CN109889003B - High frequency induction wireless feeding electric excitation synchronous motor - Google Patents

Abstract

The invention relates to a high-frequency induction type wireless feed electric excitation synchronous motor, which comprises a shell part, a rotating shaft, a rotatable transformer part, a motor main body part and a control assembly, wherein the rotatable transformer part and the motor main body part are respectively positioned at two ends of the rotating shaft. The rotatable transformer part comprises a primary side unit and a secondary side unit, the motor main body part comprises a rotor unit and a stator unit, and the control assembly is electrically connected with the primary side unit. Because the rotor of the invention does not use permanent magnet materials, and adopts a wireless feed mode, compared with a permanent magnet synchronous motor, the air gap field of the wireless feed electro-magnetic synchronous motor can be adjusted, the highest running speed of the motor can be improved without adopting weak magnetic control for reducing the efficiency of the motor, and the efficiency of the wireless feed electro-magnetic synchronous motor and a driver thereof is greatly improved during high-speed running, the speed control in all the running areas is more flexible, and the high-efficiency running in all the running areas is easier to realize.

Description

High frequency induction wireless feeding electric excitation synchronous motor

Technical Field

The invention belongs to the field of motors, and in particular relates to a high-frequency induction wireless feeding electric excitation synchronous motor.

Background Art

In the past decade, the application of synchronous motors has achieved rapid development. For example, large-capacity rolling mills, high-power hoists, fans, water pumps, etc. used in industry and mining all use synchronous motors. Now synchronous motors have been extended to many fields. For example, electric vehicles. Synchronous motors are usually divided into two types: permanent magnet synchronous motors and electrically excited synchronous motors.

In recent years, due to the control of the supply of rare earth materials used in permanent magnet steel, the price of rare earth raw materials has continued to rise, which has greatly increased the manufacturing and use costs of permanent magnet synchronous motors. At the same time, the air gap magnetic field of permanent magnet synchronous motors is difficult to adjust in an efficient and energy-saving manner in the high-speed section of a wide speed regulation range, and it is easy to cause magnetic steel demagnetization in harsh environments such as high temperature and strong magnetism. These disadvantages have also limited the application of permanent magnet synchronous motors in many fields such as offshore wind power generation to a certain extent.

Brushed electric excitation synchronous motors are still widely used in many occasions. However, due to the brush slip ring structure, brushed electric excitation synchronous motors are prone to sparks and dust during operation, which affects the safety and reliability of the motor's long-term operation and pollutes the environment. In particular, in harsh environments with flammable and explosive gases such as coal dust and gas, and in large wind power generation systems where maintenance is very difficult, the application of brushed electric excitation synchronous motors is often limited.

Summary of the invention

The present invention is made to solve the above-mentioned problem. It realizes non-contact feeding excitation and adjusts the excitation winding current through its own rotatable transformer part in conjunction with the corresponding control method, thereby changing the rotation speed of the rotating shaft and expanding the maximum speed of the motor.

The present invention provides a high-frequency induction wireless feeding electric excitation synchronous motor, which has the following characteristics, including: a shell part, which is a hollow shell; a rotating shaft, one end of which is located inside the shell part and is rotatably connected to the shell part, and the other end of which is located outside the shell part; a rotatable transformer part, which is located inside the shell part, and the rotatable transformer part is a sleeve-type structure, including a primary side unit and a secondary side unit which are coaxially arranged, the primary side unit connected to the shell part includes a primary side coil, and the secondary side unit connected to the rotating shaft includes a secondary side coil; a motor body part, which is located inside the shell part, and the motor body part includes a rotor unit and a stator unit, the stator unit is connected to the shell part, the rotor unit is connected to the rotating shaft, the rotor unit is electrically connected to the secondary side coil, and the rotor unit includes a rotor excitation winding; and a control component, which is electrically connected to the primary side coil, wherein the primary side unit and the secondary side unit are both cylindrical, the secondary side unit is located inside the primary side unit, and there is a first air gap between the secondary side unit and the primary side unit,

A stator winding current is applied to the stator unit, and a first current is passed into the primary side coil through the control component to generate a second current in the secondary side coil. The rotor unit converts the second current into an excitation winding current. The excitation winding current causes the rotor unit to generate a first magnetic field. The first magnetic field and the stator winding current work together to cause the rotor unit to drive the rotating shaft to rotate. The rotor unit generates a corresponding digital signal according to the excitation winding current. The digital signal is transmitted to the primary side unit through the secondary side unit. The primary side unit then transmits the digital signal to the control component. The control component compares the digital signal with a predetermined target excitation current value and adjusts the first current according to the comparison result, thereby changing the excitation winding current to change the rotation rate of the rotating shaft.

In the high-frequency induction wireless feeding electric excitation synchronous motor provided by the present invention, it can also have the following characteristics: wherein, the primary side unit includes a cylindrical primary side iron core, the primary side iron core is formed by pinning two symmetrically shaped iron core splicing circular rings, and the joint surface of the iron core splicing circular rings is provided with circular coil grooves along the circumference of the joint surface.

In the high-frequency induction wireless feeding electric excitation synchronous motor provided by the present invention, it can also have the following characteristics: wherein, the control component includes an inverter circuit, the inverter circuit is electrically connected to the primary side coil, and the external direct current forms a first current through the inverter circuit, and the frequency of the first current is 1KHz-10MHz.

The high-frequency induction wireless feeding electric excitation synchronous motor provided by the present invention may also have the following characteristics: wherein the first air gap is equal everywhere, and the setting range of the first air gap is 0.1 mm-2 mm.

In the high-frequency induction wireless feeding electric excitation synchronous motor provided by the present invention, it can also have the following characteristics: wherein, the rotor unit includes a rectifier circuit and a current detection circuit, the second current forms an excitation winding current through the rectifier circuit, and the current detection circuit detects the excitation winding current and generates a corresponding digital signal.

The high-frequency induction wireless feeding electric excitation synchronous motor provided by the present invention may also have the following characteristics: wherein the secondary side unit includes a first signal terminal, and the digital signal is transmitted to the primary side unit through the first signal terminal.

The high-frequency induction wireless feeding electric excitation synchronous motor provided by the present invention may also have the following feature: the transmission form of the digital signal is any one of a radio signal, an infrared signal and an ultrasonic signal.

The high-frequency induction wireless feeding electric excitation synchronous motor provided by the present invention may also have the following characteristics: wherein the primary side unit includes a second signal terminal, and the second signal terminal receives a digital signal.

The high-frequency induction wireless feeding electric excitation synchronous motor provided by the present invention may also have the following feature: wherein the control component adjusts the excitation winding current by changing the first current.

Functions and Effects of the Invention

The high-frequency induction wireless feeding electric excitation synchronous motor according to the present invention comprises a housing, a rotating shaft, a rotatable transformer, a motor body and a control assembly, wherein the rotatable transformer and the motor body are respectively located at both ends of the rotating shaft. The rotatable transformer comprises a primary side unit and a secondary side unit, the motor body comprises a rotor unit and a stator unit, and the control assembly is electrically connected to the primary side unit. Because the rotor of the high-frequency induction wireless feeding electric excitation synchronous motor of the present invention does not use permanent magnetic materials, and adopts a non-contact wireless feeding method to eliminate brushes and slip rings, compared with permanent magnet synchronous motors, the air gap magnetic field of the wireless feeding electric excitation synchronous motor can be adjusted, and there is no need to adopt weak magnetic control that reduces the efficiency of the motor, so that its maximum operating speed can be improved. In addition, the efficiency of the wireless feeding electric excitation synchronous motor and its driver is greatly improved during high-speed operation, and the speed control in all operable areas is more flexible, making it easier to achieve high-efficiency operation in all operating areas; and because the synchronous motor of the present invention adopts brushless excitation, the synchronous motor has the advantages of high reliability, simple maintenance, no maintenance, low manufacturing cost, and no arc sparks, and can be extended to various occasions requiring flameproof and explosion-proof, and the excitation winding current of the rotor unit is controllable, so that the synchronous motor has a wider speed regulation range. The above characteristics can make the present invention applicable to drive or power generation systems and many occasions requiring high performance and high reliability motor systems such as aircraft AC power supply equipment and industrial robots.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic cross-sectional view of a high frequency induction wireless feeding electric excitation synchronous motor in a first embodiment of the present invention;

2 is a cross-sectional schematic diagram of a rotatable transformer portion of a motor in Embodiment 1 of the present invention;

FIG3 is an exploded view of a primary side unit of a motor in Embodiment 1 of the present invention;

FIG4 is a schematic diagram of the internal structure of a motor in Embodiment 1 of the present invention;

FIG5 is a partial enlarged view of portion A in FIG1 ;

6 is a schematic end view of the rotatable transformer portion of the motor in the first embodiment of the present invention;

7 is a topological diagram of an inverter circuit of a motor in Embodiment 1 of the present invention;

FIG8 is a coupling topology diagram of a rectifier circuit and a chopper control circuit of a motor in Embodiment 2 of the present invention; and

FIG9 is a schematic cross-sectional view of the high-frequency induction wireless feeding electric excitation synchronous motor in Embodiment 4 of the present invention.

DETAILED DESCRIPTION

In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the following embodiments are combined with the accompanying drawings to specifically explain the high-frequency induction wireless feeding electric excitation synchronous motor of the present invention.

<Example 1>

As shown in FIG1 , a high-frequency induction wireless feeding electric excitation synchronous motor 100 realizes non-contact excitation and adjusts the excitation winding current through its own rotatable transformer part 30 in cooperation with a corresponding control method, thereby changing the rotation speed of the rotating shaft, thereby expanding the maximum speed of the motor. The motor includes a housing part 10, a rotating shaft 20, a rotatable transformer part 30, a motor body part 40, and a control component 50.

The housing 10 , serving as the housing of the synchronous motor 100 , is a hollow shell.

The rotating shaft 20 has one end located inside the housing 10 and is rotationally connected to the housing 10, and the other end located outside the housing 10, and is used as the output end of the synchronous motor 100 to output torque and speed. A first through groove 21 as shown in FIG. 4 is axially arranged on the surface of the rotating shaft 20. In this embodiment, the rotating shaft 20 is rotationally connected to the housing 10 through a bearing.

The rotatable transformer part 30 is located inside the housing part 10. The rotatable transformer part 30 is a sleeve-type structure, and includes a coaxially arranged primary side unit 31 and a secondary side unit 32. Both the primary side unit 31 and the secondary side unit 32 are cylindrical.

The primary side unit 31 is fixedly connected to the housing 10. As shown in Fig. 2, the primary side unit 31 includes a primary side iron core 311, a support frame 312, a primary side coil 313 and a plurality of second signal terminals 314. In this embodiment, the primary side unit 31 is connected to the housing 10 by screws.

The primary side iron core 311 is cylindrical, as shown in Figure 3, and the primary side iron core 311 is formed by splicing two symmetrical iron core splicing rings 311-1. The two iron core splicing rings 311-1 are both made of high-frequency and low-loss magnetic conductive materials. The joint surface of the iron core splicing ring 311-1 is provided with circular coil grooves 311-2 along the circumference of the joint surface. When the two iron core splicing rings 311-1 are spliced together, the two circular coil grooves 311-2 form a primary side coil position, and the two circular coil grooves 311-2 have one notch edge facing the outside of the primary side iron core 311 that matches each other, and one notch edge facing the inside of the primary side iron core 311 does not touch, so that a continuous first opening G1 as shown in Figure 2 is formed on the inner surface of the primary side iron core 311. In this embodiment, the two core splicing rings 311 - 1 are both made of manganese-zinc-iron oxide soft magnetic alloy, and the primary side core 311 is composed of two symmetrical core splicing rings 311 - 1 spliced together and fixed with pins.

The support frame 312 is made of a light insulating material, such as plastic or epoxy resin, and is embedded in the primary coil position, and is a wire slot structure with an opening toward the outside of the primary iron core 311. In this embodiment, the material of the support frame 312 is preferably plastic.

As shown in FIG6 , a plurality of second signal terminals 314 are distributed on the end surface of the primary iron core 311 facing the main motor portion 40, and the plurality of second signal terminals 314 are close to the edge of the primary iron core 311 and are evenly distributed along the circumferential direction of the end surface of the primary iron core 311. In this embodiment, the second signal terminals 314 are infrared receivers, a total of 8, which are welded on the end surface of the primary iron core 311.

The primary coil 313 has a first number of turns and is neatly wound around the support frame 312 . The primary coil 313 is introduced from the outside through a first wire entry hole 311 - 3 on the primary core 311 .

The pin-mounted design of the primary iron core 311 greatly reduces the difficulty of installing the primary coil 313 in the primary iron core 311 , and the support frame 312 surrounds the primary coil 313 to form a magnetic conductive circuit with low magnetic resistance.

The secondary side unit 32 is fixedly connected to the rotating shaft 20. The secondary side unit 32 is located inside the primary side unit 31 and has a first air gap with the primary side unit 31 to facilitate the free rotation of the secondary side unit 32. The setting range of the first air gap is 0.1mm-2mm. The setting of the first air gap is related to the maximum output speed of the motor design. The proper setting of the gap can make the electromagnetic energy coupling efficiency higher. The ratio of the width of the first opening G1 to the first air gap determines the electromagnetic transmission efficiency between the primary side unit 31 and the secondary side unit 32. The ratio of the width of the first opening G1 to the first air gap is 1:200 to 1:50. In this embodiment, the secondary side unit 32 is fixedly connected to the rotating shaft 20 by a key, the setting range of the first air gap is 0.5mm, and the ratio of the width of the first opening to the first air gap is 1:200.

The secondary unit 32 includes a secondary iron core 321 , a secondary coil 323 and a first signal terminal 322 .

As shown in FIG2 , the secondary side core 321 is cylindrical and made of high-frequency low-loss magnetic conductive material. The axial length of the secondary side core 321 is the same as that of the primary side core 311. A secondary side coil position surrounding the axis of the secondary side core 321 is arranged on the outer surface of the secondary side core 321. The secondary side coil position is a slot-shaped structure with a second opening G2, and the second opening G2 is opposite to the first opening G1. The ratio of the width of the second opening G2 to the first air gap determines the electromagnetic transmission efficiency between the primary side unit 31 and the secondary side unit 32. The ratio of the width of the second opening G2 to the first air gap is 1:200 to 1:50. In this embodiment, the secondary side core 321 is made of manganese-zinc iron oxide soft magnetic alloy. The ratio of the width of the second opening G2 to the first air gap is 1:100.

The secondary coil 323 has a second number of turns and is installed in the secondary coil position. When the first current is passed into the primary coil 313 through the control component 50, an induced electromotive force is induced, and the induced electromotive force causes a second current to be generated in the secondary coil 323. The secondary coil 323 is led out from the secondary coil position through the first outlet hole 3211 on the secondary iron core 321.

The first signal terminal 322 is located at the end surface of the secondary iron core 321 and close to the edge of the secondary iron core 321. The first signal terminal 322 is distributed on the end surface of the secondary iron core 321 facing the main motor part 40. In this embodiment, as shown in FIG6 , the first signal terminal 322 is an infrared emitter, the number of which is 1 and is welded to the end surface of the secondary iron core 321.

As shown in FIG. 4 , the motor body 40 is located inside the housing 10 . The motor body 40 includes a coaxially arranged rotor unit 41 and a stator unit 42 . Both the rotor unit 41 and the stator unit 42 are cylindrical.

The rotor unit 41 is connected to the rotating shaft 20, and is electrically connected to the secondary coil 323, and includes a second circuit board 411, a rotor excitation winding, and a third circuit board 412. In this embodiment, the rotor unit 41 is key-connected to the rotating shaft 20.

As shown in FIG5 , the second circuit board 411 is a circuit board, and the second circuit board 411 is fixedly connected to the rotating shaft 20 through a fixing member J. In this embodiment, there are four fixing members J, which are evenly welded on the circumference of the rotating shaft 20 and the four fixing members J are all located on a plane parallel to the axis of the rotating shaft 20. The fixing member J has a threaded hole, and the two ends of the flat second circuit board 411 are respectively fixed to two adjacent fixing members J by screws, and one side of the second circuit board 411 close to the circumference of the rotating shaft 20 is an arc side.

The second circuit board 411 has a rectifier circuit, which is connected to the secondary coil 323 through a wire. The rotor unit 41 rectifies the second current flowing out of the secondary coil 323 through the rectifier circuit and converts it into a DC excitation winding current, which is then input into the rotor excitation winding. The excitation winding current generates a first magnetic field in the rotor unit 41. In this embodiment, the wire routing is achieved by bonding and fixing it in the first through slot 21 as shown in FIG. 4 and bonding and fixing it on the surface of the secondary iron core 321.

The third circuit board 412 has a current detection circuit, and the third circuit board 412 is fixedly connected to the rotating shaft 20 through a fixing member J. The current detection circuit on the rotor unit 41 is used to detect the current of the excitation winding and generate a corresponding digital signal, and then the current detection circuit sends the digital signal to the first signal terminal 322 electrically connected thereto. In this embodiment, the current detection circuit is connected to the first signal terminal 322 through a wire, and the wire routing is achieved by bonding and fixing in the first through slot 21 and bonding and fixing on the surface of the secondary side iron core 321.

The first signal terminal 322 of the secondary side unit 32 transmits the digital signal received from the current detection circuit to the primary side unit 31 in a non-contact manner in any one of the forms of radio signals, infrared signals, ultrasonic signals or optical signals. In this embodiment, the first signal terminal 322 transmits the digital signal to the primary side unit 31 in the form of infrared signals.

The multiple second signal terminals 314 are used to receive the digital signal sent by the first signal terminal 322 and transmit it to the control component 50. This one-to-many setting of the first signal terminal 322 and the second signal terminal 314 greatly improves the real-time performance of digital signal transmission.

The stator unit 42 is fixedly connected to the housing 10, and a second air gap exists between the stator unit 42 and the rotor unit 41. In this embodiment, the stator unit 42 is fixedly connected to the housing 10 by screws.

The stator unit 42 includes a stator winding. An alternating current is supplied to the stator winding from outside to apply a stator winding current to the stator unit 42 . The stator winding current and the first magnetic field act together to enable the rotor unit 41 to drive the rotating shaft 20 to rotate.

The control component 50 is located outside the housing 10 and is electrically connected to the primary coil 313. The control component 50 includes a first circuit board (not shown in the drawings). The first current board (not shown in the drawings) has an inverter circuit and a microprocessor.

The inverter circuit is electrically connected to the primary coil 313, and the external direct current forms a first current through the inverter circuit and flows into the primary coil 313. The first current is a high-frequency alternating current with a frequency of 1KHz-10MHz. In this embodiment, the inverter circuit of the first circuit board (not shown in the drawings) is connected to the primary coil 313 through a wire.

Since the first current passed through the primary coil 313 can generate a high-frequency magnetic field, the higher the frequency of the magnetic field, the smaller the required magnetic flux and magnetic flux will become under the conditions of generating the same induced electromotive force and transmitting the same power, thereby reducing the volume of the rotatable transformer part 30 and its electromagnetic loss. At the same time, the high-frequency first current also means that the lag time of the first current control cycle is short, so that the first current can be controlled in a short time. In this embodiment: the frequency of the first current is preferably 100KHz.

The microprocessor is electrically connected to the second signal terminal 314, and the second signal terminal 314 receives a digital signal transmitted from the first signal terminal 322, which represents the magnitude of the excitation winding current. A predetermined target excitation current value is set in the microprocessor. The microprocessor compares the digital signal transmitted by the second signal terminal 314 with the predetermined target excitation current value, and adjusts the excitation winding current according to the comparison result to change the rotation rate of the rotating shaft 20. Specifically, when the digital signal is equal to the target excitation current value, the first magnetic field generated by the corresponding excitation winding current causes the rotor unit 41 to generate a target electromagnetic torque under the stator winding current, and drives the load to rotate at a predetermined rate through the rotating shaft 20; when the digital signal is not equal to the target excitation current value, the microprocessor adjusts the excitation winding current according to their comparison results until the digital signal is equal to the predetermined target excitation current value, thereby causing the motor to operate at a predetermined torque and speed. In actual application scenarios, multiple target excitation current values can be set in the microprocessor. In this embodiment, the microprocessor is connected to the second signal terminal 314 through a wire.

The microprocessor adjusts the excitation winding current by changing the first current to adjust the excitation winding current. Changing the first current specifically involves controlling the on-time of the switch tube of the inverter circuit, adjusting the duty cycle, and thus changing the value of the first current. The inverter circuit is shown in FIG7 , wherein Q1, Q2, Q3 and Q4 are switch tubes, Vg1, Vg2, Vg3 and Vg4 are gate terminals of the switch tubes Q1, Q2, Q3 and Q4 respectively, _I1 is a first current, and adjusting the on-time of the switch tube refers to applying levels of different durations to the gate terminals Vg1, Vg2, Vg3 and Vg4 of Q1, Q2, Q3 and Q4, that is, when a high level is applied to Vg1 and Vg4 at the same time and Vg2 and Vg3 are turned off at the same time, _I1 flows forward, and its flow direction is consistent with the marked flow direction of _I1 in the figure; when a high level is applied to Vg2 and Vg3 at the same time and Vg1 and Vg4 are turned off at the same time, _I1 flows negatively, and its flow direction is opposite to the marked flow direction of _I1 in the figure. The purpose of changing the amplitude of I ₁ is achieved by changing the duration ratio of the positive flow and the negative flow of I _1. When the first current I ₁ changes, the second current and the excitation winding current also change accordingly, thereby changing the rotation speed of the rotating shaft 20, thereby expanding the maximum speed of the motor.

<Example 2>

The other structures of this embodiment are the same as those of the first embodiment, except that the method of adjusting the excitation winding current is to directly adjust the excitation winding current. Accordingly, this embodiment has a chopper control circuit and an auxiliary control microprocessor more than the first embodiment, and the functions of the first signal terminal 322 and the second signal terminal 314 of this embodiment are different from those of the first embodiment.

The chopper control circuit is located on the second circuit board 411 and is coupled to the rectifier circuit. The second current flows out of the rectifier circuit and is adjusted by the chopper control circuit to form an excitation winding current that flows out of the second circuit board 411.

The auxiliary control microprocessor is located on the second circuit board 411 and is electrically connected to the first signal terminal 322 and the current detection circuit. In this embodiment, the first signal terminal 322 is an infrared receiver.

The second signal terminal 314 is electrically connected to the control component 40 and is used to transmit the target digital signal representing the predetermined target excitation current value set by the control component 40 to the first signal terminal 322 in a non-contact manner. In this embodiment, the second signal terminal 322 is an infrared transmitter.

The first signal terminal 322 is used to receive the target digital signal. The auxiliary control component compares the target digital signal received by the first signal terminal 322 with the digital signal generated by the current detection circuit, and adjusts the excitation winding current according to the comparison result to change the rotation rate of the rotating shaft 20. The digital signal represents the current intensity value of the excitation winding current. Specifically, when the digital signal is equal to the target digital signal, the first magnetic field generated by the corresponding excitation winding current causes the rotor unit 41 to generate a target electromagnetic torque under the stator winding current, and drives the load to rotate at a predetermined rate through the rotating shaft 20; when the digital signal is not equal to the target digital signal, the auxiliary control component adjusts the excitation winding current according to their comparison results until the digital signal is equal to the target digital signal, thereby allowing the motor to operate efficiently according to the required torque and speed. In actual application scenarios, multiple target excitation current values can be set in the auxiliary control component.

The auxiliary control microprocessor adjusts the excitation winding current by adjusting the on-time of the switch tube in the chopper circuit, adjusting the duty cycle and thus changing the value of the excitation winding current. The rectifier circuit coupled chopper control circuit is shown in FIG8 , wherein Q13 is the switch tube, V13 is the gate of Q13, _I2 is the second current, and _I3 is the excitation winding current. Adjusting the on-time of the switch tube refers to applying different duration levels to the gate V13 of Q13. When a high level is applied to V13, the value of _I3 is zero; when V13 is turned off, _I3 flows forward, and its flow direction is consistent with the marked flow direction of _I3 in the figure. By changing the time ratio of _I3 being present or not, the purpose of changing the amplitude of _I3 is achieved. The excitation winding current _I3 changes so that the rotation speed of the rotating shaft 20 changes, thereby expanding the maximum speed of the motor.

<Example 3>

The other structures of this embodiment are the same as those of the first embodiment, except that the current detection circuit, the first signal terminal 322 and the second signal terminal 314 are removed. A current feedback circuit is added to the first current board (not shown in the drawings) of the control component 50, and the current feedback circuit is coupled to the inverter circuit and electrically connected to the control component 50.

According to the transformer current ampere-turn balance formula,

N ₁ ×I ₁ =N ₂ ×I ₂ (Transformer current ampere-turn balance formula)

Wherein, _N1 is the first number of turns, _N2 is the second number of turns, _I1 is the first current, and _I2 is the second current.

The second current value can be obtained according to the first current value, and because the excitation winding current value is equal in magnitude to the second current value.

The current feedback circuit operates on the input first current to output a feedback signal representing the excitation winding current value. The current feedback circuit then transmits the feedback signal to the control component 50 for comparison with the target excitation current value so as to control the excitation winding current value accordingly, thereby changing the rotation speed of the rotating shaft 20 and expanding the maximum speed of the motor.

<Example 4>

The other structures of this embodiment are the same as those of the first embodiment, except that the first signal terminals 322 and the second signal terminals 314 are disposed at different positions, and the number of the second signal terminals 314 is also different.

As shown in FIG9 , the number of the first signal terminal 322 is one, which is arranged at the center of the end face of one end of the rotating shaft 20 located in the housing 10. In this embodiment, a pit structure is arranged at the center of the end face of one end of the rotating shaft 20 located in the housing 10, and the first signal terminal 322 is fixed in the pit by a screw. The current detection circuit is connected to the first signal terminal 322 through a wire, and the wire is bonded and fixed in the first through slot 21 and passes through the secondary side iron core 321 to connect the current detection circuit and the first signal terminal 322.

The number of the second signal terminal 314 is one, which is fixedly disposed on the inner wall of the housing 10 and is opposite to the first signal terminal 322. In this embodiment, the second signal terminal 314 is fixed to the housing 10 by screws.

Functions and Effects of the Embodiments

The high-frequency induction wireless feeding electric excitation synchronous motor involved in this embodiment includes a housing, a rotating shaft, a rotatable transformer, a motor body, and a control component, wherein the rotatable transformer and the motor body are respectively located at both ends of the rotating shaft. The rotatable transformer includes a primary side unit and a secondary side unit, the motor body includes a rotor unit and a stator unit, and the control component is electrically connected to the primary side unit. Because the rotor of the high-frequency induction wireless feeding electric excitation synchronous motor of this embodiment does not use permanent magnetic materials, and adopts a non-contact wireless feeding method to eliminate brushes and slip rings, compared with permanent magnet synchronous motors, the air gap magnetic field of the wireless feeding electric excitation synchronous motor can be adjusted, and it is not necessary to adopt weak magnetic control that reduces the efficiency of the motor, so that its maximum operating speed can be increased. In addition, the efficiency of the wireless feeding electric excitation synchronous motor and its driver is greatly improved during high-speed operation, and the speed control in all operable areas is more flexible, making it easier to achieve high-efficiency operation in all operating areas; and because the synchronous motor of this embodiment adopts brushless excitation, the synchronous motor has the advantages of high reliability, simple maintenance, no maintenance, low manufacturing cost, and no arc sparks, and can be extended to various occasions requiring flameproof and explosion-proof, and the excitation winding current of the rotor unit is controllable, so that the motor has a wider speed regulation range. The above characteristics enable this embodiment to be applied to drive or power generation systems and many occasions requiring high performance and high reliability motor systems such as aircraft AC power supply equipment and industrial robots.

The above-mentioned embodiments are preferred examples of the present invention and are not intended to limit the protection scope of the present invention.

Claims (4)

1. A high-frequency induction wireless feeding electric excitation synchronous motor, characterized in that it comprises: The outer shell is a hollow shell; A rotating shaft, one end of which is located inside the shell and rotatably connected to the shell, and the other end of which is located outside the shell; A rotatable transformer part is located inside the housing part, the rotatable transformer part is a sleeve-type structure, including a primary side unit and a secondary side unit coaxially arranged, the primary side unit connected to the housing part includes a primary side coil, and the secondary side unit connected to the rotating shaft includes a secondary side coil; A motor body, located inside the housing, the motor body includes a rotor unit and a stator unit, the stator unit is connected to the housing, the rotor unit is connected to the rotating shaft, the rotor unit is electrically connected to the secondary coil, and the rotor unit includes a rotor excitation winding; and a control assembly electrically connected to the primary side coil, The primary side unit and the secondary side unit are both cylindrical, the secondary side unit is located inside the primary side unit, and there is a first air gap between the secondary side unit and the primary side unit. applying a stator winding current to the stator unit, A first current is introduced into the primary coil through the control component so that a second current is generated in the secondary coil. The rotor unit converts the second current into an excitation winding current. The excitation winding current causes the rotor unit to generate a first magnetic field. The first magnetic field and the stator winding current act together to cause the rotor unit to drive the rotating shaft to rotate. The rotor unit generates a corresponding digital signal according to the excitation winding current. The digital signal is transmitted to the primary unit through the secondary unit. The primary unit then transmits the digital signal to the control component. The control component compares the digital signal with a predetermined target excitation current value and adjusts the first current according to the comparison result, thereby changing the excitation winding current so that the rotation speed of the rotating shaft changes. The control component includes an inverter circuit, which is electrically connected to the primary side coil. External direct current passes through the inverter circuit to form the first current, and the frequency of the first current is 1KHz-10MHz. The setting range of the first air gap is 0.1mm-2mm. The rotor unit includes a rectifier circuit and a current detection circuit, the second current passes through the rectifier circuit to form the excitation winding current, and the current detection circuit detects the excitation winding current and generates the corresponding digital signal. The secondary-side unit includes a first signal terminal, and the digital signal is transmitted to the primary-side unit through the first signal terminal. 2. The high-frequency induction wireless feeding electric excitation synchronous motor according to claim 1 is characterized in that: The primary side unit comprises a cylindrical primary side core, which is formed by pinning two symmetrical core splicing circular rings, and circular coil grooves are arranged on the joint surface of the core splicing circular rings along the circumference of the joint surface. 3. The high-frequency induction wireless feeding electric excitation synchronous motor according to claim 1 is characterized in that: Wherein, the primary side unit includes a second signal terminal, and the second signal terminal receives the digital signal. 4. The high-frequency induction wireless feeding electric excitation synchronous motor according to claim 1, characterized in that: Wherein, the control component adjusts the excitation winding current by changing the first current.