Control circuit, system, method and equipment for driving double motors by single inverter

Abstract

The invention relates to a control circuit, system, method and equipment for driving double motors by a single inverter, and the control circuit controls a first motor and a second motor to be synchronously started to enter a starting operation state under the condition that the initial position of a rotor of the first motor is the same as the initial position of a rotor of the second motor, and controls the first motor and the second motor to enter a starting operation state based on the starting operation state. A position error is determined according to a first sampling signal corresponding to a first motor and a second sampling signal corresponding to a second motor, then a target control signal corresponding to the position error is output, a second motor driving signal output by a second motor driving end is controlled to flow into a compensation inductor according to the target control signal, and a target compensation signal is generated; and the target compensation signal is output to the second motor to correct the rotor position of the second motor and realize position compensation, so that the stability of the double permanent magnet synchronous motors driven by the single inverter is ensured, and the problem of poor stability caused by different rotor positions of the double motors when the double permanent magnet synchronous motors are driven by the single inverter is solved.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a control circuit, system, method and device for driving dual motors with a single inverter. Background Art

[0002] In the field of motor control, the control circuit of a single inverter driving dual motors has attracted much attention due to its advantages such as low cost and compact structure.

[0003] However, the different initial rotor positions of the two motors, as well as potential positional deviations during operation, can lead to unstable dual-motor operation and reduced efficiency. Specifically, the different initial rotor positions of the two motors result in differences in their starting characteristics. This can cause imbalance during startup, manifesting as either motor failing to start, or only one starting, severely impacting system stability and response speed. Even if the motors successfully start, the rotor positions of the two motors may not be exactly the same during operation, making control difficult and prone to shutdown, impacting the stability and reliability of the single-inverter-driven dual permanent magnet synchronous motor system.

[0004] Traditional control methods typically use position sensors to monitor the motor rotor's position in real time. However, this approach increases system cost and complexity, and the reliability of the position sensor can also affect the stability of the entire system. Therefore, achieving stable control of dual motors using a single inverter without using position sensors has become a pressing issue for those skilled in the art. Summary of the Invention

[0005] In view of this, the present application provides a control circuit, system, method and device for a single inverter driving dual motors, so as to achieve stable control of dual motors by a single inverter without using a position sensor, thereby solving the problem of poor stability caused by the different rotor positions of the dual motors when a single inverter drives dual motors.

[0006] In a first aspect, an embodiment of the present application provides a control circuit for driving dual motors with a single inverter, comprising: a motor drive circuit module and a position compensation circuit module; the dual motors include a first motor and a second motor; wherein the dual motors include a first motor and a second motor; a first motor driving end of the motor driving circuit module electrically connected to each phase power supply end of the first motor, a second motor driving end of the motor driving circuit module electrically connected to an input end of the position compensation circuit module, a compensation driving end of the motor driving circuit module electrically connected to a control end of the position compensation circuit module, and an output end of the position compensation circuit module electrically connected to each phase power supply end of the second motor; The motor drive circuit module is configured to: when the initial rotor position of the first motor is the same as the initial rotor position of the second motor, control the first motor and the second motor to start synchronously to enter a startup operation state, and based on the startup operation state, determine a position error according to a first sampling signal corresponding to the first motor and a second sampling signal corresponding to the second motor, and output a target control signal corresponding to the position error to a control end of the position compensation circuit module; The position compensation circuit module includes a compensation inductor, and the position compensation circuit module is configured to: control the second motor drive signal output by the second motor drive end to flow into the compensation inductor according to the target control signal to generate a target compensation signal, and output the target compensation signal to the second motor; the target compensation signal is used to correct the rotor position of the second motor so that the rotor position of the second motor is the same as the rotor position of the first motor.

[0007] Optionally, the position compensation circuit module further includes a relay submodule; the relay submodule includes a relay switch, the control end of the relay submodule serves as the control end of the position compensation circuit module, the first switch contact of the relay switch, the second motor drive end of the motor drive circuit module, and the first end of the compensation inductor are electrically connected, the second switch contact of the relay switch is electrically connected to the second end of the compensation inductor, and the third switch contact and the fourth switch contact of the relay switch are electrically connected to serve as the output end of the position compensation circuit module; The relay submodule is configured to: when the target control signal is a preset compensation control signal, control the first switch contact to be disconnected from the fourth switch contact, and connect the second switch contact to the third switch contact, so that the second motor drive signal flows into the compensation inductor to generate the target compensation signal; when the target control signal is not the compensation control signal, control the first switch contact to be connected to the fourth switch contact, so that the second motor drive signal passes through the first switch contact and the fourth switch contact and is transmitted to the second motor.

[0008] Optionally, the second motor driving end of the motor driving circuit module includes a second single-phase driving end connected in a one-to-one correspondence with the single-phase power supply end of the second motor; the compensation inductor includes a first inductor connected in a one-to-one correspondence with the second single-phase driving end; and the output end of the position compensation circuit module includes a second driving output end connected in a one-to-one correspondence with the single-phase power supply end of the second motor; The relay submodule further includes a control transistor; a control end of the control transistor serves as a control end of the relay submodule, a first end of the control transistor is electrically connected to a first end of the coil of the relay switch, and a second end of the control transistor is electrically connected to a reference ground of the control circuit; The second end of the coil of the relay switch is electrically connected to the power supply end of the control circuit; the relay switch includes a normally closed switch connected in a one-to-one correspondence with the second single-phase drive end and a normally open switch connected in a one-to-one correspondence with the first inductor; the first end of the normally closed switch is electrically connected to the first end of the first inductor to serve as the first switch contact; the first end of the normally open switch is electrically connected to the second end of the first inductor to serve as the second switch contact; the second end of the normally open switch is electrically connected to the second end of the normally closed switch to serve as the second drive output end.

[0009] Optionally, the motor drive circuit module includes a drive controller, a first relay, and a second relay; the first drive control end of the drive controller is electrically connected to the control end of the first relay, the second drive control end of the drive controller is electrically connected to the control end of the second relay, the third drive control end of the drive controller serves as a compensation drive end of the motor drive circuit module, and the power output end of the drive controller, the first switch end of the first relay, and the first switch end of the second relay are electrically connected; The drive controller is configured to: output a power drive signal, a first drive control signal and / or a second drive control signal, and output the target control signal according to the first sampling signal and the second sampling signal; The second switch end of the first relay serves as the first motor driving end, and the first relay is configured to: transmit the power driving signal to the first motor driving end according to the first driving control signal; The second switch end of the second relay serves as the second motor driving end, and the second relay is configured to transmit the power driving signal to the second motor driving end according to the second driving control signal.

[0010] Optionally, the drive controller includes a digital signal processor and an intelligent power module; the first end of the digital signal processor serves as the first drive control end, for outputting the first drive control signal; the second end of the digital signal processor serves as the second drive control end, for outputting the second drive control signal; the third end of the digital signal processor serves as the third drive control end, for outputting the target control signal; the fourth end of the digital signal processor is electrically connected to the first end of the intelligent power module, for triggering the intelligent power module to output the power drive signal; the first sampling end of the digital signal processor is electrically connected to the first current sampling end corresponding to the first motor, for detecting the first sampling signal; the second sampling end of the digital signal processor is electrically connected to the second current sampling end corresponding to the second motor, for detecting the second sampling signal.

[0011] In a second aspect, an embodiment of the present application provides a control method for a single inverter driving dual motors, which is applied to a control circuit as described in any one of the first aspects, wherein the dual motors include a first motor and a second motor, and the control method includes: when the initial position of the rotor of the first motor is the same as the initial position of the rotor of the second motor, controlling the first motor and the second motor to start synchronously to enter a starting operation state; based on the starting operation state, determining a position error according to a first sampling signal corresponding to the first motor and a second sampling signal corresponding to the second motor, and outputting a target control signal corresponding to the position error; according to the target control signal, controlling the second motor drive signal to flow into a compensation inductor to generate a target compensation signal, and outputting the target compensation signal to the second motor; the target compensation signal is used to correct the rotor position of the second motor so that the rotor position of the second motor is the same as the rotor position of the first motor.

[0012] Optionally, determining the position error based on the first sampling signal corresponding to the first motor and the second sampling signal corresponding to the second motor includes: obtaining the current detection signals of each phase of the first motor as the first sampling signal, and obtaining the current detection signals of each phase of the second motor as the second sampling signal; based on the first sampling signal, determining any phase current detection signal of the first motor as the target phase current detection signal; extracting a second motor current detection signal that is in phase with the target phase current detection signal from the second sampling signal; determining the current difference between the first motor and the second motor based on the target phase current detection signal and the second motor current detection signal; and determining the position error based on the current difference.

[0013] Optionally, when the initial rotor position of the first motor is the same as the initial rotor position of the second motor, controlling the first motor and the second motor to start synchronously includes: when power is turned on, determining the initial rotor position of the first motor as the first initial rotor position, and determining the initial rotor position of the second motor as the second initial rotor position; when the second initial rotor position is different from the first initial rotor position, adjusting the initial rotor position of the second motor according to the first initial rotor position until the adjusted initial rotor position of the second motor is the same as the first initial rotor position; when the second initial rotor position is the same as the first initial rotor position, starting the first motor and the second motor.

[0014] Optionally, when the initial rotor position of the first motor is the same as the initial rotor position of the second motor, controlling the first motor and the second motor to start synchronously includes: when power is turned on, determining the initial rotor position of the first motor as the first initial rotor position, and determining the initial rotor position of the second motor as the second initial rotor position; when the second initial rotor position is different from the first initial rotor position, adjusting the initial rotor position of the first motor according to the second initial rotor position until the adjusted initial rotor position of the first motor is the same as the second initial rotor position; when the second initial rotor position is the same as the first initial rotor position, starting the first motor and the second motor.

[0015] In a third aspect, an embodiment of the present application provides a control system for a single inverter driving dual motors, comprising the control circuit described in any one of the first aspects of the present application.

[0016] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; the memory is used to store computer programs; and the processor is used to implement the steps of the control method as described in any one of the second aspects when executing the program stored in the memory.

[0017] The control circuit, system, method and equipment for driving dual motors with a single inverter provided in the embodiments of the present application are electrically connected to the power supply terminals of each phase of the first motor through the first motor drive end of the motor drive circuit module, the second motor drive end of the motor drive circuit module is electrically connected to the input terminal of the position compensation circuit module, and the compensation drive end of the motor drive circuit module is electrically connected to the control end of the position compensation circuit module. When the initial position of the rotor of the first motor is the same as the initial position of the rotor of the second motor, the first motor and the second motor are controlled to start synchronously to enter the starting operation state, and based on the starting operation state, the position error is determined according to the first sampling signal corresponding to the first motor and the second sampling signal corresponding to the second motor, and then the position error is output. A target control signal corresponding to the error is used to control the second motor drive signal output by the second motor drive end to flow into the compensation inductor according to the target control signal to generate a target compensation signal, and the output end of the position compensation circuit module is electrically connected to the power supply end of each phase of the second motor, so that the target compensation signal can be output to the second motor to correct the rotor position of the second motor, realize real-time correction of the rotor position of the second motor, keep it the same as the rotor position of the first motor, and then realize the synchronous operation of the dual motors, ensure the stability of the single inverter driving the dual permanent magnet synchronous motors, solve the problem of poor stability caused by the different rotor positions of the dual motors when the single inverter drives the dual permanent magnet synchronous motors, and improve the reliability of the single inverter driving the dual motors. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0021] Figure 1 A structural block diagram of a control circuit for driving dual motors with a single inverter provided in an embodiment of the present application; Figure 2 A schematic diagram showing the connection between a position compensation circuit module and a second motor provided in an optional embodiment of the present application; Figure 3A schematic diagram of a control circuit for driving dual motors using a single inverter, provided as an optional embodiment of the present application; Figure 4 A schematic diagram showing the connection between a position compensation circuit module and a second motor provided in another optional embodiment of the present application; Figure 5 A flow chart of a control method for driving dual motors with a single inverter provided in an embodiment of the present application; Figure 6 A schematic diagram of a control flow of a single inverter driving dual motors provided as an example of this application; Figure 7 The structural intention of a control system for a single inverter driving dual motors provided in an embodiment of the present application; Figure 8 A schematic diagram of the structure of an electrical device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in 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.

[0023] The disclosure below provides many different embodiments or examples for implementing different configurations of the present invention. To simplify the disclosure of the present invention, the components and configurations of specific examples are described below. Of course, these are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or configurations discussed.

[0024] The application of a sensorless algorithm to control a single inverter driving dual permanent magnet synchronous motors presents significant technical challenges. Specifically, due to the different rotor positions of the two motors, during startup, either neither motor may start, or only one may start, making simultaneous startup difficult. During operation, the positions of the two motors may not always be identical, making control difficult and prone to downtime. These issues severely impact the stability and reliability of the single-inverter dual permanent magnet synchronous motor system, hindering the further application and development of this technology.

[0025] In order to solve the problem of poor stability caused by the different rotor positions of the two permanent magnet synchronous motors when the inverter drives the two permanent magnet synchronous motors in the prior art, the embodiments of the present application provide a control circuit, system, method and equipment for driving the two motors with a single inverter. Through innovative circuit design and control strategy, stable control of the two motors is achieved without using position sensors, thereby improving the reliability and efficiency of the system and reducing costs.

[0026] The dual motors may refer to dual permanent magnet synchronous motors. In the embodiment of the present application, one of the dual motors may be referred to as the first motor, and the other of the dual motors may be referred to as the second motor. Figure 1 As shown, the control circuit for driving dual motors with a single inverter provided in an embodiment of the present application may include a motor drive circuit module 110 and a position compensation circuit module 120. The first motor drive end of the motor drive circuit module 110 is electrically connected to the power supply end of each phase of the first motor M1, and the second motor drive end of the motor drive circuit module 110 is electrically connected to the input end of the position compensation circuit module 120. When the initial position of the rotor of the first motor M1 is the same as the initial position of the rotor of the second motor M2, the motor drive circuit module 110 can be used to control the first motor M1 and the second motor M2 to start synchronously to enter a starting operation state, and based on the starting operation state, the position error is determined according to the first sampling signal corresponding to the first motor M1 and the second sampling signal corresponding to the second motor M2, and the compensation drive end of the motor drive circuit module 110 is electrically connected to the control end of the position compensation circuit module 120. The motor drive circuit module 110 can output a target control signal corresponding to the error to the control end of the position compensation circuit module 120 according to the position error, so that the position compensation circuit module 120 can generate a target compensation signal through the compensation inductor 121 according to the target control signal, and the output end of the position compensation circuit module 120 is electrically connected to the power supply ends of each phase of the second motor M2, and then the target compensation signal can be output to the second motor M2 through the output end of the position compensation circuit module 120, so as to correct the rotor position of the second motor M2 through the target compensation signal, realize motor position compensation, and make the rotor position of the second motor M2 the same as the rotor position of the first motor M1, thereby ensuring the stability of the single inverter driving the dual permanent magnet synchronous motor, solving the problem of poor stability caused by the different rotor positions of the dual motors when the single inverter drives the dual permanent magnet synchronous motor, and improving stability and reliability.

[0027] In an embodiment of the present application, the motor drive circuit module 110 is configured to: when the initial position of the rotor of the first motor M1 is the same as the initial position of the rotor of the second motor M2, control the first motor M1 and the second motor M2 to start synchronously to enter a starting operation state, and based on the starting operation state, determine the position error according to the first sampling signal corresponding to the first motor M1 and the second sampling signal corresponding to the second motor M2, so as to output the target control signal corresponding to the position error to the control end of the position compensation circuit module 120.

[0028] The position compensation circuit module 120 is provided with a compensation inductor 121, and the position compensation circuit module 120 is configured to: control the second motor drive signal output by the second motor drive end to flow into the compensation inductor 121 according to the target control signal to generate a target compensation signal, and output the target compensation signal to the second motor M2; the target compensation signal is used to correct the rotor position of the second motor M2 so that the rotor position of the second motor M2 is the same as the rotor position of the first motor M1.

[0029] It can be seen that the embodiment of the present application uses a control circuit that drives dual motors with a single inverter. When the initial rotor position of the first motor M1 is the same as the initial rotor position of the second motor M2, the first motor M1 and the second motor M2 are controlled to start synchronously to enter a startup operation state. Based on the startup operation state, the position error is determined according to the first sampling signal corresponding to the first motor M1 and the second sampling signal corresponding to the second motor M2. Then, a target control signal corresponding to the position error is output. Based on the target control signal, the second motor drive signal output from the second motor drive end is controlled to flow into the compensation inductor 121 to generate a target compensation signal. The target compensation signal is output to the second motor M2 to correct the rotor position of the second motor M2 and achieve position compensation in the motor operation stage. The rotor position of the second motor M2 is the same as the rotor position of the first motor M1, thereby ensuring the stability of the dual permanent magnet synchronous motor driven by the single inverter, solving the problem of poor stability caused by the different rotor positions of the dual motors when the single inverter drives the dual permanent magnet synchronous motor, and improving stability and reliability.

[0030] In an exemplary embodiment of the present application, a control circuit 100 for driving dual motors with a single inverter is provided, a control system for driving dual motors with a single inverter including the control circuit 100, and a control method and electrical device for driving dual motors with a single inverter applied to the control circuit 100 are provided. Figure 1As shown, the control circuit 100 for driving dual motors with a single inverter includes: a motor drive circuit module 110 and a position compensation circuit module 120, wherein the first motor drive end of the motor drive circuit module 110 is electrically connected to the power supply ends of each phase of the first motor M1, the second motor drive end of the motor drive circuit module 110 is electrically connected to the input end of the position compensation circuit module 120, the compensation drive end of the motor drive circuit module 110 is electrically connected to the control end of the position compensation circuit module 120, and the output end of the position compensation circuit module 120 is electrically connected to the power supply ends of each phase of the second motor M2.

[0031] The second motor driving end of the motor driving circuit module 110 may include a second single-phase driving end connected to the single-phase power supply end of the second motor M2 in a one-to-one correspondence, so as to output a corresponding power driving signal to the single-phase power supply end of the second motor M2 through the second single-phase driving end to supply power to the second motor M2. For example, in the case where the second motor M2 is a three-phase motor, the second motor driving end of the motor driving circuit module 110 may include three second single-phase driving ends, such as Figure 2 or Figure 3 As shown, the first second single-phase drive terminal U2 is electrically connected to the first-phase power supply terminal of the second motor M2, the second second single-phase drive terminal V2 is electrically connected to the second-phase power supply terminal of the second motor M2, and the third second single-phase drive terminal W2 is electrically connected to the third-phase power supply terminal of the second motor M2.

[0032] The first motor driving end of the motor driving circuit module 110 may include a first single-phase driving end connected to the single-phase power supply end of the first motor M1 in a one-to-one correspondence, so as to output a corresponding power driving signal to the single-phase power supply end of the first motor M1 through the first single-phase driving end to supply power to the first motor M1. For example, in the case where the first motor M1 is a three-phase motor, the first motor driving end of the motor driving circuit module 110 may include three first single-phase driving ends, such as Figure 3 As shown, the first first single-phase drive terminal U1 is electrically connected to the first phase power supply terminal of the first motor M1, the second first single-phase drive terminal V1 is electrically connected to the second phase power supply terminal of the first motor M1, and the third first single-phase drive terminal W1 is electrically connected to the third phase power supply terminal of the first motor M1.

[0033] In the embodiment of the present application, the position compensation circuit module 120 may be provided with other circuit components in addition to the compensation inductor 121 , and the embodiment of the present application does not impose any specific limitation on this.

[0034] Optional, such as Figure 2As shown, the position compensation circuit module 120 in the embodiment of the present application may include, in addition to the compensation inductor 121, a relay sub-module 122. The relay sub-module 122 is configured to: control the second motor drive signal output by the second motor drive end to flow into the compensation inductor 121 according to the target control signal to generate a target compensation signal, and output the target compensation signal to the second motor M2, so that the second motor M2 can rotate based on the target compensation signal, and then adjust the rotor position of the second motor M2 based on the target compensation signal, so that the rotor position of the second motor M2 is the same as the rotor position of the first motor M1, thereby realizing synchronous operation of the second motor M2 and the second motor M2.

[0035] For example, Figure 2 or Figure 3 As shown, the control terminal Cn of the relay submodule 122 is electrically connected to the compensation drive terminal of the motor drive circuit module 110 to serve as the control terminal of the position compensation circuit module 120; the first input terminal of the relay submodule 122, the second motor drive terminal of the motor drive circuit module 110 and the first end of the compensation inductor 121 are electrically connected, and the second input terminal of the relay submodule 122 is electrically connected to the second end of the compensation inductor 121, so that the relay submodule 122 can control the second motor drive signal output by the second motor drive terminal to flow into the compensation inductor 121 according to the target control signal to generate the target compensation signal; and The output end of the relay submodule 122 serves as the output end of the position compensation circuit module 120 and is electrically connected to the respective phase power supply ends of the second motor M2, so that the motor drive circuit module 110 can output a target compensation signal to the respective phase power supply ends of the second motor M2 through the relay submodule 122, so as to adjust the rotor position of the second motor M2 by the target compensation signal, and stop adjusting until the rotor position of the second motor M2 is the same as the rotor position of the first motor M1, so as to correct the rotor position of the second motor M2, so that the rotor position of the second motor M2 is the same as the rotor position of the first motor M1 during operation, thereby ensuring the stability and reliability of the motor operation.

[0036] In some optional embodiments of the present application, the relay submodule 122 may include a relay switch K3. The control terminal Cn of the relay submodule 122 serves as the control terminal of the position compensation circuit module 120 and is electrically connected to the compensation drive terminal of the motor drive circuit module 110, so that the relay submodule 122 can control the second motor drive signal output by the second motor drive terminal to flow into the compensation inductor 121 by controlling the relay switch K3 under the control of the target control signal output by the motor drive circuit module 110. The relay switch K3 may include multiple contacts, such as Figure 2As shown, it can include a first switch contact A, a second switch contact B, a third switch contact C, and a fourth switch contact D, so that the relay submodule 122 can control the connection of the contacts of the relay switch K3 according to the target control signal to control the transmission path of the second motor drive signal output by the second motor drive end, and then can control the second motor drive signal to flow into the compensation inductor 121 to generate a target compensation signal based on the second motor drive signal through the compensation inductor 121.

[0037] For example, Figure 2 As shown, the first switch contact A of the relay switch K3, the second motor driving end of the motor driving circuit module 110, and the first end of the compensation inductor 121 are electrically connected, so that the first switch contact A of the relay switch K3 serves as the first input end of the relay submodule 122, and the second switch contact B of the relay switch K3 is electrically connected to the second end of the compensation inductor 121, so that the second switch contact B of the relay switch K3 serves as the second input end of the relay submodule 122. The third switch contact C and the fourth switch contact D of the relay switch K3 are electrically connected to serve as the output end of the position compensation circuit module 120, so that the relay submodule 122 can control whether the first switch contact A of the relay switch K3 is disconnected from the fourth switch contact D, and control the connection between the second switch contact B and the third switch contact C of the relay switch K3 according to the target control signal, so as to control whether the second motor driving signal output by the second motor driving end passes through the compensation inductor 121.

[0038] The following description takes the relay switch K3 connected to the third second single-phase drive terminal W2 of the motor drive circuit module 110 as an example. When the first switch contact A and the fourth switch contact D of the relay switch K3 are disconnected, the second switch contact B and the third switch contact C are connected, so that the second motor drive signal output by the third second single-phase drive terminal W2 passes through the compensation inductor 121 to generate a target compensation signal. The target compensation signal is then transmitted to the power supply terminal of the second motor M2 through the connected second switch contact B and the third switch contact C to power the second motor M2, so that the second motor M2 can perform position correction according to the target compensation signal to achieve position compensation; when the first switch contact A and the fourth switch contact D of the relay switch K3 are connected, the second switch contact B and the third switch contact C are disconnected, so that the second motor drive signal output by the third second single-phase drive terminal W2 passes through the connected first switch contact A and the fourth switch contact D to the power supply terminal of the second motor M2 to power the second motor M2 to drive the second motor M2 and ensure that the second motor M2 can operate normally.

[0039] Among them, the target control signal output by the motor drive circuit module 110 can be divided into a preset compensation control signal and a non-compensation control signal; the compensation control signal can refer to a control signal generated when the position error is greater than a preset error threshold, and can specifically be used to trigger the position compensation circuit module 120 to control the second motor drive signal output by the second motor drive end to flow into the compensation inductor 121 to generate a target compensation signal for position compensation; the non-compensation control signal can refer to a control signal generated when the position error is not greater than a preset error threshold. The preset error threshold refers to a pre-set maximum error threshold, which is used to determine whether to output a preset compensation control signal. Optionally, the position compensation circuit module 120 may not generate a target compensation signal based on the non-compensation control signal, and directly transmit the second motor drive signal output by the second motor drive end to the power supply end of the second motor M2 to power the second motor M2 and ensure that the second motor M2 can operate normally.

[0040] In an embodiment of the present application, the relay submodule 122 is configured to: when the target control signal is a preset compensation control signal, control the first switch contact A and the fourth switch contact D to be disconnected, and the second switch contact B and the third switch contact C to be connected, so that the second motor drive signal flows into the compensation inductor 121 to generate the target compensation signal; when the target control signal is not the compensation control signal, control the first switch contact A and the fourth switch contact D to be connected, so that the second motor drive signal passes through the first switch contact A and the fourth switch contact D and is transmitted to the second motor M2.

[0041] In some optional embodiments of the present application, the relay switch K3 may include a normally open switch S1 and a normally closed switch S2. The first end of the normally closed switch S2 serves as a first switch contact A of the relay switch K3, electrically connected to the second motor drive terminal of the motor drive circuit module 110 and the first end of the compensation inductor 121, and the second end of the normally closed switch S2 serves as a fourth switch contact D of the relay switch K3. The first end of the normally open switch S1 serves as a second switch contact B of the relay switch K3, electrically connected to the second end of the compensation inductor 121, and the second end of the normally open switch S1 serves as a third switch contact C of the relay switch K3.

[0042] When the target control signal output by the motor drive circuit module 110 is a non-compensated control signal, that is, when the target control signal is not a preset compensation control signal, the normally open switch S1 remains in an open state, so that the second switch contact B is disconnected from the third switch contact, the normally closed switch S2 remains in a closed state, and the first switch contact A is connected to the fourth switch contact, so that the second motor drive signal output by the second motor drive end passes through the first switch contact A and the fourth switch contact and is transmitted to the second motor M2, powering the second motor M2 and ensuring that the second motor M2 can start and run normally.

[0043] When the motor drive circuit module 110 outputs a preset compensation control signal, the relay switch K3 can be controlled by the relay submodule 122 to operate, so that the normally open switch S1 enters a closed and conductive state, the second switch contact B is connected to the third switch contact, the first switch contact A is disconnected from the fourth switch contact, and the normally closed switch S2 enters an open state, so that the second motor drive signal output by the second motor drive end passes through the compensation inductor 121 to generate a target compensation signal, and the target compensation signal is transmitted to the second motor M2, so that the second motor M2 can perform position correction according to the target compensation signal, so that the rotor position of the second motor M2 is the same as the rotor position of the first motor M1, ensuring that the positions of the first motor M1 and the second motor M2 are the same, and synchronous operation is achieved.

[0044] Optionally, the compensation inductor 121 in the embodiment of the present application may include a first inductor L connected one-to-one with the second single-phase drive end, that is, the number of the first inductor L is the same as the number of the single-phase power supply ends of the second motor M2, so that the position compensation circuit module 120 can generate a corresponding target control signal for each phase power supply end of the second motor M2 through the first inductor L; the output end of the position compensation circuit module 120 may include a second drive output end connected one-to-one with the single-phase power supply end of the second motor M2, so that the position compensation circuit module 120 can output the corresponding target compensation signal to each phase power supply end of the second motor M2 through the second drive output end, so as to realize the motor position compensation of the second motor M2 through the target compensation signal.

[0045] Optionally, the relay switch K3 in the relay submodule 122 may include a normally closed switch S2 connected in a one-to-one correspondence with the second single-phase drive end and a normally open switch S1 connected in a one-to-one correspondence with the first inductor L; wherein the first end of the normally closed switch S2 is electrically connected to the first end of the first inductor L to serve as the first switch contact A; the first end of the normally open switch S1 is electrically connected to the second end of the first inductor L to serve as the second switch contact B; the second end of the normally open switch S1 is electrically connected to the second end of the normally closed switch S2 to serve as the second drive output end, so that the relay submodule 122 can control the transmission path of the second motor drive signal by controlling the normally closed switch S2 and the normally open switch S1 in the relay switch K3. For example, when the normally closed switch S2 is closed and the normally open switch S1 is disconnected, the second motor drive signal can be directly transmitted to the power supply end of the second motor M2 through the normally closed switch S2; and when the normally closed switch S2 is disconnected and the normally open switch S1 is closed, the second motor drive signal can pass through the first inductor L and be output to the second motor M2 as a target compensation signal.

[0046] Optionally, in addition to the relay switch K3, the relay submodule 122 in the embodiment of the present application may also include a control transistor Q1 to control the relay switch K3 via the control transistor Q1. Specifically, the control terminal of the control transistor Q1 may serve as the control terminal Cn of the relay submodule 122 and be electrically connected to the compensation drive terminal of the motor drive circuit module 110. The first terminal of the control transistor Q1 is electrically connected to the first terminal of the coil of the relay switch K3, the second terminal of the control transistor Q1 is electrically connected to the reference ground GND of the control circuit, and the second terminal of the coil of the relay switch K3 is electrically connected to the power supply terminal VCC of the control circuit. This allows the relay submodule 122 to control the coil current of the relay switch K3 via the control transistor Q1, thereby controlling whether the relay switch K3 is actuated.

[0047] Specifically, when alternating current passes through an inductor, a magnetic field can be formed. Therefore, when the current changes, the first inductor L in the embodiment of the present application will generate a reverse electromotive force, hindering the current change, thereby forcing a lag effect on the second motor M2, thereby reducing the position error between the second motor M2 and the first motor M1. Specifically, when the target control signal output by the motor drive circuit module 110 is a preset compensation control signal, the embodiment of the present application controls the transistor Q1 to be turned on, so that the normally open switch S1 and the normally closed switch S2 in the relay switch K3 are activated, so that the second motor drive current passes through the first inductor L, thereby hindering the change of the second motor drive current through the first inductor L, and outputting the target compensation signal to the second motor M2, thereby reducing the position error between the second motor M2 and the first motor M1. When the position error is less than a preset error threshold, it is considered that the rotor position of the second motor M2 is the same as the rotor position of the first motor M1. Then, the motor drive circuit module 110 outputs a non-compensation control signal as the target control signal and transmits it to the control transistor Q1, so that the control transistor Q1 enters an off state, thereby causing the normally open switch S1 in the relay switch K3 to enter an off state, and the normally closed switch S2 to enter a closed conductive state. Therefore, the second motor drive signal output by the second motor drive end does not pass through the first inductor L, but is directly transmitted to the second motor M2, powering the second motor M2 and ensuring synchronous operation of the second motor M2 and the first motor M1.

[0048] Among them, the second motor driving current refers to the driving current of the second motor, which can be specifically used to drive the second motor, such as including the first phase power supply driving current IU2 of the second motor, the second phase power supply driving current IV2 of the second motor, and the third phase driving power supply current W2 of the second motor.

[0049] The coil of relay switch K3 can serve as an excitation inductor. When the control transistor Q1 is turned on, the coil of relay switch K3 can generate current based on the voltage difference between the power supply terminal VCC of the control circuit and the reference ground GND, causing the normally open switch S1 and the normally closed switch S2 in relay switch K3 to operate, thereby causing the normally open switch S1 to enter a closed conductive state and the normally closed switch S2 to enter an open state. The second motor drive signal passes through the first inductor L, that is, the second motor drive current passes through the first inductor L, forcing a hysteresis effect on the second motor M2. The control transistor Q1 can be a transistor or a field-effect transistor, and this embodiment of the present application does not impose specific limitations on this.

[0050] In a specific implementation, the three-phase power supply of the second motor M2 can be connected to the same relay switch K3, such as Figure 2As shown, the coil of the same relay switch K3 is used to control the connection state of the normally closed switch S2 and the normally open switch S1 connected to the power supply terminals of each phase of the second motor M2, thereby saving space; alternatively, the three-phase power supply of the second motor M2 can be connected to two or more relay switches K3 of the same model, such as each phase power supply of the second motor M2 is connected to a relay switch K3, that is, when the three-phase power supply of the second motor M2 is connected to three relay switches K3 of the same model, as shown in FIG. Figure 3 or Figure 4 As shown, the connection states of the normally closed switch S2 and the normally open switch S1 connected to the power supply terminals of each phase of the second motor M2 can be controlled respectively by three relay switches K3 of the same model, and this embodiment of the present application does not limit this.

[0051] In addition, the embodiment of the present application can control the relay switch K3 through one or at least two control transistors Q1, and the embodiment of the present application is not limited to this. For example, the relay switch K3 connected to each power supply terminal of the second motor M2 can be controlled by a control transistor Q1 to save circuit space; for example, the control transistor Q1 can be connected to the relay switch K3 in a one-to-one correspondence, such as when each phase power supply terminal of the second motor M2 is electrically connected to the second single-phase drive terminal of the motor drive circuit module 110 through a relay switch K3, that is, when the second motor drive terminal of the motor drive circuit module 110 is electrically connected to the three-phase power supply terminal of the second motor M2 through three relay switches K3 of the same model, such as Figure 3 As shown, the relay submodule 122 can control the connection status of the relay switch K3 corresponding to the relay submodule 122 through three control transistors Q1 respectively, and this embodiment of the present application is not limited to this.

[0052] In the embodiment of the present application, the relay submodule 122 may include not only the relay switch K3 and the control transistor Q1 , but also other components, such as a diode D1 , etc., which is not limited in the embodiment of the present application.

[0053] In some optional embodiments of the present application, the relay submodule 122 includes a relay switch K3, a control transistor Q1 and a diode D1; Figure 3As shown, the anode of diode D1 is electrically connected to the first end of the control transistor Q1 and the first end of the coil of relay switch K3, and the cathode D1 of diode is electrically connected to the second end of the coil of relay switch K3, thereby demagnetizing the excitation winding when relay switch K3 is disconnected. Specifically, when the control transistor Q1 is disconnected, freewheeling current can flow through the diode. That is, the current at the first end of the coil of relay switch K3 can flow through the diode to the second end of the coil of relay switch K3, thereby eliminating the magnetic field generated by the coil of relay switch K3. This can then quickly close the normally closed switch S2 of relay switch K3 and disconnect the normally open switch S1 of relay switch K3, thereby improving the operating efficiency of relay switch K3.

[0054] Optionally, in order to realize the driving control of the dual motors, the motor driving circuit module 110 in the embodiment of the present application may include a driving controller 111, a first relay K1 and a second relay K2; Figure 3 As shown, the first drive control terminal K1c of the drive controller 111 is electrically connected to the control terminal of the first relay K1, so that the motor drive circuit module 110 can output the first drive control signal to the control terminal of the first relay K1 through the first drive control terminal K1c of the drive controller 111, so that the power drive signal output by the drive controller 111 is transmitted to the first motor drive terminal as the first motor drive signal through the first relay K1, so that the power drive signal can be transmitted to the respective phase power supply terminals of the first motor M1 through the first motor drive terminal to realize the drive control of the first motor M1; the second drive control terminal K2c of the drive controller 111 is electrically connected to the control terminal of the second relay K2, so that the motor drive circuit module 110 can output the first drive control signal to the control terminal of the second relay K2 through the second drive control terminal K2c of the drive controller 111 A second drive control signal is output to transmit the power drive signal output by the drive controller 111 as the second motor drive signal to the second motor drive end through the second relay K2, so that the power drive signal can be transmitted to the respective phase power supply ends of the second motor M2 through the second motor drive end to realize the drive control of the second motor M2; the third drive control end of the drive controller 111 serves as the compensation drive end of the motor drive circuit module 110 and is electrically connected to the control end of the position compensation circuit module 120, so that the motor drive circuit module 110 can output a target control signal corresponding to the position error to the control end of the position compensation circuit module 120 through the third drive control end of the drive controller 111, so as to control whether the second motor drive signal output by the second motor drive end passes through the compensation inductor 121 according to the target control signal.

[0055] For example, when the position error between the first motor M1 and the second motor M2 is greater than a preset error threshold, the motor drive circuit module 110 outputs a high-level signal, which is transmitted as a target control signal to the control transistor Q1 in the position compensation circuit module 120, so that the control transistor Q1 is turned on to drive the relay switch K3 in the relay submodule 122, so that the second motor drive signal output by the second motor drive end passes through the compensation inductor 121 to generate a target compensation signal, and the target compensation signal is output to the second motor M2, so as to force a hysteresis effect on the second motor M2, so that the second motor M2 and the first motor M2 are aligned. The position error between the first motor M1 and the second motor M2 is reduced; when the position error between the first motor M1 and the second motor M2 is not greater than the preset error threshold, the motor drive circuit module 110 outputs a low-level signal, which is transmitted as a target control signal to the control transistor Q1 in the position compensation circuit module 120, so that the control transistor Q1 is cut off and disconnected, the normally closed switch S2 in the relay switch K3 is in a closed and conductive state, and the normally open switch S1 in the relay switch K3 is in an open state, so that the second motor drive signal output by the second motor drive end does not pass through the compensation inductor 121, but is directly transmitted to the second motor M2 through the normally closed switch S2.

[0056] In the embodiment of the present application, the power output terminal of the drive controller 111, the first switch terminal of the first relay K1, and the first switch terminal of the second relay K2 are electrically connected so that the power drive signal is transmitted to the first motor drive terminal as the first motor drive signal via the first relay K1, and the power drive signal output by the drive controller 111 is transmitted to the second motor drive terminal as the second motor drive signal via the second relay K2. The power output terminal of the drive controller 111 is used to output the power drive signal; the drive controller 111 is configured to output the power drive signal, the first drive control signal, and / or the second drive control signal, and output the target control signal based on the first sampling signal and the second sampling signal.

[0057] Among them, the first sampling signal may refer to a signal obtained by sampling the driving current of the first motor M1. For example, when the first motor M1 is a three-phase motor, the driving current of the first motor M1 may include the first-phase power supply driving current IU1 of the first motor, the second-phase power supply driving current IV1 of the first motor, and the third-phase power supply driving current IW1 of the first motor; the second sampling signal may refer to a signal obtained by sampling the driving current of the second motor M2.

[0058] The second switch terminal of the first relay K1 serves as the first motor driving terminal of the motor driving circuit module 110, so that the motor driving circuit module 110 can transmit the power driving signal as the first motor driving signal to the first motor M1 through the first relay K1 to achieve drive control of the first motor M1. The first relay K1 is configured to transmit the power driving signal to the first motor driving terminal according to the first drive control signal.

[0059] The second switch terminal of the second relay K2 serves as the second motor drive terminal, so that the motor drive circuit module 110 can transmit the power drive signal as the second motor drive signal to the second motor M2 through the second relay K2 to achieve drive control of the second motor M2. The second relay K2 is configured to transmit the power drive signal to the second motor drive terminal based on the second drive control signal.

[0060] In some optional embodiments of the present application, the drive controller 111 may include a digital signal processor DSP and an intelligent power module IPM. The intelligent power module IPM may be a power control module in a single inverter, and may be specifically configured to output a power drive signal to drive the first motor M1 and the second motor M2 via the power drive signal.

[0061] For example, Figure 3As shown, the first terminal of the digital signal processor DSP serves as the first drive control terminal K1c, electrically connected to the control terminal of the first relay K1, and is configured to output the first drive control signal to control the switching of the first relay K1 via the first drive control signal. This allows the first relay K1 to control the first motor drive signal output to the first motor M1, thereby achieving drive control of the first motor M1. The second terminal of the digital signal processor DSP serves as the second drive control terminal K2c, electrically connected to the control terminal of the second relay K2, and is configured to output the second drive control signal to control the switching of the second relay K2 via the second drive control signal. This allows the second relay K2 to control the second motor drive signal output to the second motor M2, thereby achieving drive control of the second motor M2. The third terminal of the digital signal processor DSP serves as a third drive control terminal, serving as a compensation drive terminal of the motor drive circuit module 110, and is electrically connected to the control terminal of the position compensation circuit module 120, for outputting the target control signal. This allows the position compensation circuit module 120 to control whether the second motor drive signal output by the second motor drive terminal flows into the compensation inductor 121 based on the target control signal, thereby generating a target compensation signal when the second motor drive signal flows into the compensation inductor 121, and transmitting the target compensation signal to the power supply terminal of the second motor M2 when the second motor drive signal does not flow into the compensation inductor 121 to power the second motor M2. A fourth terminal of the digital signal processor DSP is electrically connected to the first terminal of the intelligent power module IPM, for triggering the intelligent power module IPM to output the power drive signal, so that the intelligent power module IPM can output the corresponding power drive signal according to the preset motor control requirements to achieve power control.

[0062] In which, the first sampling end of the digital signal processor DSP is electrically connected to the first current sampling end corresponding to the first motor M1, and is used to detect the first sampling signal, so that the digital signal processor DSP can determine the rotor position of the first motor M1 based on the first sampling signal; the second sampling end of the digital signal processor DSP is electrically connected to the second current sampling end corresponding to the second motor M2, and is used to detect the second sampling signal, so that the digital signal processor DSP can determine the rotor position of the second motor M2 based on the second sampling signal.

[0063] For example, the first sampling signal and the second sampling signal can both be current sampling signals, so that the digital signal processor DSP can determine the current difference between the first motor M1 and the second motor M2 based on the first sampling signal and the second sampling signal, so as to determine the position error based on the current difference, and then output the corresponding target control signal according to the position error, so as to ventilate the compensation inductor 121 according to the target control signal, generate a target compensation signal, and output the target compensation signal to the second motor M2, so as to correct the rotor position of the second motor M2 through the target compensation signal, so that the rotor position of the second motor M2 is the same as the rotor position of the first motor M1, thereby realizing synchronous operation of the first motor M1 and the second motor M2.

[0064] like Figure 5 As shown, a control method for driving dual motors with a single inverter provided in an embodiment of the present application is applied to the above-mentioned control circuit and may specifically include the following steps: Step 510: When the initial position of the rotor of the first motor is the same as the initial position of the rotor of the second motor, control the first motor and the second motor to start synchronously to enter a start-up operation state; Step 520 , based on the startup operation state, determining a position error according to a first sampling signal corresponding to the first motor and a second sampling signal corresponding to the second motor, and outputting a target control signal corresponding to the position error; Step 530 , controlling the second motor drive signal to flow into the compensation inductor according to the target control signal to generate a target compensation signal, and outputting the target compensation signal to the second motor; The target compensation signal is used to correct the rotor position of the second motor so that the rotor position of the second motor is the same as the rotor position of the first motor.

[0065] Specifically, after powering on, the motor drive circuit module can detect the initial rotor positions of the first and second motors. If the initial rotor positions of the two motors are different, the initial rotor position of one motor can be adjusted to be the same as the initial rotor position of the other motor. When the initial rotor position of the first motor is the same as the initial rotor position of the second motor, the motor drive circuit module can be used to control the first and second motors to start synchronously and enter a startup operation state.

[0066] In an optional embodiment of the present application, step 510 controls the first motor and the second motor to start synchronously when the initial position of the rotor of the first motor is the same as the initial position of the rotor of the second motor, and may specifically include the following sub-steps: Sub-step S11, when the power is turned on, determining the initial rotor position of the first motor as a first initial rotor position, and determining the initial rotor position of the second motor as a second initial rotor position; Sub-step S12: if the second initial rotor position is different from the first initial rotor position, adjusting the initial rotor position of the second motor according to the first initial rotor position until the adjusted initial rotor position of the second motor is the same as the first initial rotor position; Sub-step S13: when the second initial rotor position is the same as the first initial rotor position, starting the first motor and the second motor.

[0067] As an example of the present application, after power-on, initial position detection can be performed by the digital signal processor DSP to perform position compensation in the startup phase when the initial position of the rotor of the first motor and the initial position of the rotor of the second motor are different, thereby improving the problem of starting a dual permanent magnet synchronous motor driven by a single inverter.

[0068] For example, Figure 6 As shown, after power-on, the digital signal processor DSP can first determine the initial position of the rotor of the first motor M1. For example, when the switch of the first relay K1 is a normally closed switch and the switch of the second relay K2 is a normally open switch, the second relay K2 can be de-energized, and the initial position of the rotor of the first motor M1 is detected by a motor rotor position detection method such as an injection current method, so as to determine the initial position of the rotor of the first motor M1 as the first initial rotor position; then, the digital signal processor DSP drives the first relay K1 to be energized to cut off the connection of the first motor M1, and drives the second relay K2 to be energized to determine the initial position of the rotor of the second motor M2, so as to determine the initial position of the rotor of the second motor M2 as the second initial rotor position; then, based on the first initial rotor position and the second initial rotor position, it can be determined whether the position error exceeds a preset error threshold.

[0069] Among them, the preset error threshold can be set according to the synchronous starting requirements of the first motor M1 and the second motor M2. When the position error exceeds the preset error threshold, it means that the rotor position error is too large, and the motor start-up failure or only one motor is likely to occur. For example, the preset error threshold can be set to 0, and this application example does not limit this.

[0070] The following uses the preset error threshold of 0 as an example to illustrate the embodiments of the present application. If the position error exceeds the preset error threshold, it is considered that the position error is too large, and then the position loop can be used to make the rotor position of the second motor M2 the same as the initial rotor position of the first motor M1, that is, the rotor position of the second motor M2 is controlled by the position loop of the motor to adjust the initial rotor position of the second motor according to the first initial rotor position, so that the position error becomes 0. If the position error does not exceed the preset error threshold, it can be considered that the initial rotor position of the second motor is the same as the initial rotor position of the first motor M1, and the first motor M1 and the second motor M2 can be directly driven by a single inverter to achieve simultaneous starting of the two motors.

[0071] Of course, in the embodiment of the present application, when the initial positions of the two motor rotors are different, in addition to adjusting the rotor position of the second motor M2 according to the initial position of the rotor of the first motor M1, other methods can also be used to make the initial positions of the two motor rotors the same. For example, the rotor position of the first motor M1 can be adjusted according to the initial position of the rotor of the second motor M2, so that the initial positions of the two motor rotors are the same after the rotor position of the first motor M1 is adjusted. The embodiment of the present application does not impose any specific restrictions on this.

[0072] In another optional embodiment of the present application, the above-mentioned step 510 controls the first motor and the second motor to start synchronously when the initial rotor position of the first motor is the same as the initial rotor position of the second motor. Specifically, it may include the following sub-steps: Sub-step S21, when the power is turned on, the initial rotor position of the first motor is determined as the first initial rotor position, and the initial rotor position of the second motor is determined as the second initial rotor position; Sub-step S22, when the second initial rotor position is different from the first initial rotor position, adjust the initial rotor position of the first motor according to the second initial rotor position until the adjusted initial rotor position of the first motor is the same as the second initial rotor position; Sub-step S23, when the second initial rotor position is the same as the first initial rotor position, start the first motor and the second motor.

[0073] Specifically, after powering on, the embodiment of the present application determines whether the initial position of the rotor of the first motor and the initial position of the rotor of the second motor are the same by detecting the initial position of the rotor of the first motor and the initial position of the rotor of the second motor. When the initial position of the rotor of the first motor and the initial position of the rotor of the second motor are different, the rotor position of the first motor or the second motor is adjusted so that the initial positions of the rotors of the two motors are the same. Therefore, the first motor and the second motor can be started when the initial positions of the rotors of the two motors are the same, which effectively solves the problem of starting difficulty of the dual motors due to different initial positions and improves the success rate of simultaneous starting of the dual motors.

[0074] In the startup operation state, the embodiment of the present application can collect the current signals of the first motor and the second motor in real time through the motor drive circuit module to determine the position error between the two motors based on the first sampling signal corresponding to the first motor and the second sampling signal corresponding to the second motor. Optionally, the embodiment of the present application determines the position error based on the first sampling signal corresponding to the first motor and the second sampling signal corresponding to the second motor, and specifically may include the following sub-steps: sub-step S31, obtaining the current detection signal of each phase of the first motor as the first sampling signal, and obtaining the current detection signal of each phase of the second motor as the second sampling signal; sub-step S32, based on the first sampling signal, determining any phase current detection signal of the first motor as the target phase current detection signal; sub-step S33, extracting the second motor current detection signal that is in phase with the target phase current detection signal from the second sampling signal; sub-step S34, determining the current difference between the first motor and the second motor based on the target phase current detection signal and the second motor current detection signal; sub-step S34, determining the position error based on the current difference.

[0075] Specifically, after the first motor and the second motor are started, they enter the operation phase. During the operation of the motors, the motor drive circuit module can obtain the current detection signals of each phase of the first motor and the current detection signals of each phase of the second motor, and use the current detection signals of each phase of the first motor as the first sampling signal and the current detection signals of each phase of the second motor as the second sampling signal. Based on the first sampling signal and the second sampling signal, the position error between the rotor positions of the two motors can be calculated in real time, and whether position compensation is required can be determined based on the position error.

[0076] As an example of the present application, during the operation of the motors, the motor drive circuit module 110 can detect the current of a phase of the two motors through the digital signal processor DSP, calculate the current difference between the first motor and the second motor in the operation phase in real time, and use the current difference as a position error to determine whether position compensation is required based on the position error. Specifically, when the current difference is greater than a preset threshold, it is considered that the position error is greater than the preset error threshold, and a pulse signal can be output through the digital signal processor DSP as a target control signal corresponding to the position error, which is transmitted to the relay switch K3, thereby driving the relay switch K3, forcing the second motor drive current to flow through a first inductor L, that is, controlling the second motor drive signal to flow into the compensation inductor to generate a target compensation signal, output the second motor M2, and force a hysteresis effect on the second motor M2.

[0077] For example, Figure 6As shown, during the operation stage, the digital signal processor DSP can detect the phase currents of the first motor M1 and the second motor M2 in real time to determine whether the phase current difference is greater than a preset threshold value. When the phase current difference is greater than the preset threshold value, it is considered that the position error between the first motor and the second motor exceeds the preset error threshold value, that is, when |IU1-IU2|>threshold value, |IV1-IV2|>threshold value, and |IW1-IW2|>threshold value, it is considered that the position error between the first motor and the second motor exceeds the preset error threshold value, and the digital signal processor DSP outputs a pulse signal as a target control signal, which is transmitted to the relay switch K3 to drive the relay switch K3, so that each phase power supply terminal of the second motor is respectively connected to a first inductor L, so that the second motor driving current is forced to flow into the first inductor L, forcing a hysteresis effect on the second motor M2, so that the second motor M2 performs position correction, and then the position of the second motor M2 is judged. The phase current difference between the two motors is cut off. For example, it is judged whether the phase current difference between the two motors is less than a preset threshold value. If the phase current difference between the two motors is not less than the preset threshold value, it is considered that the position error between the two motors is still relatively large, and the digital signal processor DSP gives another pulse signal to drive the relay switch K3 to perform a hysteresis until the position error between the two motors is reduced to a threshold range. For example, when |IU1-IU2| is less than the threshold value, |IV1-IV2| is less than the threshold value, and |IW1-IW2| is less than the threshold value, that is, when the phase current difference between the two motors is less than the preset threshold value, the digital signal processor DSP no longer gives a pulse signal, and the normally open switch S1 in the relay switch K3 is disconnected. The second motor drive current is directly transmitted to the power supply terminal of the second motor, that is, the second motor drive signal is directly transmitted to the second motor M2 without passing through the first inductor, so as to drive the second motor M2 to run synchronously with the first motor.

[0078] It can be seen that in the embodiment of the present application, during the motor operation phase, the first sampling signal and the second sampling signal can be determined by detecting the phase currents of the first motor and the second motor, so as to determine the position error between the two motors based on the first sampling signal and the second sampling signal; when it is detected that the position error exceeds a preset error threshold, the motor drive circuit module can output a compensation control signal to the position compensation circuit module, so that after receiving the compensation control signal, the position compensation circuit module controls the relay switch to operate, so that the second motor drive signal flows into the compensation inductor, so as to generate a target compensation signal through the compensation inductor, and output the target compensation signal to the second motor to correct the rotor position of the second motor so that it remains the same as the rotor position of the first motor. When the position error decreases below the preset error threshold, the motor drive circuit module stops outputting the compensation control signal, and the position compensation circuit module can control the relay switch K3 to restore the original state, so that the circuit is restored to normal connection, that is, the second motor drive signal is directly transmitted to the second motor, thereby achieving stable control of the single inverter driving the dual motors without using a position sensor, solving the problem of poor stability caused by the different rotor positions of the dual motors when the single inverter drives the dual motors.

[0079] like Figure 7As shown, the embodiment of the present application further provides a control system 700 for a single inverter driving dual motors, and the control system 700 for a single inverter driving dual motors includes the control circuit 100 for a single inverter driving dual motors in any of the above embodiments, so that the control system for a single inverter driving dual motors can detect the initial rotor positions of the first motor M1 and the second motor M2 through the control circuit 100 after power-on, and determine the initial positions of the two motors. When the initial positions of the two motors are different, the rotor position of one of the motors is adjusted to be the same as the rotor position of the other motor, thereby achieving position compensation in the startup phase. Then, the motor drive circuit module 110 is used to control the first motor M1 and the second motor M2 to start synchronously and enter a startup operation state. Based on the startup operation state, the position error is determined according to the first sampling signal corresponding to the first motor M1 and the second sampling signal corresponding to the second motor M2, so as to obtain the position error according to the position. The error is used to determine whether positioning is required; when the position error exceeds a preset error threshold, the motor drive circuit module 110 can output a target control signal corresponding to the position error to the position compensation circuit module 120, so that the position compensation circuit module 120 controls the second motor drive signal output by the second motor drive end to flow into the compensation inductor 121 according to the target control signal, generates a target compensation signal, and outputs the target compensation signal to the second motor M2, so as to correct the rotor position of the second motor in real time during the startup operation state, so that it remains the same as the rotor position of the first motor, thereby realizing synchronous operation of the dual motors. Without using a position sensor, stable control of the dual motors by a single inverter is realized, possible failure of the position sensor is avoided, the reliability and stability of the entire system is improved, and the position sensor used in the traditional control method is omitted, reducing the hardware cost and complexity of the system and reducing the cost.

[0080] In a specific implementation, the control system of a single inverter driving dual motors can be integrated into electrical equipment as the motor drive control system of the electrical equipment, so that the electrical equipment can drive the control circuit of the dual motors through a single inverter, and achieve stable control of the dual motors without using position sensors, thereby reducing costs and improving the reliability and stability of the system.

[0081] like Figure 8 As shown, an embodiment of the present application further provides an electrical device, which includes: a processor 811, a communication interface 812, a memory 813 and a communication bus 814, wherein the processor 811, the communication interface 812, and the memory 813 communicate with each other through the communication bus 814, and the memory 813 is used to store computer programs; the processor 811 is used to implement the steps of the control method of a single inverter driving dual motors provided in any of the aforementioned embodiments when executing the computer program stored in the memory 813.

[0082] In specific implementations, the electrical equipment in the embodiments of the present application may include but is not limited to refrigeration equipment such as air conditioners and refrigerators, and may also include fans, washing machines and other types of electrical equipment. The embodiments of the present application do not impose specific restrictions on this.

[0083] The circuit and device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0084] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform, and of course can also be implemented by hardware.

[0085] Based on this understanding, the above technical solution can essentially or the part that contributes to the relevant technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0086] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the order of execution is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0087] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A control circuit for driving dual motors with a single inverter, characterized in that: include: Motor drive circuit module and position compensation circuit module; Wherein, the dual motors include a first motor and a second motor; a first motor driving end of the motor driving circuit module electrically connected to each phase power supply end of the first motor, a second motor driving end of the motor driving circuit module electrically connected to an input end of the position compensation circuit module, a compensation driving end of the motor driving circuit module electrically connected to a control end of the position compensation circuit module, and an output end of the position compensation circuit module electrically connected to each phase power supply end of the second motor; The motor drive circuit module is configured to: when the initial rotor position of the first motor is the same as the initial rotor position of the second motor, control the first motor and the second motor to start synchronously to enter a startup operation state, and based on the startup operation state, determine a position error according to a first sampling signal corresponding to the first motor and a second sampling signal corresponding to the second motor, and output a target control signal corresponding to the position error to a control end of the position compensation circuit module; The position compensation circuit module includes a compensation inductor, and the position compensation circuit module is configured to: control the second motor drive signal output by the second motor drive terminal to flow into the compensation inductor according to the target control signal to generate a target compensation signal, and output the target compensation signal to the second motor; The target compensation signal is used to correct a rotor position of the second motor so that the rotor position of the second motor is the same as the rotor position of the first motor.

2. The control circuit according to claim 1, wherein: The position compensation circuit module further includes a relay submodule; The relay submodule includes a relay switch, a control end of the relay submodule serves as a control end of the position compensation circuit module, a first switch contact of the relay switch, a second motor drive end of the motor drive circuit module, and a first end of the compensation inductor are electrically connected, a second switch contact of the relay switch is electrically connected to the second end of the compensation inductor, and a third switch contact and a fourth switch contact of the relay switch are electrically connected to serve as an output end of the position compensation circuit module; The relay submodule is configured to: when the target control signal is a preset compensation control signal, control the first switch contact to be disconnected from the fourth switch contact, and connect the second switch contact to the third switch contact, so that the second motor drive signal flows into the compensation inductor to generate the target compensation signal; when the target control signal is not the compensation control signal, control the first switch contact to be connected to the fourth switch contact, so that the second motor drive signal passes through the first switch contact and the fourth switch contact and is transmitted to the second motor.

3. The control circuit according to claim 2, characterized in that: The second motor driving end of the motor driving circuit module includes a second single-phase driving end connected to the single-phase power supply end of the second motor in a one-to-one correspondence; The compensation inductor includes a first inductor connected to the second single-phase drive end in a one-to-one correspondence; The output end of the position compensation circuit module includes a second driving output end connected to the single-phase power supply end of the second motor in a one-to-one correspondence; The relay submodule further includes a control transistor; The control end of the control transistor serves as the control end of the relay submodule, the first end of the control transistor is electrically connected to the first end of the coil of the relay switch, and the second end of the control transistor is electrically connected to the reference ground of the control circuit; The second end of the coil of the relay switch is electrically connected to the power supply end of the control circuit; The relay switch includes a normally closed switch connected to the second single-phase drive end in a one-to-one correspondence and a normally open switch connected to the first inductor in a one-to-one correspondence; The first end of the normally closed switch is electrically connected to the first end of the first inductor to serve as the first switch contact; The first end of the normally open switch is electrically connected to the second end of the first inductor to serve as the second switch contact; The second end of the normally-open switch is electrically connected to the second end of the normally-closed switch to serve as the second driving output end.

4. The control circuit according to any one of claims 1 to 3, characterized in that: The motor drive circuit module includes a drive controller, a first relay and a second relay; The first drive control end of the drive controller is electrically connected to the control end of the first relay, the second drive control end of the drive controller is electrically connected to the control end of the second relay, the third drive control end of the drive controller serves as the compensation drive end of the motor drive circuit module, and the power output end of the drive controller, the first switch end of the first relay, and the first switch end of the second relay are electrically connected; The drive controller is configured to: output a power drive signal, a first drive control signal and / or a second drive control signal, and output the target control signal according to the first sampling signal and the second sampling signal; The second switch end of the first relay serves as the first motor driving end, and the first relay is configured to: transmit the power driving signal to the first motor driving end according to the first driving control signal; The second switch end of the second relay serves as the second motor driving end, and the second relay is configured to transmit the power driving signal to the second motor driving end according to the second driving control signal.

5. The control circuit according to claim 4, characterized in that: The drive controller includes a digital signal processor and an intelligent power module; The first terminal of the digital signal processor serves as the first driving control terminal, for outputting the first driving control signal; The second terminal of the digital signal processor serves as the second driving control terminal, for outputting the second driving control signal; The third terminal of the digital signal processor serves as a third driving control terminal, for outputting the target control signal; The fourth terminal of the digital signal processor is electrically connected to the first terminal of the intelligent power module, and is used to trigger the intelligent power module to output the power driving signal; The first sampling terminal of the digital signal processor is electrically connected to the first current sampling terminal corresponding to the first motor, and is used to detect the first sampling signal; The second sampling terminal of the digital signal processor is electrically connected to the second current sampling terminal corresponding to the second motor, and is used to detect the second sampling signal.

6. A control method for driving dual motors with a single inverter, characterized in that: Applied to the control circuit according to any one of claims 1 to 5, the dual motor includes a first motor and a second motor, and the control method includes: When the initial position of the rotor of the first motor is the same as the initial position of the rotor of the second motor, controlling the first motor and the second motor to start synchronously to enter a starting operation state; Based on the startup running state, determining a position error according to a first sampling signal corresponding to the first motor and a second sampling signal corresponding to the second motor, and outputting a target control signal corresponding to the position error; controlling the second motor drive signal to flow into the compensation inductor according to the target control signal to generate a target compensation signal, and outputting the target compensation signal to the second motor; The target compensation signal is used to correct a rotor position of the second motor so that the rotor position of the second motor is the same as the rotor position of the first motor.

7. The control method for driving dual motors with a single inverter according to claim 6, characterized in that: The determining of the position error according to the first sampling signal corresponding to the first motor and the second sampling signal corresponding to the second motor includes: Acquire a current detection signal of each phase of the first motor as the first sampling signal, and acquire a current detection signal of each phase of the second motor as the second sampling signal; determining any phase current detection signal of the first motor as a target phase current detection signal based on the first sampling signal; extracting a second motor current detection signal having the same phase as the target phase current detection signal from the second sampling signal; determining a current difference between the first motor and the second motor based on the target phase current detection signal and the second motor current detection signal; The position error is determined based on the current difference.

8. The control method for driving dual motors with a single inverter according to claim 6 or 7, characterized in that: When the initial position of the rotor of the first motor is the same as the initial position of the rotor of the second motor, controlling the first motor and the second motor to start synchronously includes: When the motor is powered on, an initial rotor position of the first motor is determined as a first initial rotor position, and an initial rotor position of the second motor is determined as a second initial rotor position; When the second initial rotor position is different from the first initial rotor position, adjusting the initial rotor position of the second motor according to the first initial rotor position until the adjusted initial rotor position of the second motor is the same as the first initial rotor position; When the second initial rotor position is the same as the first initial rotor position, the first motor and the second motor are started.

9. A control system for a single inverter driving dual motors, characterized in that: The device comprises a control circuit as claimed in any one of claims 1 to 5.

10. An electrical device, characterized in that: include: A processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus; Memory for storing computer programs; The processor is configured to implement the steps of the control method according to any one of claims 6 to 8 when executing the program stored in the memory.

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