A permanent magnet synchronous motor and motor starting method

Abstract

The present application provides a permanent magnet synchronous motor and a motor starting method. The permanent magnet synchronous motor includes a casing, a cavity is formed inside the casing; a stator assembly is arranged on the inner wall of the cavity inside the casing; a stator winding is connected and arranged on the stator assembly; a rotor assembly is arranged on the inner wall of the stator assembly opposite to the casing; and a control assembly is arranged on one end surface of the stator assembly and is used to control the power on and off of the motor.

Description

Technical Field

[0001] The present application relates to the field of motor manufacturing, and in particular to a permanent magnet synchronous motor and a motor starting method. Background Art

[0002] The current motor uses the current passing through the coil to generate a magnetic field, and forms a directional magnetic force between the stator and the rotor through the on-off or reversing of the current to drive the motor. The working state of the iron core electric excitation is generally in the nonlinear region. However, it has the problems of slow starting speed and low safety. Summary of the invention

[0003] The purpose of the present application is to provide a permanent magnet synchronous motor and a motor starting method, which are used to solve the problems of slow motor starting speed and low safety in the prior art.

[0004] In order to achieve the above-mentioned objectives, in the first aspect, an embodiment provides a permanent magnet synchronous motor, including a casing, a cavity formed inside the casing; a stator assembly, arranged on the inner wall of the cavity inside the casing; a stator winding, connected and arranged on the stator assembly; a rotor assembly, arranged on the inner wall of the stator assembly opposite to the casing; and a control assembly, arranged on one end face of the stator assembly, for controlling the power on and off of the motor.

[0005] In the above implementation process, the stator winding arranged on the stator assembly can accelerate the starting speed of the rotor assembly and enter synchronous rotation more quickly when the control assembly controls the motor to be energized.

[0006] In an alternative embodiment, the stator assembly includes a stator frame.

[0007] In an optional embodiment, the stator assembly includes windings including: a first winding, arranged around the outer ring of the stator frame, and one end of which is connected to an external power source; and a second winding, arranged around the inner ring of the stator frame, and one end of which is connected to an external power source.

[0008] In an optional embodiment, the other end of the first winding is connected to the other end of the second winding.

[0009] In an optional embodiment, the housing includes: a front end cover; and a rear end cover, which is snap-connected to the front end cover to form the housing.

[0010] In an optional embodiment, the rotor assembly includes: a rotating shaft connected between the front cover and the rear cover; and a rotor disposed between the rotating shaft and the stator assembly and sleeved on the rotating shaft.

[0011] In an optional embodiment, the control component includes: a control board, which is arranged on one end surface of the stator assembly; a first AC switch, which is arranged on the control board, and one end of which is connected to the first winding and the second winding; a second AC switch, which is arranged on the control board, and one end of which is electrically connected to the other end of the first AC switch, and the other end of the second AC switch is electrically connected to the second winding.

[0012] In the above implementation process, when the motor is powered on, the control component collects the AC input voltage signal and the rotor position signal in real time. When these two signals meet certain conditions, the control component controls the stator winding to be turned on. Thereafter, the motor is driven to rotate continuously by continuously detecting and matching the AC voltage and the rotor position. The motor speed gradually increases to the synchronous operation speed, and the motor enters the synchronous operation state.

[0013] In a second aspect, an embodiment provides a motor starting method, which is applied to a permanent magnet synchronous motor of any one of the aforementioned implementation items, including: controlling the first AC switch to be turned on and the second AC switch to be turned off; simultaneously obtaining the AC input voltage information of the motor and the initial position information of the rotor; judging whether the AC input voltage information and the initial position information simultaneously meet the first preset condition; when the AC input voltage information and the initial position information simultaneously meet the first preset condition, maintaining the open and closed states of the two switches; obtaining the rotor speed; judging whether the speed meets the second preset condition; when it is judged that the speed meets the second preset condition, controlling the first AC switch to be turned off and the second AC switch to be turned on.

[0014] In an optional implementation, after determining whether the AC input voltage information and the initial position information simultaneously satisfy the first preset condition, the method further includes: when the AC input voltage information and the initial position information do not satisfy the first preset condition, controlling the first AC switch to disconnect.

[0015] In an optional implementation, after determining whether the rotation speed satisfies the second preset condition, the method further includes: when determining that the rotation speed does not satisfy the second preset condition, maintaining the open and closed states of the two switches until the rotation speed satisfies the second preset condition.

[0016] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1is a cross-sectional view of a permanent magnet synchronous motor provided in an embodiment of the present application;

[0019] Figure 2 yes Figure 1 A schematic structural diagram of the stator assembly shown;

[0020] Figure 3 yes Figure 1 The schematic diagram of the installation of the stator winding is shown;

[0021] Figure 4 yes Figure 2 The installation diagram of the first winding is shown;

[0022] Figure 5 yes Figure 2 The installation diagram of the second winding is shown;

[0023] Figure 6 yes Figure 1 The circuit diagram of the permanent magnet synchronous motor shown;

[0024] Figure 7 A motor starting method provided in an embodiment of the present application;

[0025] Figure 8 It is another motor starting method provided by an embodiment of the present application;

[0026] Fig. 9 This is another motor starting method provided in an embodiment of the present application.

[0027] Icon: motor 1, housing 10, front cover 11, rear cover 12;

[0028] Stator assembly 20, stator frame 21, spacer 22, stator pole 23;

[0029] Stator winding 30, first winding 31, second winding 32;

[0030] Rotor assembly 40, rotating shaft 41, rotor 42;

[0031] Control component 50 , first AC switch 51 , second AC switch 52 . DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0033] In the description of this application, it should be noted that the terms "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0034] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0035] Figure 1 1 is a cross-sectional view of a permanent magnet synchronous motor 1 provided in an embodiment of the present application, wherein the motor 1 comprises a housing 10, a stator assembly 20, a stator winding 30, a rotor assembly 40 and a control assembly 50. A cavity is formed inside the housing 10 to accommodate the various components.

[0036] In one embodiment, the stator assembly 20 is arranged on the inner wall of the cavity inside the housing 10. The stator winding 30 is connected to the stator assembly 20. The rotor assembly 40 is arranged on the side of the stator assembly 20 opposite to the inner wall of the housing 10. The control assembly 50 is arranged on an end surface of the stator assembly 20, and is used to control the power on and off of the motor 1. Under the action of the built-in control assembly 50, the permanent magnet synchronous motor 1 controls the conduction form of the stator winding 30, so that when the permanent magnet synchronous motor 1 is powered on, a magnetic field is formed in the air gap between the stator assembly 20 and the rotor assembly 40, so that the rotor assembly 40 rotates.

[0037] In one embodiment, the power supply of the permanent magnet synchronous motor 1 is a single-phase input alternating current, and its voltage is 110V or 220V.

[0038] In one embodiment, the housing 10 is composed of a front cover 11 and a rear cover 12 , and the front cover 11 and the rear cover 12 can form the housing 10 by at least one or more connection forms of snap connection, threaded connection, rigid connection, and sleeve connection.

[0039] In one embodiment, the rotor assembly 40 includes a rotating shaft 41 and a rotor 42. The rotating shaft 41 is connected and arranged between the front cover 11 and the rear cover 12. The rotor 42 is sleeved on the rotating shaft 41 and arranged between the rotating shaft 41 and the stator assembly 20, and a gap is left between the rotating shaft 41 and the stator assembly 20 to form an air gap. In one embodiment, the number of rotor poles of the rotor 42 is the same as that of the stator poles 23, and the number of pairs is the same.

[0040] Figure 2 yes Figure 1 As shown in the schematic diagram of the stator assembly 20, the stator frame 21 of the stator assembly 20 is connected with a spacer 22 from the outside to the inside, one end of the spacer 22 is connected to the outer frame of the stator assembly 20, and the other end is provided with a stator pole 23. A slot is formed between the spacers 22, such as Figure 2 In the embodiment shown, the stator assembly 20 may be a structure of four slots and four poles. In one embodiment, the stator frame 21, the spacers 22 and the stator poles 23 are integrally stamped.

[0041] Figure 3 , 4 5 Yes Figure 1 The stator winding 30 is shown as an installation diagram, and the stator winding 30 includes a first winding 31 and a second winding 32. The first winding 31 is arranged around the inner ring of the stator frame 21, and one end is connected to an external power supply. The second winding 32 is arranged around the outer ring of the stator frame 21, and one end is connected to an external power supply.

[0042] In one embodiment, one end of the second winding 32 is connected to an external power source, and the other end is wound around any spacer 22 for several turns, and then, in a clockwise or counterclockwise order, it extends along the stator frame 21 to the next spacer 22 and is wound for several turns. After winding all the spacers 22 in sequence, the other end of the second winding 31 is connected to one end of the first winding 31, and the other end of the first winding 31 is wound around the spacers 22 in sequence in the opposite order to the second winding 32. After the first winding 31 is wound around the spacer 22 for several turns, it extends along the stator pole 23 to the next spacer 22 and is wound for several turns, and is connected to an external power source. In one embodiment, an alternating current is connected between one end of the first winding 31 and the other end of the second winding 32.

[0043] Figure 6 yes Figure 1 The circuit diagram of the permanent magnet synchronous motor 1 is shown. The control component 50 includes: a control board, a first AC switch 51 and a second AC switch 52. The control board is arranged on one end surface of the stator assembly 20; the first AC switch 51 is arranged on the control board, one end of which is electrically connected to the first winding 31 and the second winding 32, and the other end of which is electrically connected to the second AC switch 52; the second AC switch 52 is arranged on the control board, one end of which is electrically connected to the first AC switch 51, and the other end of which is electrically connected to the second winding 32.

[0044] Figure 7 A motor starting method provided in an embodiment of the present application is applied to the control of the above-mentioned permanent magnet synchronous motor 1. In one embodiment, a processor and a memory are provided on the control component 50, the memory is used to store executable programs, and the processor can be used to execute programs. Among them, the control component 50 is used to control the motor 1 to enter the synchronous speed operation process after the motor 1 is successfully started according to the AC input voltage information and the on-off status of the first AC switch 51 and the second AC switch 52 during the starting process of the motor 1. The control component 50 executes:

[0045] Step 701 controls the first AC switch 51 to be turned on, and the second AC switch 52 to be turned off.

[0046] In this step, the permanent magnet synchronous motor 1 needs to be powered on when it is started, so that the stator winding 30 forms a unidirectional rotating magnetic field in the air gap under the action of the alternating current, and further the rotor 42 starts to rotate. When the first AC switch 51 is turned on alone, the starting current of the permanent magnet synchronous motor 1 and the current density of the first winding 31 are increased, so that the starting torque of the rotor 42 is increased, and the time for it to reach the synchronous speed is reduced.

[0047] Step 702 obtains the AC input voltage information of the motor 1 .

[0048] In this step, when the AC power input to the motor 1 is single-phase AC power, the AC input voltage is a single-phase sine wave.

[0049] Step 703 obtains the initial position information of the rotor 42 while obtaining the AC input voltage information of the motor 1 .

[0050] In this step, the position information of the rotor 42 may be the current polarity of the rotor 42 .

[0051] Step 704 determines whether the AC input voltage information and the initial position information simultaneously meet a first preset condition.

[0052] In this step, in order to achieve safe startup, the speed synchronization will continue only when the AC input voltage information and the initial position information simultaneously meet the preset conditions.

[0053] When the AC input voltage information and the initial position information simultaneously meet the first preset condition, the on-off state of the two switches is maintained.

[0054] In one embodiment, the position information is rotor magnetic pole information, and the first preset condition is that the magnetic pole information and the direction of the AC input voltage and current change simultaneously.

[0055] In this step, the AC input voltage information and the initial position information simultaneously meet the first preset condition, and the current state is maintained to continue synchronization.

[0056] Step 705 obtains the rotation speed of the rotor 42 .

[0057] In this step, the rotation speed of the rotor 42 is obtained to determine whether the motor 1 has reached a synchronous state.

[0058] Step 706 determines whether the rotation speed meets a second preset condition.

[0059] In this step, the synchronous state is determined according to the rotation speed. The second preset condition is the ratio range of the current rotation speed to the target rotation speed. In one embodiment, the second preset condition may be that the current rotation speed is 70% of the target rotation speed when the motor 1 enters the synchronous state.

[0060] In step 707, when it is determined that the rotation speed meets the second preset condition, the first AC switch 51 is controlled to be turned off and the second AC switch 52 is controlled to be turned on.

[0061] In this step, after the motor 1 speed reaches 70% of the synchronous speed, it switches to a mode in which the first winding 31 and the second winding 32 are connected in series and then turned on, and the permanent magnet synchronous motor 1 smoothly enters the synchronous speed operation state.

[0062] Figure 8 This is an embodiment of a motor starting method provided by an embodiment of the present application, wherein the control component 50 is used to control the process of self-protection of the motor 1 after the start-up fails according to the AC input voltage information and the on-off status of the first AC switch 51 and the second AC switch 52 during the start-up process of the motor 1. The control component 50 executes:

[0063] Step 801 controls the first AC switch 51 to be turned on, and the second AC switch 52 to be turned off.

[0064] In this step, refer to the description of step 701 in the above embodiment.

[0065] Step 802 obtains the AC input voltage information of the motor 1 .

[0066] In this step, refer to the description of step 702 in the above embodiment.

[0067] Step 803 obtains the initial position information of the rotor 42 .

[0068] In this step, refer to the description of step 703 in the above embodiment.

[0069] Step 804 determines whether the AC input voltage information and the initial position information simultaneously meet a first preset condition.

[0070] In this step, refer to the description of step 704 in the above embodiment.

[0071] Step 805: When the AC input voltage information and the initial position information do not satisfy the first preset condition, the first AC switch 51 is controlled to be disconnected.

[0072] In this step, in order to prevent damage to the permanent magnet synchronous motor 1 and ensure safety during the starting process, once the starting fails, the power supply to the first winding 31 is immediately disconnected.

[0073] Fig. 9 This is another embodiment of a motor starting method provided in an embodiment of the present application, wherein the control component 50 is used to control the restart of the motor 1 according to the AC input voltage information and the on-off status of the first AC switch 51 and the second AC switch 52 during the starting process of the motor 1.

[0074] Step 901 controls the first AC switch 51 to be turned on, and the second AC switch 52 to be turned off.

[0075] In this step, refer to the description of step 701 in the above embodiment.

[0076] Step 902 obtains the AC input voltage information of the motor 1 .

[0077] In this step, refer to the description of step 702 in the above embodiment.

[0078] Step 903 obtains the initial position information of the rotor 42 .

[0079] In this step, refer to the description of step 703 in the above embodiment.

[0080] Step 904 determines whether the AC input voltage information and the initial position information simultaneously meet a first preset condition.

[0081] In this step, refer to the description of step 704 in the above embodiment.

[0082] Step 905 obtains the rotation speed of the rotor 42 .

[0083] In this step, refer to the description of step 705 in the above embodiment.

[0084] Step 906 determines whether the rotation speed meets a second preset condition.

[0085] In this step, refer to the description of step 706 in the above embodiment.

[0086] In one embodiment, when it is determined that the rotation speed does not satisfy the second preset condition, the on-off state of the two switches is maintained until the rotation speed satisfies the second preset condition.

[0087] In this step, the rotation speed of the rotor 42 during the startup process is continuously detected until the rotation speed meets the condition for entering synchronization.

[0088] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A motor starting method, applied to a permanent magnet synchronous motor whose input alternating current is single-phase alternating current, characterized in that: The permanent magnet synchronous motor comprises a housing, a stator assembly, a stator winding, a rotor assembly and a control assembly; a cavity is formed inside the housing; the stator assembly is arranged on the inner wall of the cavity inside the housing; the stator winding is connected and arranged on the stator assembly; the stator assembly comprises a stator frame, and the stator winding comprises a first winding and a second winding, the first winding is arranged around the inner ring of the stator frame, and one end is connected to an external power supply; the second winding is arranged around the outer ring of the stator frame, and one end is connected to an external power supply; the other end of the first winding is connected to the other end of the second winding The first AC switch is provided on the control board, and one end of the first AC switch is electrically connected to the first winding and the second winding; the second AC switch is provided on the control board, and one end of the second AC switch is electrically connected to the other end of the first AC switch, and the other end of the second AC switch is electrically connected to the second winding; The motor starting method comprises: Controlling the first AC switch to be turned on and the second AC switch to be turned off; At the same time, the AC input voltage information of the motor and the initial position information of the rotor are obtained; Determine whether the AC input voltage information and the initial position information simultaneously satisfy a first preset condition; the initial position information is rotor magnetic pole information, and the first preset condition is that the rotor magnetic pole information and the AC input voltage and current direction change simultaneously; When the AC input voltage information and the initial position information simultaneously meet the first preset condition, maintaining the open and closed states of the two switches; Obtaining the rotation speed of the rotor; Determine whether the rotation speed satisfies a second preset condition; the second preset condition is a ratio range of the current rotation speed to the target rotation speed of the motor when the motor enters a synchronous state; When it is determined that the rotation speed meets the second preset condition, the first AC switch is controlled to be disconnected and the second AC switch is controlled to be turned on.

2. The motor starting method according to claim 1, characterized in that: After determining whether the AC input voltage information and the initial position information simultaneously meet the first preset condition, the method further includes: When the AC input voltage information and the initial position information do not satisfy the first preset condition, the first AC switch is controlled to be disconnected.

3. The motor starting method according to claim 2, characterized in that: After determining whether the rotation speed satisfies the second preset condition, the method further includes: When it is determined that the rotation speed does not meet the second preset condition, the on-off state of the two switches is maintained until the rotation speed meets the second preset condition.

4. The motor starting method according to claim 1, characterized in that: The housing comprises: Front end cover; The rear end cover is connected to the front end cover through buckles to form the housing.

5. The motor starting method according to claim 4, characterized in that: The rotor assembly comprises: A rotating shaft, connected and arranged between the front end cover and the rear end cover; The rotor is arranged between the rotating shaft and the stator assembly and is sleeved on the rotating shaft.

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