Motor brake control system

Abstract

The present invention provides a motor brake control system. When a control circuit determines to brake, the control circuit controls a drive circuit to close a first upper bridge switch and a second upper bridge switch, and fully open a first lower bridge switch and a second lower bridge switch. After a period of time, the control circuit controls the drive circuit to close one of the first and second lower bridge switches, while keeping the other fully open. After a period of time, the control circuit controls the drive circuit to close the other of the first and second lower bridge switches, while fully opening one of the first and second lower bridge switches.

Description

Technical Field

[0001] The present invention relates to a motor, and in particular to a motor brake control system. Background Art

[0002] The circuit components of electronic products generate heat during operation, especially in sealed enclosures or other confined spaces. The heat generated by each circuit component circulates within the enclosure, heating other circuit components and potentially causing overheating and damage. Therefore, fans are essential for cooling the circuit components of electronic products. During the cooling process, when the circuit components cool below a temperature threshold, the motor speed can be appropriately reduced. However, conventional motors reduce speed too slowly, potentially causing the motor to run for too long and resulting in unnecessary energy consumption. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a motor brake control system, comprising a first upper bridge switch, a first lower bridge switch, a second upper bridge switch, a second lower bridge switch, a drive circuit, and a control circuit. The first end of the first upper bridge switch is coupled to an input voltage. The first end of the first lower bridge switch is connected to the second end of the first upper bridge switch. The second end of the first lower bridge switch is grounded, and a node between the first end of the first lower bridge switch and the second end of the first upper bridge switch is connected to the first end of the motor. The first end of the second upper bridge switch is coupled to the input voltage. The first end of the second lower bridge switch is connected to the second end of the second upper bridge switch. The second end of the second lower bridge switch is grounded. A node between the first end of the second lower bridge switch and the second end of the second upper bridge switch is connected to the second end of the motor. The drive circuit is connected to the control end of the first upper bridge switch, the control end of the first lower bridge switch, the control end of the second upper bridge switch, and the control end of the second lower bridge switch. The control circuit is connected to the drive circuit. When a braking decision is made, the control circuit is configured to control the drive circuit to sequentially perform a braking deceleration operation and a first braking rest operation. During a braking deceleration operation, the control circuit controls the drive circuit to close the first upper bridge switch and the second upper bridge switch and fully open the first lower bridge switch and the second lower bridge switch, or the control circuit controls the drive circuit to open the first upper bridge switch and the second upper bridge switch and close the first lower bridge switch and the second lower bridge switch. During a first braking rest operation, the control circuit controls the drive circuit to keep the first upper bridge switch and the second upper bridge switch closed, but to close one of the first lower bridge switch and the second lower bridge switch, while keeping the other of the first lower bridge switch and the second lower bridge switch fully open.

[0004] In one embodiment, the control circuit controls the driver circuit to sequentially perform a braking deceleration operation, a first braking rest operation, and a second braking rest operation. During the second braking rest operation, the driver circuit continuously closes the first and second high-bridge switches, closes the other of the first and second low-bridge switches, and fully opens one of the first and second low-bridge switches.

[0005] In one embodiment, the driving circuit sequentially performs the braking deceleration operation, the first braking rest operation, and the second braking rest operation multiple times until the rotation speed of the motor drops to a target rotation speed value.

[0006] In an embodiment, when the control circuit determines that the motor speed drops below the speed threshold, the control circuit controls the drive circuit to stop executing the first brake rest operation and the second brake rest operation, and then continues to execute the brake deceleration operation until the motor speed drops to the target speed value.

[0007] In one embodiment, the control circuit controls the driving circuit to perform a plurality of braking cycles. In each braking cycle, the control circuit controls the driving circuit to perform a braking deceleration operation, and then sequentially perform one or more first braking rest operations and second braking rest operations in turn.

[0008] In one embodiment, the motor brake control system includes a Hall effect sensor connected to a control circuit. The Hall effect sensor is configured to sense changes in magnetic strength of the motor rotor as it rotates, generating positive and negative voltages to output Hall effect signals. The control circuit controls the drive circuit based on the Hall effect signals.

[0009] In one embodiment, when the current time reaches a transition point of the Hall signal, the driver circuit begins executing a braking deceleration operation. When the current time reaches the next transition point of the Hall signal, the driver circuit ends executing the braking deceleration operation and begins executing a first braking rest operation. When the current time reaches the next transition point of the Hall signal, the driver circuit ends executing the first braking rest operation and begins executing a second braking rest operation.

[0010] In an embodiment, each of the transition time point, the next transition time point, and the next transition time point is a time point of a rising edge or a time point of a falling edge of a Hall signal.

[0011] In one embodiment, when the control circuit determines based on the Hall signal that the Hall signal has reached a first level, the control circuit controls the driver circuit to turn off the first high-bridge switch and the second high-bridge switch, while fully opening the first low-bridge switch and turning off the second low-bridge switch. When the control circuit determines based on the Hall signal that the Hall signal has reached a second level different from the first level, the control circuit controls the driver circuit to turn off the first high-bridge switch and the second high-bridge switch, while fully opening the second low-bridge switch and turning off the first low-bridge switch.

[0012] As described above, the present invention provides a motor brake control system, which has at least the following characteristics:

[0013] When the motor is to be decelerated, a braking deceleration operation is performed to fully close the first upper bridge switch and the second upper bridge switch and simultaneously fully open the first lower bridge switch and the second lower bridge switch, or to fully open the first upper bridge switch and the second upper bridge switch and simultaneously close the first lower bridge switch and the second lower bridge switch, so as to rapidly reduce the speed of the motor;

[0014] After performing the braking deceleration operation for a period of time, performing a braking rest operation, such as complementary switching of one of the first lower bridge switch and the second lower bridge switch once or multiple times, to prevent the temperature of the first lower bridge switch and the second lower bridge switch from being too high;

[0015] When the motor speed drops below the speed threshold and the current flowing through the bridge circuit is lower than the current threshold, the first lower bridge switch and the second lower bridge switch can be continuously fully opened to accelerate the motor speed down to the target speed;

[0016] During the braking operation, the first upper bridge switch and the second upper bridge switch are always fully closed, so there is no problem of current recharging the input voltage of the bridge circuit.

[0017] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and illustration and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. 4 is a block diagram of a motor brake control system according to an embodiment of the present invention.

[0019] Figure 2 FIG. 4 is a switching diagram of a bridge circuit of a motor brake control system according to an embodiment of the present invention.

[0020] Figure 3 FIG. 4 is a switching diagram of a bridge circuit of a motor brake control system according to an embodiment of the present invention.

[0021] Figure 4FIG. 4 is a switching diagram of a bridge circuit of a motor brake control system according to an embodiment of the present invention.

[0022] Figure 5 FIG. 4 is a switching diagram of a bridge circuit of a motor brake control system according to an embodiment of the present invention.

[0023] Figure 6 FIG. 4 is a switching diagram of a bridge circuit of a motor brake control system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following embodiments will further explain the relevant technical content of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention. In addition, the term "or" used herein may include any one or more combinations of the associated listed items depending on the actual situation.

[0025] See also Figures 1 to 3 ,in Figure 1 is a block diagram of a motor brake control system according to an embodiment of the present invention; Figure 2 and Figure 3 FIG. 4 is a switching diagram of a bridge circuit of a motor brake control system according to an embodiment of the present invention.

[0026] The motor brake control system of this embodiment may include the following Figure 1 The first high-bridge switch HD1 , the first low-bridge switch LD1 , the second high-bridge switch HD2 , the second low-bridge switch LD2 , the driving circuit 300 and the control circuit 200 are suitable for reducing the rotational speed of the motor MT.

[0027] like Figure 1 As shown, a first end of the first high-bridge switch HD1 can be coupled to the input voltage VCC. A first end of the first low-bridge switch LD1 can be connected to the second end of the first high-bridge switch HD1. The second end of the first low-bridge switch LD1 can be grounded. A node between the first end of the first low-bridge switch LD1 and the second end of the first high-bridge switch HD1 can be connected to a first end OUT1 of the inductor L of the motor MT. The second end of the inductor L can be connected to a first end of the resistor R. The second end of the resistor R can be connected to a second end OUT2 of the motor MT.

[0028] A first terminal of the second high-bridge switch HD2 can be coupled to the input voltage VCC. A first terminal of the second low-bridge switch LD2 can be connected to the second terminal of the second high-bridge switch HD2. The second terminal of the second low-bridge switch LD2 is grounded. A node between the first terminal of the second low-bridge switch LD2 and the second terminal of the second high-bridge switch HD2 can be connected to the second terminal OUT2 of the resistor R of the motor MT.

[0029] The driving circuit 300 can be connected to the control terminals of the first high-bridge switch HD1 , the first low-bridge switch LD1 , the second high-bridge switch HD2 , and the second low-bridge switch LD2 .

[0030] When the control circuit 200 determines to brake, the control circuit 200 may perform a braking deceleration operation for a period of time, and then perform a first braking rest operation for a period of time. After performing the braking deceleration operation and the first braking rest operation in sequence, the control circuit 200 may perform the braking deceleration operation and the first braking rest operation in sequence one or more times.

[0031] During braking and deceleration, the control circuit 200 controls the driver circuit 300 to drive the first high-bridge switch HD1, the second high-bridge switch HD2, the first low-bridge switch LD1, and the second low-bridge switch LD2, generating a reverse current within the motor MT to achieve a braking effect. For example, in this embodiment, during braking and deceleration, the control circuit 200 controls the driver circuit 300 to turn off the first high-bridge switch HD1 and the second high-bridge switch HD2, while fully turning on the first low-bridge switch LD1 and the second low-bridge switch LD2. Alternatively, in practice, during braking and deceleration, the control circuit 200 may control the driver circuit 300 to turn on the first high-bridge switch HD1 and the second high-bridge switch HD2, while turning off the first low-bridge switch LD1 and the second low-bridge switch LD2.

[0032] During the first brake rest operation, the control circuit 200 controls the driving circuit 300 to continuously turn off the first upper bridge switch HD1 and the second upper bridge switch HD2, but turns off one of the first lower bridge switch LD1 and the second lower bridge switch LD2, while continuously fully opening the other of the first lower bridge switch LD1 and the second lower bridge switch LD2.

[0033] If necessary, after the braking deceleration operation and the first braking rest operation are sequentially executed, a second braking rest operation can be performed for a period of time. During the second braking rest operation, the control circuit 200 controls the driver circuit 300 to continuously turn off the first high-bridge switch HD1 and the second high-bridge switch HD2, but to turn off the other of the first low-bridge switch LD1 and the second low-bridge switch LD2, while fully turning on one of the first low-bridge switch LD1 and the second low-bridge switch LD2.

[0034] When the control circuit 200 determines to brake, the braking deceleration operation, the first braking rest operation and the second braking rest operation may be sequentially performed once, or the braking deceleration operation, the first braking rest operation and the second braking rest operation may be performed alternately multiple times.

[0035] For example, if Figure 1 The control circuit 200 shown can control the driving circuit 300 as shown in FIG. Figure 2 As shown, the first high-bridge switch HD1 and the second high-bridge switch HD2 are turned off, while the first low-bridge switch LD1 and the second low-bridge switch LD2 are fully turned on. After a period of time, the control circuit 200 can control the driver circuit 300 to continue turning off the first high-bridge switch HD1 and the second high-bridge switch HD2, while turning off the second low-bridge switch LD2, and fully turning on the first low-bridge switch LD1. After another period of time, the control circuit 200 can control the driver circuit 300 to continue turning off the first high-bridge switch HD1 and the second high-bridge switch HD2, while turning off the first low-bridge switch LD1, and fully turning on the second low-bridge switch LD2.

[0036] Or, as Figure 3 As shown, Figure 1 The control circuit 200 shown can control the driving circuit 300 as shown in FIG. Figure 2 As shown, the first high-bridge switch HD1 and the second high-bridge switch HD2 are turned off, while the first low-bridge switch LD1 and the second low-bridge switch LD2 are fully turned on. After a period of time, the control circuit 200 can control the driver circuit 300 to continue turning off the first high-bridge switch HD1 and the second high-bridge switch HD2, while turning off the first low-bridge switch LD1, and fully turning on the second low-bridge switch LD2. After another period of time, the control circuit 200 can control the driver circuit 300 to continue turning off the first high-bridge switch HD1 and the second high-bridge switch HD2, while turning off the second low-bridge switch LD2, and fully turning on the first low-bridge switch LD1.

[0037] See also Figure 1 and Figure 4 ,in Figure 1 is a block diagram of a motor brake control system according to an embodiment of the present invention; Figure 4 FIG. 4 is a switching diagram of a bridge circuit of a motor brake control system according to an embodiment of the present invention.

[0038] The motor brake control system according to an embodiment of the present invention may include a Hall sensor 100. The Hall sensor 100 may be connected to a control circuit 200. The Hall sensor 100 senses the changes in magnetic strength during the rotation of the motor MT rotor, generating positive and negative voltages to output a Hall signal HS. Based on the Hall signal HS, the control circuit 200 controls the drive circuit 300 to drive the first high-bridge switch HD1, the first low-bridge switch LD1, the second high-bridge switch HD2, and the second low-bridge switch LD2.

[0039] In the normal operation mode of the motor MT, the control circuit 200 may control the driving circuit 300 to sequentially perform the first normal switching operation and the second normal switching operation once or multiple times, or in practice, sequentially perform the second normal switching operation and the first normal switching operation once or multiple times.

[0040] In the normal operation mode of the motor MT, when the current time reaches a transition point of the Hall signal HS (e.g., the time point at which the Hall signal HS transitions from a first level, such as a low level, to a second level, such as a high level), the control circuit 200 can control the driver circuit 300 to perform a first normal operation. During the first normal operation, the control circuit 200 can control the driver circuit 300 to fully open the first low-bridge switch LD1 and the second high-bridge switch HD2, while simultaneously closing the first high-bridge switch HD1 and the second low-bridge switch LD2.

[0041] In the normal operation mode of the motor MT, when the current time reaches the next transition point of the Hall signal HS (e.g., the time point at which the Hall signal HS transitions from a second level, such as a high level, to a first level, such as a low level), the control circuit 200 can control the driver circuit 300 to perform a second normal operation. During the second normal operation, the control circuit 200 can control the driver circuit 300 to fully open the first high-bridge switch HD1 and the second low-bridge switch LD2, while simultaneously closing the first low-bridge switch LD1 and the second high-bridge switch HD2.

[0042] As described above, the first level of the Hall signal HS is a low level and the second level of the Hall signal HS is a high level, but the present invention is not limited thereto. In practice, the first level of the Hall signal HS can be a high level and the second level of the Hall signal HS can be a low level.

[0043] It is worth noting that when the normally running motor MT is to be decelerated, the control circuit 200 can control the driving circuit 300 to switch the first high-bridge switch HD1, the first low-bridge switch LD1, the second high-bridge switch HD2, and the second low-bridge switch LD2 according to the level of the Hall signal HS currently sensed by the Hall sensor 100.

[0044] Specifically, when the control circuit 200 determines that the motor MT is operating normally within the first phase time of the Hall signal HS, the control circuit 200 uses a transition time point of the Hall signal HS after the first phase time as the braking start time point. Figure 4 The braking start time point is the time point when the Hall signal HS changes from the second level (eg, high level) to the first level (eg, low level).

[0045] When the current time reaches the braking start time point, a braking deceleration operation is performed. During the braking deceleration operation, the control circuit 200 controls the driver circuit 300 to turn off all high-bridge switches, such as the first high-bridge switch HD1 and the second high-bridge switch HD2, and to fully turn on all low-bridge switches, such as the first low-bridge switch LD1 and the second low-bridge switch LD2.

[0046] In this embodiment, each transition time point of the Hall signal HS, i.e., the time point when the Hall signal HS transitions from a low level to a high level (i.e., the time point of the rising edge of the Hall signal HS) and the time point when the Hall signal HS transitions from a high level to a low level (i.e., the time point of the falling edge of the Hall signal HS), is used as a time point for switching the bridge circuit, but the present invention is not limited thereto.

[0047] After braking and deceleration, current no longer flows through the first high-bridge switch HD1 and the second high-bridge switch HD2 of the bridge circuit, but only flows through the first low-bridge switch LD1 and the second low-bridge switch LD2. As a result, the motor MT will coast and its speed will gradually decrease.

[0048] However, if current flows through the first and second low-bridge switches LD1 and LD2 for too long, they may overheat and burn out. To prevent this, after fully opening the first and second low-bridge switches LD1 and LD2 for a period of time during a braking deceleration operation, the following first and second braking rest operations can be performed one or more times in sequence. These two operations serve as resting operations during the braking process.

[0049] When the control circuit 200 determines that the current time has reached the next transition point of the Hall signal HS (e.g., the time point at which the Hall signal HS transitions from a first level, such as a low level, to a second level, such as a high level), the control circuit 200 begins executing a first brake rest operation. During the first brake rest operation, the control circuit 200 controls the driver circuit 300 to continuously close the first high-bridge switch HD1 and the second high-bridge switch, close the second low-bridge switch LD2, and fully open the first low-bridge switch LD1. The control circuit 200 continues executing the first brake rest operation for a second phase period after the next transition point of the Hall signal HS, i.e., while the Hall signal HS remains at the second level, such as a high level.

[0050] Next, when the control circuit 200 determines that the current time has reached the next transition point of the Hall signal HS (e.g., the time point at which the Hall signal HS transitions from a second level, such as a high level, to a first level, such as a low level), the second brake rest operation begins. During the second brake rest operation, the control circuit 200 controls the driver circuit 300 to continuously close the first high-bridge switch HD1 and the second high-bridge switch, close the first low-bridge switch LD1, and fully open the second low-bridge switch LD2. The control circuit 200 continues to perform the second brake rest operation for a third phase period after the next transition point of the Hall signal HS, i.e., while the Hall signal HS remains at the first level, such as a low level.

[0051] See also Figure 1 、 Figure 4 and Figure 5 ,in Figure 1 is a block diagram of a motor brake control system according to an embodiment of the present invention; Figure 4 and Figure 5 FIG. 4 is a switching diagram of a bridge circuit of a motor brake control system according to an embodiment of the present invention.

[0052] The control circuit 200 can sequentially execute multiple braking cycles. Each braking cycle can include a braking deceleration operation, one or more first braking rest operations, and one or more second braking rest operations. In other words, each braking cycle can include a braking deceleration operation, one or more first braking rest operations, and one or more second braking rest operations.

[0053] For example, if Figure 5 As shown, the control circuit 200 configures a braking deceleration operation, a first braking rest operation, and a second braking rest operation as a braking cycle. During the first phase of the Hall signal HS, the control circuit 200 performs a braking deceleration operation. Next, during the second phase of the Hall signal HS, the control circuit 200 performs a first braking rest operation. Next, during the third phase of the Hall signal HS, the control circuit 200 performs a second braking rest operation. This completes a braking cycle. After completing one braking cycle, the next braking cycle is executed, and so on.

[0054] It should be understood that when the motor MT is to be decelerated, the number of brake cycles to be performed can be determined based on actual needs, and the number of first brake rest operations and second brake rest operations to be performed in each brake cycle can be determined.

[0055] That is, the control circuit 200 may only sequentially execute the aforementioned braking deceleration operation, the first braking rest operation, and the second braking rest operation once or multiple times until the speed of the motor MT decreases to a target speed value, which may be zero or a speed value greater than zero.

[0056] See also Figure 1 、 Figure 4 and Figure 6 ,in Figure 1 is a block diagram of a motor brake control system according to an embodiment of the present invention; Figure 6 FIG. 4 is a switching diagram of a bridge circuit of a motor brake control system according to an embodiment of the present invention.

[0057] When the control circuit 200 performs the braking deceleration operation, the first braking rest operation, and the second braking rest operation (the first braking phase operation) one or more times, causing the speed of the motor MT to drop below the speed threshold, the current falls below the current threshold. At this point, current continues to flow through the first and second low-bridge switches LD1 and LD2, preventing the first and second low-bridge switches LD1 and LD2 from overheating and burning out.

[0058] Therefore, when the control circuit 200 determines that the speed of the motor MT drops below the speed threshold, regardless of the level of the Hall signal HS, the control circuit 200 may continue to turn off the first high-bridge switch HD1 and the second high-bridge switch HD2, and simultaneously continue to fully open both the first low-bridge switch LD1 and the second low-bridge switch LD2 until the speed of the motor MT drops to the target speed value.

[0059] That is to say, when the control circuit 200 determines that the current flowing through the first low-bridge switch LD1 and the second low-bridge switch LD2 is lower than the current threshold, it is no longer necessary to perform the first brake rest operation and the second brake rest operation (both of which serve as rest operations during the braking process), and the braking deceleration operation can be continuously performed to accelerate the speed of the motor MT to the target speed value.

[0060] In summary, the present invention provides a motor brake control system having at least the following features:

[0061] When the motor is to be decelerated, a braking deceleration operation is performed to fully close the first upper bridge switch and the second upper bridge switch and simultaneously fully open the first lower bridge switch and the second lower bridge switch, or to fully open the first upper bridge switch and the second upper bridge switch and simultaneously close the first lower bridge switch and the second lower bridge switch, so as to rapidly reduce the speed of the motor;

[0062] After performing the braking deceleration operation for a period of time, performing a braking rest operation, such as complementary switching of one of the first lower bridge switch and the second lower bridge switch once or multiple times, to prevent the temperature of the first lower bridge switch and the second lower bridge switch from being too high;

[0063] When the motor speed drops below the speed threshold and the current flowing through the bridge circuit is lower than the current threshold, the first lower bridge switch and the second lower bridge switch can be continuously fully opened to accelerate the motor speed down to the target speed;

[0064] During the braking operation, the first upper bridge switch and the second upper bridge switch are always fully closed, so there is no problem of current recharging the input voltage of the bridge circuit.

[0065] The contents disclosed above are only preferred feasible embodiments of the present invention and are not intended to limit the claims of the present invention. Therefore, all equivalent technical changes made using the description and drawings of the present invention are included in the claims of the present invention.

Claims

1. A motor brake control system, characterized in that: The motor brake control system includes: a first upper bridge switch, wherein a first terminal of the first upper bridge switch is coupled to an input voltage; a first lower bridge switch, wherein a first end of the first lower bridge switch is connected to a second end of the first upper bridge switch, a second end of the first lower bridge switch is grounded, and a node between the first end of the first lower bridge switch and the second end of the first upper bridge switch is connected to a first end of a motor; a second upper bridge switch, wherein a first terminal of the second upper bridge switch is coupled to the input voltage; a second lower bridge switch, wherein a first end of the second lower bridge switch is connected to the second end of the second upper bridge switch, the second end of the second lower bridge switch is grounded, and a node between the first end of the second lower bridge switch and the second end of the second upper bridge switch is connected to the second end of the motor; a driving circuit connected to the control end of the first upper bridge switch, the control end of the first lower bridge switch, the control end of the second upper bridge switch, and the control end of the second lower bridge switch; as well as A control circuit connected to the driving circuit and configured to control the driving circuit to sequentially perform a braking deceleration operation, a first braking rest operation, and a second braking rest operation when braking is determined; During the braking and deceleration operation, the control circuit controls the drive circuit to close the first upper bridge switch and the second upper bridge switch and fully open the first lower bridge switch and the second lower bridge switch, or the control circuit controls the drive circuit to open the first upper bridge switch and the second upper bridge switch and close the first lower bridge switch and the second lower bridge switch; In the first brake rest operation, the control circuit controls the drive circuit to continuously close the first upper bridge switch and the second upper bridge switch, but close one of the first lower bridge switch and the second lower bridge switch, while continuously fully opening the other of the first lower bridge switch and the second lower bridge switch; During the second brake rest operation, the drive circuit continuously closes the first upper bridge switch and the second upper bridge switch, but closes the other of the first lower bridge switch and the second lower bridge switch, and fully opens one of the first lower bridge switch and the second lower bridge switch.

2. The motor brake control system according to claim 1, characterized in that: The driving circuit sequentially performs the braking deceleration operation, the first braking rest operation, and the second braking rest operation multiple times until the rotation speed of the motor drops to a target rotation speed value.

3. The motor brake control system according to claim 2, characterized in that: When the control circuit determines that the speed of the motor drops below the speed threshold, the control circuit controls the drive circuit to stop executing the first brake rest operation and the second brake rest operation, and then continues to execute the brake deceleration operation until the speed of the motor drops to the target speed value.

4. The motor brake control system according to claim 1, characterized in that: The control circuit controls the drive circuit to perform multiple brake cycle operations. In each brake cycle operation, the control circuit controls the drive circuit to perform the brake deceleration operation once, and then sequentially performs the first brake rest operation and the second brake rest operation one or more times in turn.

5. The motor brake control system according to claim 1, characterized in that: The motor brake control system also includes a Hall sensor connected to the control circuit and configured to sense changes in magnetic strength when the motor rotor rotates, and to generate positive and negative voltages to output Hall signals. The control circuit controls the drive circuit based on the Hall signal.

6. The motor brake control system according to claim 5, characterized in that: When the current time reaches a transition time point of the Hall signal, the driving circuit starts to perform the braking deceleration operation; When the current time reaches the next transition time point of the Hall signal, the driving circuit ends the braking deceleration operation and starts the first braking rest operation; When the current time reaches the next transition time point of the Hall signal, the driving circuit ends executing the first brake rest operation and starts executing the second brake rest operation.

7. The motor brake control system according to claim 6, characterized in that: Each of the transition time point, the next transition time point, and the next transition time point is a time point of a rising edge or a time point of a falling edge of the Hall signal.

8. The motor brake control system according to claim 5, characterized in that: When the control circuit determines, based on the Hall signal, that the Hall signal reaches a first level, the control circuit controls the driving circuit to turn off the first upper bridge switch and the second upper bridge switch, and simultaneously fully turn on the first lower bridge switch but turn off the second lower bridge switch; When the control circuit determines, based on the Hall signal, that the Hall signal reaches a second level different from the first level, the control circuit controls the drive circuit to turn off the first upper bridge switch and the second upper bridge switch, and simultaneously fully turn on the second lower bridge switch but turn off the first lower bridge switch.

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