 400, and the aforementioned brake unlocking circuit 100. The power supply voltage of the drive power supply 200 can be 24V, 35V, etc., and is not specifically limited here. The motor 300 can be a servo motor, stepper motor, asynchronous motor, or synchronous motor, etc., and is not specifically limited here. The motor drive device can be a robot, an electric vehicle, a washing machine, etc., and is not specifically limited here.

[0050] The drive power supply 200 is connected to the input terminal of the main control module 400; the first output terminal of the main control module 400 is connected to the motor 300; and the second output terminal of the main control module 400 is connected to the motor 300 via the brake unlocking circuit 100.

[0051] The brake unlocking circuit 100 includes at least: a step-down conversion module, a voltage regulation control module, and a current sampling module; The input terminal of the buck converter module is connected to the drive power supply via the main control module, and the output terminal of the buck converter module is connected to one end of the voltage regulation control module; the buck converter module is used to step down the power supply voltage of the drive power supply. The other end of the voltage regulation control module is connected to one end of the current sampling module, and the other end of the current sampling module is connected to the three-phase windings of the motor; the current sampling module is used to sample the winding current of the motor and feed it back to the voltage regulation control module. When the motor is in a state of brake jamming and three-phase winding short-circuited and locked, the main control module cuts off the direct power supply circuit from the drive power supply to the motor and connects the power supply circuit from the drive power supply to the step-down converter module. The voltage regulation control module is used to control the output voltage of the buck converter module to stabilize the output voltage of the buck converter module to a preset buck range after the stall current value is satisfied by the preset brake engagement condition, based on the stall current value fed back by the current sampling module; wherein, the release torque generated by the motor stall within the preset buck range is equivalent to the release torque corresponding to the power supply voltage of the drive power supply.

[0052] It is understood that in the embodiments of this application, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0053] The above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them. Although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of the embodiments of this application.

[0054] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0055] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0056] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

Claims

1. A brake unlocking circuit, characterized in that, include: The module consists of a step-down converter, a voltage regulator control module, and a current sampling module. The input terminal of the buck converter module is connected to the drive power supply via the main control module, and the output terminal of the buck converter module is connected to one end of the voltage regulation control module; the buck converter module is used to step down the power supply voltage of the drive power supply. The other end of the voltage regulation control module is connected to one end of the current sampling module, and the other end of the current sampling module is connected to the three-phase windings of the motor; the current sampling module is used to sample the winding current of the motor and feed it back to the voltage regulation control module. When the motor is in a state of brake jamming and three-phase winding short-circuited and locked, the main control module cuts off the direct power supply circuit from the drive power supply to the motor and connects the power supply circuit from the drive power supply to the step-down converter module. The voltage regulation control module is used to control the output voltage of the buck converter module to stabilize the output voltage of the buck converter module to a preset buck range after the stall current value is satisfied by the preset brake engagement condition, based on the stall current value fed back by the current sampling module; wherein, the release torque generated by the motor stall within the preset buck range is equivalent to the release torque corresponding to the power supply voltage of the drive power supply.

2. The brake unlocking circuit according to claim 1, characterized in that, The stall current value satisfies the preset brake engagement condition as follows: the electromagnetic torque established based on the stall current value within a preset time period is sufficient to complete brake engagement; wherein, the preset time period is less than a preset time threshold.

3. The brake unlocking circuit according to claim 1, characterized in that, The voltage regulation control module is specifically used to control the output voltage of the buck converter module to stabilize the stall current value to the stall steady-state current value, so that the output voltage of the buck converter module is stabilized to a preset buck range; wherein, the stall steady-state current value is less than the stall current value that meets the preset release brake condition.

4. The brake unlocking circuit according to claim 1, characterized in that, When the driving power supply is 24V, the preset step-down range is 7V±0.5V.

5. The brake unlocking circuit according to claim 4, characterized in that, The voltage regulation control module is specifically used to control the output voltage of the buck converter module to stabilize the stall current value to the stall steady-state current value, wherein the stall steady-state current value is less than 7A.

6. The brake unlocking circuit according to claim 4, characterized in that, The voltage regulation control module is also used to provide a warning when the output voltage of the step-down converter module is less than 6.5V, indicating insufficient release torque of the output motor; and to provide a warning when the output voltage of the step-down converter module is greater than 7.5V, indicating that the temperature rise of the output motor winding exceeds the safety threshold.

7. The brake unlocking circuit according to claim 1, characterized in that, Also includes: Temperature detection module; The temperature detection module is used to detect the winding temperature of the motor, determine and output the temperature rise information of the motor winding within a preset time period based on the winding temperature of the motor.

8. The brake unlocking circuit according to claim 1, characterized in that, The step-down converter module is an isolated DC step-down circuit.

9. The brake unlocking circuit according to claim 1, characterized in that, Also includes: Motor status detection module; The motor status detection module is used to detect the operating status of the motor; The motor status detection module is connected to the main control module. When the motor's operating status is determined to be normal, the motor status detection module triggers the main control module to close the direct power supply circuit from the drive power supply to the motor.

10. A motor drive device, characterized in that, Includes a drive power supply, a motor, a main control module, and the brake unlocking circuit as described in any one of claims 1 to 9; The drive power supply is connected to the input terminal of the main control module; The first output terminal of the main control module is connected to the motor; The second output terminal of the main control module is connected to the motor via the brake unlocking circuit.

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