KR101767002B1 - Wound rotor synchronous motor and operating method thereof - Google Patents

Abstract

A wound rotor synchronous motor is provided. The wound rotor synchronous motor includes a stator where stator windings arranged in a circumferential direction are disposed; a rotor which rotates about the stator and includes a harmonic winding and a field winding; a current supply part for supplying at least one sinusoidal current to the stator winding. The sinusoidal current may have a value close to zero and comprise a first current that excites the harmonic winding and a second current that interacts with the flux of the field winding to generate the rotational force of the rotor. It is possible to form a harmonic field.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous motor,

The present invention relates to a method of driving a wire wound type synchronous motor and a wire wound type synchronous motor, and more particularly, to a wire wound type synchronous motor and a wire wound type synchronous motor which form a harmonic field through a current of a sine wave, As shown in FIG.

A synchronous motor (SM) is an electric motor in which a rotor can rotate at a constant speed in synchronism with a rotation field of a stator. The rotor of the synchronous motor is advantageous in that it can maintain a constant rotation speed even in a variable voltage environment.

These synchronous motors include a permanent magnet synchronous motor (PMSM) and a wound rotor synchronous motor (WRSM).

Permanent magnet synchronous motors can use permanent magnets to generate rotor flux. Permanent magnet synchronous motors are capable of providing a fixed speed in synchronism with the frequency of the power source in spite of charge or voltage fluctuations and are widely used in a variety of industrial and residential applications due to their high efficiency and high torque density performance . In particular, permanent magnet synchronous motors may be useful in that they can provide a fixed speed in synchronization with the main frequency within the limits allowed by the design specifications of the motor. However, rare-earth magnets have a limited application because they are expensive.

On the other hand, the winding synchronous motor has advantages in terms of cost because it does not use a permanent magnet unlike a permanent magnet motor. These wound synchronous motors use field windings instead of permanent magnets in the rotor, where field windings are fed with DC current to create rotor flux.

However, since a field winding of a rotor receives a current, a brush or a slip-ring must be used. Therefore, the winding-type synchronous motor generates frictional losses and difficulties in repairing the same. do.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a wire wound type synchronous motor which does not use a brush and a slip ring.

It is another object of the present invention to provide a winding synchronous motor driven by a single inverter.

The technical problem to be solved by the present invention is not limited to the above.

A wired synchronous motor according to an embodiment of the present invention includes a stator in which stator windings arranged in a circumferential direction are arranged, a rotor rotating about the stator, including a harmonic winding and a field winding, and at least one Wherein the sinusoidal current has a magnitude close to zero and interacts with a magnetic flux of the field winding to generate a first current that excites the harmonic winding, And a second current that generates a rotational force of the motor.

According to one embodiment, the current supply may include a first switch and a second switch arranged in parallel with the stator winding.

According to an embodiment, the first switch and the second switch may be made of a thyristor, and the first and second switches may be anti-parallel to each other.

According to an embodiment, when the magnitude of the sinusoidal current has a positive value, the first switch is turned off to generate the second current, and when the second switch is turned on, State, the first current can be generated.

According to an embodiment, when the magnitude of the sinusoidal current has a negative value, the second switch is turned off so that the second current is generated, and when the second switch is turned on, State, the first current can be generated.

According to one embodiment, the magnitude of the current of the first current over time may be a triangular shape having one side on the time axis.

According to an embodiment, the frequency of the first current may be higher than the frequency of the second current.

According to one embodiment, the number of poles for forming the stator windings may be equal to the number of poles for forming the field windings.

A method of driving a wire wound type synchronous motor according to an embodiment of the present invention includes the steps of supplying a stator winding of a stator with a first current having a magnitude close to zero of a magnitude of a sine wave current, Wherein the harmonic winding of the rotor is excited by a harmonic field to be formed, a current generated by the excited harmonic winding is supplied to a field winding of the rotor, a magnetic flux generated by the field winding, And rotating the rotor with respect to the stator by interaction of a rotating magnetic flux generated by a second current other than a first current of the current.

According to one embodiment, the magnitude of the current of the first current over time may be a triangular shape having one side on the time axis.

A wired synchronous motor according to an embodiment of the present invention includes a stator in which stator windings arranged in a circumferential direction are arranged, a rotor rotating about the stator, including a harmonic winding and a field winding, and at least one Wherein the sinusoidal current has a magnitude close to zero and interacts with a magnetic flux of the field winding to generate a first current that excites the harmonic winding, And a second current that generates a rotational force of the motor.

The first current and the second current are generated by dividing the sinusoidal current. It is needless to say that an additional inverter is not necessary, and the harmonic winding is excited by the stator winding, thereby providing the effect of driving by brushless operation.

1 is a view for explaining a wire wound type synchronous motor according to an embodiment of the present invention.
2 is a view for explaining current application of a wire wound type synchronous motor according to an embodiment of the present invention.
3 is a diagram illustrating a waveform for generating a rotation field according to an embodiment of the present invention.
4 is a view showing a waveform for exciting a harmonic winding according to an embodiment of the present invention.
5 is a view for explaining a method of driving a wire wound type synchronous motor according to an embodiment of the present invention.
6 to 10 are graphs showing performance test results of a wire wound type synchronous motor according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical spirit of the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In this specification, when an element is referred to as being on another element, it may be directly formed on another element, or a third element may be interposed therebetween. Also, in the drawings, the shapes and thicknesses of the structures are exaggerated for an effective description of the technical content.

Also, while the terms first, second, third, etc. in the various embodiments of the present disclosure are used to describe various components, these components should not be limited by these terms. These terms have only been used to distinguish one component from another. Thus, what is referred to as a first component in any one embodiment may be referred to as a second component in another embodiment. Each embodiment described and exemplified herein also includes its complementary embodiment. Also, in this specification, 'and / or' are used to include at least one of the front and rear components.

The singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It is also to be understood that the terms such as " comprises "or" having "are intended to specify the presence of stated features, integers, Should not be understood to exclude the presence or addition of one or more other elements, elements, or combinations thereof. Also, in this specification, the term "connection " is used to include both indirectly connecting and directly connecting a plurality of components.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a view for explaining a wire wound type synchronous motor according to an embodiment of the present invention.

1, a wire wound type synchronous motor 100 according to an embodiment of the present invention includes a stator 110, a stator winding 112, a rotor 120, a harmonic winding 122, And a field winding (124). Each configuration will be described in detail below.

The stator 110 may be provided at one side of the rotor 120, for example, at a radially outer side, and may provide a rotational force to the rotor 120. For this purpose, the stator 110 may be formed in a cylindrical shape including a hollow inside, and the rotor 120 may be rotated in a state of being drawn into the hollow of the stator 110.

The stator 110 may be made of a material having excellent magnetic flux path characteristics and high mechanical strength, for example, silicon and steel.

The stator 110 may include a stator winding 112 for generating a magnetic flux to provide a rotational force to the rotor 120. The stator windings 112 may be arranged along the circumferential direction of the stator 110. More specifically, a plurality of teeth are arranged along the circumferential direction of the stator 110, and the stator windings 112 may be formed on a plurality of teeth provided along the circumferential direction of the stator 110.

The current applied to the stator winding 112 may be a plurality of phases. According to one embodiment, the stator winding 112 may be supplied with a current of three phases. Accordingly, as shown in FIG. 1, the stator winding 112 may be divided into a winding to which the A-phase is applied, a winding to which the B-phase is applied, and a winding to which the C-phase is to be applied.

The stator winding 112 may form a field corresponding to the applied current. Specifically, the stator winding 112 may generate a harmonic field for exciting the rotor corresponding to the applied current and a rotation field for rotating the rotor. Details of the harmonic field and the rotation field will be described later.

The rotor 120 is provided on one side of the stator 110 and may be rotated with respect to the stator 110 by receiving a magnetic flux from the stator 110. For this purpose, the rotor 120 may be made of a material having excellent magnetic flux path characteristics and high mechanical strength, for example, silicon and steel.

The rotor 120 may include at least one of a harmonic winding 122, a field winding 124, and a rectifier 126 (see FIG. 2).

The harmonic winding 122 and the field winding 124 may be arranged along the circumferential direction of the rotor 120. Specifically, values are provided along the circumferential direction of the rotor 120, and the harmonic windings 122 and the field windings 124 may be formed on the teeth, respectively.

The harmonic windings 122 may be excited by the harmonic field generated by the stator windings 110 to generate a current.

The field winding 124 can generate a magnetic flux by receiving and converting the current generated by the harmonic winding 122. The magnetic flux generated by the field winding 124 interacts with the rotation field generated by the stator winding 112, so that the rotor 120 has a rotational force.

According to one embodiment, the number of poles for forming the stator winding 120 may be equal to the number of poles for forming the field winding 124. As shown in FIG. 1, there are four pawls for forming the stator windings 120, and the number of poles for forming the field windings 124 may be equal to each other.

According to one embodiment, the field winding 124 may be positioned radially inward of the rotor 120 relative to the harmonic winding 122.

1 is a block diagram of a wire wound type synchronous motor according to an embodiment of the present invention. Hereinafter, current application of a wire wound type synchronous motor according to an embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a view for explaining a current application of a wire wound type synchronous motor according to an embodiment of the present invention. FIG. 3 is a diagram showing a waveform for generating a rotation field according to an embodiment of the present invention, 1 is a diagram showing a waveform for exciting a harmonic winding according to an embodiment of the present invention.

A current supply for applying at least one sinusoidal wave to the stator winding 112 may be provided. Referring to FIG. 2, the current supply unit may include an inverter 130, a first switch 132, and a second switch 134.

The inverter 130 may apply a current to the stator winding 112. A three-phase sinusoidal wave consisting of Ia, Ib, and Ic can be applied to the stator winding 112. The sinusoids Ia, Ib, and Ic of the three phases can be defined by the following equations so that the magnitude of the current is the same and the phase difference is 60 degrees.

Ia = I sin we * t

Ib = I sin (we * t - (2? / 3) t)

Ic = I sin (we * t + (2? / 3) t)

The first and second switches 132 and 134 may be connected in parallel with the stator winding 112. More specifically, the first and second switches 132 and 134 may be formed of a thyristor. Also, the first and second switches 132 and 134 may be anti-parallel to each other.

The first and second switches 132 and 134 are connected to the stator winding 112 through an on / off operation. The first and second switches 132 and 134 have a magnitude close to zero and excite the harmonic winding 122, It is possible to apply a second current that generates a rotational force by interacting with the magnetic flux of the winding 124.

Referring to FIG. 4, the first current may be a partial current for a predetermined time in the vicinity of a sine wave current of zero in a sinusoidal current. More specifically, the first current may have a positive value in a region where the slope of the sinusoidal wave is negative, and a negative value in a region where the slope of the sinusoidal wave is positive. Also, the magnitude of the current according to the time of the first current may be a substantially triangular shape having one side on the time axis.

The substantial triangular shape includes not only a case where one side of a triangle is straight but also a case where it is a gentle curve, and the term triangle in the present specification can be understood as a concept including a substantial triangle.

The second current may be a sinusoidal current other than the first current. Referring to FIG. 3, the current may be obtained by subtracting the first current described with reference to FIG. 4 from a full sinusoidal wave.

The first and second switches 132 and 134 can be turned on / off to generate a first current and a second current, and more specifically, whether a positive sinusoidal wave or a negative sinusoidal wave is supplied And can operate accordingly.

For example, when a sinusoidal current having a positive magnitude is applied, the first switch 132 is driven in an off state so that the second current can be generated. Alternatively, by driving the first switch 132 to the on state, a first current can be generated.

Also, for example, when a sinusoidal current whose magnitude is a negative value is applied, the second switch 134 is driven in the off state, so that a second current can be generated, The first current can be generated.

Hereinafter, the principle of generating the rotational force when the first and second currents are applied to the stator winding 112 will be described.

When the first current is applied to the stator winding 112, the stator winding 112 may generate a harmonic field. The generated harmonic field may excite the harmonic winding 122 of the rotor 120. The generated current as the harmonic winding 122 is excited can be applied to the field winding 124 via the rectifier 126. The field winding 124 generates a magnetic flux upon receiving a current. Meanwhile, as the second current is applied to the stator winding 112, a rotation field is generated. Accordingly, the rotating field generated by the magnetic flux generated by the field winding 124 and the second current applied to the stator winding 112 interact to generate a rotational force.

According to one embodiment, the first current and the second current may have different frequencies. In particular, the frequency of the first current may be n times (n is an integer of 2 or more) times the second current frequency. For example, if the frequency of the second current is 60 Hz, the frequency of the first current may be 180 Hz. That is, the harmonic winding 122 is excited by a current having a frequency of 180 Hz, and the rotor 120 can be supplied with a rotational force at a frequency of 60 Hz.

1 to 4, a winding type synchronous motor according to an embodiment of the present invention has been described. Hereinafter, a method of driving a wire wound type synchronous motor according to an embodiment of the present invention will be described with reference to FIG.

5 is a view for explaining a method of driving a wire wound type synchronous motor according to an embodiment of the present invention. It is a matter of course that the driving method of the wire wound type synchronous motor according to the embodiment of the present invention can be implemented by the above-described wire type synchronous electric motor.

Referring to FIG. 5, the stator winding 112 of the stator 110 may be supplied with a first current having a magnitude of a current of a sine-wave current near zero (S100).

For step S100, the inverter 130 may provide a current consisting of at least one sinusoidal wave. At this time, when the supplied sinusoidal wave has a positive value, the first switch 132 is driven in the on state, thereby generating the first current, and when the supplied sinusoidal wave has a negative value In this case, the second switch 134 is turned on, so that a first current can be generated.

Accordingly. The stator winding 112 may generate a harmonic field by a first current.

The harmonic winding 122 of the rotor 120 may be excited by the harmonic field generated by the first current (S110).

The current generated by the excited harmonic winding 122 may be supplied to the field winding 124 of the rotor 120 (S120).

For example, the current generated by the excited harmonic winding 122 may be provided to the field winding 124 through the rectifier 126 and rectified.

The rotor 120 can be rotated relative to the stator 110 by the interaction of the magnetic flux generated by the field winding and the rotating magnetic flux generated by the second current other than the first current of the full sinusoidal current (S130).

The winding synchronous motor according to the embodiment of the present invention has been described with reference to FIG. Hereinafter, the performance test results of the wire wound type synchronous motor according to the embodiment of the present invention will be described with reference to FIGS. 6 to 10. FIG.

6 to 10 are graphs showing performance test results of a wire wound type synchronous motor according to an embodiment of the present invention.

For the performance test, the winding type synchronous motor described with reference to Fig. 1 was prepared so as to have the specifications of Table 1 below.

parameter value unit Stator Outer Diameter 130 mm Stator inner Diameter 80 mm Rotor Outer Diameter 79 mm Reference Speed 1800 rpm Rated Frequency 60 Hz Turns of stator winding 270 Turns of harmonic winding 15 Turns of field winding 150 Stack length 120 Air gap length 0.5 The number of harmonic winding poles 12 The number of field winding poles 4 The number of stator winding poles 4

Referring to FIG. 6, the steady state of the static pressure excited in the harmonic winding by the first current applied to the stator winding is shown, and the peak voltage is confirmed to be about 7 volts. Referring to FIG. 7, the steady state of the current excited in the harmonic winding by the first current applied to the stator winding is shown, and the peak current is confirmed to be about 15 amperes.

8, there is shown a steady-state voltage when the current generated by the harmonic winding is rectified and provided as a field winding. Referring to FIG. 9, when the current generated by the harmonic winding is rectified and provided as a field winding Lt; / RTI > Referring to FIG. 9, the peak current was found to be 14 amperes.

Referring to FIG. 10, FIG. 10 shows the torque in steady state, with an average torque of 20 Nm and a torque ripple of 45%.

The performance test results of the wire wound type synchronous motor according to the embodiment of the present invention have been described with reference to FIGS. 6 to 10. FIG.

The winding synchronous motor according to an embodiment of the present invention may generate a first current to generate a harmonic field and a second current to generate a rotation field by dividing a sinusoidal wave applied to the stator winding in a temporal manner.

Alternatively, a conventional wire wound type synchronous motor may use a brush or a slip ring to generate a harmonic field, use two or more inverters to apply two different kinds of electric signals to a stator winding, Physically divided into two groups of stator windings, each of the two groups generated a harmonic field and a rotation field. In such a case, efficiency deterioration due to the brush or slip ring can not be avoided, problems due to the inverter price, and a problem that power is dispersed have occurred.

However, the winding synchronous motor according to an embodiment of the present invention generates a first current to generate a harmonic field and a second current to generate a rotation field in a full sinusoidal wave, wherein the first current is a sinusoidal wave having a magnitude of 0 So that the problem of the prior art can be solved. That is, the winding type synchronous motor according to an embodiment of the present invention does not use a brush or a slip ring, and can operate with a single inverter, and the problem of power dispersion can be solved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments. It will also be appreciated that many modifications and variations will be apparent to those skilled in the art without departing from the scope of the invention.

100: Cyclic synchronous motor
110: stator
112: stator winding
120: rotor
122: Harmonic winding
124: Field winding

Claims (10)

A stator in which stator windings arranged in the circumferential direction are disposed;
A rotor rotating relative to the stator, the rotor comprising a harmonic winding and a field winding; And
And a current supply unit for supplying at least one sinusoidal current to the stator winding,
Wherein the sinusoidal current comprises a first current that excites the harmonic winding and a current that is temporally separated from the first current and excludes the first current at the sinusoidal current and that interacts with the magnetic flux of the field winding, And a second current for generating a rotational force of the rotor. The method according to claim 1,
And the current supply section includes a first switch and a second switch arranged in parallel with the stator winding. 3. The method of claim 2,
Wherein the first switch and the second switch are made of a thyristor, and the first and second switches are anti-parallel to each other in opposite directions. 3. The method of claim 2,
Wherein when the magnitude of the sinusoidal current has a positive value, the first switch is turned off to generate the second current, and when the first switch is turned on, And a first current is generated. 3. The method of claim 2,
When the magnitude of the sinusoidal current has a negative value, the second current is generated by driving the second switch in an off state, and the second switch is turned on, And a first current is generated. The method according to claim 1,
Wherein the magnitude of the current according to the time of the first current is a triangular shape having one side of the time axis. The method according to claim 1,
Wherein the frequency of the first current is higher than the frequency of the second current. The method according to claim 1,
Wherein the first current has a positive value in a region where the slope of the sinusoidal current is negative and has a negative value in a region where the slope of the sinusoidal current is positive. Supplying a first current consisting of a partial current of a sinusoidal current to a stator winding of the stator;
Exciting a harmonic winding of the rotor by a harmonic field formed by the first current;
Supplying a current generated by the excited harmonic winding to a field winding of the rotor; And
The rotor rotates with respect to the stator by the interaction of the rotating magnetic flux generated by the second current excluding the first current of the sinusoidal current and the magnetic flux generated by the field winding, And a step of driving the synchronous motor. 10. The method of claim 9,
Wherein the magnitude of the current according to the time of the first current is a triangular shape having one side on the time axis.

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