Synchronous motor driving circuit, driving motor, and motor driving system

Abstract

The present application discloses a synchronous motor driving circuit, a driving motor, and a motor driving system. The circuit comprises: a plurality of synchronous motors, wherein three-phase windings of the synchronous motors are sequentially connected in series, and the three-phase winding of the last synchronous motor is short-circuited; and a motor driver module, wherein a first end of the motor driver module is connected to the three-phase winding of the first synchronous motor, a second end of the motor driver module is connected to the acquisition end of each synchronous motor, and the motor driver module is used for acquiring rotor position information and output current information of the acquisition end of each synchronous motor, and determining a control instruction on the basis of the rotor position information and the output current information so as to drive each synchronous motor on the basis of the control instruction.

Description

Synchronous motor drive circuit, drive motor and motor drive system

[0001] This application claims priority to Chinese patent application No. 202410159417.6, filed on February 4, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the technical field of synchronous motors, and in particular to a synchronous motor drive circuit, a drive motor, and a motor drive system. Background Art

[0003] With the development of synchronous motor technology, synchronous motor drives are being used more and more frequently in various fields, which also makes users put forward higher requirements on synchronous motor drive circuits.

[0004] The traditional synchronous motor drive circuit directly drives a synchronous motor through a motor driver. This synchronous motor drive circuit has a major defect. The motor driver can only drive one synchronous motor at a time. Therefore, a new synchronous motor drive circuit is urgently needed to enable a single motor driver to drive multiple synchronous motors. Technical issues

[0005] The main purpose of this application is to propose a synchronous motor drive circuit, a drive motor and a motor drive system, aiming to solve the technical problem of how to realize a single motor driver driving multiple synchronous motors. Technical Solutions

[0006] To achieve the above objectives, the present application provides a synchronous motor drive circuit, the synchronous motor drive circuit comprising:

[0007] Multiple synchronous motors, the three-phase windings of the synchronous motors are connected in series in sequence, and the three-phase winding of the last synchronous motor is short-circuited;

[0008] A motor driver module, wherein the first end of the motor driver module is connected to the three-phase winding of the first synchronous motor, and the second end of the motor driver module is connected to the acquisition end of each synchronous motor. The motor driver module is used to obtain the rotor position information and output current information of the acquisition end of each synchronous motor, and determine the control instruction based on the rotor position information and the output current information, so as to drive each synchronous motor based on the control instruction.

[0009] In one embodiment, the synchronous motor comprises:

[0010] A first-phase stator winding, wherein a first end of the first-phase stator winding is connected to a second end of a first-phase stator winding of a previous synchronous motor, and a second end of the first-phase stator winding is connected to a first end of a first-phase stator winding of a next synchronous motor;

[0011] a second-phase stator winding, wherein a first end of the second-phase stator winding is connected to a second end of the second-phase stator winding of the previous synchronous motor, and a second end of the two-phase stator winding is connected to a first end of the second-phase stator winding of the next synchronous motor;

[0012] a third-phase stator winding, wherein a first end of the third-phase stator winding is connected to a second end of the third-phase stator winding of the previous synchronous motor, and a second end of the three-phase stator winding is connected to a first end of the third-phase stator winding of the next synchronous motor;

[0013] The motor rotor is arranged concentrically with a stator circle composed of the first-phase stator winding, the second-phase stator winding, and the third-phase stator winding.

[0014] In one embodiment, when the synchronous motor is the first synchronous motor, the first end of the first-phase stator winding is connected to the first end of the motor driver module, the first end of the second-phase stator winding is connected to the first end of the motor driver module, and the first end of the third-phase stator winding is connected to the first end of the motor driver module;

[0015] When the synchronous motor is the last synchronous motor, the second end of the first-phase stator winding, the second end of the second-phase stator winding, and the second end of the third-phase stator winding are short-circuited.

[0016] In one embodiment, the synchronous motor further comprises:

[0017] A rotor position sensor is provided at a detection position of the motor rotor, wherein an output end of the rotor position sensor serves as a collection end of the synchronous motor and is connected to a second end of the motor driver module.

[0018] In one embodiment, the motor driver module includes a drive circuit and a control chip, the drive circuit includes a first drive bridge arm, a second drive bridge arm, and a third drive bridge arm, wherein the first end of the first drive bridge arm, the first end of the second drive bridge arm, and the first end of the third drive bridge arm are connected in sequence and serve as the positive electrode of the power input terminal, and the second end of the first drive bridge arm, the second end of the second drive bridge arm, and the second end of the third drive bridge arm are connected in sequence and serve as the negative electrode of the power input terminal;

[0019] The first driving bridge arm includes a first switching tube and a second switching tube. The first end of the first switching tube serves as the first end of the first driving bridge arm. The second end of the first switching tube and the first end of the second switching tube are connected together to form a bridge arm midpoint of the first driving bridge arm and are connected to the first end of the first phase stator winding of the first synchronous motor. The second end of the second switching tube serves as the second end of the first driving bridge arm. The third ends of the first switching tube and the second switching tube are respectively connected to the control chip.

[0020] The second driving bridge arm includes a third switching tube and a fourth switching tube. The first end of the third switching tube serves as the first end of the second driving bridge arm. The second end of the third switching tube and the first end of the fourth switching tube are connected together to form the midpoint of the second driving bridge arm and are connected to the first end of the second-phase stator winding of the first synchronous motor. The second end of the fourth switching tube serves as the second end of the second driving bridge arm. The third ends of the third switching tube and the third ends of the fourth switching tube are respectively connected to the control chip.

[0021] The third drive bridge arm includes a fifth switch tube and a sixth switch tube. The first end of the fifth switch tube is the first end of the third drive bridge arm. The second end of the fifth switch tube and the first end of the sixth switch tube are connected together to form the midpoint of the third drive bridge arm and are connected to the first end of the third phase stator winding of the first synchronous motor. The second end of the sixth switch tube is the second end of the third drive bridge arm. The third end of the fifth switch tube and the third end of the sixth switch tube are respectively connected to the control chip.

[0022] In one embodiment, the control chip includes a position acquisition port, a current acquisition port, and a drive control port, wherein the position acquisition port is connected to the output terminal of each of the rotor position sensors, and the drive control port is connected to the third terminal of each switching tube. The motor driver module further includes:

[0023] Multiple current sensors, wherein the first end of the current sensor is connected to a midpoint of the bridge arm, the second end of the current sensor is connected to the phase stator winding corresponding to the midpoint of the bridge arm, and the third end of the current sensor is connected to the current acquisition port.

[0024] In one embodiment, the high-side reference voltage circuit includes:

[0025] The seventh resistor obtains the current rotor position based on a preset power-on state before the synchronous motor drive circuit works, and determines the angle deviation value based on the current rotor position. When the angle deviation value meets the preset angle deviation threshold, it is determined that the hardware of the synchronous motor drive circuit is normal.

[0026] In one embodiment, when the hardware of the synchronous motor drive circuit is normal and the drive is working, the rotor position information collected by each of the rotor position sensors and the output current information of the current sensor are obtained, and a control instruction is determined based on the rotor position information and the output current information, and the drive circuit is driven based on the control instruction, wherein the rotor position information includes the rotor position information that meets the preset rotor deviation condition in the collected information of each of the rotor position sensors.

[0027] In addition, the present application also provides a drive motor, which includes the above-mentioned synchronous motor drive circuit.

[0028] In addition, the present application also provides a motor drive system, the motor drive system including the above-mentioned drive motor, and the motor drive system further including:

[0029] A host computer, wherein the output terminal of the host computer is connected to the control terminal of the control chip in the drive motor, and the power input terminal of the drive motor is connected to an external power supply;

[0030] A motor load is connected to the motor rotor of each synchronous motor in the drive motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG1 is a schematic structural diagram of a synchronous motor drive circuit of the present application;

[0032] FIG2 is a connection diagram of a commonly used synchronous motor drive circuit;

[0033] FIG3 is a connection diagram of a synchronous motor drive circuit of the present application;

[0034] FIG4 is another connection diagram of the synchronous motor drive circuit of the present application;

[0035] FIG5 is a schematic diagram of the position adjustment process of the synchronous motor drive circuit of the present application;

[0036] FIG6 is a schematic structural diagram of the motor drive system of the present application.

[0037] Description of Figure Numbers:

[0038] Reference number name Reference number name 100 driving motor 200 host computer 300 motor load 400 external power supply 101-10n synchronous motor 20 motor driver module BUT power input terminal T1-T6 first switch tube-sixth switch tube 211 current sensor 21 driving circuit 22 control chip 13 rotor position sensor 12 motor rotor 11 motor stator 1a1 first phase stator winding 1b1 second phase stator winding 1c1 third phase stator winding 1d1 neutral point 310-330 motor load

[0039] The purpose, features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Modes for Carrying Out the Invention

[0040] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0041] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0043] In this application, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0045] The present application provides a synchronous motor drive circuit. Referring to FIG1 , the synchronous motor drive circuit includes:

[0046] Multiple synchronous motors 101-10n, the three-phase windings of the synchronous motors 101-10n are connected in series in sequence, and the three-phase winding of the last synchronous motor 10n is short-circuited;

[0047] A motor driver module 20, wherein a first end of the motor driver module 20 is connected to the three-phase winding of the first synchronous motor 101, and a second end of the motor driver module 20 is connected to the acquisition end of each of the synchronous motors 101-10n. The motor driver module 20 is used to obtain rotor position information and output current information of the acquisition end of each of the synchronous motors 101-10n, and determine a control instruction based on the rotor position information and the output current information, so as to drive each of the synchronous motors 101-10n based on the control instruction.

[0048] For example, refer to FIG2 , which is a connection diagram of a commonly used synchronous motor drive circuit. The synchronous motor is a three-phase motor. The driver power section is a three-phase half-bridge (or full-bridge) circuit, consisting of six power transistors and their control chip. The host computer 200 is used to output control instructions to the control chip 22, which then performs subsequent drive control based on the collected rotor position information and three-phase current. In current industrial applications, there is often a need to use a single driver (i.e., consisting of the drive circuit 21 and the control chip 22) to control multiple motors. This is especially true when the electromechanical parameters (rotor parameters, stator parameters, winding parameters, etc.) and load conditions (actual rotor-driven load) of the multiple motors are substantially the same. Using a single driver with a higher power rating to control multiple motors can reduce the number of drivers, lower costs, reduce size, and improve reliability. Currently, the only technology available is to use a single driver to drive multiple asynchronous motors in parallel. However, research has found that using a single driver to control multiple permanent magnet synchronous motors in parallel can essentially maintain synchronous operation of the motors at low speeds. However, as the motor speed increases, the parallel motors become unstable, making stable parallel operation difficult. This is because the instability of permanent magnet synchronous motors when using a three-phase half-bridge driver for parallel control is related to slight changes in the motor parameters and load conditions. While increasing the phase resistance can improve the stability of the motor, increasing the resistance will increase the motor's losses and reduce the motor's efficiency. Based on the above-mentioned lack of a solution for driving multiple synchronous motors and the shortcomings of driving parallel synchronous motors, the synchronous motor drive circuit of this embodiment is proposed, thereby enabling a single motor driver to drive multiple synchronous motors.

[0049] In this embodiment, multiple synchronous motors 101-10n are wound in a star-shaped winding form, that is, the starting end and the tail end of each phase winding of each synchronous motor are led out of the motor in the form of lead wires, and the three-phase windings of the synchronous motors 101-10n are connected in series in sequence, and the three-phase winding of the last synchronous motor 10n is short-circuited. For example, the coils of a three-phase synchronous motor are Ua1, Ua1n, Ub1, Ub1n, Uc1, and Uc1n, respectively. Ua1 and Ua1n represent the starting and ending ends of the U-phase coil of the three-phase synchronous motor, Ub1 and Ub1n represent the starting and ending ends of the V-phase coil, and Uc1 and Uc1n represent the starting and ending ends of the W-phase coil. The starting and ending ends of all three-phase synchronous motors are then connected in sequence, i.e., the ending end of the corresponding phase of the first motor is connected to the starting end of the corresponding phase of the second motor, the ending end of the corresponding phase of the second motor is connected to the starting end of the corresponding phase of the third motor, and so on. If the three-phase synchronous motor is the last synchronous motor 10n, then Ua1n, Ub1n, and Uc1n are connected together. If the three-phase synchronous motor is the first synchronous motor, then Ua1, Ub1, and Uc1 are connected to the first end of the motor driver module 20. At the same time, each synchronous motor 101-10n is equipped with an acquisition terminal, that is, a sensor for collecting the motor's rotor position. The motor driver module 20 then obtains rotor position information and output current information from the acquisition terminal of each synchronous motor 101-10n. Based on the rotor position information and output current information, a control instruction is determined to drive each synchronous motor 101-10n based on the control instruction. Here, rotor position information refers to the position of the rotor in the motor, output current information refers to the actual current output to the motor, and control instruction refers to the instruction for controlling the motor to drive. It is worth noting that when controlling based on rotor position information, because there are multiple synchronous motors 101-10n, the position of each synchronous motor is determined for control. For example, if synchronous motor 1 is at position A, synchronous motor 2 is at position B, and synchronous motor 3 is at position A, and position B is close to a synchronous motor out-of-step condition (e.g., position A is 30° and position B is 15°), then the position of synchronous motor 2, position B, is used as the rotor position information for subsequent control, thereby ensuring synchronization of subsequent drive control and ensuring the accuracy of drive control.

[0050] It is worth noting that the multiple synchronous motors 101-10n can be synchronous motors with identical parameters in all respects, or they can differ in some parameters under specific circumstances, without limitation. This embodiment utilizes the aforementioned serial connection of the multiple synchronous motors 101-10n, while simultaneously connecting the lead wires of the position sensors mounted on the rotor shaft ends of the motors (i.e., the acquisition terminals of the synchronous motors 101-10n) to the interface of the motor driver module 20. Control instructions can then be determined based on the rotor position information and output current information, and each synchronous motor can be driven based on the control instructions, thereby enabling a single motor driver to drive multiple synchronous motors.

[0051] This embodiment provides a synchronous motor drive circuit, which includes multiple synchronous motors, the three-phase windings of the synchronous motors are connected in series in sequence, and the three-phase winding of the last synchronous motor is short-circuited; a motor driver module, the first end of the motor driver module is connected to the three-phase winding of the first synchronous motor, and the second end of the motor driver module is connected to the acquisition end of each of the synchronous motors. The motor driver module is used to obtain rotor position information and output current information of the acquisition end of each of the synchronous motors, and determine control instructions based on the rotor position information and the output current information, so as to drive each of the synchronous motors based on the control instructions. By connecting the three-phase windings of the synchronous motors in series in sequence, the three-phase winding of the last synchronous motor is short-circuited, and at the same time, the first end of the motor driver module is connected to the three-phase winding of the first synchronous motor, thereby realizing power supply to multiple synchronous motors, and the second end of the motor driver module is connected to the acquisition end of each synchronous motor, thereby obtaining the rotor position information and output current information of the acquisition end of each synchronous motor, and then determining the control instruction based on the rotor position information and output current information to drive each synchronous motor based on the control instruction, thereby avoiding the phenomenon in the prior art that the motor driver can only drive one synchronous motor at the same time. This synchronous motor drive circuit obtains the rotor position information and output current information of the acquisition end of each synchronous motor through the connection relationship of the synchronous motors and the motor driver module, and then determines the control instruction based on the rotor position information and output current information to drive each synchronous motor based on the control instruction, thereby realizing a single motor driver driving multiple synchronous motors.

[0052] Furthermore, in another embodiment of the synchronous motor drive circuit of the present application, referring to FIG. 3 , which is a connection diagram of the synchronous motor drive circuit of the present application, the synchronous motors 101 - 10n include:

[0053] a first-phase stator winding 1a1, wherein a first end of the first-phase stator winding 1a1 is connected to a second end of the first-phase stator winding 1a1 of the previous synchronous motor, and a second end of the first-phase stator winding 1a1 is connected to a first end of the first-phase stator winding 1a1 of the next synchronous motor;

[0054] a second-phase stator winding 1b1, wherein a first end of the second-phase stator winding 1b1 is connected to a second end of the second-phase stator winding 1b1 of the previous synchronous motor, and a second end of the two-phase stator winding 1b1 is connected to a first end of the second-phase stator winding 1b1 of the next synchronous motor;

[0055] a third-phase stator winding 1c1, wherein a first end of the third-phase stator winding 1c1 is connected to a second end of the third-phase stator winding 1c1 of the previous synchronous motor, and a second end of the three-phase stator winding 1c1 is connected to a first end of the third-phase stator winding 1c1 of the next synchronous motor;

[0056] The motor rotor 12 is coaxially arranged with a stator circle composed of the first-phase stator winding 1a1, the second-phase stator winding 1b1, and the third-phase stator winding 1c1.

[0057] For example, the composition of the synchronous motors 101-10n is the same as that of common synchronous motors. The difference is that, to ensure the series connection of multiple synchronous motors 101-10n, the first-phase stator winding 1a1, the second-phase stator winding 1b1, and the third-phase stator winding 1c1 of each synchronous motor are not directly connected to the neutral point within each synchronous motor, but are instead led outside the synchronous motor (the second end of the stator winding of the last synchronous motor 101-10n in the multiple synchronous motors 101-10n may not be led outside the synchronous motor). This allows the multiple synchronous motors 101-10n to be connected in series, allowing a single motor driver to drive multiple synchronous motors.

[0058] Specifically, when the synchronous motor 101-10n is the first synchronous motor 101, the first end of the first-phase stator winding 1a1 is connected to the first end of the motor driver module 20, the first end of the second-phase stator winding 1b1 is connected to the first end of the motor driver module 20, and the first end of the third-phase stator winding 1c1 is connected to the first end of the motor driver module 20;

[0059] When the synchronous motor 101 - 10n is the last synchronous motor 10n, the second end of the first-phase stator winding 1a1, the second end of the second-phase stator winding 1b1, and the second end of the third-phase stator winding 1c1 are short-circuited.

[0060] Specifically, the synchronous motors 101 - 10n further include:

[0061] The rotor position sensor 13 is arranged at the detection position of the motor rotor 12 . The output end of the rotor position sensor 13 serves as the acquisition end of the synchronous motor 101 - 10n and is connected to the second end of the motor driver module 20 .

[0062] In this embodiment, referring to Figure 4, Figure 4 is another connection diagram of the synchronous motor drive circuit of the present application. When the synchronous motor 101-10n is the first synchronous motor 101, the first end of the first-phase stator winding 1a1 is connected to the first end of the motor driver module 20, the first end of the second-phase stator winding 1b1 is connected to the first end of the motor driver module 20, and the first end of the third-phase stator winding 1c1 is connected to the first end of the motor driver module 20; when the synchronous motor 101-10n is the last synchronous motor 10n, the second end of the first-phase stator winding 1a1, the second end of the second-phase stator winding 1b1 and the second end of the third-phase stator winding 1c1 are short-circuited, wherein the short-circuiting can be performed after the synchronous motor is led out, or it can be performed directly at the neutral point inside the synchronous motor, that is, the last synchronous motor can directly use the existing synchronous motor without leading the three wires connecting the neutral point out of the motor. A rotor position sensor 13 is also installed on the rotor of the synchronous motor 101-10n, and the rotor position sensor 13 on each synchronous motor 101-10n is connected to the control chip 22 in the motor driver module 20, so that the control chip 22 can perform drive control based on the position information collected by the rotor position sensor 13, thereby realizing the driving of multiple synchronous motors.

[0063] For example, taking the drive of three synchronous motors as an example, the U, V, and W phases are used to replace the first, second, and third phases of this embodiment respectively. Outside the motor, the head end of the U-phase coil of synchronous motor 1 is connected to the midpoint of the first drive bridge arm of the drive circuit 21, and its tail end is connected to the head end of the U-phase coil of synchronous motor 2, and the tail end of the U-phase coil of synchronous motor 2 is connected to the head end of the U-phase coil of synchronous motor 3, wherein the head end and tail end of the coil correspond to the two ends of the winding coil respectively. The head end of the V-phase coil of synchronous motor 1 is connected to the midpoint of the second drive bridge arm of the drive circuit 21, and its tail end is connected to the head end of the V-phase coil of synchronous motor 2, and the tail end of the V-phase coil of synchronous motor 2 is connected to the head end of the V-phase coil of synchronous motor 3. The head end of the W-phase coil of synchronous motor 1 is connected to the midpoint of the third drive bridge arm of the drive circuit 21, and its tail end is connected to the head end of the W-phase coil of synchronous motor 2, and the tail end of the W-phase coil of synchronous motor 2 is connected to the head end of the W-phase coil of synchronous motor 3. Finally, the three coil ends of the synchronous motor 3 are short-circuited, which can be achieved by using a short-circuit ring or directly short-circuiting the neutral point inside the motor. This allows multiple synchronous motors to be connected in series, and can then be driven by specific drive control.

[0064] Furthermore, in another embodiment of the synchronous motor drive circuit of the present application, the motor driver module 20 includes a drive circuit 21 and a control chip 22, wherein the drive circuit 21 includes a first drive bridge arm, a second drive bridge arm, and a third drive bridge arm, wherein the first end of the first drive bridge arm, the first end of the second drive bridge arm, and the first end of the third drive bridge arm are connected in sequence and serve as the positive electrode of the power input terminal BUT, and the second end of the first drive bridge arm, the second end of the second drive bridge arm, and the second end of the third drive bridge arm are connected in sequence and serve as the negative electrode of the power input terminal BUT;

[0065] The first driving bridge arm includes a first switching transistor T1 and a second switching transistor T2. The first end of the first switching transistor T1 serves as the first end of the first driving bridge arm. The second end of the first switching transistor T1 and the first end of the second switching transistor T2 are connected together to form the midpoint of the first driving bridge arm and are connected to the first end of the first-phase stator winding 1a1 of the first synchronous motor 101. The second end of the second switching transistor T2 serves as the second end of the first driving bridge arm. The third end of the first switching transistor T1 and the third end of the second switching transistor T2 are respectively connected to the control chip 22.

[0066] The second driving bridge arm includes a third switching tube T3 and a fourth switching tube T4. The first end of the third switching tube T3 serves as the first end of the second driving bridge arm. The second end of the third switching tube T3 and the first end of the fourth switching tube T4 are connected together to form the midpoint of the second driving bridge arm and are connected to the first end of the second-phase stator winding 1b1 of the first synchronous motor 101. The second end of the fourth switching tube T4 serves as the second end of the second driving bridge arm. The third ends of the third switching tube T3 and the fourth switching tube T4 are respectively connected to the control chip 22.

[0067] The third driving bridge arm includes a fifth switching tube T5 and a sixth switching tube T6. The first end of the fifth switching tube T5 is the first end of the third driving bridge arm. The second end of the fifth switching tube T5 and the first end of the sixth switching tube T6 are connected together to form the midpoint of the third driving bridge arm and are connected to the first end of the third-phase stator winding 1c1 of the first synchronous motor 101. The second end of the sixth switching tube T6 is the second end of the third driving bridge arm. The third end of the fifth switching tube T5 and the third end of the sixth switching tube T6 are respectively connected to the control chip 22.

[0068] Specifically, the control chip 22 includes a position acquisition port, a current acquisition port, and a drive control port, wherein the position acquisition port is connected to the output end of each of the rotor position sensors 13, and the drive control port is connected to the third end of each switch tube. The motor driver module also includes:

[0069] Multiple current sensors 211, the first end of the current sensor 211 is connected to a bridge arm midpoint, the second end of the current sensor 211 is connected to the phase stator winding corresponding to the bridge arm midpoint, and the third end of the current sensor 211 is connected to the current acquisition port.

[0070] In this embodiment, the drive circuit 21 includes a first drive bridge arm, a second drive bridge arm, and a third drive bridge arm. The first end of the first drive bridge arm, the first end of the second drive bridge arm, and the first end of the third drive bridge arm are sequentially connected and serve as the positive electrode of the power input terminal BUT. The second end of the first drive bridge arm, the second end of the second drive bridge arm, and the second end of the third drive bridge arm are sequentially connected and serve as the negative electrode of the power input terminal BUT. The power input terminal BUT can be directly connected to an internal power supply or an external voltage 400, which is not limited here. Each drive bridge arm is composed of two identical switching transistors, and their connection relationship is the connection relationship shown in Figures 3-4. The switching transistors can be transistors, IGBTs, or triodes. The midpoint of the first drive bridge arm is the U-phase output of the drive circuit 21, which is connected to the head end of the U-phase coil of the synchronous motor 1; the midpoint of the second drive bridge arm is the V-phase output of the drive circuit 21, which is connected to the head end of the V-phase coil of the synchronous motor 1; the midpoint of the first drive bridge arm is the W-phase output of the drive circuit 21, which is connected to the head end of the W-phase coil of the synchronous motor 1.

[0071] The control chip 22 includes a position acquisition port, a current acquisition port, and a drive control port. The position acquisition port is connected to the rotor position sensor 13 of each synchronous motor, thereby enabling rotor position acquisition of each synchronous motor. The current acquisition port is connected to the current sensor 211, thereby enabling current acquisition of the input synchronous motor. Because the current is three-phase, only two phases of current can be acquired to calculate the current of the third phase. The drive control port is connected to the gate of each switching tube, that is, the third terminal, thereby enabling the output of the three-phase control voltage. It is worth noting that each of the above ports can be controlled using a single port or multiple ports, which is not limited here.

[0072] It should be noted that the switching transistors used in all embodiments of the present application may be TFTs (Thin Film Transistors), field-effect transistors, or other devices with similar characteristics. Taking an IGBT as an example, since the second and second terminals of the switching transistors used here are symmetrical, their source and drain terminals are interchangeable. In the embodiments of the present application, to distinguish the two terminals of the transistor other than the gate, one terminal is referred to as the source, and the other as the drain. The remaining transistors can be defined according to the configuration shown in FIG3 : the middle terminal (third terminal) of each transistor is the gate, the signal input terminal is the source, and the signal output terminal is the drain. Furthermore, the transistors used in the embodiments of the present application may include P-type transistors and / or N-type transistors. P-type transistors are turned on when the gate is low and turned off when the gate is high, while N-type transistors are turned on when the gate is high and turned off when the gate is low. The corresponding first gate drive voltage Vgate and second gate drive voltage Share_Vgate for N-type and P-type transistors have different conduction modes and corresponding control methods. The specific control is performed according to the actual transistor and is not limited here.

[0073] Furthermore, in some feasible embodiments, the switch transistor can be a low-temperature polysilicon thin-film transistor, an oxide semiconductor thin-film transistor, or an amorphous silicon thin-film transistor. The transistors in the driving circuit provided in the embodiments of the present application are made of the same material, thereby avoiding the impact of differences between transistors of different materials on the driving circuit.

[0074] Furthermore, in another embodiment of the synchronous motor drive circuit of the present application, referring to Figure 5, Figure 5 is a schematic diagram of the position adjustment process of the synchronous motor drive circuit of the present application. Before the synchronous motor drive circuit works, the current rotor position is obtained based on a preset power-on state, and the angle deviation value is determined based on the current rotor position. When the angle deviation value meets the preset angle deviation threshold, it is determined that the hardware of the synchronous motor drive circuit is normal.

[0075] In this embodiment, since the initial positions of multiple motors cannot be at the same mechanical angle, when controlling multiple motors, the rotor positions should first be positioned at substantially the same electrical angle using a specific method. Based on the angular relationship of the feedback position sensors, the reference position should be adjusted appropriately to avoid problems such as loss of step or excessive current. As shown in Figure 5, by energizing two phases with a current equal to a specified value IS and a time equal to a specified time ts, the initial positions of each synchronous motor are obtained and recorded as initial positions P1S, P2S, ..., PnS, representing the initial positions of n synchronous motors. The (customized) reference of the pilot motor is then set to a predetermined value, and motor control is performed using the position of pilot motor k as the angular basis. During motor control, the rotor angle is observed, and the angular deviations of the other motors relative to motor k are calculated using the position of motor k as a reference. Among them, the preset power-on state is two-phase power-on, the current = specified value IS, the time = specified time ts power-on condition, the current rotor position refers to the actual drive angle of each motor under motor control, the angle deviation value refers to the difference between the actual drive angle of the navigation motor and each motor, and the preset angle deviation threshold refers to a user-defined angle difference, such as 3°. Then, when determining that the angle deviation values ​​are all within the preset angle deviation threshold during the entire drive process, it is determined that the hardware of the synchronous motor drive circuit is normal and simultaneous drive control can be performed. If the angle deviation values ​​are all outside the preset angle deviation threshold, the synchronous motor with the largest angle deviation value in the drive process is determined as the navigation motor to re-carry out drive control and angle deviation value detection. If the angle deviation values ​​are still outside the preset angle deviation threshold at this time, it is determined that the synchronous motor drive circuit hardware does not meet the simultaneous control conditions and simultaneous drive control is not performed. Then, through the above detection, the accuracy of subsequent simultaneous control can be guaranteed.

[0076] Furthermore, in another embodiment of the synchronous motor drive circuit of the present application, when the hardware of the synchronous motor drive circuit is normal and the drive is working, the rotor position information collected by each of the rotor position sensors 13 and the output current information of the current sensor are obtained, and a control instruction is determined based on the rotor position information and the output current information, and the drive circuit 21 is driven based on the control instruction, wherein the rotor position information includes the rotor position information in the collected information of each of the rotor position sensors 13 that meets the preset rotor deviation condition.

[0077] In this embodiment, the operating principle of the synchronous motor drive circuit is as follows: when the synchronous motor drive circuit hardware is normal and the drive is working (normal hardware means that the synchronous motors in the entire circuit have been determined to be operating stably), the motor driver module 20 treats multiple synchronous motors as a single motor and uses universal permanent magnet synchronous motor control technology to control the multiple motors. Taking Figure 3 as an example, the control chip 22 in the motor driver module 20 uses the current sensor 211 to collect the U-phase current and V-phase current, and simultaneously collects the rotor position of each synchronous motor through the rotor position sensor 13. Then, based on the rotor position and current, the control instruction is determined, and the control instruction is then provided to the drive circuit 21, which then synchronously drives the multiple synchronous motors based on the drive circuit 21. Among them, the host computer 200 is used to input the speed or torque instruction, and through logical operations, it forms the switching logic and provides it to the drive circuit 21, realizing the control of multiple motors at the same time. Subsequently, the control instruction is determined based on the rotor position and current to perform control. It is worth noting that the rotor position can be the rotor position of any synchronous motor. For example, synchronous motor 1 is at position A, synchronous motor 2 is at position B, and synchronous motor 3 is at position A. At this time, position B is close to the synchronous motor losing step, such as A is at an angle of 30 degrees and B is at an angle of 15 degrees. Then, at this time, position B of synchronous motor 2 is used as the rotor position information for subsequent control, thereby ensuring the synchronization of subsequent drive control and ensuring the accuracy of drive control. In other words, the rotor position information includes the rotor position information that meets the preset rotor deviation condition in the information collected by each of the rotor position sensors 13. The preset rotor deviation condition refers to the rotor position with the largest downward deviation from the normal position among the multiple synchronous motors, that is, the rotor position that has not reached the normal position and has the largest deviation from the normal position is used as the position information for subsequent drive control. Then, based on the rotor position that has not reached the normal position and has the largest deviation from the normal position as the position information for subsequent drive control, the synchronous drive of the multiple synchronous motors can be ensured to avoid the synchronous motor drive losing step.

[0078] In addition, based on the above embodiments, the present application further provides a drive motor 100 , which includes the above synchronous motor drive circuit.

[0079] Based on the above embodiments, the present application also proposes a motor drive system.

[0080] As shown in FIG6 , the motor drive system according to an embodiment of the present application may include:

[0081] Drive motor 100;

[0082] A host computer 200, wherein the output terminal of the host computer 200 is connected to the control terminal of the control chip 22 in the drive motor 100, and the power input terminal of the drive motor 100 is connected to the external power supply 400;

[0083] The motor load 300 is connected to the motor rotor 12 of each synchronous motor 101 - 10n in the drive motor 100 .

[0084] Among them, the power input end of the driving motor 400 is connected to the external power supply 400, and the control end of the control chip 22 in the driven motor 100 is connected to the output end of the host computer 200, so that the driving motor 400 can be controlled by the control instruction of the host computer 200 to work. In the working process, based on the connection relationship of the synchronous motors in the driving motor 400, the rotor position information and output current information of the acquisition end of each synchronous motor are obtained through the motor driver module in the driving motor 100. The control instruction can be determined based on the rotor position information and the output current information, so as to drive each synchronous motor based on the control instruction, thereby realizing a single motor driver driving multiple synchronous motors.

[0085] The above description is merely an optional embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification and drawings under the inventive concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A synchronous motor drive circuit, wherein: The synchronous motor driving circuit includes: Multiple synchronous motors, the three-phase windings of the synchronous motors are connected in series in sequence, and the three-phase winding of the last synchronous motor is short-circuited; A motor driver module, wherein the first end of the motor driver module is connected to the three-phase winding of the first synchronous motor, and the second end of the motor driver module is connected to the acquisition end of each synchronous motor. The motor driver module is used to obtain the rotor position information and output current information of the acquisition end of each synchronous motor, and determine the control instruction based on the rotor position information and the output current information, so as to drive each synchronous motor based on the control instruction.

2. The synchronous motor drive circuit according to claim 1, wherein: The synchronous motor comprises: A first-phase stator winding, wherein a first end of the first-phase stator winding is connected to a second end of a first-phase stator winding of a previous synchronous motor, and a second end of the first-phase stator winding is connected to a first end of a first-phase stator winding of a next synchronous motor; a second-phase stator winding, wherein a first end of the second-phase stator winding is connected to a second end of the second-phase stator winding of the previous synchronous motor, and a second end of the two-phase stator winding is connected to a first end of the second-phase stator winding of the next synchronous motor; a third-phase stator winding, wherein a first end of the third-phase stator winding is connected to a second end of the third-phase stator winding of the previous synchronous motor, and a second end of the three-phase stator winding is connected to a first end of the third-phase stator winding of the next synchronous motor; The motor rotor is arranged concentrically with a stator circle consisting of the first-phase stator winding, the second-phase stator winding, and the third-phase stator winding.

3. The synchronous motor drive circuit according to claim 2, wherein: When the synchronous motor is the first synchronous motor, the first end of the first-phase stator winding is connected to the first end of the motor driver module, the first end of the second-phase stator winding is connected to the first end of the motor driver module, and the first end of the third-phase stator winding is connected to the first end of the motor driver module; When the synchronous motor is the last synchronous motor, the second end of the first-phase stator winding, the second end of the second-phase stator winding, and the second end of the third-phase stator winding are short-circuited.

4. The synchronous motor drive circuit according to claim 2 or 3, wherein: The synchronous motor further comprises: A rotor position sensor is provided at a detection position of the motor rotor, wherein an output end of the rotor position sensor serves as a collection end of the synchronous motor and is connected to a second end of the motor driver module.

5. The synchronous motor drive circuit according to any one of claims 1 to 4, wherein: The motor driver module includes a drive circuit and a control chip, wherein the drive circuit includes a first drive bridge arm, a second drive bridge arm, and a third drive bridge arm, wherein the first end of the first drive bridge arm, the first end of the second drive bridge arm, and the first end of the third drive bridge arm are connected in sequence and serve as the positive electrode of the power input terminal, and the second end of the first drive bridge arm, the second end of the second drive bridge arm, and the second end of the third drive bridge arm are connected in sequence and serve as the negative electrode of the power input terminal; The first driving bridge arm includes a first switching tube and a second switching tube. The first end of the first switching tube serves as the first end of the first driving bridge arm. The second end of the first switching tube and the first end of the second switching tube are connected together to form a bridge arm midpoint of the first driving bridge arm and are connected to the first end of the first phase stator winding of the first synchronous motor. The second end of the second switching tube serves as the second end of the first driving bridge arm. The third ends of the first switching tube and the second switching tube are respectively connected to the control chip. The second driving bridge arm includes a third switching tube and a fourth switching tube. The first end of the third switching tube serves as the first end of the second driving bridge arm. The second end of the third switching tube and the first end of the fourth switching tube are connected together to form the midpoint of the second driving bridge arm and are connected to the first end of the second-phase stator winding of the first synchronous motor. The second end of the fourth switching tube serves as the second end of the second driving bridge arm. The third ends of the third switching tube and the third ends of the fourth switching tube are respectively connected to the control chip. The third drive bridge arm includes a fifth switch tube and a sixth switch tube. The first end of the fifth switch tube is the first end of the third drive bridge arm. The second end of the fifth switch tube and the first end of the sixth switch tube are connected together to form the midpoint of the third drive bridge arm and are connected to the first end of the third phase stator winding of the first synchronous motor. The second end of the sixth switch tube is the second end of the third drive bridge arm. The third end of the fifth switch tube and the third end of the sixth switch tube are respectively connected to the control chip.

6. The synchronous motor drive circuit according to claim 4 or 5, wherein: The control chip includes a position acquisition port, a current acquisition port, and a drive control port, wherein the position acquisition port is connected to the output end of each rotor position sensor, and the drive control port is connected to the third end of each switch tube. The motor driver module also includes: Multiple current sensors, wherein the first end of the current sensor is connected to a midpoint of the bridge arm, the second end of the current sensor is connected to the phase stator winding corresponding to the midpoint of the bridge arm, and the third end of the current sensor is connected to the current acquisition port.

7. The synchronous motor drive circuit according to any one of claims 1 to 6, wherein: Before the synchronous motor drive circuit works, the current rotor position is obtained based on a preset power-on state, and an angle deviation value is determined based on the current rotor position. When the angle deviation value meets a preset angle deviation threshold, it is determined that the hardware of the synchronous motor drive circuit is normal.

8. The synchronous motor driving circuit according to claim 7, wherein: When the hardware of the synchronous motor drive circuit is normal and the drive is working, the rotor position information collected by each of the rotor position sensors and the output current information of the current sensor are obtained, and a control instruction is determined based on the rotor position information and the output current information, and the drive circuit is driven based on the control instruction, wherein the rotor position information includes the rotor position information that meets the preset rotor deviation condition in the collected information of each of the rotor position sensors.

9. A drive motor, wherein: The drive motor includes the synchronous motor drive circuit according to any one of claims 1 to 8.

10. A motor drive system, wherein: The motor drive system includes the drive motor according to claim 9, and further includes: A host computer, wherein the output terminal of the host computer is connected to the control terminal of the control chip in the drive motor, and the power input terminal of the drive motor is connected to an external power supply; A motor load is connected to the motor rotor of each synchronous motor in the drive motor.

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