阅读说明：本技术 一种风机直驱异步起动永磁同步电动机 (Fan direct-drive asynchronous starting permanent magnet synchronous motor ) 是由 王国栋 马宏伟 于 2019-07-29 设计创作，主要内容包括：本发明公开了一种风机直驱异步起动永磁同步电动机,包括电动机和转换器,转换器安装在电动机上,所述电动机内设有绕组U1—U2、绕组V1—V2和绕组W1—W2,所述电动机内部设有转子机构,所述转换器通过控制机构控制电动机内的三组绕组进行三角形连接和星型连接的转换控制方法；电动机在启动时将绕组接成三角形连接使电机牵入同步转矩得到提高,起动完成后切换成星形连接使电动机在额定状态下运行,通过采用这种技术方案较为经济的解决了低速直驱电动机牵入同步的技术难题,低廉的成本可实现在风机节能领域的广泛应用,这与国家倡导的节能减排大政方针相适应。(The invention discloses a fan direct-drive asynchronous starting permanent magnet synchronous motor, which comprises a motor and a converter, wherein the converter is arranged on the motor, a winding U1-U2, a winding V1-V2 and a winding W1-W2 are arranged in the motor, a rotor mechanism is arranged in the motor, and the converter controls three groups of windings in the motor to carry out a conversion control method of triangular connection and star connection through a control mechanism; the winding of the motor is connected into the triangular connection when the motor is started, so that the traction synchronous torque of the motor is improved, the star connection is switched after the motor is started, so that the motor runs in a rated state, the technical problem of traction synchronization of the low-speed direct-drive motor is solved economically by adopting the technical scheme, the low cost can be realized in the field of energy conservation of the fan, and the method is suitable for the national advocated energy conservation and emission reduction policy.)

1. A fan direct-drive asynchronous starting permanent magnet synchronous motor comprises a motor (1) and a converter (2), wherein the converter (2) is installed on the motor (1), and windings U1-U2, V1-V2 and W1-W2 are arranged in the motor (1), and the fan direct-drive asynchronous starting permanent magnet synchronous motor is characterized in that a control circuit is arranged in the converter (2), and the converter (2) controls three groups of windings in the motor (1) to perform conversion in a triangular connection mode or a star connection mode through the control circuit, so that the motor (1) is driven to rotate synchronously;

the control circuit comprises a starting switch K, an alternating current contactor coil J, an alternating current contactor normally closed contact K, an alternating current contactor normally open contact K, a time delay relay coil J and a time delay relay normally open contact K, wherein the time delay relay coil J is connected with the alternating current contactor coil J in parallel, the alternating current contactor coil J is connected with the time delay relay normally open contact K in series, the alternating current contactor coil J is connected with the starting switch K in series through the normally open contact K, three groups of contacts of the starting switch K are respectively connected with the U, V and W ends of a winding U-U, a winding V-V and a winding W-W, the U, V and W ends of the winding U-U, the winding V-V and the winding W are connected with the alternating current contactor normally closed contact K in parallel, the U end of the winding U-U and the V end of the winding V-V are connected with the AC contactor normally open contact K in series, the normally open contact K11 of the alternating current contactor is connected with the V2 end of a winding V1-V2 and the W1 end of a winding W1-W2 in series, the normally open contact K11 of the alternating current contactor is connected with the W2 end of a group W1-W2 and the U1 end of a winding U1-U2 in series, and when a coil of the J1 alternating current contactor is not electrified, the U1-U2, the winding V1-V2 and the U2, V2 and W2 ends of a winding W1-W2 are connected into star connection through the normally closed contact K1;

the conversion control method of the control circuit comprises the following steps: step one, when a starting switch K is closed, a coil J2 of a time delay relay is electrified, a normally open contact K2 is connected, a coil J1 of an alternating current contactor is electrified, a normally closed contact K1 is disconnected, a normally open contact K11 is closed, and by connecting a normally open contact K11 of the alternating current contactor, a U2 end of a winding is connected with a V1 end, a V2 end is connected with a W1 end, and a W2 end is connected with a U1 end, so that the winding is connected into a triangle, the starting voltage is improved in a phase-changing manner, and the synchronous torque is improved; and step two, when the motor is delayed for 3-5 seconds and the synchronous speed is involved, after the motor is started, the J2 loses power, the normally open contact K11 of the alternating current contactor is disconnected through the control of the delayer, the normally closed contact K1 of the alternating current contactor is connected through the control of the delayer, and at the moment, the winding is in star connection, so that the motor runs under the rated state.

2. The fan direct-drive asynchronous starting permanent magnet synchronous motor as recited in claim 1, wherein a rotor mechanism in the motor (1) comprises a rotor shaft (3), the rotor shaft (3) is located inside the motor (1), the rotor shaft (3) is connected with the motor (1) through a bearing, a plurality of rotor punching sheets (7) are arranged on the rotor shaft (3), the rotor shaft (3) penetrates through shaft holes of the rotor punching sheets (7), the rotor punching sheets (7) are regularly stacked on the rotor shaft (3), a plurality of rotor magnetism isolating cavities (4) are formed in the outer side of the rotor shaft (3) and on the rotor punching sheets (7), the rotor magnetism isolating cavities (4) are uniformly distributed on the rotor punching sheets (7), magnetism isolating tiles (5) are installed in the rotor magnetism isolating cavities (4), and magnetic steel (6) is installed at the center of the outer side surface of the magnetism isolating tiles (5), the magnetic steel (6) is uniformly distributed in the rotor punching sheet (7), and the magnetic steel (6) in the rotor punching sheet (7) is radially distributed.

3. The fan direct-drive asynchronous starting permanent magnet synchronous motor as claimed in claim 1, wherein the torque calculation method of the rotor shaft is as follows:

average torque when motor windings are connected in star:

a rotor resistance;a reduced value of rotor leakage reactance; c₁＝1+X₁/X_m，X_mFor excitation reactance:

when starting, the windings are connected into a delta connection, the power supply voltage is unchanged, namely the winding voltage is increased compared with the winding voltage in normal workDouble, handle U²Change toThe average torque formula is:

。

4. the fan direct-drive asynchronous starting permanent magnet synchronous motor as claimed in claim 2, wherein the magnetic isolation tile (5) is made of aluminum.

Technical Field

The invention relates to the field of motors, in particular to a fan direct-drive asynchronous starting permanent magnet synchronous motor.

Background

At present, the energy conservation in the field of motors is developed and popularized towards high efficiency and super high efficiency. The permanent magnet synchronous motor is more prominent. Its advantages are high power density, high volume reduction 1/3 and high efficiency (3-4%) under same power and number of poles. The permanent magnet motor is divided into two categories, namely a frequency converter driving permanent magnet synchronous motor and an asynchronous starting permanent magnet synchronous motor according to a starting mode. The permanent magnet synchronous motor is applied less in the field of fans, and particularly, the low-power asynchronous starting permanent magnet synchronous motor is not applied basically.

In a variable magnetic bridge asynchronous starting permanent magnet synchronous motor disclosed in patent CN201611193921.X, a rotor core of a variable magnetic bridge is adopted, the smaller the width of a magnetic isolation magnetic bridge is, the larger the magnetic resistance of the magnetic bridge part is, the more the magnetic leakage of a permanent magnet can be limited, the more obvious the magnetic leakage limitation effect on the permanent magnet in the whole rotating shaft direction is, and the aims of reducing the magnetic leakage, improving the starting quality factor and reducing the using amount of the permanent magnet with unit power are fulfilled; the rotor cage is formed by casting with molten aluminum, so that the rotor cage and the rotor core are connected into a whole, the weakening of the mechanical strength of the rotor due to the reduction of the width of the magnetic isolation bridge of the rotor core can be offset, and the high mechanical strength of the rotor is ensured.

In order to meet the requirement of starting pull-in synchronization, the power of the small-power asynchronous starting permanent magnet synchronous motor is designed according to pull-in synchronous torque, namely the power of the small-power asynchronous starting permanent magnet synchronous motor is designed according to about 3 times of load power, and the actual operation is greatly wasted. The volume of the motor is increased by about 2 times, the occupied space is large, materials are wasted, and the application to narrow and small space places is limited. The frequency converter is used for driving the motor, so that the cost is greatly increased, and the popularization is limited.

Disclosure of Invention

The invention aims to solve the problems, designs a fan direct-drive asynchronous starting permanent magnet synchronous motor, has the functions of improving the pull-in synchronous torque and saving the cost, solves the technical problem of pull-in synchronization of a low-speed direct-drive motor, improves the pull-in synchronous torque of the motor by connecting windings into triangular connection when the motor is started, and effectively improves the pull-in synchronous torque and is more economic at the same time by switching the windings into star connection after the motor is started to run in a rated state.

The technical scheme of the invention is that the fan direct-drive asynchronous starting permanent magnet synchronous motor comprises a motor and a converter, wherein the converter is arranged on the motor, windings U1-U2, windings V1-V2 and windings W1-W2 are arranged in the motor, a control circuit is arranged in the converter, and the converter controls three groups of windings in the motor to perform conversion in a triangular connection mode or a star connection mode through the control circuit so that the motor is driven to rotate synchronously;

the control circuit comprises a starting switch K, an alternating current contactor coil J, an alternating current contactor normally closed contact K, an alternating current contactor normally open contact K, a time delay relay coil J and a time delay relay normally open contact K, wherein the time delay relay coil J is connected with the alternating current contactor coil J in parallel, the alternating current contactor coil J is connected with the time delay relay normally open contact K in series, the alternating current contactor coil J is connected with the starting switch K in series through the normally open contact K, three groups of contacts of the starting switch K are respectively connected with the U, V and W ends of a winding U-U, a winding V-V and a winding W-W, the U, V and W ends of the winding U-U, the winding V-V and the winding W are connected with the alternating current contactor normally closed contact K in parallel, the U end of the winding U-U and the V end of the winding V-V are connected with the AC contactor normally open contact K in series, the normally open contact K11 of the alternating current contactor is connected with the V2 end of a winding V1-V2 and the W1 end of a winding W1-W2 in series, the normally open contact K11 of the alternating current contactor is connected with the W2 end of a group W1-W2 and the U1 end of a winding U1-U2 in series, and when a coil of the J1 alternating current contactor is not electrified, the U1-U2, the winding V1-V2 and the U2, V2 and W2 ends of a winding W1-W2 are connected into star connection through the normally closed contact K1;

the conversion control method of the control circuit comprises the following steps: step one, when a starting switch K is closed, a coil J2 of a time delay relay is electrified, a normally open contact K2 is connected, a coil J1 of an alternating current contactor is electrified, a normally closed contact K1 is disconnected, a normally open contact K11 is closed, and a normally open contact K11 of the alternating current contactor is connected, so that the U2 end of a winding is connected with a V1 end, the V2 end is connected with a W1 end, and the W2 end is connected with a U1 end, so that the winding is connected into a triangle, the starting voltage is improved in a phase-changing manner, and the pull-in synchronous torque is improved; and step two, when the motor is delayed for 3-5 seconds and the synchronous speed is involved, after the motor is started, the J2 loses power, the normally open contact K11 of the alternating current contactor is disconnected through the control of the delayer, the normally closed contact K1 of the alternating current contactor is connected through the control of the delayer, and at the moment, the winding is in star connection, so that the motor runs under the rated state.

Rotor mechanism in the motor includes the rotor shaft, the rotor shaft is located inside the motor, the rotor shaft passes through the bearing with the motor and is connected, be equipped with a plurality of rotor punching on the rotor shaft, the rotor shaft is worn in the shaft hole of rotor punching, the rotor punching is neatly folded and is pressed on the rotor shaft, the rotor shaft outside just has a plurality of rotors to separate the magnetism chamber on the rotor punching, the rotor separates magnetism chamber evenly distributed on the rotor punching, the rotor separates the magnetism intracavity and installs and separates the magnetic shoe, separate magnetic shoe outside surface center department and install the magnet steel, magnet steel evenly distributed is in the rotor punching, the magnet steel is radial distribution in the rotor punching.

The torque calculation method of the rotor shaft comprises the following steps:

average torque when motor windings are connected in star:

a rotor resistance;a reduced value of rotor leakage reactance; c₁＝1+X₁/X_m，X_mFor excitation reactance:

when starting, the windings are connected into a delta connection, the power supply voltage is unchanged, namely the winding voltage is increased compared with the winding voltage in normal workDouble, handle U²Change toThe average torque formula is:

the magnetic isolation tile is made of aluminum.

The blower direct-drive asynchronous starting permanent magnet synchronous motor manufactured by the technical proposal of the invention does not determine the rated power of the motor according to the torque involved in synchronization, the rotor core, the permanent magnet and the coil winding are designed according to rated power and optimal power density, the windings are connected into a triangular connection when the motor is started so that the motor traction synchronous torque is improved, the star connection is switched after the motor is started so that the motor runs in a rated state, by adopting the technical scheme, the technical problem that the low-speed direct-drive motor is involved in synchronization is solved economically, the asynchronous starting permanent magnet synchronous direct-drive motor is particularly suitable for the fan type load with mechanical power below 4kw and involved in synchronous rotating speed, the low cost can be widely applied to the field of fan energy conservation, and the method is suitable for the national advocated energy-saving and emission-reducing policy.

Drawings

FIG. 1 is a schematic circuit structure diagram of a fan direct-drive asynchronous starting permanent magnet synchronous motor according to the invention;

FIG. 2 is a schematic exterior view of the motor of the present invention;

FIG. 3 is a schematic view of the rotor mechanism of the present invention;

FIG. 4 is a schematic circuit diagram of the delta connection of the present invention;

FIG. 5 is a schematic circuit diagram of the star connection of the present invention;

in the figure, 1, a motor; 2. a converter; 3. a rotor shaft; 4. a rotor magnetic isolation cavity; 5. magnetic isolation tiles; 6. magnetic steel; 7. rotor punching.

Detailed Description

The invention is described in detail below with reference to the accompanying drawings, as shown in FIGS. 1-5, in this embodiment:

the invention is characterized in that the control circuit and the control method are designed, and the control circuit is combined with an attached figure 1, an attached figure 4 and an attached figure 5, the control circuit comprises a starting switch K, an alternating current contactor coil J, an alternating current contactor normally closed contact K, an alternating current contactor normally open contact K, a time delay relay coil J and a time delay relay normally open contact K, the time delay relay coil J is connected with the alternating current contactor coil J in parallel, the alternating current contactor coil J is connected with the time delay relay normally open contact K in series, the alternating current contactor coil J is connected with the starting switch K in series through the normally open contact K, three groups of contacts of the starting switch K are respectively connected with a winding U, a winding V, and a winding W end of the winding U-U, a winding V-V and a winding W end of the winding W-W, the winding U-U, the winding V, and the winding W end of the winding V-W are connected in parallel through the alternating current contactor normally closed contact K, the alternating current contactor, an AC contactor normally-open contact K11 is connected with a V2 end of a winding V1-V2 and a W1 end of a winding W1-W2 in series, the AC contactor normally-open contact K11 is connected with a W2 end of a group W1-W2 and a U1 end of a winding U1-U2 in series, and when a J1 AC contactor coil is not electrified, the winding U1-U2, the winding V1-V2 and the U2, V2 and W2 ends of the winding W1-W2 are connected into star connection through the normally-closed contact K1; the conversion control method of the control circuit comprises the following steps: step one, when a starting switch K is closed, a coil J2 of a time delay relay is electrified, a normally open contact K2 is connected, a coil J1 of an alternating current contactor is electrified, a normally closed contact K1 is disconnected, a normally open contact K11 is closed, and by connecting a normally open contact K11 of the alternating current contactor, a U2 end of a winding is connected with a V1 end, a V2 end is connected with a W1 end, and a W2 end is connected with a U1 end, so that the winding is connected into a triangle, the starting voltage is improved in a phase-changing manner, and the synchronous torque is improved; step two, when the motor is delayed for 3-5 seconds and the synchronous speed is involved, after the motor is started, J2 loses power, the normally open contact K11 of the alternating current contactor is disconnected through the control of a delayer, the normally closed contact K1 of the alternating current contactor is connected through the control of the delayer, and at the moment, the winding is in star connection, so that the motor runs under the rated state; the winding is subjected to triangle-star connection conversion through the delay circuit and the alternating current contactor during starting, and the winding connection method can be changed during starting, so that the electromagnetic torque and the average torque are improved by phase-changing and winding voltage lifting, the motor is smoothly driven to be synchronous, the size of the motor is effectively reduced, a frequency converter is not needed, and the cost is saved.

The invention is characterized in structural design of a rotor mechanism in a motor, and with reference to the attached drawing 3, the rotor mechanism in the motor 1 comprises a rotor shaft 3, the rotor shaft 3 is positioned inside the motor 1, the rotor shaft 3 is connected with the motor 1 through a bearing, a plurality of rotor punching sheets 7 are arranged on the rotor shaft 3, the rotor shaft 3 penetrates through shaft holes of the rotor punching sheets 7, the rotor punching sheets 7 are orderly stacked on the rotor shaft 3, a plurality of rotor magnetic isolation cavities 4 are arranged on the outer side of the rotor shaft 3 and on the rotor punching sheets 7, the rotor magnetic isolation cavities 4 are uniformly distributed on the rotor punching sheets 7, magnetic isolation tiles 5 are arranged in the rotor magnetic isolation cavities 4, magnetic steel 6 is arranged at the centers of the outer side surfaces of the magnetic isolation tiles 5, the magnetic steel 6 is uniformly distributed in the rotor punching sheets 7, and the magnetic steel 6 in the rotor punching sheets 7; through separate the inside magnetic shoe 5 that separates that sets up in rotor magnetism chamber 4 and fill, can effectual solution rotor lead to the problem of intensity reduction because of separating the existence in magnetism chamber to make the intensity of rotor increase, guarantee the intensity of rotor, rotor magnetism chamber 4's setting and magnet steel 6 are radial distribution simultaneously, rotor resistance moment when can effectual reduction starts, thereby make motor 1 start-up draw into synchronous speed more easily.

The working principle of the device is as follows: when the motor 1 is started, the starting switch K is closed, the normally open contact K11 of the alternating current contactor is switched on, and at the moment, the U2 end of the winding is connected with the V1 end, the V2 end is connected with the W1 end, the W2 end is connected with the U1 end, and the motor winding is connected into a triangular connection. Average torque when motor windings are connected in a star connection:

a rotor resistance;a reduced value of rotor leakage reactance; c₁＝1+X₁/X_m，X_mFor excitation reactance:

when starting, the windings are connected into a delta connection, the power supply voltage is unchanged, namely the winding voltage is increased compared with the winding voltage in normal workDouble, handle U²Change toThe average torque formula is:

when the motor 1 is started, the windings are connected into a triangular connection, so that the phase change improves the starting voltage, the synchronous torque is improved, the electromagnetic torque is improved by more than three times, the rotor can be quickly drawn into the synchronous rotating speed, and then the windings are connected into a star connection through the converter 2, so that the motor 1 operates under the rated design parameters, and the optimal operation effect is achieved;

after the starting is finished, the normally open contact K11 of the alternating current contactor is disconnected through the control of the delayer, the normally closed contact K1 of the alternating current contactor is connected through the control of the delayer, at the moment, the winding is in star connection, the motor runs under a rated state, and the starting of the motor 1 is finished.

The technical solutions described above only represent the preferred technical solutions of the present invention, and some possible modifications to some parts of the technical solutions by those skilled in the art all represent the principles of the present invention, and fall within the protection scope of the present invention.