Variable flux memory motor off-line magnetizing and demagnetizing device and method

Abstract

The invention provides an off-line magnetizing and demagnetizing device and method for a variable flux memory motor, and relates to the technical field of motor magnetizing and demagnetizing, the device comprises an upper computer, a controller and a magnetizing and demagnetizing circuit, and the magnetizing and demagnetizing circuit comprises three electromagnetic switches and a plurality of magnetizing and demagnetizing capacitors; one end of each magnetizing and demagnetizing capacitor is electrically connected with the positive end of the direct-current power supply, and the other end of each magnetizing and demagnetizing capacitor is electrically connected with the negative end of the direct-current power supply; one end of the magnetizing and demagnetizing capacitor is electrically connected with a first winding in the memory motor through the first electromagnetic switch, and the other end of the magnetizing and demagnetizing capacitor is electrically connected with a second winding and a third winding of the memory motor through the second electromagnetic switch and the third electromagnetic switch respectively; the control end of the first electromagnetic switch, the control end of the second electromagnetic switch and the control end of the third electromagnetic switch are all electrically connected with a controller, and the controller is electrically connected with an upper computer. According to the invention, the controller is used for controlling the on-off of the electromagnetic switch, and the magnetizing and demagnetizing capacitor can accurately magnetize the three-phase armature winding of the memory motor.

Description

Technical Field

[0001] The present invention relates to the technical field of charging and demagnetizing of a variable flux memory motor, and in particular to an off-line charging and demagnetizing device and method for a variable flux memory motor. Background Art

[0002] By combining low-coercivity AlNiCo permanent magnets with high-coercivity permanent magnets like NdFeB, variable flux memory motors achieve high remanence while also allowing for adjustable magnetic field strength within a certain range. This allows for a higher speed range and a wider range of optimal efficiency. The process of changing the motor's magnetic field strength is called "magnetization" and "demagnetization," and requires the use of a magnetizing and demagnetizing device.

[0003] According to different usage scenarios, the current variable flux memory motor charging and demagnetization devices are mainly divided into: online charging and demagnetization devices and offline charging and demagnetization devices. Among them, the online charging and demagnetization device is used for charging and demagnetization during the operation of the motor. Specifically, it can be charged and demagnetized through the motor controller or designed by another charging and demagnetization method. This charging and demagnetization method is mainly suitable for the control of actual use scenarios of the motor, such as patent: 202010533491.1 "A closed-loop control method and system for the magnetization state of a variable flux permanent magnet motor". Offline charging and demagnetization device: A device for charging and demagnetizing the motor when the motor is not running. The current main method is to magnetize through the capacitor discharge characteristics and design another charging and demagnetization method for charging and demagnetization. This type of charging and demagnetization method is mainly suitable for precise charging and demagnetization in the motor design verification stage, and to find a more accurate magnetization state of the memory motor. Compared with the online charging and demagnetization device, the charging and discharging current is larger, the cost advantage is obvious, the control strategy is simple, and the assembly speed is fast under batch testing.

[0004] Among them, in the offline magnetizing and demagnetizing device, the traditional single capacitor magnetizing method system block diagram proposed in the paper "Research on Variable Flux Memory Motor Weak Field Control Technology" is as follows Figure 1 As shown, one of the circuit construction methods is Figure 2 This method is easy to build and the magnetization method is simple, but it has several problems. 1. The discharge amount cannot be accurately determined. The discharge current of a single capacitor will fluctuate over time, and the discharge trend of the capacitor is uncontrollable. 2. Traditional contact switches experience air breakdown, which can cause uncontrollable current fluctuations and affect control accuracy. 3. The switch is manually controlled, and the magnetization time cannot be controlled. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that accurate magnetization cannot be performed in an offline magnetizing and demagnetizing device in the prior art. In order to overcome the above defects of the prior art, the present invention provides an offline magnetizing and demagnetizing device and method for a variable flux memory motor.

[0006] The application provides a variable magnetic flux memory motor off-line magnetizing and demagnetizing device, a memory motor is internally provided with a three-phase armature winding, the three-phase armature winding is in star connection, and the device comprises an upper computer, a controller and a magnetizing and demagnetizing circuit.

[0007] The plurality of magnetizing and demagnetizing capacitors are connected in parallel, one end of the magnetizing and demagnetizing capacitors is electrically connected to a positive terminal of a direct current power supply, and the other end of the magnetizing and demagnetizing capacitors is electrically connected to a negative terminal of the direct current power supply.

[0008] One end of the magnetizing and demagnetizing capacitors is electrically connected to a first end contact of the first electromagnetic switch, a second end contact of the first electromagnetic switch is electrically connected to a first winding in the three-phase armature winding, the other end of the magnetizing and demagnetizing capacitors is respectively electrically connected to a first end contact of the second electromagnetic switch and a first end contact of the third electromagnetic switch, a second end contact of the second electromagnetic switch is electrically connected to a second winding in the three-phase armature winding, and a second end contact of the third electromagnetic switch is electrically connected to a third winding in the three-phase armature winding.

[0009] The control end of the first electromagnetic switch, the control end of the second electromagnetic switch and the control end of the third electromagnetic switch are all electrically connected to the controller, and the controller is electrically connected to the upper computer.

[0010] Compared with the prior art, the variable magnetic flux memory motor off-line magnetizing and demagnetizing device has the following advantages: the controller is used for controlling the on-off of the electromagnetic switch, so that the magnetizing and demagnetizing capacitors can precisely magnetize the three-phase armature winding of the memory motor without manual operation, the power demand of the direct current power supply and the demand of the controller in the magnetizing process are reduced, the magnetizing and demagnetizing process is easier to perform, and the magnetizing and demagnetizing process is more precise.

[0011] In a possible implementation, the first electromagnetic switch, the second electromagnetic switch and the third electromagnetic switch are all silicon carbide field effect tubes.

[0012] Compared with the prior art, the controller is used for controlling the on-off of the silicon carbide field effect tube, so that the discharge waveform of the charged magnetizing and demagnetizing capacitors can be controlled, the magnetizing waveform is controllable to be a fixed waveform, the silicon carbide field effect tube replaces the mechanical manual switch in the traditional scheme, millisecond-level accurate control can be realized, the magnetizing amount is more controllable, and current fluctuation caused by the on-off of the mechanical switch can be eliminated.

[0013] In a possible implementation, one end of the magnetizing and demagnetizing capacitors is connected in series with a first switch and then electrically connected to the positive terminal of the direct current power supply, and the other end of the magnetizing and demagnetizing capacitors is connected in series with a second switch and then electrically connected to the negative terminal of the direct current power supply.

[0014] Compared with the prior art, by controlling the conduction and turn-off of the first switch and the second switch, whether the charging and demagnetizing capacitor is charged is realized by the direct current power supply control.

[0015] In a possible implementation, one end of the charging and demagnetizing capacitor is connected to the first end contact of the first electromagnetic switch in series with a first resistor, and the other end of the charging and demagnetizing capacitor is connected to the first end contact of the second electromagnetic switch and the first end contact of the third electromagnetic switch in series with a second resistor, respectively.

[0016] Compared with the prior art, by setting the first resistor and the second resistor, the charging current is filtered, and external interference is reduced.

[0017] Another technical solution of the present application is to provide a method for off-line charging and demagnetizing of a variable magnetic flux memory motor, comprising a charging method, the charging method comprising the following steps:

[0018] S1, the memory motor stops rotating;

[0019] S2, the direct current power supply charges the charging and demagnetizing capacitor;

[0020] S3, the upper computer sends a charging instruction to the controller, the controller drives the first electromagnetic switch, the second electromagnetic switch and the third electromagnetic switch to conduct or turn off, and charges the three-phase armature winding with a first current;

[0021] S4, after the three-phase armature winding reaches a preset charging amount, the direct current power supply stops charging the charging and demagnetizing capacitor;

[0022] S5, the controller controls the first electromagnetic switch, the second electromagnetic switch and the third electromagnetic switch to trickle discharge until complete discharge.

[0023] In a possible implementation, after step S2 and before step S3, there is also a step S21: the upper computer sends a memory motor positioning instruction, and the controller drives the first electromagnetic switch, the second electromagnetic switch and the third electromagnetic switch to conduct or turn off to charge the three-phase armature winding with a second current until the memory motor position is corrected, and step S3 is entered; wherein the second current is less than the first current.

[0024] Compared with the prior art, the three-phase armature winding is first charged by a small current, the memory motor position is corrected, and the three-phase armature winding is charged more accurately.

[0025] In a possible implementation, in step S3, the waveform of the first current is a sine wave, a square wave or a trapezoidal wave.

[0026] Compared with the prior art, by controlling the waveform of the first current, the control accuracy and the magnetizing effect of the three-phase armature winding can be increased, the magnetizing amount is more controllable, and the error caused by the magnetizing process is reduced.

[0027] In summary, the present application has the following advantages over the prior art:

[0028] 1. The silicon carbide field effect tube is used to control the discharge waveform of the charged capacitor. Compared with the uncontrollable pulse waveform of the traditional single-capacitor magnetizing, the discharge process of the present method makes the magnetizing waveform accurately controllable as a fixed waveform, such as a sine wave or a square wave or a trapezoidal wave pulse, increasing the control accuracy and the magnetizing effect. Meanwhile, the silicon carbide field effect tube replaces the traditional mechanical manual switch, which can realize millisecond-level accurate control, the magnetizing amount is more controllable, the error caused by the magnetizing process is reduced, and the current fluctuation caused by the mechanical switch can be eliminated.

[0029] 2. The controller is used to control the magnetizing of the three-phase armature winding of the memory motor, realizing millisecond-level accurate magnetizing time. Compared with the magnetizing method using a separate electric brake and a capacitor, the present application can realize accurate and quantitative magnetizing.

[0030] 3. The controller controls the conduction and turn-off of the silicon carbide field effect tube to control the magnetizing of the three-phase armature winding. The control difficulty is low, the system price is low, and the control algorithm is not complex, which can accurately control the magnetizing and demagnetizing process of the variable flux memory motor, has good cost control, and has strong universality. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The system block diagram of the single-capacitor magnetizing method in the prior art;

[0032] Figure 2 The single-capacitor off-line magnetizing and demagnetizing circuit in the prior art;

[0033] Figure 3 The connection diagram of the variable flux memory motor off-line magnetizing and demagnetizing device of the present application;

[0034] Figure 4 The magnetizing and demagnetizing circuit in the variable flux memory motor off-line magnetizing and demagnetizing device of the present application;

[0035] Figure 5 The magnetizing method flow chart of the variable flux memory motor off-line magnetizing and demagnetizing device of the present application.

[0036] BRIEF DESCRIPTION OF DRAWINGS:

[0037] 1-Three-phase armature winding; 21-First electromagnetic switch; 22-Second electromagnetic switch 23-Third electromagnetic switch; 3-Magnetizing and demagnetizing capacitor; 4-Direct current power supply. DETAILED DESCRIPTION

[0038] First, those skilled in the art should understand that the embodiments are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can adjust them as needed in order to adapt to specific application occasions.

[0039] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0040] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0041] Referring to Figures 1-4 As shown in the figure, the embodiments of the present application disclose an off-line magnetizing and demagnetizing device for a variable flux memory motor, the memory motor is provided with a three-phase armature winding 1, the three-phase armature winding 1 is in star connection, and comprises an upper computer, a controller and a magnetizing and demagnetizing circuit, the magnetizing and demagnetizing circuit comprises a first electromagnetic switch 21, a second electromagnetic switch 22, a third electromagnetic switch 23 and a plurality of magnetizing and demagnetizing capacitors 3;

[0042] The plurality of magnetizing and demagnetizing capacitors 3 are connected in parallel, one end of the magnetizing and demagnetizing capacitors 3 is electrically connected with a positive electrode end of a direct current power supply 4, and the other end of the magnetizing and demagnetizing capacitors 3 is electrically connected with a negative electrode end of the direct current power supply 4;

[0043] One end of the magnetizing and demagnetizing capacitors 3 is electrically connected with a first end contact of the first electromagnetic switch 21, a second end contact of the first electromagnetic switch 21 is electrically connected with a first winding in the three-phase armature winding 1, the other end of the magnetizing and demagnetizing capacitors 3 is respectively electrically connected with a first end contact of the second electromagnetic switch 22 and a first end contact of the third electromagnetic switch 23, a second end contact of the second electromagnetic switch 22 is electrically connected with a second winding in the three-phase armature winding 1, and a second end contact of the third electromagnetic switch 23 is electrically connected with a third winding in the three-phase armature winding 1;

[0044] The control end of the first electromagnetic switch 21, the control end of the second electromagnetic switch 22 and the control end of the third electromagnetic switch 23 are all electrically connected with the controller, and the controller is electrically connected with the upper computer.

[0045] Compared with the online magnetizing and demagnetizing, a large power controller and a large power supply are needed to output the magnetizing and demagnetizing current. The embodiment belongs to an offline magnetizing and demagnetizing device system, and the magnetizing and demagnetizing capacitor 3 is used for magnetizing and demagnetizing, that is, a device for magnetizing and demagnetizing control after the memory motor is stopped. The power demand of the direct current power supply 4 and the controller demand in the magnetizing process are reduced, the magnetizing and demagnetizing is easier to perform, and the equipment cost is reduced.

[0046] In the embodiment, the first electromagnetic switch 21, the second electromagnetic switch 22 and the third electromagnetic switch 23 are all silicon carbide field effect tubes.

[0047] The silicon carbide field effect tube is controlled by the controller to control the conduction and turn-off of the silicon carbide field effect tube, so that the discharge waveform of the charged magnetizing and demagnetizing capacitor 3 can be controlled, and the magnetizing waveform is controllable to a fixed waveform. Meanwhile, the silicon carbide field effect tube replaces the mechanical manual switch in the traditional scheme, so that millisecond-level accurate control can be realized, the magnetizing amount is more controllable, and the current fluctuation caused by the on-off of the mechanical switch can be eliminated.

[0048] In the embodiment, one end of the magnetizing and demagnetizing capacitor 3 is connected to the positive terminal of the direct current power supply 4 in series with the first switch, and the other end of the magnetizing and demagnetizing capacitor 3 is connected to the negative terminal of the direct current power supply 4 in series with the second switch.

[0049] The conduction and turn-off of the first switch and the second switch are controlled to realize whether the direct current power supply 4 controls the charging of the magnetizing and demagnetizing capacitor 3. The first switch and the second switch can be manual key switches or electromagnetic switches. If the first switch and the second switch are electromagnetic switches, the first switch and the second switch also need to be electrically connected to the controller to control the conduction or turn-off of the first switch and the second switch by the controller.

[0050] In the embodiment, one end of the magnetizing and demagnetizing capacitor 3 is connected to the first end contact of the first electromagnetic switch 21 in series with the first resistor, and the other end of the magnetizing and demagnetizing capacitor 3 is connected to the first end contact of the second electromagnetic switch 22 and the first end contact of the third electromagnetic switch 23 in series with the second resistor.

[0051] The first resistor and the second resistor are set to filter the magnetizing current and reduce external interference.

[0052] The offline magnetizing and demagnetizing device of the variable magnetic flux memory motor in the embodiment has the advantages of simple and easy-to-use precision in the magnetizing and demagnetizing process, and is suitable for rapid magnetizing and demagnetizing function verification in motor mass production testing.

[0053] Referring to Figure 5 The method for the offline magnetizing and demagnetizing device of the variable magnetic flux memory motor includes a magnetizing method, and the magnetizing method includes the following steps:

[0054] S1, the memory motor is stopped. The memory motor is an alnico-ndfeb hybrid magnet memory motor, and the memory motor needs to be stopped offline before magnetizing. S2, the magnetizing and demagnetizing capacitor 3 is charged by the direct current power supply 4.

[0055] S2, the direct current power supply 4 charges the charge and demagnetization capacitor 3.

[0056] The first switch and the second switch are closed and conductive, and the direct current power supply 4 can charge the charge and demagnetization capacitor 3.

[0057] After step S2 is performed, step S21 is performed: the host computer sends a memory motor positioning instruction, and after the controller receives the memory motor positioning instruction, the controller drives the first electromagnetic switch 21, the second electromagnetic switch 22, and the third electromagnetic switch 23 to be conductive or closed, to charge the three-phase armature winding 1 with a second current until the memory motor position is corrected, and step S3 is entered; wherein the second current is less than the first current.

[0058] The three-phase armature winding 1 is first charged with a small current to complete the memory motor position correction, facilitating more accurate charging of the three-phase armature winding 1.

[0059] S3, the host computer sends a magnetizing instruction to the controller, the controller drives the first electromagnetic switch 21, the second electromagnetic switch 22, and the third electromagnetic switch 23 to be conductive or closed, and charges the three-phase armature winding 1 with a first current.

[0060] The waveform of the first current is a sine wave, a square wave, or a trapezoidal wave.

[0061] The controller drives the first electromagnetic switch 21, the second electromagnetic switch 22, and the third electromagnetic switch 23 to be conductive and closed at a certain time in a period, to achieve a specific first current waveform, that is, to charge the three-phase armature winding 1 with a specific large pulse magnetizing current. By controlling the waveform of the first current, the control accuracy and the magnetizing effect of the three-phase armature winding 1 can be increased, the magnetizing amount is more controllable, and the error caused by the magnetizing process is reduced.

[0062] S4, when the three-phase armature winding 1 reaches a preset magnetizing amount, the direct current power supply 4 stops charging the charge and demagnetization capacitor 3.

[0063] S5, the controller controls the first electromagnetic switch 21, the second electromagnetic switch 22, and the third electromagnetic switch 23 to perform a trickle discharge until complete discharge.

[0064] The present embodiment has the following beneficial effects compared to the prior art:

[0065] 1. The silicon carbide field effect tube is used for discharging the capacitor after charging, and compared with the uncontrollable pulse waveform of the traditional single capacitor magnetizing, the discharging process of the method makes the magnetizing waveform accurately controllable as a fixed waveform, such as a sine wave or a square wave or a trapezoidal wave pulse, which increases the control accuracy and magnetizing effect; at the same time, the silicon carbide field effect tube replaces the traditional mechanical manual switch, which can realize millisecond-level accurate control, more controllable magnetizing quantity, reduce the error caused by the magnetizing process, and eliminate the current fluctuation caused by the mechanical switch.

[0066] 2. The controller is used for magnetizing control of the three-phase armature winding 1 of the memory motor, to realize millisecond-level accurate magnetizing time, compared with the magnetizing mode of using a separate electric brake and a capacitor, the embodiment can realize accurate and quantitative magnetizing.

[0067] 3. The controller controls the conduction and turn-off of the silicon carbide field effect tube to control the magnetizing of the three-phase armature winding 1, which has low control difficulty, low system price, and does not need complex control algorithm to accurately control the magnetizing and demagnetizing process of the variable flux memory motor, has good cost control and strong universality.

[0068] In the description of the embodiments of the present application, it should be noted that in the description of the present application, the terms indicating the direction or position relationship are based on the direction or position relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or member must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0069] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "in this embodiment", "specific examples" or "some examples" means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, the skilled in the art can combine and combine the different embodiments or features of the embodiments or examples described in the present specification without contradiction.

[0070] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An off-line charging and demagnetizing device for a variable flux memory motor, wherein a three-phase armature winding (1) is provided in the memory motor, and the three-phase armature winding (1) is star-connected, and is characterized in that: It comprises a host computer, a controller and a charging and demagnetizing circuit, wherein the charging and demagnetizing circuit comprises a first electromagnetic switch (21), a second electromagnetic switch (22), a third electromagnetic switch (23) and a plurality of charging and demagnetizing capacitors (3); A plurality of the charging and demagnetizing capacitors (3) are connected in parallel, and one end of the charging and demagnetizing capacitors (3) is electrically connected to the positive terminal of a DC power supply (4), and the other end of the charging and demagnetizing capacitors (3) is electrically connected to the negative terminal of the DC power supply (4); One end of the charging and demagnetizing capacitor (3) is electrically connected to a first end contact of a first electromagnetic switch (21), a second end contact of the first electromagnetic switch (21) is electrically connected to a first winding in a three-phase armature winding (1), and the other end of the charging and demagnetizing capacitor (3) is electrically connected to a first end contact of a second electromagnetic switch (22) and a first end contact of a third electromagnetic switch (23), respectively, a second end contact of the second electromagnetic switch (22) is electrically connected to a second winding in a three-phase armature winding (1), and a second end contact of the third electromagnetic switch (23) is electrically connected to a third winding in a three-phase armature winding (1); The control end of the first electromagnetic switch (21), the control end of the second electromagnetic switch (22) and the control end of the third electromagnetic switch (23) are all electrically connected to the controller, and the controller is electrically connected to the host computer.

2. The offline charging and demagnetization device for a variable flux memory motor according to claim 1, characterized in that: The first electromagnetic switch (21), the second electromagnetic switch (22) and the third electromagnetic switch (23) are all silicon carbide field effect transistors.

3. The off-line charging and demagnetization device for a variable flux memory motor according to claim 1 or 2, characterized in that: One end of the charging and demagnetizing capacitor (3) is connected in series with a first switch and then electrically connected to the positive terminal of the DC power supply (4); the other end of the charging and demagnetizing capacitor (3) is connected in series with a second switch and then electrically connected to the negative terminal of the DC power supply (4).

4. The offline charging and demagnetization device for a variable flux memory motor according to claim 1, characterized in that: One end of the charging and demagnetizing capacitor (3) is connected in series with a first resistor and then electrically connected to a first end contact of a first electromagnetic switch (21); the other end of the charging and demagnetizing capacitor (3) is connected in series with a second resistor and then electrically connected to a first end contact of a second electromagnetic switch (22) and a first end contact of a third electromagnetic switch (23).

5. A method for offline charging and demagnetizing a variable flux memory motor according to any one of claims 1 to 4, characterized in that: The invention comprises a magnetizing method, which comprises the following steps: S1, memory motor stops rotating; S2, a DC power supply (4) charges the charging and demagnetizing capacitor (3); S3, the host computer sends a magnetization instruction to the controller, and the controller drives the first electromagnetic switch (21), the second electromagnetic switch (22), and the third electromagnetic switch (23) to be turned on or off, and magnetizes the three-phase armature winding (1) with the first current; S4, after the three-phase armature winding (1) reaches a preset magnetization amount, the DC power supply (4) stops charging the charging and demagnetizing capacitor (3); S5. The controller controls the first electromagnetic switch (21), the second electromagnetic switch (22), and the third electromagnetic switch (23) to perform trickle discharge until complete discharge.

6. The offline charging and demagnetization method of a variable flux memory motor according to claim 5, characterized in that: After step S2 and before step S3, the method further includes step S21: The host computer sends a memory motor positioning instruction. After the controller receives the memory motor positioning instruction, the controller drives the first electromagnetic switch (21), the second electromagnetic switch (22), and the third electromagnetic switch (23) to turn on or off, and magnetizes the three-phase armature winding (1) with the second current until the memory motor position is corrected, and then enters step S3; The second current is smaller than the first current.

7. The offline charging and demagnetization method of a variable flux memory motor according to claim 5, characterized in that: In step S3, the waveform of the first current is a sine wave, a square wave or a trapezoidal wave.

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