Motor driving circuit and motor driving method

Abstract

The invention discloses a motor driving circuit and a motor driving method. The motor driving circuit comprises a controller, a voltage conversion branch, a first driving branch, a second driving branch and a third driving branch. The first driving branch comprises a first switch unit and a second switch unit. The first driving branch generates a first driving voltage when the first switch unit is switched on, and generates a second driving voltage when the second switch unit is switched on. The second driving branch comprises a third switch unit and a fourth switch unit. The second driving branch generates a third driving voltage when the third switch unit is switched on, and generates a fourth driving voltage when the fourth switch unit is switched on. And the third driving branch comprises a fifth switch unit and a sixth switch unit. And the third driving branch generates a fifth driving voltage when the fifth switch unit is switched on, and generates a sixth driving voltage when the sixth switch unit is switched on. Through the mode, the risk that the motor is damaged can be reduced, and the reliability is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of motor drive technology, and in particular to a motor drive circuit and a motor drive method. Background Art

[0002] With the continuous improvement of home appliance standards and people's increasing attention to energy consumption, frequency conversion technology is increasingly used in home appliances, among which the use of BLDC motors has become the mainstream of frequency conversion motors and is widely used in various fields, including home appliances, automobiles, industrial automation, medical equipment, etc. BLDC frequency conversion motors have significant advantages, especially in some occasions requiring high precision, high speed, and high reliability.

[0003] At present, the circuit for driving BLDC variable frequency motor is usually as follows Figure 1 The bridge circuit shown in the figure has a specific control method of driving the BLDC motor by switching on different upper and lower bridges. However, this driving method may cause an abnormal situation in which the upper and lower bridges are turned on at the same time, which may even damage the motor. Summary of the invention

[0004] The embodiments of the present application provide a motor driving circuit and a motor driving method, which can reduce the risk of motor damage and improve reliability.

[0005] In a first aspect, an embodiment of the present application provides a motor drive circuit, wherein the motor includes a first winding, a second winding, and a third winding, wherein a first end of the first winding is connected to a first end of the second winding and a first end of the third winding, respectively, and the motor drive circuit includes:

[0006] A controller, outputting a first control signal, a second control signal, a third control signal, a fourth control signal, a fifth control signal and a sixth control signal;

[0007] a voltage conversion branch, wherein a first end of the voltage conversion branch is connected to an input power supply and is configured to generate a first supply voltage and a second supply voltage based on the input power supply;

[0008] A first driving branch, comprising a first switch unit and a second switch unit, wherein the first switch unit is connected between the second end of the voltage conversion branch and the second end of the first winding, and the second switch unit is connected between the third end of the voltage conversion branch and the second end of the second winding;

[0009] The first driving branch is configured to generate a first driving voltage based on the first supply voltage to drive the motor and generate a current flowing from the second end of the first winding to the second end of the second winding when the first switch unit is turned on in response to the first control signal;

[0010] The first driving branch is further configured to generate a second driving voltage based on the second supply voltage to drive the motor and generate a current flowing from the second end of the second winding to the second end of the first winding when the second switch unit is turned on in response to the second control signal;

[0011] The second driving branch includes a third switch unit and a fourth switch unit, wherein the third switch unit is connected between the fourth end of the voltage conversion branch and the second end of the first winding, and the fourth switch unit is connected between the fifth end of the voltage conversion branch and the second end of the third winding;

[0012] The second driving branch is configured to generate a third driving voltage based on the first supply voltage to drive the motor and generate a current flowing from the second end of the first winding to the second end of the third winding when the third switch unit is turned on in response to the third control signal;

[0013] The second driving branch is further configured to generate a fourth driving voltage based on the second supply voltage to drive the motor and generate a current flowing from the second end of the third winding to the second end of the first winding when the fourth switch unit is turned on in response to the fourth control signal;

[0014] a third driving branch, comprising a fifth switch unit and a sixth switch unit, wherein the fifth switch unit is connected between the sixth end of the voltage conversion branch and the second end of the second winding, and the fifth switch unit is connected between the seventh end of the voltage conversion branch and the second end of the third winding;

[0015] The third driving branch is configured to generate a fifth driving voltage based on the first supply voltage to drive the motor and generate a current flowing from the second end of the second winding to the second end of the third winding when the fifth switch unit is turned on in response to the fifth control signal;

[0016] The third driving branch is also configured to generate a sixth driving voltage based on the second supply voltage to drive the motor and generate a current flowing from the second end of the third winding to the second end of the second winding when the sixth switching unit is turned on in response to the sixth control signal.

[0017] In one or more embodiments, the voltage conversion branch includes:

[0018] A transformer, comprising a first primary side, a first secondary side, a second secondary side, a third secondary side and a fourth secondary side, wherein the second end of the first primary side is the first end of the voltage conversion branch, the first end of the second secondary side is the second end of the voltage conversion branch, the second end of the second secondary side is the third end of the voltage conversion branch, the first end of the third secondary side is the fourth end of the voltage conversion branch, the second end of the third secondary side is the fifth end of the voltage conversion branch, the first end of the fourth secondary side is the sixth end of the voltage conversion branch, and the second end of the fourth secondary side is the seventh end of the voltage conversion branch;

[0019] a seventh switch unit, connected to the controller and to the input power supply through the first primary side, configured to generate the first supply voltage on the first primary side based on the input power supply in response to the pulse width modulation signal output by the controller, wherein the product of the voltage of the input power supply and the duty cycle of the pulse width modulation signal is the first supply voltage;

[0020] The power supply unit is connected to the first secondary side and is configured to generate the second supply voltage based on the voltage on the first primary side when the seventh switch unit is turned off.

[0021] In one or more embodiments, the seventh switch unit includes a first switch tube, and the voltage conversion branch further includes a first capacitor;

[0022] The first end of the first switch tube is connected to the controller, the second end of the first switch tube and the second end of the first capacitor are both grounded, the third end of the first switch tube is connected to the same-name end of the first primary side, and the opposite-name end of the first primary side and the first end of the first capacitor are both connected to the input power supply.

[0023] In one or more embodiments, the transformer further includes a second primary side, and the voltage conversion branch further includes a second switch tube and a first diode;

[0024] The same-name end of the second primary side is connected to the input power supply, the opposite-name end of the second primary side is connected to the second end of the second switch tube, the third end of the second switch tube is connected to the cathode of the first diode, the anode of the first diode is grounded, and the first end of the second switch tube is connected to the controller.

[0025] In one or more embodiments, the power supply unit includes a second diode, a second capacitor and a first resistor;

[0026] The anode of the second diode is connected to the same-name end of the first secondary side, the cathode of the second diode is respectively connected to the first end of the second capacitor and the first end of the first resistor, and the opposite-name end of the first secondary side, the second end of the second capacitor and the second end of the first resistor are all grounded.

[0027] In one or more embodiments, the first switch unit includes a third switch tube having a parasitic diode, the second switch unit includes a fourth switch tube having a parasitic diode, and the first driving branch further includes a third diode, a fourth diode, a second resistor, a third capacitor and a first inductor;

[0028] The first end of the third switch tube and the first end of the fourth switch tube are both connected to the controller, the third end of the third switch tube is connected to the same-name end of the second secondary side, the second end of the third switch tube is respectively connected to the anode of the third diode, the first end of the second resistor and the second end of the first winding, the cathode of the third diode is respectively connected to the first end of the first inductor, the cathode of the fourth diode and the second end of the fourth switch tube, the third end of the fourth switch tube is connected to the opposite-name end of the second secondary side, the second end of the first inductor is respectively connected to the anode of the fourth diode, the second end of the second resistor and the second end of the second winding, and the third capacitor is connected in parallel with the second resistor.

[0029] In one or more embodiments, the third switch unit includes a fifth switch tube having a parasitic diode, the fourth switch unit includes a sixth switch tube having a parasitic diode, and the second driving branch further includes a fifth diode, a sixth diode, a third resistor, a fourth capacitor and a second inductor;

[0030] The first end of the fifth switch tube and the first end of the sixth switch tube are connected to the controller, the third end of the fifth switch tube is connected to the same-name end of the third secondary side, the second end of the fifth switch tube is respectively connected to the anode of the fifth diode, the first end of the third resistor and the second end of the first winding, the cathode of the fifth diode is respectively connected to the first end of the second inductor, the cathode of the sixth diode and the second end of the sixth switch tube, the anode of the sixth diode is respectively connected to the second end of the third resistor, the second end of the second inductor and the second end of the third winding, the third end of the sixth switch tube is connected to the opposite-name end of the third secondary side, and the fourth capacitor is connected in parallel with the third resistor.

[0031] In one or more embodiments, the fifth switch unit includes a seventh switch tube having a parasitic diode, the sixth switch unit includes an eighth switch tube having a parasitic diode, and the third driving branch further includes a seventh diode, an eighth diode, a fourth resistor, a fifth capacitor and a third inductor;

[0032] The first end of the seventh switch tube and the first end of the eighth switch tube are both connected to the controller, the third end of the seventh switch tube is connected to the same-name end of the fourth secondary side, the second end of the seventh switch tube is respectively connected to the anode of the seventh diode, the first end of the fourth resistor and the second end of the second winding, the cathode of the seventh diode is respectively connected to the second end of the eighth switch tube, the first end of the third inductor and the cathode of the eighth diode, the second end of the third inductor is respectively connected to the anode of the eighth diode, the second end of the fourth resistor and the second end of the third winding, the fifth capacitor is connected in parallel with the fourth resistor, and the third end of the eighth switch tube is connected to the opposite-name end of the fourth secondary side.

[0033] In a second aspect, an embodiment of the present application provides a motor driving method, which is applied to the motor driving circuit as described above, and the motor driving method includes:

[0034] Controlling the first switch tube in the motor drive circuit to be alternately turned on and off;

[0035] Controlling the sixth switch tube in the motor drive circuit to be turned on, and controlling the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube in the motor drive circuit to be turned off, so that the motor is in a first driving state;

[0036] Controlling the fourth switch tube to be turned on, and controlling the second switch tube, the third switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in a second driving state;

[0037] Controlling the second switch tube and the seventh switch tube to be turned on, and controlling the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, and the eighth switch tube to be turned off, so that the motor is in a third driving state;

[0038] Controlling the second switch tube and the fifth switch tube to be turned on, and controlling the third switch tube, the fourth switch tube, the sixth switch tube, the seventh switch tube, and the eighth switch tube to be turned off, so that the motor is in a fourth driving state;

[0039] controlling the second switch tube and the third switch tube to be turned on, and controlling the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in a fifth driving state;

[0040] The eighth switch tube is controlled to be turned on, and the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube and the seventh switch tube are controlled to be turned off, so that the motor is in a sixth driving state.

[0041] In one or more embodiments, the motor driving method further includes:

[0042] Controlling the motor to be in a first driving state, a second driving state, a third driving state, a fourth driving state, a fifth driving state and a sixth driving state in sequence, so that the motor runs in a first direction;

[0043] Alternatively, the motor is controlled to be in a sixth driving state, a fifth driving state, a fourth driving state, a third driving state, a second driving state and a first driving state in sequence, so that the motor runs in a second direction, wherein the second direction is opposite to the first direction.

[0044] The beneficial effects of the present application are as follows: the motor of the embodiment of the present application includes a first winding, a second winding and a third winding, the first end of the first winding is connected to the first end of the second winding and the first end of the third winding respectively, and the motor drive circuit includes a controller, a voltage conversion branch, a first drive branch, a second drive branch and a third drive branch. Among them, the controller outputs a first control signal, a second control signal, a third control signal, a fourth control signal, a fifth control signal and a sixth control signal. The voltage conversion branch is configured to generate a first supply voltage and a second supply voltage based on an input power supply. The first drive branch includes a first switch unit and a second switch unit, and the first drive branch is configured to generate a first drive voltage based on the first supply voltage when the first switch unit is turned on in response to the first control signal, so as to drive the motor and generate a current flowing from the second end of the first winding to the second end of the second winding. The first drive branch is also configured to generate a second drive voltage based on the second supply voltage when the second switch unit is turned on in response to the second control signal, so as to drive the motor and generate a current flowing from the second end of the second winding to the second end of the first winding. The second driving branch includes a third switch unit and a fourth switch unit, and the second driving branch is configured to generate a third driving voltage based on the first power supply voltage when the third switching unit is turned on in response to a third control signal, so as to drive the motor and generate a current flowing from the second end of the first winding to the second end of the third winding. The second driving branch is also configured to generate a fourth driving voltage based on the second power supply voltage when the fourth switching unit is turned on in response to a fourth control signal, so as to drive the motor and generate a current flowing from the second end of the third winding to the second end of the first winding. The third driving branch includes a fifth switch unit and a sixth switch unit, and the third driving branch is configured to generate a fifth driving voltage based on the first power supply voltage when the fifth switching unit is turned on in response to a fifth control signal, so as to drive the motor and generate a current flowing from the second end of the second winding to the second end of the third winding. The third driving branch is also configured to generate a sixth driving voltage based on the second power supply voltage when the sixth switching unit is turned on in response to a sixth control signal, so as to drive the motor and generate a current flowing from the second end of the third winding to the second end of the second winding. Through the above method, the driving process of the motor can be realized, and there is no upper and lower bridge connection relationship between the two switch units in each driving branch, such as between the first switch unit and the second switch unit of the first driving branch, so there will be no abnormal situation that the same upper and lower bridges are turned on at the same time, thereby reducing the risk of damage to the motor and improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplary descriptions are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0046] Figure 1 It is a schematic diagram of the circuit structure of a driving motor in the related art;

[0047] Figure 2 The structure of the motor drive circuit provided in the embodiment of the present application is shown in FIG. Figure 1 ;

[0048] Figure 3 The structure of the motor drive circuit provided in the embodiment of the present application is shown in FIG. Figure 2 ;

[0049] Figure 4 is a circuit structure diagram of a motor drive circuit provided in an embodiment of the present application;

[0050] Figure 5 The process of the motor driving method provided in the embodiment of the present application is Figure 1 ;

[0051] Figure 6 The process of the motor driving method provided in the embodiment of the present application is Figure 2 . DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0053] It should be noted that, when an element is described as being “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0054] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0055] In the related art, the circuit structure of the driving motor is usually a bridge circuit, such as Figure 1 As shown. The motor M1 includes a first winding L1, a second winding L2 and a third winding L3. The bridge circuit includes a switch tube QA1, a switch tube QA2, a switch tube QA3, a switch tube QA4, a switch tube QA5 and a switch tube QA6. The motor M1 is an electric motor powered by three AC phases, that is, a three-phase motor, such as a BLDC motor (Brushless DC Motor).

[0056] Specifically, the switch tube QA1 is connected to the switch tube QA2 and is connected to the second end of the first winding L1. The switch tube QA3 is connected to the switch tube QA4 and is connected to the second end of the second winding L2. The switch tube QA5 is connected to the switch tube QA6 and is connected to the second end of the third winding L3. The first end of the first winding L1 is respectively connected to the first end of the second winding L2 and the first end of the third winding L3.

[0057] In actual applications, the motor is driven by selecting different upper and lower bridges (for example, selecting switch tube QA1 and switch tube QA4). However, this driving method may cause an abnormal situation in which the same upper and lower bridges are turned on at the same time (for example, switch tube QA1 and switch tube QA2 are turned on at the same time), and even cause the motor M1 to be damaged.

[0058] Based on this, an embodiment of the present application provides a motor drive circuit, which realizes the driving of the motor M1 while adopting a connection relationship without upper and lower bridges to avoid the abnormal situation that the same upper and lower bridges are turned on at the same time, thereby reducing the risk of motor damage and improving reliability.

[0059] Please refer to Figure 2 , Figure 2 A schematic diagram of the structure of a motor drive circuit provided in an embodiment of the present application. Among them, the motor M1 includes a first winding L1, a second winding L2 and a third winding L3. The first end of the first winding L1 is connected to the first end of the second winding L2 and the first end of the third winding L3 respectively. The motor drive circuit 1000 includes a first drive branch 100, a second drive branch 200, a third drive branch 300, a voltage conversion branch 400 and a controller 500. The first drive branch 100 includes a first switch unit 101 and a second switch unit 102. The second drive branch 200 includes a third switch unit 201 and a fourth switch unit 202. The third drive branch 300 includes a fifth switch unit 301 and a sixth switch unit 302.

[0060] The controller 500 may be a microcontroller unit (MCU) or a digital signal processing (DSP) controller.

[0061] The first end of the voltage conversion branch 400 is connected to the input power source V1. The first switch unit 101 is connected between the second end of the voltage conversion branch 400 and the second end of the first winding L1, and the second switch unit 102 is connected between the third end of the voltage conversion branch 400 and the second end of the second winding L2. The third switch unit 201 is connected between the fourth end of the voltage conversion branch 400 and the second end of the first winding L1, and the fourth switch unit 202 is connected between the fifth end of the voltage conversion branch 400 and the second end of the third winding L3. The fifth switch unit 301 is connected between the sixth end of the voltage conversion branch 400 and the second end of the second winding L2, and the fifth switch unit 301 is connected between the seventh end of the voltage conversion branch 400 and the second end of the third winding L3.

[0062] Specifically, the controller 500 outputs a first control signal, a second control signal, a third control signal, a fourth control signal, a fifth control signal, and a sixth control signal. The voltage conversion branch 400 is configured to generate a first supply voltage and a second supply voltage based on the input power supply V1. The first driving branch 100 is configured to generate a first driving voltage based on the first supply voltage when the first switch unit 101 is turned on in response to the first control signal, so as to drive the motor M1 and generate a current flowing from the second end of the first winding L1 to the second end of the second winding L2. The first driving branch 100 is also configured to generate a second driving voltage based on the second supply voltage when the second switch unit 102 is turned on in response to the second control signal, so as to drive the motor M1 and generate a current flowing from the second end of the second winding L2 to the second end of the first winding L1. The second driving branch 200 is configured to generate a third driving voltage based on the first supply voltage when the third switch unit 201 is turned on in response to the third control signal, so as to drive the motor M1 and generate a current flowing from the second end of the first winding L1 to the second end of the third winding L3. The second driving branch 200 is further configured to generate a fourth driving voltage based on the second power supply voltage to drive the motor M1 and generate a current flowing from the second end of the third winding L3 to the second end of the first winding L1 when the fourth switch unit 202 is turned on in response to the fourth control signal. The third driving branch 300 is configured to generate a fifth driving voltage based on the first power supply voltage to drive the motor M1 and generate a current flowing from the second end of the second winding L2 to the second end of the third winding L3 when the fifth switch unit 301 is turned on in response to the fifth control signal. The third driving branch 300 is further configured to generate a sixth driving voltage based on the second power supply voltage to drive the motor M1 and generate a current flowing from the second end of the third winding L3 to the second end of the second winding L2 when the sixth switch unit 302 is turned on in response to the sixth control signal.

[0063] By the above method, it is possible to generate a current flowing from the second end of the first winding L1 to the second end of the second winding L2, a current flowing from the second end of the second winding L2 to the second end of the first winding L1, a current flowing from the second end of the first winding L1 to the second end of the third winding L3, a current flowing from the second end of the third winding L3 to the second end of the first winding L1, a current flowing from the second end of the second winding L2 to the second end of the third winding L3, and a current flowing from the second end of the third winding L3 to the second end of the second winding L2. It can be seen that the driving process of the motor M1 can be realized. In addition, between the two switch units in each driving branch, such as between the first switch unit 101 and the second switch unit 102 of the first driving branch 100, there is no upper and lower bridge connection relationship, so there will be no abnormal situation that the same upper and lower bridges are turned on at the same time, thereby reducing the risk of damage to the motor M1 and improving reliability. Secondly, in the present application, it is not necessary to set the voltage of the input power supply V1 to be equal to the driving voltage of the motor M1. This is because even if the voltage of the input power supply V1 is lower than the driving voltage of the motor M1, the driving voltage of the motor M1 can be met by stepping up or down the voltage conversion branch 400. Figure 1 The circuit structure shown must satisfy the requirement that the voltage of the input power supply is equal to the voltage of the motor M1. This application can be applied to more application scenarios and is more practical.

[0064] In one embodiment, if Figure 3 As shown, the voltage conversion branch 400 includes a transformer, a seventh switch unit 401 and a power supply unit 402. The transformer includes a first primary side LA1, a first secondary side LB1, a second secondary side LB2, a third secondary side LB3 and a fourth secondary side LB4.

[0065] Among them, the second end of the first primary side LA1 is the first end of the voltage conversion branch 400, the first end of the second secondary side LB2 is the second end of the voltage conversion branch 400, the second end of the second secondary side LB2 is the third end of the voltage conversion branch 400, the first end of the third secondary side LB3 is the fourth end of the voltage conversion branch 400, the second end of the third secondary side LB3 is the fifth end of the voltage conversion branch 400, the first end of the fourth secondary side LB4 is the sixth end of the voltage conversion branch 400, and the second end of the fourth secondary side LB4 is the seventh end of the voltage conversion branch 400. The seventh switch unit 401 is connected to the controller 500 and is connected to the input power supply V1 through the first primary side LA1. The power supply unit 402 is connected to the first secondary side LB1.

[0066] Specifically, the seventh switch unit 401 is configured to generate a first supply voltage on the first primary side LA1 based on the input power supply V1 in response to the pulse width modulation signal output by the controller 500, wherein the product of the voltage of the input power supply V1 and the duty cycle of the pulse width modulation signal is the first supply voltage. A pulse width modulation (PWM) signal is a periodic signal characterized in that the pulse width of the signal changes over time and is usually used to represent a digitized version of an analog signal. The power supply unit 402 is configured to generate a second supply voltage based on the voltage on the first primary side LA1 when the seventh switch unit 401 is turned off.

[0067] In practical applications, when the controller 500 outputs a pulse width modulation signal to the seventh switch unit 401, the seventh switch unit 401 is continuously switched on and off alternately. When the seventh switch unit 401 is turned on, the input power supply V1 charges the first primary LA1; when the seventh switch unit 401 is turned off, the first primary LA1 generates a temporary reverse current, which is called a reverse induced current. The existence of the reverse induced current will cause a voltage to be generated across the inductor, which is called a self-induced voltage. The first supply voltage is obtained by the voltage charged by the input power supply V1 to the first power supply LA1. Since the input power supply V1 charges the first primary LA1 only when the seventh switch unit 401 is turned on, the first supply voltage (denoted as VO1) is obtained by multiplying the voltage of the input power supply V1 by the duty cycle (denoted as D) of the pulse width modulation signal, that is, VO1=V1*D. The second supply voltage is obtained based on the voltage on the first primary side LA1 when the seventh switch unit 401 is turned off, that is, the second supply voltage (denoted as VO2) is obtained by multiplying the ratio of the number of winding coils of the first secondary side LB1 (denoted as N2) to the number of winding coils of the first primary side LA1 (denoted as N1) and the self-induction voltage (denoted as VL1), that is, VO2=N2 / N1*VL1.

[0068] Please refer to Figure 4 , Figure 4 FIG. 1 shows an exemplary circuit structure of a motor drive circuit 1000. Figure 4 As shown, the seventh switch unit 401 includes a first switch tube Q1, and the voltage conversion branch 400 also includes a first capacitor C1.

[0069] Among them, the first end of the first switch tube Q1 is connected to the controller 500, the second end of the first switch tube Q1 and the second end of the first capacitor C1 are both grounded GND, the third end of the first switch tube Q1 is connected to the same-name end of the first primary side LA1, and the opposite-name end of the first primary side LA1 and the first end of the first capacitor C1 are both connected to the input power supply V1.

[0070] Specifically, the first capacitor C1 is a filter capacitor. When the first switch tube Q1 is turned on, the input power source V1 charges the first primary LA1, and the opposite-name end of the first primary LA1 is positive, and the same-name end is negative; when the first switch tube Q1 is turned off, the input power source V1 stops charging the first primary LA1, and the first primary LA1 generates a self-induced voltage, and the same-name end of the first primary LA1 is positive, and the opposite-name end is negative.

[0071] In this embodiment, the first switch tube Q1 is an NMOS tube as an example. The gate of the NMOS tube is the first end of the first switch tube Q1, the source of the NMOS tube is the second end of the first switch tube Q1, and the drain of the NMOS tube is the third end of the first switch tube Q1.

[0072] In addition, the first switch tube Q1 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0073] In this embodiment, the transformer further includes a second primary side LA2, and the voltage conversion branch 400 further includes a second switch tube Q2 and a first diode D1.

[0074] Among them, the same-name end of the second primary side LA2 is connected to the input power supply V1, the opposite-name end of the second primary side LA2 is connected to the second end of the second switch tube Q2, the third end of the second switch tube Q2 is connected to the cathode of the first diode D1, the anode of the first diode D1 is grounded, and the first end of the second switch tube Q2 is connected to the controller 500.

[0075] Specifically, the controller 500 is also used to output a seventh control signal. The second switch tube Q2 is turned on when receiving the seventh control signal (corresponding to a high level signal in this embodiment), and is turned off when not receiving the seventh control signal (which can also be understood as the second switch tube Q2 receiving a low level signal). When the second switch tube Q2 is turned on, the second primary side LA2 acts as a reset winding to reset the magnetic flux, thereby avoiding the magnetic flux saturation of the first primary side LA1; when the second switch tube Q2 is turned off, the second primary side LA2 does not work.

[0076] In this embodiment, the second switch tube Q2 is a PMOS tube as an example. The gate of the PMOS tube is the first end of the second switch tube Q2, the source of the PMOS tube is the second end of the second switch tube Q2, and the drain of the PMOS tube is the third end of the second switch tube Q2.

[0077] In addition, the second switch tube Q2 can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0078] In this embodiment, the power supply unit 402 includes a second diode D2 , a second capacitor C2 , and a first resistor R1 .

[0079] Among them, the anode of the second diode D2 is connected to the same-name end of the first secondary side LB1, the cathode of the second diode D2 is respectively connected to the first end of the second capacitor C2 and the first end of the first resistor R1, and the opposite-name end of the first secondary side LB1, the second end of the second capacitor C2 and the second end of the first resistor R1 are all grounded GND.

[0080] Specifically, the second diode D2 is a freewheeling diode. The second capacitor C2 is a filter capacitor. The first resistor R1 is a dummy load of the first secondary side LB1, and is used to output a stable first supply voltage at the first end of the second capacitor C2.

[0081] In this embodiment, the first switch unit 101 includes a third switch tube Q3 having a parasitic diode, the second switch unit 102 includes a fourth switch tube Q4 having a specific parasitic diode, and the first driving branch 100 also includes a third diode D3, a fourth diode D4, a second resistor R2, a third capacitor C3 and a first inductor LC1.

[0082] Among them, the first end of the third switch tube Q3 and the first end of the fourth switch tube Q4 are both connected to the controller 500, the third end of the third switch tube Q3 is connected to the same-name end of the second secondary side LB2, the second end of the third switch tube Q3 is respectively connected to the anode of the third diode D3, the first end of the second resistor R2 and the second end of the first winding L1, the cathode of the third diode D3 is respectively connected to the first end of the first inductor LC1, the cathode of the fourth diode D4 and the second end of the fourth switch tube Q4, the third end of the fourth switch tube Q4 is connected to the opposite-name end of the second secondary side LB2, the second end of the first inductor LC1 is respectively connected to the anode of the fourth diode D4, the second end of the second resistor R2 and the second end of the second winding L2, and the third capacitor C3 is connected in parallel with the second resistor R2.

[0083] Specifically, the third diode D3 is a freewheeling diode. The fourth diode D4 is used to short-circuit the first inductor LC1.

[0084] In this embodiment, the third switch tube Q3 and the fourth switch tube Q4 are PMOS tubes as an example. The gate of the PMOS tube is the first end of the third switch tube Q3 (fourth switch tube Q4), the source of the PMOS tube is the second end of the third switch tube Q3 (fourth switch tube Q4), and the drain of the PMOS tube is the third end of the third switch tube Q3 (fourth switch tube Q4).

[0085] In addition, the third switch tube Q3 and the fourth switch tube Q4 can be any controllable switches, such as insulated gate bipolar transistor (IGBT) devices, integrated gate commutated thyristor (IGCT) devices, gate turn-off thyristor (GTO) devices, silicon controlled rectifier (SCR) devices, junction gate field effect transistor (JFET) devices, MOS controlled thyristor (MCT) devices, etc.

[0086] In addition, when the third switch tube Q3 and the fourth switch tube Q4 use devices without parasitic diodes, diodes need to be added accordingly. For example, when the third switch tube Q3 uses a triode, a diode connected in parallel between the emitter and the collector of the third switch tube Q3 needs to be added, the anode of the diode is connected to the same-name end of the second secondary side LB2, and the cathode is connected to the anode of the third diode D3.

[0087] In this embodiment, the third switch unit 201 includes a fifth switch tube Q5 having a parasitic diode, the fourth switch unit 202 includes a sixth switch tube Q6 having a specific parasitic diode, and the second driving branch 200 also includes a fifth diode D5, a sixth diode D6, a third resistor R3, a fourth capacitor C4 and a second inductor LC2.

[0088] Among them, the first end of the fifth switch tube Q5 and the first end of the sixth switch tube Q6 are connected to the controller 500, the third end of the fifth switch tube Q5 is connected to the same-name end of the third secondary side LB3, the second end of the fifth switch tube Q5 is respectively connected to the anode of the fifth diode D5, the first end of the third resistor R3 and the second end of the first winding L1, the cathode of the fifth diode D5 is respectively connected to the first end of the second inductor LC2, the cathode of the sixth diode D6 and the second end of the sixth switch tube Q6, the anode of the sixth diode D6 is respectively connected to the second end of the third resistor R3, the second end of the second inductor LC2 and the second end of the second winding L2, the third end of the sixth switch tube Q6 is connected to the opposite-name end of the third secondary side LB3, and the fourth capacitor C4 is connected in parallel with the third resistor R3.

[0089] Specifically, the fifth diode D5 is a freewheeling diode. The sixth diode D6 is used to short-circuit the first inductor LC1.

[0090] In this embodiment, the fifth switch tube Q5 and the sixth switch tube Q6 are PMOS tubes as an example. The gate of the PMOS tube is the first end of the fifth switch tube Q5 (sixth switch tube Q6), the source of the PMOS tube is the second end of the fifth switch tube Q5 (sixth switch tube Q6), and the drain of the PMOS tube is the third end of the fifth switch tube Q5 (sixth switch tube Q6).

[0091] In addition, the fifth switch tube Q5 and the sixth switch tube Q6 can be any controllable switches, such as insulated gate bipolar transistor (IGBT) devices, integrated gate commutated thyristor (IGCT) devices, gate turn-off thyristor (GTO) devices, silicon controlled rectifier (SCR) devices, junction gate field effect transistor (JFET) devices, MOS controlled thyristor (MCT) devices, etc.

[0092] In addition, when the fifth switch tube Q5 and the sixth switch tube Q6 are devices without parasitic diodes, diodes need to be added accordingly. For example, when the fifth switch tube Q5 is a triode, a diode connected in parallel between the emitter and the collector of the fifth switch tube Q5 needs to be added, the anode of the diode is connected to the same-name end of the third secondary side LB3, and the cathode is connected to the anode of the fifth diode D5.

[0093] In this embodiment, the fifth switch unit 301 includes a seventh switch tube Q7 having a parasitic diode, the sixth switch unit 302 includes an eighth switch tube Q8 having a specific parasitic diode, and the third driving branch 300 also includes a seventh diode D7, an eighth diode D8, a fourth resistor R4, a fifth capacitor C5 and a third inductor LC3.

[0094] Among them, the first end of the seventh switch tube Q7 and the first end of the eighth switch tube Q8 are both connected to the controller 500, the third end of the seventh switch tube Q7 is connected to the same-name end of the fourth secondary side LB4, the second end of the seventh switch tube Q7 is respectively connected to the anode of the seventh diode D7, the first end of the fourth resistor R4 and the second end of the second winding L2, the cathode of the seventh diode D7 is respectively connected to the second end of the eighth switch tube Q8, the first end of the third inductor LC3 and the cathode of the eighth diode D8, the second end of the third inductor LC3 is respectively connected to the anode of the eighth diode D8, the second end of the fourth resistor R4 and the second end of the third winding L3, the fifth capacitor C5 is connected in parallel with the fourth resistor R4, and the third end of the eighth switch tube Q8 is connected to the opposite-name end of the fourth secondary side LB4.

[0095] Specifically, the seventh diode D7 is a freewheeling diode. The eighth diode D8 is used to short-circuit the first inductor LC1.

[0096] In this embodiment, the seventh switch tube Q7 and the eighth switch tube Q8 are PMOS tubes as an example. The gate of the PMOS tube is the first end of the seventh switch tube Q7 (the eighth switch tube Q8), the source of the PMOS tube is the second end of the seventh switch tube Q7 (the eighth switch tube Q8), and the drain of the PMOS tube is the third end of the seventh switch tube Q7 (the eighth switch tube Q8).

[0097] In addition, the seventh switch tube Q7 and the eighth switch tube Q8 can be any controllable switches, such as insulated gate bipolar transistor (IGBT) devices, integrated gate commutated thyristor (IGCT) devices, gate turn-off thyristor (GTO) devices, silicon controlled rectifier (SCR) devices, junction gate field effect transistor (JFET) devices, MOS controlled thyristor (MCT) devices, etc.

[0098] In addition, when the seventh switch tube Q7 and the eighth switch tube Q8 are devices without parasitic diodes, diodes need to be added accordingly. For example, when the seventh switch tube Q7 is a triode, a diode connected in parallel between the emitter and the collector of the seventh switch tube Q7 needs to be added, the anode of the diode is connected to the same-name end of the fourth secondary side LB4, and the cathode is connected to the anode of the seventh diode D7.

[0099] The following Figure 4 The principle of the circuit structure shown is explained.

[0100] When the controller 500 does not output the seventh control signal (corresponding to a high level signal) to the second switch tube Q2, the second switch tube Q2 is turned off. At the same time, the controller 500 outputs a pulse width modulation signal to the first switch tube Q1 to turn the first switch tube Q1 on and off alternately.

[0101] In this case, if the controller 500 outputs a second control signal (corresponding to a high level signal) to the fourth switch tube Q4 to turn on the fourth switch tube Q4, a second driving voltage will be generated at both ends of the third capacitor C3 to drive the motor M1 and generate a current flowing from the second end of the first winding L1 to the second end of the second winding L2. Specifically, when the first switch tube Q1 is turned on, the input power supply V1 charges the first primary side LA1, and the opposite-name ends of the first primary side LA1, the first secondary side LB1 and the second secondary side LB2 are positive, and the same-name ends are negative, and then the second diode D2 and the third diode D3 are both reversely cut off. When the first switch tube Q1 is turned off, the input power supply V1 stops charging the first primary side LA1, and the first primary side LA1 generates a self-induced voltage, and the same-name ends of the first primary side LA1, the first secondary side LB1 and the second secondary side LB2 are positive, and the opposite-name ends are negative, and then the second diode D2 is forward-conducted. On the one hand, the voltage on the first secondary side LB1 charges the second capacitor C2 through the second diode D2 to generate the second power supply voltage VO2 at the first end of the second capacitor C2; on the other hand, the second secondary side LB2, the parasitic diode of the third switch tube Q3, the third capacitor C3, the fourth diode D4 and the fourth switch tube Q4 form a loop, and the third capacitor C3 is charged by the voltage on the second secondary side LB2, so that the two ends of the third capacitor C3 generate the second driving voltage VD2 (the voltage of the third capacitor C3 is positive at the top and negative at the bottom). The second driving voltage VD2 is obtained by the ratio between the number of winding coils of the first secondary side LB1 (denoted as N2) and the number of winding coils of the second secondary side LB2 (denoted as N3) and the product of the second power supply voltage VO2, that is, VD2=N3 / N2*VO2. It can be seen from the above embodiment that the second power supply voltage VO2 is obtained by the self-induction voltage VL1 of the first primary LA1, and the self-induction voltage of the first primary LA1 is related to the duty cycle of the pulse width modulation signal input to the first switch tube Q1. Therefore, by adjusting the duty cycle of the pulse width modulation signal, the second power supply voltage VO2 can be adjusted, and then the second driving voltage VD2 for driving the motor M1 can be adjusted. Therefore, there is no need to set the voltage of the input power supply V1 equal to the driving voltage of the motor M1 as in the related art, which can be applied to more application scenarios and is more practical.

[0102] If the controller 500 outputs a fourth control signal (corresponding to a high level signal) to the sixth switch tube Q6 to turn on the sixth switch tube Q6, a fourth driving voltage will be generated at both ends of the fourth capacitor C4 to drive the motor M1 and generate a current flowing from the second end of the first winding L1 to the second end of the third winding L3. Specifically, when the first switch tube Q1 is turned on, the input power supply V1 charges the first primary side LA1, and the opposite-name ends of the first primary side LA1, the first secondary side LB1 and the third secondary side LB3 are positive, and the same-name ends are negative, and then the second diode D2 and the fifth diode D5 are both reversely cut off. When the first switch tube Q1 is turned off, the input power supply V1 stops charging the first primary side LA1, and the first primary side LA1 generates a self-induced voltage, and the same-name ends of the first primary side LA1, the first secondary side LB1 and the third secondary side LB3 are positive, and the opposite-name ends are negative, and then the second diode D2 is forward-conducted. On the one hand, the voltage on the first secondary side LB1 charges the second capacitor C2 through the second diode D2 to generate the second power supply voltage VO2 at the first end of the second capacitor C2; on the other hand, the third secondary side LB3, the parasitic diode of the fifth switch tube Q5, the fourth capacitor C4, the sixth diode D6 and the sixth switch tube Q6 form a loop, and the fourth capacitor C4 is charged by the voltage on the third secondary side LB3, so that the fourth drive voltage VD4 (the voltage of the fourth capacitor C4 is positive at the top and negative at the bottom) is generated at both ends of the fourth capacitor C4. The fourth drive voltage VD4 is obtained by the ratio between the number of winding coils N2 of the first secondary side LB1 and the number of winding coils (recorded as N4) of the third secondary side LB3 and the product of the second power supply voltage VO2, that is, VD4=N4 / N2*VO2. Similarly, by adjusting the duty cycle of the pulse width modulation signal, the second power supply voltage VO2 can be adjusted, and then the fourth drive voltage VD4 used to drive the motor M1 can be adjusted, so that there is no need to set the voltage of the input power supply V1 equal to the drive voltage of the motor M1 as in the related art, which can be applied to more application scenarios and has stronger practicality.

[0103] If the controller 500 outputs a sixth control signal (corresponding to a high level signal) to the eighth switch tube Q8 to turn on the eighth switch tube Q8, a sixth driving voltage will be generated at both ends of the fifth capacitor C5 to drive the motor M1 and generate a current flowing from the second end of the second winding L2 to the second end of the third winding L3. Specifically, when the first switch tube Q1 is turned on, the input power supply V1 charges the first primary side LA1, and the opposite-name ends of the first primary side LA1, the first secondary side LB1 and the fourth secondary side LB4 are positive, and the same-name ends are negative, and then the second diode D2 and the seventh diode D7 are both reversely cut off. When the first switch tube Q1 is turned off, the input power supply V1 stops charging the first primary side LA1, and the first primary side LA1 generates a self-induced voltage, and the same-name ends of the first primary side LA1, the first secondary side LB1 and the fourth secondary side LB4 are positive, and the opposite-name ends are negative, and then the second diode D2 is forward-conducted. On the one hand, the voltage on the first secondary side LB1 charges the second capacitor C2 through the second diode D2 to generate the second power supply voltage VO2 at the first end of the second capacitor C2; on the other hand, the fourth secondary side LB4, the parasitic diode of the seventh switch tube Q7, the fifth capacitor C5, the eighth diode D8 and the eighth switch tube Q8 form a loop, and the fifth capacitor C5 is charged by the voltage on the fourth secondary side LB4, so that the two ends of the fifth capacitor C5 generate the sixth drive voltage VD6 (the voltage of the fifth capacitor C5 is positive at the top and negative at the bottom). The sixth drive voltage VD6 is obtained by the ratio between the number of winding coils N2 of the first secondary side LB1 and the number of winding coils (recorded as N5) of the fourth secondary side LB4 and the product of the second power supply voltage VO2, that is, VD6=N5 / N2*VO2. Similarly, by adjusting the duty cycle of the pulse width modulation signal, the second power supply voltage VO2 can be adjusted, and then the sixth drive voltage VD6 for driving the motor M1 can be adjusted, so that there is no need to set the voltage of the input power supply V1 equal to the drive voltage of the motor M1 as in the related art, which can be applied to more application scenarios and has stronger practicality.

[0104] When the controller 500 outputs the seventh control signal (corresponding to a high level signal) to the second switch tube Q2, the second switch tube Q2 is turned on. At the same time, the controller 500 outputs a pulse width modulation signal to the first switch tube Q1 to turn the first switch tube Q1 on and off alternately.

[0105] In this case, if the controller 500 outputs a first control signal (corresponding to a high level signal) to the third switch tube Q3 to turn on the third switch tube Q3, a first driving voltage will be generated at both ends of the third capacitor C3 to drive the motor M1 and generate a current flowing from the second end of the second winding L2 to the second end of the first winding L1. Specifically, when the first switch tube Q1 is turned on, the input power supply V1 charges the first primary side LA1, and the opposite-name ends of the first primary side LA1, the first secondary side LB1 and the second secondary side LB2 are positive, and the same-name ends are negative. Then, on the one hand, the second diode D2 is reversely cut off, and the second power supply voltage VO2 does not exist; on the other hand, the second secondary side LB2, the parasitic diode of the fourth switch tube Q4, the first inductor LC1, the third capacitor C3 and the third switch tube Q3 form a loop, and the third capacitor C3 is charged by the voltage on the second secondary side LB2, so that the first driving voltage VD1 (the voltage of the third capacitor C3 is negative at the top and positive at the bottom) is generated at both ends of the third capacitor C3. When the first switch tube Q1 is turned off, the input power supply V1 stops charging the first primary LA1, and the first primary LA1 generates a self-induced voltage. The same-name terminals of the first primary LA1, the first secondary LB1 and the second secondary LB2 are positive, and the opposite-name terminals are negative. Then, the second diode D2 is forward-conducted, the third diode D3 and the fourth diode D4 are reverse-cut off, and the first inductor LC1 is discharged to maintain the voltage across the third capacitor C3. The first driving voltage VD1 is obtained by multiplying the ratio of the number of windings N3 of the second secondary LB2 to the number of windings N1 of the first primary LA1 and the first power supply voltage VO1, that is, VD1=N3 / N1*VO1=N3 / N1*V1*D. It can be obtained from this equation that by adjusting the duty cycle D of the pulse width modulation signal, the first power supply voltage VO1 can be adjusted, and then the first driving voltage VD1 used to drive the motor M1 can be adjusted. Therefore, there is no need to set the voltage of the input power supply V1 equal to the driving voltage of the motor M1 as in the related art. It can be applied to more application scenarios and is more practical.

[0106] If the controller 500 outputs a third control signal (corresponding to a high level signal) to the fifth switch tube Q5 to turn on the fifth switch tube Q5, a third driving voltage will be generated at both ends of the fourth capacitor C4 to drive the motor M1 and generate a current flowing from the second end of the third winding L3 to the second end of the first winding L1. Specifically, when the first switch tube Q1 is turned on, the input power supply V1 charges the first primary side LA1, and the opposite-name ends of the first primary side LA1, the first secondary side LB1 and the third secondary side LB3 are positive, and the same-name ends are negative. Then, on the one hand, the second diode D2 is reversely cut off, and the second power supply voltage VO2 does not exist; on the other hand, the third secondary side LB3, the parasitic diode of the sixth switch tube Q6, the second inductor LC2, the fourth capacitor C4 and the fifth switch tube Q5 form a loop, and the fourth capacitor C4 is charged by the voltage on the third secondary side LB3, so that the third driving voltage VD3 (the voltage of the fourth capacitor C4 is negative at the top and positive at the bottom) is generated at both ends of the fourth capacitor C4. When the first switch tube Q1 is turned off, the input power supply V1 stops charging the first primary LA1, and the first primary LA1 generates a self-induced voltage. The same-name terminals of the first primary LA1, the first secondary LB1 and the third secondary LB3 are positive, and the opposite-name terminals are negative. Then, the second diode D2 is forward-conducted, the fifth diode D5 and the sixth diode D6 are reverse-cut off, and the second inductor LC2 is discharged to maintain the voltage across the fourth capacitor C4. The third driving voltage VD3 is obtained by multiplying the ratio of the number of windings N4 of the third secondary LB3 to the number of windings N1 of the first primary LA1 and the first power supply voltage VO1, that is, VD3 = N4 / N1*VO1 = N4 / N1*V1*D. It can be obtained from this equation that by adjusting the duty cycle D of the pulse width modulation signal, the first power supply voltage VO1 can be adjusted, and then the third driving voltage VD3 used to drive the motor M1 can be adjusted. Therefore, there is no need to set the voltage of the input power supply V1 equal to the driving voltage of the motor M1 as in the related art. It can be applied to more application scenarios and is more practical.

[0107] If the controller 500 outputs a fifth control signal (corresponding to a high level signal) to the seventh switch tube Q7 to turn on the seventh switch tube Q7, a fifth driving voltage will be generated at both ends of the fifth capacitor C5 to drive the motor M1 and generate a current flowing from the second end of the third winding L3 to the second end of the second winding L2. Specifically, when the first switch tube Q1 is turned on, the input power supply V1 charges the first primary side LA1, and the opposite-name ends of the first primary side LA1, the first secondary side LB1 and the fourth secondary side LB4 are positive, and the same-name ends are negative. Then, on the one hand, the second diode D2 is reversely cut off, and the second power supply voltage VO2 does not exist; on the other hand, the fourth secondary side LB4, the parasitic diode of the eighth switch tube Q8, the third inductor LC3, the fifth capacitor C5 and the seventh switch tube Q7 form a loop, and the fifth capacitor C5 is charged by the voltage on the fourth secondary side LB4, so that the fifth driving voltage VD5 (the voltage of the fifth capacitor C5 is negative at the top and positive at the bottom) is generated at both ends of the fifth capacitor C5. When the first switch tube Q1 is turned off, the input power supply V1 stops charging the first primary LA1, and the first primary LA1 generates a self-induced voltage. The same-name terminals of the first primary LA1, the first secondary LB1 and the fourth secondary LB4 are positive, and the opposite-name terminals are negative. Then, the second diode D2 is forward-conducted, the seventh diode D7 and the eighth diode D8 are reverse-cut off, and the third inductor LC3 is discharged to maintain the voltage across the fifth capacitor C5. The fifth driving voltage VD5 is obtained by multiplying the ratio of the number of windings N5 of the fourth secondary LB4 to the number of windings N1 of the first primary LA1 and the first power supply voltage VO1, that is, VD5=N5 / N1*VO1=N5 / N1*V1*D. It can be obtained from this equation that by adjusting the duty cycle D of the pulse width modulation signal, the first power supply voltage VO1 can be adjusted, and then the fifth driving voltage VD5 used to drive the motor M1 can be adjusted. Therefore, there is no need to set the voltage of the input power supply V1 equal to the driving voltage of the motor M1 as in the related art. It can be applied to more application scenarios and is more practical.

[0108] In summary, the driving process of the motor M1 is realized. In addition, since there is no upper and lower bridge connection relationship between the various switch tubes (including the first switch tube Q1 to the eighth switch tube Q8), there will be no abnormal situation where the same upper and lower bridges are turned on at the same time, thereby reducing the risk of damage to the motor M1 and improving reliability. Secondly, by setting up a transformer, the power supply can also be isolated, so even if the input power supply V1 is strong, it can avoid the abnormal situation of electric shock caused by contact with the motor.

[0109] It can be understood that the controller 500 only outputs one of the first control signal, the second control signal, the third control signal, the fourth control signal, the fifth control signal and the sixth control signal at a time. For example, if the controller 500 outputs the first control signal, the controller 500 stops outputting the second control signal, the third control signal, the fourth control signal, the fifth control signal and the sixth control signal.

[0110] In addition, if Figure 4 The hardware structure of the motor drive circuit 1000 shown is only an example, and the motor drive circuit 1000 may have more or fewer components than shown in the figure, may combine two or more components, or may have a different component configuration. The various components shown in the figure may be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application-specific integrated circuits.

[0111] For example, in some embodiments, Figure 4 The fourth diode D4, the sixth diode D6 and the eighth diode D8 shown are replaced by switching tubes such as MOS tubes or transistors, then the forward conduction of each diode corresponds to the conduction of the replaced switching tube. For example, the fourth diode D4 is replaced by a transistor, then the forward conduction of the fourth diode D4 corresponds to the conduction of the transistor; the reverse cutoff of the fourth diode D4 corresponds to the turn-off of the transistor.

[0112] Please refer to Figure 5 , Figure 5 A flow chart of a motor driving method provided in an embodiment of the present application. The motor driving method is applied to the motor driving circuit in any embodiment of the present application. The specific implementation of the motor driving circuit can refer to Figure 1-Figure 4 The description of , will not be repeated here. Figure 5 As shown, the motor driving method includes the following method steps:

[0113] Step 51: Control the first switch tube in the motor drive circuit to be alternately turned on and off.

[0114] Step 52: Control the sixth switch tube in the motor drive circuit to be turned on, and control the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube in the motor drive circuit to be turned off, so that the motor is in the first driving state.

[0115] Step 53: Control the fourth switch tube to be turned on, and control the second switch tube, the third switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in the second driving state.

[0116] Step 54: Control the second switch tube and the seventh switch tube to be turned on, and control the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube and the eighth switch tube to be turned off, so that the motor is in the third driving state.

[0117] Step 55: Control the second switch tube and the fifth switch tube to be turned on, and control the third switch tube, the fourth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in the fourth driving state.

[0118] Step 56: Control the second switch tube and the third switch tube to be turned on, and control the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in the fifth driving state.

[0119] Step 57: Control the eighth switch tube to be turned on, and control the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube and the seventh switch tube to be turned off, so that the motor is in the sixth driving state.

[0120] When the motor is in the first driving state, the current of the motor flows in from the first winding L1 and flows out from the third winding L3; when the motor is in the second driving state, the current of the motor flows in from the first winding L1 and flows out from the second winding L2; when the motor is in the third driving state, the current of the motor flows in from the third winding L3 and flows out from the second winding L2; when the motor is in the fourth driving state, the current of the motor flows in from the third winding L3 and flows out from the first winding L1; when the motor is in the fifth driving state, the current of the motor flows in from the second winding L2 and flows out from the first winding L1; when the motor is in the sixth driving state, the current of the motor flows in from the second winding L2 and flows out from the third winding L3. By controlling the motor to be in the first driving state, the second driving state, the third driving state, the fourth driving state, the fifth driving state and the sixth driving state in sequence, the driving process of the motor is realized, and the motor is made to run in the first direction.

[0121] Please refer to Figure 6 , Figure 6 Another flow chart of the motor driving method provided in the embodiment of the present application. The motor driving method is applied to the motor driving circuit in any embodiment of the present application. The specific implementation of the motor driving circuit can refer to Figure 1-Figure 4 The description of , will not be repeated here. Figure 6 As shown, the motor driving method includes the following method steps:

[0122] Step 61: Control the first switch tube in the motor drive circuit to be alternately turned on and off.

[0123] Step 62: Control the eighth switch tube to be turned on, and control the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube and the seventh switch tube to be turned off, so that the motor is in the sixth driving state.

[0124] Step 63: Control the second switch tube and the third switch tube to be turned on, and control the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in the fifth driving state.

[0125] Step 64: Control the second switch tube and the fifth switch tube to be turned on, and control the third switch tube, the fourth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in the fourth driving state.

[0126] Step 65: Control the second switch tube and the seventh switch tube to be turned on, and control the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube and the eighth switch tube to be turned off, so that the motor is in the third driving state.

[0127] Step 66: Control the fourth switch tube to be turned on, and control the second switch tube, the third switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in the second driving state.

[0128] Step 67: Control the sixth switch tube in the motor drive circuit to be turned on, and control the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube in the motor drive circuit to be turned off, so that the motor is in the first driving state.

[0129] By controlling the motor to be in the sixth driving state, the fifth driving state, the fourth driving state, the third driving state, the second driving state and the first driving state in sequence, the driving process of the motor is realized, and the motor is operated in the second direction. The second direction is opposite to the first direction, that is, if the first direction is the forward rotation direction of the motor, the second direction is the reverse rotation direction of the motor; if the first direction is the reverse rotation direction of the motor, the second direction is the forward rotation direction of the motor.

[0130] It should be understood that the specific control of the motor drive circuit in the method embodiment and the beneficial effects produced can refer to the corresponding description in the above-mentioned motor drive circuit embodiment, and for the sake of brevity, it will not be repeated here.

[0131] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0132] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Under the idea of ​​the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. It should be understood by ordinary technicians in this field that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A motor drive circuit, It is characterized in that The motor includes a first winding, a second winding and a third winding, the first end of the first winding is connected to the first end of the second winding and the first end of the third winding respectively, and the motor drive circuit includes: A controller, outputting a first control signal, a second control signal, a third control signal, a fourth control signal, a fifth control signal and a sixth control signal; a voltage conversion branch, wherein a first end of the voltage conversion branch is connected to an input power supply and is configured to generate a first supply voltage and a second supply voltage based on the input power supply; A first driving branch, comprising a first switch unit and a second switch unit, wherein the first switch unit is connected between the second end of the voltage conversion branch and the second end of the first winding, and the second switch unit is connected between the third end of the voltage conversion branch and the second end of the second winding; The first driving branch is configured to generate a first driving voltage based on the first supply voltage to drive the motor and generate a current flowing from the second end of the first winding to the second end of the second winding when the first switch unit is turned on in response to the first control signal; The first driving branch is further configured to generate a second driving voltage based on the second supply voltage to drive the motor and generate a current flowing from the second end of the second winding to the second end of the first winding when the second switch unit is turned on in response to the second control signal; The second driving branch includes a third switch unit and a fourth switch unit, wherein the third switch unit is connected between the fourth end of the voltage conversion branch and the second end of the first winding, and the fourth switch unit is connected between the fifth end of the voltage conversion branch and the second end of the third winding; The second driving branch is configured to generate a third driving voltage based on the first supply voltage to drive the motor and generate a current flowing from the second end of the first winding to the second end of the third winding when the third switch unit is turned on in response to the third control signal; The second driving branch is further configured to generate a fourth driving voltage based on the second supply voltage to drive the motor and generate a current flowing from the second end of the third winding to the second end of the first winding when the fourth switch unit is turned on in response to the fourth control signal; a third driving branch, comprising a fifth switch unit and a sixth switch unit, wherein the fifth switch unit is connected between the sixth end of the voltage conversion branch and the second end of the second winding, and the fifth switch unit is connected between the seventh end of the voltage conversion branch and the second end of the third winding; The third driving branch is configured to generate a fifth driving voltage based on the first supply voltage to drive the motor and generate a current flowing from the second end of the second winding to the second end of the third winding when the fifth switch unit is turned on in response to the fifth control signal; The third driving branch is also configured to generate a sixth driving voltage based on the second supply voltage to drive the motor and generate a current flowing from the second end of the third winding to the second end of the second winding when the sixth switching unit is turned on in response to the sixth control signal.

2. The motor drive circuit according to claim 1, It is characterized in that The voltage conversion branch comprises: A transformer, comprising a first primary side, a first secondary side, a second secondary side, a third secondary side and a fourth secondary side, wherein the second end of the first primary side is the first end of the voltage conversion branch, the first end of the second secondary side is the second end of the voltage conversion branch, the second end of the second secondary side is the third end of the voltage conversion branch, the first end of the third secondary side is the fourth end of the voltage conversion branch, the second end of the third secondary side is the fifth end of the voltage conversion branch, the first end of the fourth secondary side is the sixth end of the voltage conversion branch, and the second end of the fourth secondary side is the seventh end of the voltage conversion branch; a seventh switch unit, connected to the controller and to the input power supply through the first primary side, configured to generate the first supply voltage on the first primary side based on the input power supply in response to the pulse width modulation signal output by the controller, wherein the product of the voltage of the input power supply and the duty cycle of the pulse width modulation signal is the first supply voltage; The power supply unit is connected to the first secondary side and is configured to generate the second supply voltage based on the voltage on the first primary side when the seventh switch unit is turned off.

3. The motor drive circuit according to claim 2, It is characterized in that The seventh switch unit includes a first switch tube, and the voltage conversion branch also includes a first capacitor; The first end of the first switch tube is connected to the controller, the second end of the first switch tube and the second end of the first capacitor are both grounded, the third end of the first switch tube is connected to the same-name end of the first primary side, and the opposite-name end of the first primary side and the first end of the first capacitor are both connected to the input power supply.

4. The motor drive circuit according to claim 3, It is characterized in that The transformer further includes a second primary side, and the voltage conversion branch further includes a second switch tube and a first diode; The same-name end of the second primary side is connected to the input power supply, the opposite-name end of the second primary side is connected to the second end of the second switch tube, the third end of the second switch tube is connected to the cathode of the first diode, the anode of the first diode is grounded, and the first end of the second switch tube is connected to the controller.

5. The motor drive circuit according to claim 2, It is characterized in that The power supply unit includes a second diode, a second capacitor and a first resistor; The anode of the second diode is connected to the same-name end of the first secondary side, the cathode of the second diode is respectively connected to the first end of the second capacitor and the first end of the first resistor, and the opposite-name end of the first secondary side, the second end of the second capacitor and the second end of the first resistor are all grounded.

6. The motor drive circuit according to claim 2, It is characterized in that The first switch unit includes a third switch tube having a parasitic diode, the second switch unit includes a fourth switch tube having a specific parasitic diode, and the first driving branch further includes a third diode, a fourth diode, a second resistor, a third capacitor and a first inductor; The first end of the third switch tube and the first end of the fourth switch tube are both connected to the controller, the third end of the third switch tube is connected to the same-name end of the second secondary side, the second end of the third switch tube is respectively connected to the anode of the third diode, the first end of the second resistor and the second end of the first winding, the cathode of the third diode is respectively connected to the first end of the first inductor, the cathode of the fourth diode and the second end of the fourth switch tube, the third end of the fourth switch tube is connected to the opposite-name end of the second secondary side, the second end of the first inductor is respectively connected to the anode of the fourth diode, the second end of the second resistor and the second end of the second winding, and the third capacitor is connected in parallel with the second resistor.

7. The motor drive circuit according to claim 2, It is characterized in that The third switch unit includes a fifth switch tube having a parasitic diode, the fourth switch unit includes a sixth switch tube having a parasitic diode, and the second driving branch further includes a fifth diode, a sixth diode, a third resistor, a fourth capacitor and a second inductor; The first end of the fifth switch tube and the first end of the sixth switch tube are connected to the controller, the third end of the fifth switch tube is connected to the same-name end of the third secondary side, the second end of the fifth switch tube is respectively connected to the anode of the fifth diode, the first end of the third resistor and the second end of the first winding, the cathode of the fifth diode is respectively connected to the first end of the second inductor, the cathode of the sixth diode and the second end of the sixth switch tube, the anode of the sixth diode is respectively connected to the second end of the third resistor, the second end of the second inductor and the second end of the third winding, the third end of the sixth switch tube is connected to the opposite-name end of the third secondary side, and the fourth capacitor is connected in parallel with the third resistor.

8. The motor drive circuit according to claim 2, It is characterized in that The fifth switch unit includes a seventh switch tube having a parasitic diode, the sixth switch unit includes an eighth switch tube having a parasitic diode, and the third driving branch further includes a seventh diode, an eighth diode, a fourth resistor, a fifth capacitor and a third inductor; The first end of the seventh switch tube and the first end of the eighth switch tube are both connected to the controller, the third end of the seventh switch tube is connected to the same-name end of the fourth secondary side, the second end of the seventh switch tube is respectively connected to the anode of the seventh diode, the first end of the fourth resistor and the second end of the second winding, the cathode of the seventh diode is respectively connected to the second end of the eighth switch tube, the first end of the third inductor and the cathode of the eighth diode, the second end of the third inductor is respectively connected to the anode of the eighth diode, the second end of the fourth resistor and the second end of the third winding, the fifth capacitor is connected in parallel with the fourth resistor, and the third end of the eighth switch tube is connected to the opposite-name end of the fourth secondary side.

9. A motor driving method, It is characterized in that Applied to the motor driving circuit according to any one of claims 1 to 7, the motor driving method comprises: Controlling the first switch tube in the motor drive circuit to be alternately turned on and off; Controlling the sixth switch tube in the motor drive circuit to be turned on, and controlling the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the seventh switch tube and the eighth switch tube in the motor drive circuit to be turned off, so that the motor is in a first driving state; Controlling the fourth switch tube to be turned on, and controlling the second switch tube, the third switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in a second driving state; Controlling the second switch tube and the seventh switch tube to be turned on, and controlling the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube, and the eighth switch tube to be turned off, so that the motor is in a third driving state; Controlling the second switch tube and the fifth switch tube to be turned on, and controlling the third switch tube, the fourth switch tube, the sixth switch tube, the seventh switch tube, and the eighth switch tube to be turned off, so that the motor is in a fourth driving state; controlling the second switch tube and the third switch tube to be turned on, and controlling the fourth switch tube, the fifth switch tube, the sixth switch tube, the seventh switch tube and the eighth switch tube to be turned off, so that the motor is in a fifth driving state; The eighth switch tube is controlled to be turned on, and the second switch tube, the third switch tube, the fourth switch tube, the fifth switch tube, the sixth switch tube and the seventh switch tube are controlled to be turned off, so that the motor is in a sixth driving state.

10. The motor driving method according to claim 9, It is characterized in that Also includes: Controlling the motor to be in a first driving state, a second driving state, a third driving state, a fourth driving state, a fifth driving state and a sixth driving state in sequence, so that the motor runs in a first direction; Alternatively, the motor is controlled to be in a sixth driving state, a fifth driving state, a fourth driving state, a third driving state, a second driving state and a first driving state in sequence, so that the motor runs in a second direction, wherein the second direction is opposite to the first direction.

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