Motor speed regulation circuit and motor power supply system

Abstract

The invention provides a motor speed regulation circuit and a motor power supply system. The motor speed regulation circuit comprises a current detection module, a control module and a driving module, the current detection module is connected with the control module and the motor. The driving module is connected with the control module and the motor. The current detection module detects the current current of the motor; the control module determines the current motor rotating speed according to the current current and adjusts the PWM driving signal according to the current motor rotating speed and the target motor rotating speed; and the driving module drives the motor by using the adjusted PWM driving signal, so that the rotating speed of the motor is adjusted to the target rotating speed of the motor. The current current of the motor is detected, the current motor rotating speed is determined based on the current current, then the PWM driving signal is adjusted and driven according to the current motor rotating speed and the target motor rotating speed, the motor is driven through the adjusted PWM driving signal, motor rotating speed adjustment is not limited by gears, and stepless speed adjustment of the motor rotating speed is achieved.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and particularly to a motor speed regulation circuit and a motor power supply system. Background Art

[0002] Currently, when using a single-phase asynchronous motor, a scheme of series resistance or center tap of the winding is usually adopted to adjust the motor speed. Among them, the scheme of series resistance is mainly related to the specific number of series resistors, and the number of resistors is usually several; the number of taps set by the way of center tap in the winding is also limited, and it is impossible to adjust the motor speed to any value. Therefore, both of these two schemes can only adjust the speed limitedly and cannot achieve stepless speed change.

[0003] The above content is only used to assist in understanding the technical solution of the present invention, and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The main object of the present invention is to provide a motor speed regulation circuit and a motor power supply system, aiming to solve the technical problem that stepless speed change cannot be achieved in the prior art for motor speed regulation.

[0005] To achieve the above object, the present invention provides a motor speed regulation circuit, including: a current detection module, a control module, and a drive module;

[0006] Wherein, the current detection module is respectively connected to the control module and the motor, and the drive module is respectively connected to the control module and the motor;

[0007] The current detection module is configured to detect the current of the motor and output the current to the control module;

[0008] The control module is configured to determine the current motor speed according to the current, adjust the PWM drive signal according to the current motor speed and the target motor speed, and output the adjusted PWM drive signal to the drive module; and

[0009] The drive module is further configured to drive the motor by using the adjusted PWM drive signal when receiving the adjusted PWM drive signal, so as to adjust the speed of the motor to the target motor speed.

[0010] Optionally, the motor speed regulation circuit further includes: a zero-crossing detection module;

[0011] The zero-crossing detection module is respectively connected to the power supply and the control module;

[0012] The zero-crossing detection module is configured to detect the phase of the power supply voltage output by the power supply and send the phase to the control module;

[0013] The control module is further configured to determine a drive circuit based on the phase, and send the adjusted PWM drive signal to the drive module through a pin corresponding to the drive circuit; and

[0014] The drive module is configured to drive the motor according to the adjusted PWM drive signal and the drive circuit, so as to adjust the rotational speed of the motor to the target motor rotational speed.

[0015] Optionally, the drive module includes: a drive management unit and a first drive circuit;

[0016] The drive management unit is respectively connected to the control module and the first drive circuit;

[0017] The control module is further configured to, when the phase is less than a preset phase, send the adjusted PWM drive signal to the drive management unit through a pin corresponding to the first drive circuit;

[0018] The drive management unit is configured to, when receiving the adjusted PWM drive signal, output the adjusted PWM drive signal to a corresponding first drive circuit; and

[0019] The first drive circuit is configured to drive the motor based on the received adjusted PWM drive signal, so as to adjust the rotational speed of the motor to the target motor rotational speed.

[0020] Optionally, the drive module further includes: a second drive circuit;

[0021] The second drive circuit is connected to the drive management unit;

[0022] The control module is further configured to, when the phase is not less than the preset phase, send the adjusted PWM drive signal to the drive management unit through a pin corresponding to the second drive circuit;

[0023] The drive management unit is configured to, when receiving the adjusted PWM drive signal, output the adjusted PWM drive signal to a corresponding second drive circuit; and

[0024] The second drive circuit is configured to drive the motor based on the received adjusted PWM drive signal, so as to adjust the rotational speed of the motor to the target motor rotational speed.

[0025] Optionally, the drive management unit includes:

[0026] a management chip and first to second resistors;

[0027] Among them, the first input terminal of the management chip is connected to the first output pin of the control module through a first resistor;

[0028] The second input terminal of the management chip is connected to the second output pin of the control module through a second resistor;

[0029] The first output pin of the management chip is connected to the first drive circuit; and

[0030] The second output pin of the management chip is connected to the second drive circuit.

[0031] Optionally, the first drive circuit includes: a first switching tube, third to fourth resistors, and a first diode;

[0032] Among them, the anode of the first diode is connected to the live wire of the power supply, and the cathode of the first diode is connected to the input terminal of the first switching tube;

[0033] The control terminal of the first switching tube is respectively connected to the second end of the third resistor and the first end of the fourth resistor, and the output terminal of the first switching tube is connected to the neutral wire of the power supply through the motor; and

[0034] The first end of the third resistor is connected to the first output pin of the management chip, and the second end of the fourth resistor is connected to the output terminal of the first switching tube.

[0035] Optionally, the second drive circuit includes: a second switching tube, fifth to sixth resistors, and a second diode;

[0036] Among them, the anode of the second diode is connected to the output terminal of the second switching tube, and the cathode of the second diode is connected to the live wire of the power supply;

[0037] The control terminal of the second switching tube is respectively connected to the second end of the fifth resistor and the first end of the sixth resistor, and the input terminal of the second switching tube is connected to the neutral wire of the power supply through the motor; and

[0038] The first end of the fifth resistor is connected to the second output pin of the management chip, and the second end of the sixth resistor is connected to the output terminal of the second switching tube.

[0039] Optionally, the current detection module includes: a seventh resistor;

[0040] The first end of the seventh resistor is respectively connected to the output terminal of the second switching tube and the second end of the sixth resistor, and the second end of the seventh resistor is connected to the anode of the second diode.

[0041] Optionally, the motor speed regulation circuit further includes: a first energy storage capacitor and a second energy storage capacitor;

[0042] The first energy storage capacitor is connected in parallel with the first drive circuit between the live wire and the neutral wire; and

[0043] The second energy storage capacitor is connected in parallel with the second drive circuit between the live wire and the neutral wire.

[0044] In addition, to achieve the above object, the present invention further provides a motor power supply system, including: a power supply and the motor speed regulation circuit described above.

[0045] The present invention provides a motor speed regulation circuit and a motor power supply system. The motor speed regulation circuit includes: a current detection module, a control module, and a drive module; the current detection module is respectively connected to the control module and the motor, and the drive module is respectively connected to the control module and the motor; the current detection module detects the current of the motor and outputs the current to the control module; the control module determines the current motor speed according to the current, adjusts the PWM drive signal according to the current motor speed and the target motor speed, and outputs the adjusted PWM drive signal to the drive module; the drive module is further configured to drive the motor by using the adjusted PWM drive signal when receiving the adjusted PWM drive signal, so that the speed of the motor is adjusted to the target motor speed. By detecting the current of the motor, determining the current motor speed based on the current, and then adjusting the drive PWM drive signal according to the current motor speed and the target motor speed, the speed regulation of the motor is not limited by the gear position, and stepless speed regulation of the motor speed is achieved. Description of the Drawings

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on the structures shown in these drawings without creative efforts.

[0047] Figure 1 It is a schematic structural diagram of the first embodiment of the motor speed regulation circuit proposed by the present invention;

[0048] Figure 2 It is a schematic structural diagram of the second embodiment of the motor speed regulation circuit proposed by the present invention;

[0049] Figure 3 It is a circuit schematic diagram of the second embodiment of the motor speed regulation circuit proposed by the present invention;

[0050] Figure 4 It is a schematic flow chart of the speed regulation process of the motor speed regulation circuit proposed by the present invention.

[0051] The reference numerals in the specific embodiments are as follows:

[0052] 10: Current detection module; 20: Control module; 30: Driving module; 40: Zero-crossing detection module; 301: Driving management unit; 302: First driving circuit; 303: Second driving circuit;

[0053] R1 to R7: First to seventh resistors; U1: Management chip; Q1 to Q2: First to second switching transistors; C1 to C2: First to second capacitors; EC1 to EC2: First to second electrolytic capacitors; VCC: Power supply; M: Motor; D1 to D3: First to third diodes; Vp: First voltage; IN1 to IN2: First to second input terminals of the management chip; OUT1 to OUT2: First to second output terminals of the management chip; GND: Ground.

[0054] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0055] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0057] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0058] In addition, the descriptions involving "first", "second", etc. in the present invention are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments may be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0059] Refer to Figure 1 , Figure 1 is a schematic flow chart of the first embodiment of the motor speed regulation circuit of the present invention. The first embodiment of the motor speed regulation circuit of the present invention is proposed.

[0060] As Figure 1 shown, in this embodiment, the motor speed regulation circuit includes: a current detection module 10, a control module 20, and a drive module 30;

[0061] Among them, the current detection module 10 is respectively connected to the control module 20 and the motor, and the drive module 30 is respectively connected to the control module 20 and the motor.

[0062] It should be understood that generally, some speed regulation gears are set in the motor power supply system to adjust the speed of the motor. This adjustment method causes the motor speed to only be switched between several gears, and the speed change between gears is relatively large. When a small-range speed adjustment is required, this method cannot adjust the motor to the target speed. Stepless speed regulation refers to a speed regulation method without gears. This stepless speed regulation method can control the motor to adjust between any speeds and is not affected by the motor speed regulation gears.

[0063] It should be noted that the current detection module 10 is a structure for detecting the current in the motor drive circuit. The current detection module 10 can be a current sensor and is set in the drive circuit in series. The control module 20 is a module for controlling the motor drive process. The control module 20 can be an integrated controller or a separately provided controller for controlling the motor. The control module 20 can output a drive signal to control the drive module 30 to drive the motor to operate. The drive module 30 is a structure for driving the motor. The drive module 30 can output a corresponding power supply signal or turn on the power supply circuit according to the drive signal output by the control module to supply power to the motor, thereby driving the motor. The motor can be a single-phase asynchronous motor with a constant resistance value and is set in series between the live wire and the neutral wire.

[0064] It can be understood that the current detection module 10 can detect the current flowing through the motor in real time and output the current to the control module 20; the control module 20 can determine the current motor speed according to the current, and then adjust the PWM drive signal according to the current motor speed and the target motor speed, and output the adjusted PWM drive signal to the drive module 30; when receiving the adjusted PWM drive signal, the drive module 30 can drive the motor with the adjusted PWM drive signal to adjust the speed of the motor to the target motor speed. Among them, the process of determining the current motor speed according to the current mainly depends on the mapping relationship between the motor speed and the current. For different motors, this mapping relationship may be somewhat different, but when the motor is determined, this mapping relationship has been determined. When the current is determined, the current motor speed can be directly determined according to this current.

[0065] In this embodiment, a motor speed regulation circuit is provided. The motor speed regulation circuit includes: a current detection module, a control module, and a drive module; the current detection module is respectively connected to the control module and the motor, and the drive module is respectively connected to the control module and the motor; the current detection module detects the current of the motor and outputs the current to the control module; the control module determines the current motor speed according to the current, adjusts the PWM drive signal according to the current motor speed and the target motor speed, and outputs the adjusted PWM drive signal to the drive module; the drive module is further configured to drive the motor with the adjusted PWM drive signal when receiving the adjusted PWM drive signal to adjust the speed of the motor to the target motor speed. In this embodiment, by detecting the current of the motor and determining the current motor speed based on the current, and then adjusting the drive PWM drive signal according to the current motor speed and the target motor speed, the adjustment of the motor speed will not be restricted by the gear at this time, realizing stepless speed regulation of the motor speed.

[0066] Refer to Figure 2 , Figure 2 which is a schematic flowchart of the second embodiment of the motor speed regulation circuit of the present invention. The second embodiment of the motor speed regulation circuit of the present invention is proposed based on the first embodiment of the above motor speed regulation circuit.

[0067] In this embodiment, the motor speed regulation circuit further includes: a zero-crossing detection module 40;

[0068] The zero-crossing detection module 40 is respectively connected to the power supply and the control module 20.

[0069] It should be understood that the power supply voltage output by the power supply of the motor is usually an AC voltage. During the process of adjusting the motor speed, the current flows in different directions in the drive circuit for voltages of different phases. Therefore, when adjusting the motor speed, considering the adjustment of a complete cycle, in this embodiment, the phase of the power supply voltage can also be detected. Then, different power supply methods are selected according to the different phases of the power supply current, so as to adjust the speed during the entire cycle. Considering that the power supply is an alternating current, in this embodiment, the zero-crossing detection module 40 can be directly used to detect whether the current phase of the power supply voltage is in the first half cycle or the second half cycle.

[0070] It should be noted that during the power supply process of the AC power supply voltage, the phase in the first half cycle is usually in the positive phase, and the current is transmitted in one direction in the drive circuit; while the phase in the second half cycle is usually in the negative phase, and the current is transmitted in the opposite direction in the drive circuit. Therefore, different drive circuits can be selected to drive the motor according to the different voltage phases, so that the motor speed can be adjusted at each phase of the power supply voltage.

[0071] In a specific implementation, the zero-crossing detection module 40 can detect the phase of the power supply voltage output by the power supply and send the phase to the control module 20; the control module 20 can determine the corresponding drive circuit based on the phase and send the adjusted PWM drive signal to the drive module 30 through the pin corresponding to the drive circuit; the drive module 30 drives the motor according to the adjusted PWM drive signal and uses the drive circuit corresponding to the PWM drive signal to adjust the speed of the motor to the target motor speed.

[0072] Further, in this embodiment, the drive module includes: a drive management unit 301 and a first drive circuit 302;

[0073] The drive management unit 301 is respectively connected to the control module 20 and the first drive circuit 302; the motor is connected in series in the first drive circuit.

[0074] It can be understood that the drive management unit 301 is a unit that controls the drive process. The drive management unit 301 can establish connections with the control module 20 through multiple pins, and then select different drive circuits to drive the motor according to the PWM drive signals input through different pins. The first drive circuit 302 is the drive circuit for the positive half cycle. The first drive circuit 302 can receive the PWM drive signal when the phase of the power supply voltage is less than 180 degrees, and turn on or off the connection of the motor according to the PWM drive signal to achieve the drive of the motor and the adjustment of the motor speed.

[0075] In a specific implementation, when the phase is less than a preset phase, the control module 20 may send the adjusted PWM drive signal to the drive management unit 301 through the pin corresponding to the first drive circuit; when receiving the adjusted PWM drive signal, the drive management unit 301 may output the adjusted PWM drive signal to the corresponding first drive circuit 302; when receiving the adjusted PWM signal, the first drive circuit 302 may control the conduction or cut-off of the drive circuit based on the received adjusted PWM drive signal to drive the motor, so that the speed of the motor is adjusted to the target motor speed.

[0076] The preset phase is a phase preset for determining the specific drive circuit of the motor. In single-phase power supply, the preset phase may be a phase of 180 degrees; in three-phase power supply, the preset phase may also be a phase of 120 degrees. The preset phase can be determined according to the specific drive type of the motor.

[0077] In addition, in this embodiment, the drive module 30 further includes: a second drive circuit 303;

[0078] The second drive circuit 303 is connected to the drive management unit 301; of course, the motor is also connected in series in the second drive circuit.

[0079] It should be understood that the second drive circuit 303 is a drive circuit for the negative half cycle. The second drive circuit 303 can receive the PWM drive signal when the phase of the supply voltage is not less than 180 degrees, and control the connection of the motor to conduct or cut off according to the PWM drive signal, so as to drive the motor and adjust the speed of the motor.

[0080] In a specific implementation, when the phase is not less than the preset phase, the control module 20 may also send the adjusted PWM drive signal to the drive management unit 301 through the pin corresponding to the second drive circuit; when the drive management unit 301 also receives the adjusted PWM drive signal, it may output the adjusted PWM drive signal to the corresponding second drive circuit 303; when receiving the adjusted PWM signal, the second drive circuit 303 may control the conduction or cut-off of the drive circuit based on the received adjusted PWM drive signal to drive the motor, so that the speed of the motor is adjusted to the target motor speed.

[0081] Refer to Figure 3 In this embodiment, the drive management unit includes: a management chip U1 and first to second resistors;

[0082] Among them, the first input terminal IN1 of the management chip U1 is connected to the first output pin of the control module 20 through a first resistor R1; the second input terminal IN2 of the management chip U1 is connected to the second output pin of the control module 20 through a second resistor R2; the first output pin OUT1 of the management chip U1 is connected to the first drive circuit 302; the second output pin OUT2 of the management chip U1 is connected to the second drive circuit 303.

[0083] It should be noted that the management chip U1 can be a normal input-output chip. When a signal is received at one input terminal, the signal can be output through the corresponding output terminal. In this embodiment, the first input terminal of the management chip U1 corresponds to the first output terminal, and the second input terminal corresponds to the second output terminal. The control module 20 can determine whether the PWM drive signal is output to the management chip U1 through the first output terminal or the second output terminal according to the phase of the supply voltage output by the power supply. Among them, the first resistor R1 and the second resistor R2 are step-down resistors for signal transmission. When the management chip U1 receives the PWM drive signal through the first input terminal, it outputs the PWM drive signal to the first drive circuit through the first output terminal; when it receives the PWM drive signal through the second input terminal, it can output the PWM drive signal to the second drive circuit through the second output terminal.

[0084] In addition, when the management chip U1 receives the PWM drive signal, it can also adjust the amplitude value of the PWM drive signal so that the PWM drive signal can accurately drive the switching tube in the drive circuit, avoiding the abnormal operation of the drive circuit caused by the mismatch of the amplitude value of the PWM drive signal and affecting the speed regulation of the motor.

[0085] In Figure 3 the management chip U1 is also connected to the power supply VCC to receive the power supply voltage output by the power supply VCC for operation. The first capacitor C1 and the second capacitor C2 are filter capacitors. The power supply VCC can also output a voltage to another pin of the management chip U1 through the third diode D3.

[0086] Referring to Figure 3 in this embodiment, the first drive circuit 302 includes: a first switching tube Q1, third to fourth resistors, and a first diode D1;

[0087] Among them, the anode of the first diode D1 is connected to the live wire ACL of the power supply, and the cathode of the first diode D1 is connected to the input end of the first switching tube Q1; the control end of the first switching tube Q1 is respectively connected to the second end of the third resistor R3 and the first end of the fourth resistor R4, and the output end of the first switching tube Q1 is connected to the neutral wire ACN of the power supply through the motor; the first end of the third resistor R3 is connected to the first output pin of the management chip U1, and the second end of the fourth resistor R4 is connected to the output end of the first switching tube Q1.

[0088] It should be understood that the first switching tube Q1 is a power tube that presents different states according to the PWM drive signal and is used to control the on-off state of the first drive circuit 302. For example, an NPN-type triode, an NMOS tube, etc. During the effective duty cycle time of the PWM drive signal, the first switching tube Q1 can be turned on, and during the invalid duty cycle time of the PWM drive signal, the first switching tube Q1 is turned off. Of course, the first switching tube Q1 can also be a PNP-type triode, a PMOS tube, etc., but an inverter needs to be introduced between the first switching tube Q1 and the management chip U1 to invert the PWM drive signal. Among them, the third resistor R3 and the fourth resistor R4 are voltage-dividing resistors. The first diode D1 is an anti-reverse diode.

[0089] In a specific implementation, the adjusted PWM drive signal output by the management chip U1 through the first output pin can control the on-off state of the first switching tube Q1 after being voltage-divided by the second resistor R2 and the first resistor R1, so as to control the on-off state of the first drive circuit 302, and further adjust the electrode rotation speed during the positive half cycle of the output voltage of the live wire ACL. The voltage on the live wire ACL can form a first voltage Vp at the input end of the first switching tube Q1 through the first diode D1, and this first voltage Vp is output to the motor through the first switching tube Q1. The drive current in the first drive circuit 302 is adjusted by the on or off of the first switching tube Q1, and further the rotation speed of the motor is adjusted.

[0090] In addition, in Figure 3 the second drive circuit 303 includes: a second switching tube Q2, fifth to sixth resistors, and a second diode D2;

[0091] Among them, the anode of the second diode D2 is connected to the output terminal of the second switching transistor Q2, and the cathode of the second diode D2 is connected to the live wire ACL of the power supply; the control terminal of the second switching transistor Q2 is respectively connected to the second terminal of the fifth resistor R5 and the first terminal of the sixth resistor R6, and the input terminal of the second switching transistor Q2 is connected to the neutral wire ACN of the power supply through the motor; the first terminal of the fifth resistor R5 is connected to the second output pin of the management chip U1, and the second terminal of the sixth resistor R6 is connected to the output terminal of the second switching transistor Q2.

[0092] It should be understood that the second switching transistor Q2 is also a power transistor that presents different states according to the PWM drive signal and is used to control the on-off state of the second drive circuit 303. For example, an NPN transistor, an NMOS transistor, etc. During the effective duty cycle time of the PWM drive signal, the second switching transistor Q2 can be turned on, and during the invalid duty cycle time of the PWM drive signal, the second switching transistor Q2 is turned off. Among them, the fifth resistor R5 and the sixth resistor R6 are voltage-dividing resistors. The second diode D2 is also an anti-reverse diode.

[0093] In a specific implementation, the management chip U1 can control the on-off state of the second switching transistor Q2 by dividing the voltage of the adjusted PWM drive signal output through the second output pin by the fourth resistor R4 and the third resistor R3, so as to control the on-off state of the second drive circuit 303, and further adjust the electrode rotation speed during the negative half cycle of the output voltage of the live wire ACL. During the negative half cycle, the voltage on the live wire ACL can be output to the motor through the second diode D2 and the second switching transistor Q2, and the drive current in the second drive circuit 303 can be adjusted by the on or off of the second switching transistor Q2, thereby adjusting the rotation speed of the motor.

[0094] Optionally, in this embodiment, the current detection module 10 includes: a seventh resistor R7;

[0095] The first terminal of the seventh resistor R7 is respectively connected to the output terminal of the second switching transistor Q2 and the second terminal of the sixth resistor R6, and the second terminal of the seventh resistor R7 is connected to the anode of the second diode D2.

[0096] It should be noted that the seventh resistor R7 is a current sampling resistor for collecting the drive current in the second drive circuit 303. In addition, considering that during the driving process of the motor, the current directions in the first drive circuit 302 and the second drive circuit 303 are different, but the current values in a complete cycle are the same. By setting a sampling resistor in the second drive circuit 303, although only the current in the second drive circuit 303 can be collected, the control module 20 can determine the current in the first drive circuit 302 based on the current in the second drive circuit 303, and then determine the current for driving the motor in a complete cycle. Of course, a current sampling resistor can also be separately set in the first drive circuit 302, or current sampling resistors can be set in both the first drive circuit 302 and the second drive circuit 303, which can be set according to specific situations and will not be elaborated here.

[0097] Referring to Figure 4 , in this embodiment, during the normal operation of the motor, the seventh resistor R7 can be used to collect the current current for driving the motor, and then the current motor speed can be determined through an algorithm or a mapping relationship. Then, through a preset algorithm, the duty cycle and frequency of the PWM drive signal are adjusted based on the current motor speed and the target motor speed to obtain the adjusted PWM drive signal. The drive circuit of the motor is determined according to the phase of the output voltage. Then, when the phase is less than 180 degrees, the control module 20 outputs the adjusted PWM drive signal to the first drive circuit 302 through the first output pin, and uses the adjusted PWM drive signal to drive the motor, thereby completing the motor speed regulation process during the positive half-cycle of the power supply; when the phase is greater than or equal to 180 degrees, the control module 20 outputs the adjusted PWM drive signal to the second drive circuit 303 through the second output pin, and uses the adjusted PWM drive signal to drive the motor, thereby completing the motor speed regulation process during the negative half-cycle of the power supply, and when the second drive circuit 303 is conducting, the seventh resistor R7 is used to continue collecting the current current for driving the motor.

[0098] In Figure 3 , when the second drive circuit 303 is conducting, the voltage between the seventh resistor R7 and the sixth resistor R6 can be collected by using the seventh resistor R7, and then the current in the second drive circuit 302 is determined according to the collected voltage value and the resistance value of the seventh resistor R7.

[0099] In Figure 3 , the motor speed regulation circuit further includes: a first energy storage capacitor EC1 and a second energy storage capacitor EC2;

[0100] The first energy storage capacitor EC1 is connected in parallel with the first drive circuit 303 between the live wire ACL and the neutral wire ACN;

[0101] The second energy storage capacitor EC2 is arranged in parallel with the second drive circuit 303 between the live wire ACL and the neutral wire ACN.

[0102] It can be understood that during the motor drive process, there is a motor freewheeling process, and this motor freewheeling process requires an additional power supply. In this embodiment, by setting up an energy storage capacitor, the energy stored in the energy storage capacitor can execute the motor freewheeling process to avoid the abnormal execution of the motor freewheeling process. Of course, the energy storage capacitor can store energy using the voltage between the live wire ACL and the neutral wire ACN of the power supply when the corresponding drive circuit is turned on, and execute the motor freewheeling during the freewheeling process.

[0103] In addition, to achieve the above object, the present invention also proposes a motor power supply system, including: a power supply and the motor speed control circuit according to any one of the embodiments.

[0104] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied to other related technical fields, are equally included in the patent protection scope of the present invention.

Claims

1. A motor speed regulation circuit, characterized in that, it includes: a current detection module, a control module, and a drive module; wherein, the current detection module is respectively connected to the control module and the motor, and the drive module is respectively connected to the control module and the motor; the current detection module is configured to detect the current current of the motor and output the current current to the control module; the control module is configured to determine the current motor speed according to the current current, adjust the PWM drive signal according to the current motor speed and the target motor speed, and output the adjusted PWM drive signal to the drive module; and the drive module is further configured to drive the motor by using the adjusted PWM drive signal when receiving the adjusted PWM drive signal, so that the speed of the motor is adjusted to the target motor speed.

2. The motor speed regulation circuit according to claim 1, characterized in that, the motor speed regulation circuit further includes: a zero-crossing detection module; the zero-crossing detection module is respectively connected to the power supply and the control module; the zero-crossing detection module is configured to detect the phase of the power supply voltage output by the power supply and send the phase to the control module; the control module is further configured to determine the drive loop based on the phase and send the adjusted PWM drive signal to the drive module through the pin corresponding to the drive loop; and the drive module is configured to drive the motor according to the adjusted PWM drive signal and the drive loop, so that the speed of the motor is adjusted to the target motor speed.

3. The motor speed regulation circuit according to claim 2, characterized in that, the drive module includes: a drive management unit and a first drive loop; the drive management unit is respectively connected to the control module and the first drive circuit; the control module is further configured to send the adjusted PWM drive signal to the drive management unit through the pin corresponding to the first drive loop when the phase is less than the preset phase; the drive management unit is configured to output the adjusted PWM drive signal to the corresponding first drive loop when receiving the adjusted PWM drive signal; and the first drive loop is configured to drive the motor based on the received adjusted PWM drive signal, so that the speed of the motor is adjusted to the target motor speed.

4. The motor speed regulation circuit according to claim 3, characterized in that, the drive module further includes: a second drive loop; the second drive loop is connected to the drive management unit; the control module is further configured to send the adjusted PWM drive signal to the drive management unit through the pin corresponding to the second drive loop when the phase is not less than the preset phase; the drive management unit is configured to output the adjusted PWM drive signal to the corresponding second drive loop when receiving the adjusted PWM drive signal; and The second driving circuit is used to drive the motor based on the received adjusted PWM driving signal, so as to adjust the rotational speed of the motor to the target motor rotational speed.

5. The motor speed regulation circuit according to claim 4, wherein, the driving management unit includes: a management chip and first to second resistors; wherein, a first input terminal of the management chip is connected to a first output pin of the control module through a first resistor; a second input terminal of the management chip is connected to a second output pin of the control module through a second resistor; a first output pin of the management chip is connected to the first driving circuit; and a second output pin of the management chip is connected to the second driving circuit.

6. The motor speed regulation circuit according to claim 5, wherein, the first driving circuit includes: a first switching tube, third to fourth resistors, and a first diode; wherein, an anode of the first diode is connected to a live wire of the power supply, and a cathode of the first diode is connected to an input terminal of the first switching tube; a control terminal of the first switching tube is respectively connected to a second end of the third resistor and a first end of the fourth resistor, and an output terminal of the first switching tube is connected to a neutral wire of the power supply through the motor; and a first end of the third resistor is connected to the first output pin of the management chip, and a second end of the fourth resistor is connected to the output terminal of the first switching tube.

7. The motor speed regulation circuit according to claim 5, wherein, the second driving circuit includes: a second switching tube, fifth to sixth resistors, and a second diode; wherein, an anode of the second diode is connected to an output terminal of the second switching tube, and a cathode of the second diode is connected to the live wire of the power supply; a control terminal of the second switching tube is respectively connected to a second end of the fifth resistor and a first end of the sixth resistor, and an input terminal of the second switching tube is connected to the neutral wire of the power supply through the motor; and a first end of the fifth resistor is connected to the second output pin of the management chip, and a second end of the sixth resistor is connected to the output terminal of the second switching tube.

8. The motor speed regulation circuit according to claim 7, wherein, the current detection module includes: a seventh resistor; a first end of the seventh resistor is respectively connected to the output terminal of the second switching tube and a second end of the sixth resistor, and a second end of the seventh resistor is connected to an anode of the second diode.

9. The motor speed regulation circuit according to claim 6, wherein, the motor speed regulation circuit further includes: a first energy storage capacitor and a second energy storage capacitor; the first energy storage capacitor is arranged in parallel with the first driving circuit between the live wire and the neutral wire; and the second energy storage capacitor is arranged in parallel with the second driving circuit between the live wire and the neutral wire.

10. A motor power supply system, wherein, it includes: a power supply and the motor speed regulation circuit according to any one of claims 1-9.

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