A dual rotor electric machine and a control method thereof

Abstract

The application discloses a double-rotor motor and a control method thereof, and belongs to the field of driving motors. The same output shaft can be commonly driven by two motor rotors to drive a high-power load, and the two motors can be started in sequence to reduce starting current. Therefore, in the application, the rotors of a first motor and a second motor in the double-rotor motor are connected with the output shaft, and a control device can control the second motor to start after the first motor is started, so that the two motors commonly drive the output shaft. Since the two motors commonly drive the output shaft, two motors with relatively small rated power can be selected, so that the starting current of the first motor is reduced. In addition, the second motor can be started when the output shaft has rotated, so that the starting current of the second motor is reduced. That is, the double-rotor motor realizes low-current starting, replaces a frequency converter, and has high operation stability and low maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of drive motors, and in particular to a dual-rotor motor and its control method. Background Technology

[0002] High-power load equipment in fields such as metallurgy, mining, and building materials, such as the crushing host in mobile crushing and screening equipment, requires a drive motor to provide sufficient driving power to drive the load during operation. However, there is a lack of mature drive motors for such high-power load equipment in the relevant technology. Current drive motors need to use frequency converters to achieve reduced voltage starting in order to reduce the impact on the power grid. However, the protection level and low temperature resistance of frequency converters are limited, resulting in poor operating stability of the drive motor and high maintenance costs.

[0003] Therefore, how to provide a solution to the above-mentioned technical problems is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-rotor motor and its control method. The dual-rotor motor includes a first motor, a second motor, an output shaft, and a control device. The rotors of both the first motor and the second motor are connected to the output shaft. The control device is connected to both the first motor and the second motor. The control device is used to control the first motor to start so that the first motor drives the output shaft to rotate. After the first motor starts, the control device controls the second motor to start so that the second motor and the first motor jointly drive the output shaft to rotate, thereby making the driving power required by the load shared by the first motor and the second motor.

[0005] To solve the above-mentioned technical problems, the present invention provides a dual-rotor motor, including a first motor, a second motor, an output shaft, and a control device; The rotors of the first motor and the second motor are both connected to the output shaft, and the control device is connected to the first motor and the second motor respectively; The control device is used to control the first motor to start so that the first motor drives the output shaft to rotate; and after the first motor starts, control the second motor to start so that the second motor and the first motor jointly drive the output shaft to rotate.

[0006] On the other hand, the rated power of the second motor is greater than that of the first motor; The control device is specifically used to control the first motor to connect to the power supply so that the output shaft and the load connected to the output shaft rotate from a stationary state to the rated speed of the first motor under the drive of the first motor. When the output shaft is rotating, the second motor is controlled to connect to the power supply so that the second motor outputs torque to the output shaft while the output shaft is rotating.

[0007] On the other hand, the control device includes a controller, a detection unit, a start control circuit for the first motor, and a start control circuit for the second motor; The detection unit is connected to the first motor, and the controller is connected to the output terminal of the detection unit, the start control circuit of the first motor, and the start control circuit of the second motor, respectively. The detection unit is used to detect the operating status of the first motor and output speed feedback signal and current feedback signal to the controller; The controller is used to determine, after starting the first motor through the starting control loop of the first motor, whether the duration for which the preset speed stabilization condition and the current stabilization condition are simultaneously satisfied has reached a preset duration based on the speed feedback signal and the current feedback signal; the speed stabilization condition is that the speed represented by the speed feedback signal is greater than a preset speed threshold, and the current stabilization condition is that the deviation between the operating current represented by the current feedback signal and the rated current of the first motor is less than a preset deviation threshold. If the duration reaches the preset duration, the first motor is determined to be in a stable operating state, and the second motor is started through the start control loop of the second motor.

[0008] On the other hand, the control device also includes an interlock relay; The controller is connected to the interlock relay, and the normally open contact of the interlock relay is connected in series as an interlock contact in the starting control circuit of the second motor. The controller is further configured to, when determining that the first motor is in the stable operating state, control the interlock relay to operate so that the interlock contacts are closed; If it is determined that the first motor is not in the stable operating state, the interlock relay is reset so that the interlock contacts are opened.

[0009] On the other hand, the control device includes a first circuit breaker, a first AC contactor and a first switch module, as well as a second circuit breaker, a second AC contactor and a second switch module; The input terminal of the first circuit breaker is connected to a three-phase power supply, the output terminal of the first circuit breaker is connected to the first end of the main contact of the first AC contactor, the second end of the main contact of the first AC contactor is connected to the first motor, and the first switch module is connected to the coil of the first AC contactor. The input terminal of the second circuit breaker is connected to the three-phase power supply, the output terminal of the second circuit breaker is connected to the first end of the main contact of the second AC contactor, the second end of the main contact of the second AC contactor is connected to the second motor, and the second switch module is connected to the coil of the second AC contactor. The first switch module is used to receive a first start command and turn on, so that the coil of the first AC contactor is energized, the main contacts of the first AC contactor are closed, and the first motor is connected to the three-phase power supply. The second switch module is used to receive a second start command and turn on after the first motor starts, so that the coil of the second AC contactor is energized, the main contacts of the second AC contactor are closed, and the second motor is connected to the three-phase power supply.

[0010] On the other hand, the first switch module includes a first start button, a first stop button, and a first intermediate relay; The first start button and the first stop button are connected in series with the coil of the first intermediate relay, the normally open contact of the first intermediate relay is connected in series with the coil of the first AC contactor, and the auxiliary normally open contact of the first AC contactor is connected in parallel with the first start button. The first start button is used to switch the on / off state of the contact point when pressed; the first stop button is used to switch the on / off state of the contact point when pressed. The second switch module includes a second start button, a second stop button, and a second intermediate relay; The second start button, the second stop button and the coil of the second intermediate relay are connected in series, the normally open contact of the second intermediate relay is connected in series with the coil of the second AC contactor, and the auxiliary normally open contact of the second AC contactor is connected in parallel with the second start button; The second start button is used to switch the on / off state of the contact point when pressed; the second stop button is used to switch the on / off state of the contact point when pressed.

[0011] On the other hand, the control device also includes a first protection device and a second protection device; The first protection device is connected in series between the second end of the main contact of the first AC contactor and the first motor; the second protection device is connected in series between the second end of the main contact of the second AC contactor and the second motor; the normally closed contact of the first protection device is connected in series in the circuit where the coil of the first AC contactor is located; the normally closed contact of the second protection device is connected in series in the circuit where the coil of the second AC contactor is located. The first protection device is used to activate in the event of overload, phase loss, or stall of the first motor, so that the normally closed contact of the first protection device is opened. The second protection device is used to activate in the event of overload, phase loss, or stall of the second motor, so that the normally closed contact of the second protection device is opened. Both the first protection device and the second protection device are any one of motor protectors, thermal relays, current relays, and temperature relays; The first switch module is also configured to disconnect upon receiving a first stop command, so that the coil of the first AC contactor is de-energized; The second switch module is also configured to disconnect upon receiving a second stop command, so that the coil of the second AC contactor is de-energized.

[0012] On the other hand, the controller is also used for: The start-up duration is calculated from the moment the first motor is started via the start-up control circuit of the first motor. If the startup duration reaches the preset timeout duration but the duration does not reach the preset duration, the first motor is stopped by controlling the startup control circuit of the first motor, and the startup control circuit of the second motor is kept in the disconnected state.

[0013] On the other hand, the stator windings of the first motor and the stator windings of the second motor are arranged sequentially at intervals along the axial direction of the output shaft, and an interval region is formed between the stator windings of the first motor and the stator windings of the second motor. An electromagnetic shielding component is provided in the interval area. The electromagnetic shielding component is sleeved on the outer periphery of the output shaft, and there is a gap between the inner edge of the electromagnetic shielding component and the output shaft. The electromagnetic shielding extends radially along the output shaft, and the outer edge of the electromagnetic shielding extends beyond the outer edge of the stator winding of the first motor and the outer edge of the stator winding of the second motor. The electromagnetic shielding component is a metal magnetic shielding plate, and the electromagnetic shielding component is grounded.

[0014] To address the aforementioned technical problems, the present invention also provides a control method for a dual-rotor motor, applied to the control device for the dual-rotor motor described above. The control method for the dual-rotor motor includes: Control the start of the first motor so that the first motor drives the output shaft to rotate; After the first motor starts, the second motor is controlled to start so that the second motor and the first motor together drive the output shaft to rotate.

[0015] Beneficial Effects: This invention provides a dual-rotor motor. Considering that two motor rotors can jointly drive the same output shaft to drive high-power loads, and that the two motors can be started sequentially to reduce starting current, in this invention, the rotors of both the first and second motors are connected to the output shaft. The control device can control the second motor to start after controlling the first motor to start, so that the two motors jointly drive the output shaft. Since the two motors jointly drive the output shaft, two motors with relatively small rated power can be selected, thereby reducing the starting current of the first motor. Furthermore, starting the second motor while the output shaft is already rotating can reduce the starting current of the second motor. In other words, this dual-rotor motor achieves low-current starting, replacing the frequency converter. The protection capability of the dual-rotor motor is not limited by the frequency converter, it has high operational stability, and low maintenance costs.

[0016] The present invention also provides a control method for a dual-rotor motor, which has the same beneficial effects as the dual-rotor motor described above. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the relevant technologies and the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a first structural schematic diagram of the dual-rotor motor provided by the present invention; Figure 2 This is a second structural schematic diagram of the dual-rotor motor provided by the present invention; Figure 3 A schematic diagram of the primary circuit of a dual-rotor motor provided by the present invention; Figure 4 The schematic diagram of the secondary circuit of the dual-rotor motor provided by the present invention; Figure 5 This is a flowchart illustrating the control method for a dual-rotor motor provided by the present invention. Detailed Implementation

[0019] The core of this invention is to provide a dual-rotor motor and its control method. The dual-rotor motor includes a first motor, a second motor, an output shaft, and a control device. The rotors of both the first motor and the second motor are connected to the output shaft. The control device is connected to both the first motor and the second motor. The control device is used to control the first motor to start so that the first motor drives the output shaft to rotate. After the first motor starts, the control device controls the second motor to start so that the second motor and the first motor jointly drive the output shaft to rotate, thereby making the driving power required by the load shared by the first motor and the second motor.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please refer to Figure 1 , Figure 1 This is a first structural schematic diagram of the dual-rotor motor provided by the present invention. The dual-rotor motor includes a first motor 1, a second motor 2, an output shaft 3, and a control device 4. The rotors of both the first motor 1 and the second motor 2 are connected to the output shaft 3. The control device 4 is connected to both the first motor 1 and the second motor 2. The control device 4 is used to control the first motor 1 to start, so that the first motor 1 drives the output shaft 3 to rotate; and after the first motor 1 starts, it controls the second motor 2 to start, so that the second motor 2 and the first motor 1 jointly drive the output shaft 3 to rotate.

[0022] Specifically, considering that the dual-rotor motor in this embodiment of the invention is used to drive high-power loads, if a single-rotor motor is used to achieve the same driving power, the motor itself will be larger in size and weight, and the starting current generated by the motor during startup will also increase. Therefore, in this embodiment of the invention, the driving power that originally needed to be borne by a single motor is distributed to two motors with relatively smaller rated power by driving the same output shaft 3 together with the first motor 1 and the second motor 2. This reduces the starting current of a single motor while meeting the driving requirements of high-power loads.

[0023] It should be noted that the dual-rotor motor may also include a housing. Both the first motor 1 and the second motor 2 are housed within the housing, with one end of the output shaft 3 extending out of the housing for outputting torque to an external load. The housing adopts a single-shell structure, and the first motor 1 and the second motor 2 share the housing and a cooling structure for heat dissipation. The cooling structure can be an air-cooled structure or a water-cooled structure; this embodiment of the invention is not limited thereto. The housing is externally equipped with a first junction box and a second junction box, which are independent of each other. The first junction box is connected to the stator winding of the first motor 1, and the second junction box is connected to the stator winding of the second motor 2. The first and second junction boxes are respectively used to connect the first motor 1 and the second motor 2 to a power source, thereby enabling the first motor 1 and the second motor 2 to be connected to a power source independently and to achieve their respective start-stop control.

[0024] Please refer to Figure 2 , Figure 2This is a second structural schematic diagram of the dual-rotor motor provided by the present invention. The control device 4 of the dual-rotor motor can be structurally divided into a primary circuit 41 and a secondary circuit 42. The primary circuit 41 is used to carry the drive current of the first motor 1 and the second motor 2, and the secondary circuit 42 is used to realize the on / off control of the primary circuit 41. The following describes the process in conjunction with... Figure 3 and Figure 4 The specific structures of the primary circuit 41 and the secondary circuit 42 will be explained separately.

[0025] As an optional embodiment, the rated power of the second motor 2 is greater than the rated power of the first motor 1; the control device 4 is specifically used to control the first motor 1 to connect to the power supply so that the output shaft 3 and the load connected to the output shaft 3 rotate from a stationary state to the rated speed of the first motor 1 under the drive of the first motor 1; when the output shaft 3 is in the rotating state, the control device 4 controls the second motor 2 to connect to the power supply so that the second motor 2 outputs torque to the output shaft 3 while the output shaft 3 is rotating.

[0026] Specifically, the rated power of the first motor 1 can be, for example, 50 kilowatts, and the rated power of the second motor 2 can be, for example, 220 kilowatts. The sum of the rated power of the first motor 1 and the second motor 2 covers the driving power range required by high-power loads. In this embodiment of the invention, the specific rated power values ​​of the first motor 1 and the second motor 2 are not limited.

[0027] Specifically, considering that if the first motor 1 and the second motor 2 are connected to the power supply at the same time, their starting currents will be superimposed at the same moment, causing a large impact on the power grid. In addition, the speed and operating current of the first motor 1 and the second motor 2 are in a process of drastic change, that is, they act together on the same output shaft 3, which can easily generate torsional impact on the output shaft 3. Therefore, in this embodiment of the invention, the first motor 1 is first controlled to be connected to the power supply and drive the output shaft 3 to rotate. After the first motor 1 drives the output shaft 3 to rotate, the second motor 2 is then controlled to be connected to the power supply. At this time, the output shaft 3 is already in a rotating state. The second motor 2 superimposes the output torque on the already rotating output shaft 3, rather than providing torque at the same time as the first motor 1 when the output shaft 3 is stationary. This makes it possible for the starting currents of the first motor 1 and the second motor 2 not to be superimposed at the same moment, thereby reducing the impact on the power grid and reducing the torsional impact on the output shaft 3. In other words, the effect of connecting the driving power to the output shaft 3 in batches is achieved.

[0028] This invention provides a dual-rotor motor. Considering that two motor rotors can jointly drive the same output shaft to drive a high-power load, and that the two motors can be started sequentially to reduce the starting current, in this invention, the rotors of both the first and second motors in the dual-rotor motor are connected to the output shaft. The control device can control the second motor to start after controlling the first motor to start, so that the two motors jointly drive the output shaft. Since the two motors jointly drive the output shaft, two motors with relatively small rated power can be selected, thereby reducing the starting current of the first motor. Furthermore, starting the second motor while the output shaft is already rotating can reduce the starting current of the second motor. In other words, this dual-rotor motor achieves low-current starting, replacing the frequency converter. The protection capability of the dual-rotor motor is not limited by the frequency converter, it has high operational stability, and low maintenance costs.

[0029] Based on the above embodiments: As an optional embodiment, the control device 4 includes a controller, a detection unit, a start control circuit for the first motor 1, and a start control circuit for the second motor 2. The detection unit is connected to the first motor 1, and the controller is connected to the output terminal of the detection unit, the start control circuit for the first motor 1, and the start control circuit for the second motor 2, respectively.

[0030] The controller is used to determine, after starting the first motor 1 through the start control loop of the first motor 1, whether the duration for which the preset speed stabilization condition and the current stabilization condition are simultaneously met has reached a preset duration based on the speed feedback signal and the current feedback signal. The speed stabilization condition is that the speed represented by the speed feedback signal is greater than a preset speed threshold, and the current stabilization condition is that the deviation between the operating current represented by the current feedback signal and the rated current of the first motor 1 is less than a preset deviation threshold. If the duration reaches the preset duration, the controller determines that the first motor 1 is in a stable operating state and starts the second motor 2 through the start control loop of the second motor 2.

[0031] It should be noted that the controller, detection unit, and interlocking relay are embodiments of the present invention. Figure 3 , Figure 4 The additional components added based on the circuit structure shown. Figure 3 , Figure 4 The reference numerals are not shown separately in the accompanying drawings. The specific placement can be determined according to the actual wiring requirements, and this embodiment of the invention does not impose any limitations on it. The controller can transmit signals to the detection unit and the interlocking relay via wired connection or via fieldbus, and this embodiment of the invention does not impose any limitations on it either.

[0032] The detection unit is used to detect the operating status of the first motor 1 and output speed feedback signals and current feedback signals to the controller. Specifically, the detection unit may include a speed measuring element and a current measuring element. The speed measuring element is used to detect the speed of the first motor 1 and output a speed feedback signal. The speed measuring element may be, for example, an encoder, a tachogenerator, or a non-contact speed sensor. This embodiment of the invention is not limited to these specific types.

[0033] Specifically, the current detection element is used to detect the operating current of the first motor 1 and output a current feedback signal. The current detection element can be, for example, a current transformer or a motor protector with current acquisition function. This embodiment of the invention is not limited to these two types of elements.

[0034] Specifically, the preset speed threshold can be, for example, 95% of the rated speed of the first motor 1, the preset deviation threshold can be, for example, 5% of the rated current of the first motor 1, and the preset duration can be, for example, three seconds. This embodiment of the invention does not limit the specific values ​​of the preset speed threshold, the preset deviation threshold, and the preset duration.

[0035] The controller can be, for example, a programmable logic controller (PLC), a microcontroller, or other control units with signal acquisition and logic judgment functions. This embodiment of the invention does not limit the scope of the invention.

[0036] Specifically, considering that if the first motor 1 is judged to have entered a stable operating state simply because its speed reaches a preset speed threshold, it may be a misjudgment because the operating current of the first motor 1 is still fluctuating, the present invention introduces both speed stability conditions and current stability conditions, and requires that the state in which both conditions are met must be sustained for a certain period of time, so as to more accurately determine whether the first motor 1 has entered a true stable operating state and avoid the second motor 2 being put into operation prematurely due to misjudgment.

[0037] As an optional embodiment, the control device 4 also includes an interlock relay, the controller is connected to the interlock relay, and the normally open contact of the interlock relay is connected in series as an interlock contact in the starting control circuit of the second motor 2.

[0038] The controller is also used to control the interlock relay to operate when the first motor 1 is determined to be in a stable operating state, so that the interlock contacts are closed; and to control the interlock relay to reset when the first motor 1 is determined to be in a unstable operating state, so that the interlock contacts are opened.

[0039] Specifically, considering that determining whether the first motor 1 is in a stable operating state solely through the aforementioned judgment logic in the control logic still carries the possibility of the second motor 2 being prematurely connected to the power supply due to logic anomalies or operator errors, this embodiment of the invention implements the determination result of whether the first motor 1 is in a stable operating state as an interlocking relationship in the circuit structure by connecting an interlocking contact in series in the starting control circuit of the second motor 2. That is, when the interlocking contact is disconnected, the starting control circuit of the second motor 2 is in a disconnected state in the circuit structure. Even if the starting command of the second motor 2 is mistakenly triggered, the second motor 2 cannot be connected to the power supply, thereby effectively avoiding confusion in the two-stage starting sequence of the first motor 1 and the second motor 2.

[0040] Please refer to Figure 3 , Figure 3 The schematic diagram of the primary circuit of the dual-rotor motor provided by the present invention, as an optional embodiment, includes a first circuit breaker (corresponding to...). Figure 3 QF1 in the middle), the first AC contactor (corresponding to) Figure 3 , Figure 4 KM1 and the first switch module, and the second circuit breaker (corresponding to Figure 3 QF2 in the middle), the second AC contactor (corresponding to) Figure 3 , Figure 4 The circuit consists of KM2 and a second switch module. The input terminal of the first circuit breaker is connected to the three-phase power supply, the output terminal of the first circuit breaker is connected to the first end of the main contact of the first AC contactor, the second end of the main contact of the first AC contactor is connected to the first motor 1, and the first switch module is connected to the coil of the first AC contactor. The input terminal of the second circuit breaker is connected to the three-phase power supply, the output terminal of the second circuit breaker is connected to the first end of the main contact of the second AC contactor, the second end of the main contact of the second AC contactor is connected to the second motor 2, and the second switch module is connected to the coil of the second AC contactor.

[0041] The first switch module is used to receive the first start command and turn on, so that the coil of the first AC contactor is energized, the main contacts of the first AC contactor are closed, and the first motor 1 is connected to the three-phase power supply; the second switch module is used to receive the second start command after the first motor 1 starts and turn on, so that the coil of the second AC contactor is energized, the main contacts of the second AC contactor are closed, and the second motor 2 is connected to the three-phase power supply.

[0042] in, Figure 3 In the diagram, M1 is the first motor 1, and M2 is the second motor 2.

[0043] Specifically, both the first motor 1 and the second motor 2 are connected to the three-phase power supply in a way that the three-phase power supply is directly connected to the corresponding motor at full voltage without any voltage reduction or speed regulation. That is, neither the first motor 1 nor the second motor 2 needs to be connected to the three-phase power supply during startup. In this embodiment of the invention, by distributing the driving power to two motors with relatively small rated power, the starting current of the first motor 1 and the second motor 2 is kept at a low level. This allows the first motor 1 and the second motor 2 to be connected to the three-phase power supply directly at full voltage without the need for a frequency converter to achieve voltage reduction startup.

[0044] Please refer to Figure 4 , Figure 4 The schematic diagram of the secondary circuit 42 of the dual-rotor motor provided by the present invention, as an optional embodiment, shows that V+ is the positive terminal of the power supply, V- is the negative terminal of the power supply, and the first switching module includes a first start button (corresponding to...). Figure 4 SB1), the first stop button (corresponding to) Figure 4 SB2) and the first intermediate relay (corresponding to Figure 4 In the first switch module, the first start button and the first stop button are connected in series with the coil of the first intermediate relay. The normally open contact of the first intermediate relay is connected in series with the coil of the first AC contactor. The auxiliary normally open contact of the first AC contactor is connected in parallel with the first start button. The first start button is used to switch the on / off state of its contact when pressed, and the first stop button is used to switch the on / off state of its contact when pressed. The second switch module includes a second start button (corresponding to...). Figure 4 SB3), the second stop button (corresponding to) Figure 4 SB4) and the second intermediate relay (corresponding to Figure 4 In the second AC contactor, the coil of the second start button and the second stop button are connected in series with the coil of the second intermediate relay. The normally open contact of the second intermediate relay is connected in series with the coil of the second AC contactor. The auxiliary normally open contact of the second AC contactor is connected in parallel with the second start button. The second start button is used to switch the on / off state of the contact when it is pressed. The second stop button is used to switch the on / off state of the contact when it is pressed.

[0045] Specifically, in combination Figure 4The operation process of the first switch module is explained as follows: When the operator presses the first start button, the coil of the first intermediate relay is energized because the first start button is connected in series with the coil of the first intermediate relay, and its normally open contact closes. Since the normally open contact of the first intermediate relay is connected in series with the coil of the first AC contactor, the coil of the first AC contactor is energized, and its main contact closes, and the first motor 1 is connected to the three-phase power supply and starts to start. At the same time, the auxiliary normally open contact of the first AC contactor also closes. Since the auxiliary normally open contact of the first AC contactor is connected in parallel with the first start button, even if the operator releases the first start button, the current can still continue to supply power to the coil of the first intermediate relay through the already closed auxiliary normally open contact of the first AC contactor, so that the coil of the first intermediate relay remains energized, thus realizing the self-locking function, without the operator needing to continuously press the first start button. When the operator presses the first stop button, the series circuit between the first stop button and the coil of the first intermediate relay is broken, the coil of the first intermediate relay is de-energized, its normally open contact opens, and the coil of the first AC contactor is also de-energized, its main contact and auxiliary normally open contact both open, the first motor 1 is de-energized and stops running, and the self-locking state is released. The operation process between the second start button, the second stop button, the second intermediate relay and the second AC contactor in the second switch module is the same as the operation process of the first switch module described above, and will not be repeated here in this embodiment of the invention.

[0046] As an optional embodiment, the control device 4 further includes a first protection device and a second protection device. The first protection device is connected in series between the second end of the main contact of the first AC contactor and the first motor 1, and the second protection device is connected in series between the second end of the main contact of the second AC contactor and the second motor 2. The normally closed contact of the first protection device is connected in series in the circuit where the coil of the first AC contactor is located, and the normally closed contact of the second protection device is connected in series in the circuit where the coil of the second AC contactor is located.

[0047] The first protection device is activated in the event of overload, phase loss, or stall in the first motor 1. This activates the normally closed contact of the first protection device, which is connected in series with the coil of the first AC contactor. When the normally closed contact opens, the coil of the first AC contactor is de-energized, its main contacts open, and the first motor 1 stops running, thus preventing damage to the first motor 1 due to continuous overload, phase loss, or stall. The second protection device operates in the same way as the first protection device, and will not be described further in this embodiment.

[0048] Specifically, in Figure 3In this embodiment, the first protection device is represented by MP1 and the second protection device is represented by MP2. Both the first and second protection devices can be motor protectors, thermal relays, current relays, or temperature relays. This embodiment of the invention does not limit the specific protection device.

[0049] For example, thermal relays can use the principle of bimetallic strips deforming under the heat of current to achieve overload protection. That is, when the current flowing through the thermal relay exceeds the preset value and continues for a certain period of time, the bimetallic strip inside the thermal relay deforms due to heat, thereby causing its normally closed contacts to operate and disconnect.

[0050] In addition, as an optional embodiment, the first switch module is also configured to disconnect upon receiving a first stop command so that the coil of the first AC contactor is de-energized; the second switch module is also configured to disconnect upon receiving a second stop command so that the coil of the second AC contactor is de-energized.

[0051] Specifically, the shutdown methods of the dual-rotor motor in this embodiment of the invention include the following two types: The first type is a synchronous shutdown method, in which the coils of the first AC contactor and the second AC contactor are simultaneously de-energized when the first switch module and the second switch module simultaneously receive the first shutdown command and the second shutdown command, the main circuits of the first motor 1 and the second motor 2 are synchronously disconnected, the output shaft 3 loses power, and the dual-rotor motor stops running as a whole; The second type is an automatic shutdown protection method, in which if either the first motor 1 or the second motor 2 experiences an overload, phase loss, or stall fault, the first protection device or the second protection device corresponding to the faulty motor will operate, disconnecting only one circuit of the faulty motor without affecting the normal operation of the other motor, thereby reducing the impact of a single motor fault on the overall drive power while avoiding the expansion of the fault.

[0052] Among them, the whole machine synchronous shutdown mode is suitable for scenarios where the equipment needs to be stopped as a whole after normal operation or routine maintenance, and it is easy to operate; the automatic fault shutdown protection mode is suitable for scenarios where a sudden fault occurs during operation. It can disconnect the faulty motor in time without interrupting the normal operation of another motor, reduce the scope of the fault's impact, and facilitate subsequent fault location and maintenance.

[0053] It should be noted that after the second motor 2 starts, if the torque output by the second motor 2 to the output shaft 3 can meet the load demand on its own, the first motor 1 can be controlled to stop running so that the output shaft 3 can be driven by the second motor 2 alone, thereby reducing the overall operating energy consumption of the dual rotor motor under low load conditions.

[0054] As an optional embodiment, the controller is also used to count the start-up duration from the moment when the first motor 1 is started by the start-up control loop of the first motor 1; when the start-up duration reaches the preset timeout duration and the duration of operation does not reach the preset duration, the controller controls the first motor 1 to stop running by the start-up control loop of the first motor 1, and keeps the start-up control loop of the second motor 2 in the open state.

[0055] Specifically, the preset timeout duration can be a value ranging from tens of seconds to several minutes, and can be determined based on factors such as the rated power of the first motor 1 and the inertia of the load. This embodiment of the invention does not limit this.

[0056] Specifically, considering that if the first motor 1 fails to meet the aforementioned speed and current stability conditions for an extended period due to abnormal load, grid voltage fluctuations, or other reasons, the first motor 1 will continuously operate in a state where both speed and current fluctuate, posing a risk of overheating. Furthermore, if the second motor 2 is put into operation under such circumstances, it will act together with the still fluctuating first motor 1 on the same output shaft 3, which may easily cause shaft impact. Therefore, this embodiment of the invention includes the aforementioned start-up timeout protection method. If the first motor 1 fails to enter a stable operating state after a preset timeout period following its start-up, the first motor 1 is controlled to stop operating, and the start-up control circuit of the second motor 2 is kept disconnected to prevent the second motor 2 from being put into operation, thereby providing further protection against the aforementioned risks.

[0057] As an optional embodiment, the control device 4 further includes a first indicator light (corresponding to...) Figure 4 P1 in the middle) and the second indicator light (corresponding to Figure 4 In the P2 section, the first indicator light is connected in series with the auxiliary normally open contact of the first AC contactor, and the second indicator light is connected in series with the auxiliary normally open contact of the second AC contactor; the first indicator light is used to indicate whether the first motor 1 is energized, and the second indicator light is used to indicate whether the second motor 2 is energized.

[0058] Specifically, when the main contacts of the first AC contactor are closed and the first motor 1 is energized, the auxiliary normally open contacts of the first AC contactor are closed simultaneously, and the first indicator light is lit. The operator can then intuitively determine whether the first motor 1 is currently energized. The function of the second indicator light is the same as that of the first indicator light, and will not be described again in this embodiment of the invention.

[0059] Alternatively, as an optional embodiment, the stator windings of the first motor 1 and the second motor 2 are arranged sequentially at intervals along the axial direction of the output shaft 3, forming a gap between them. An electromagnetic shielding component is provided within the gap, fitted around the outer periphery of the output shaft 3, with a gap between the inner edge of the shielding component and the output shaft 3. The electromagnetic shielding component extends radially along the output shaft 3, with its outer edge extending beyond the outer edges of both the stator windings of the first motor 1 and the second motor 2. The electromagnetic shielding component is a metal magnetic shielding plate and is grounded.

[0060] Specifically, considering that the stator windings of the first motor 1 and the second motor 2 are both located in the same housing and are physically close to each other, the alternating magnetic fields generated during their operation may couple with each other, thereby interfering with each other's operating characteristics. Therefore, in this embodiment of the invention, an electromagnetic shield is provided in the gap between the stator windings of the first motor 1 and the stator windings of the second motor 2 to reduce electromagnetic interference between them.

[0061] The electromagnetic shielding component has a gap between its inner edge and the output shaft 3 to prevent contact friction between them. The outer edge of the electromagnetic shielding component extends beyond the stator windings of both the first motor 1 and the second motor 2, covering areas where leakage magnetic flux is concentrated at the ends of the two stator windings, thus improving the shielding effect. Grounding the electromagnetic shielding component provides a discharge path for the leakage magnetic flux it shields, further enhancing the shielding effect. Specifically, the electromagnetic shielding component can be grounded by connecting it to the housing via a conductive cable and grounding it through the housing as a whole, thereby guiding the induced leakage magnetic current on the electromagnetic shielding component to the ground. Alternatively, the electromagnetic shielding component can be directly grounded with a separate grounding terminal; this embodiment of the invention does not limit the specific grounding method.

[0062] It should be noted that, in addition to the aforementioned, the first switch module and the second switch module in this embodiment of the invention... Figure 4 In addition to the button implementation described, it can also be implemented using a programmable logic control unit (PLC). That is, through a PLC or microcontroller, the hierarchical start-up sequence, drive power distribution, and operating status of the first motor 1 and the second motor 2 can be automatically controlled to adapt to different requirements for control precision and automation. This embodiment of the invention does not limit the scope of the invention.

[0063] Please refer to Figure 5 , Figure 5 This is a flowchart illustrating the control method for a dual-rotor motor provided by the present invention. The control method is applied to the control device 4 of the dual-rotor motor as described in any of the foregoing embodiments, and includes: S101: Control the first motor 1 to start so that the first motor 1 drives the output shaft 3 to rotate; S102: After the first motor 1 starts, control the second motor 2 to start so that the second motor 2 and the first motor 1 jointly drive the output shaft 3 to rotate.

[0064] The specific implementation of each step in the control method of the dual rotor motor can be referred to the relevant description of the control device 4 in the aforementioned embodiments of the dual rotor motor. The embodiments of the present invention will not be repeated here, and the control method of the dual rotor motor has the same technical effect as the aforementioned dual rotor motor.

[0065] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should also be noted that in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0066] The above description of the disclosed embodiments enables those skilled in the art to make or use the 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dual-rotor motor, characterized in that, Includes a first motor, a second motor, an output shaft, and a control device; The rotors of the first motor and the second motor are both connected to the output shaft, and the control device is connected to the first motor and the second motor respectively; The control device is used to control the first motor to start so that the first motor drives the output shaft to rotate; and after the first motor starts, control the second motor to start so that the second motor and the first motor jointly drive the output shaft to rotate.

2. The dual-rotor motor according to claim 1, characterized in that, The rated power of the second motor is greater than the rated power of the first motor; The control device is specifically used to control the first motor to connect to the power supply so that the output shaft and the load connected to the output shaft rotate from a stationary state to the rated speed of the first motor under the drive of the first motor. When the output shaft is rotating, the second motor is controlled to connect to the power supply so that the second motor outputs torque to the output shaft while the output shaft is rotating.

3. The dual-rotor motor according to claim 1, characterized in that, The control device includes a controller, a detection unit, a start control circuit for the first motor, and a start control circuit for the second motor. The detection unit is connected to the first motor, and the controller is connected to the output terminal of the detection unit, the start control circuit of the first motor, and the start control circuit of the second motor, respectively. The detection unit is used to detect the operating status of the first motor and output speed feedback signal and current feedback signal to the controller; The controller is used to determine, after starting the first motor through the starting control loop of the first motor, whether the duration for which the preset speed stabilization condition and the current stabilization condition are simultaneously satisfied has reached a preset duration based on the speed feedback signal and the current feedback signal; the speed stabilization condition is that the speed represented by the speed feedback signal is greater than a preset speed threshold, and the current stabilization condition is that the deviation between the operating current represented by the current feedback signal and the rated current of the first motor is less than a preset deviation threshold. If the duration reaches the preset duration, the first motor is determined to be in a stable operating state, and the second motor is started through the start control loop of the second motor.

4. The dual-rotor motor according to claim 3, characterized in that, The control device also includes an interlocking relay; The controller is connected to the interlock relay, and the normally open contact of the interlock relay is connected in series as an interlock contact in the starting control circuit of the second motor. The controller is further configured to, when determining that the first motor is in the stable operating state, control the interlock relay to operate so that the interlock contacts are closed; If it is determined that the first motor is not in the stable operating state, the interlock relay is reset so that the interlock contacts are opened.

5. The dual-rotor motor according to claim 1, characterized in that, The control device includes a first circuit breaker, a first AC contactor and a first switch module, as well as a second circuit breaker, a second AC contactor and a second switch module; The input terminal of the first circuit breaker is connected to a three-phase power supply, the output terminal of the first circuit breaker is connected to the first end of the main contact of the first AC contactor, the second end of the main contact of the first AC contactor is connected to the first motor, and the first switch module is connected to the coil of the first AC contactor. The input terminal of the second circuit breaker is connected to the three-phase power supply, the output terminal of the second circuit breaker is connected to the first end of the main contact of the second AC contactor, the second end of the main contact of the second AC contactor is connected to the second motor, and the second switch module is connected to the coil of the second AC contactor. The first switch module is used to receive a first start command and turn on, so that the coil of the first AC contactor is energized, the main contacts of the first AC contactor are closed, and the first motor is connected to the three-phase power supply. The second switch module is used to receive a second start command and turn on after the first motor starts, so that the coil of the second AC contactor is energized, the main contacts of the second AC contactor are closed, and the second motor is connected to the three-phase power supply.

6. The dual-rotor motor according to claim 5, characterized in that, The first switch module includes a first start button, a first stop button, and a first intermediate relay; The first start button and the first stop button are connected in series with the coil of the first intermediate relay, the normally open contact of the first intermediate relay is connected in series with the coil of the first AC contactor, and the auxiliary normally open contact of the first AC contactor is connected in parallel with the first start button. The first start button is used to switch the on / off state of the contact point when it is pressed; The first stop button is used to switch the on / off state of the contact point when it is pressed; The second switch module includes a second start button, a second stop button, and a second intermediate relay; The second start button, the second stop button and the coil of the second intermediate relay are connected in series, the normally open contact of the second intermediate relay is connected in series with the coil of the second AC contactor, and the auxiliary normally open contact of the second AC contactor is connected in parallel with the second start button; The second start button is used to switch the on / off state of the contact point when it is pressed; The second stop button is used to switch the on / off state of the contact point when it is pressed.

7. The dual-rotor motor according to claim 5, characterized in that, The control device also includes a first protection device and a second protection device; The first protection device is connected in series between the second end of the main contact of the first AC contactor and the first motor; the second protection device is connected in series between the second end of the main contact of the second AC contactor and the second motor; the normally closed contact of the first protection device is connected in series in the circuit where the coil of the first AC contactor is located; the normally closed contact of the second protection device is connected in series in the circuit where the coil of the second AC contactor is located. The first protection device is used to activate in the event of overload, phase loss, or stall of the first motor, so that the normally closed contact of the first protection device is opened. The second protection device is used to activate in the event of overload, phase loss, or stall of the second motor, so that the normally closed contact of the second protection device is opened. Both the first protection device and the second protection device are any one of motor protectors, thermal relays, current relays, and temperature relays; The first switch module is also configured to disconnect upon receiving a first stop command, so that the coil of the first AC contactor is de-energized; The second switch module is also configured to disconnect upon receiving a second stop command, so that the coil of the second AC contactor is de-energized.

8. The dual-rotor motor according to claim 3, characterized in that, The controller is also used for: The start-up duration is calculated from the moment the first motor is started via the start-up control circuit of the first motor. If the startup duration reaches the preset timeout duration but the duration does not reach the preset duration, the first motor is stopped by controlling the startup control circuit of the first motor, and the startup control circuit of the second motor is kept in the disconnected state.

9. The dual-rotor motor according to any one of claims 1 to 8, characterized in that, The stator windings of the first motor and the stator windings of the second motor are arranged sequentially at intervals along the axial direction of the output shaft, and an interval region is formed between the stator windings of the first motor and the stator windings of the second motor. An electromagnetic shielding component is provided in the interval area. The electromagnetic shielding component is sleeved on the outer periphery of the output shaft, and there is a gap between the inner edge of the electromagnetic shielding component and the output shaft. The electromagnetic shielding extends radially along the output shaft, and the outer edge of the electromagnetic shielding extends beyond the outer edge of the stator winding of the first motor and the outer edge of the stator winding of the second motor. The electromagnetic shielding component is a metal magnetic shielding plate, and the electromagnetic shielding component is grounded.

10. A control method for a dual-rotor motor, characterized in that, The control device for the dual-rotor motor as described in any one of claims 1 to 9, wherein the control method for the dual-rotor motor comprises: Control the start of the first motor so that the first motor drives the output shaft to rotate; After the first motor starts, the second motor is controlled to start so that the second motor and the first motor together drive the output shaft to rotate.

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