WO2018079967A1

WO2018079967A1 - Variable inductor device for power conversion

Info

Publication number: WO2018079967A1
Application number: PCT/KR2017/005808
Authority: WO
Inventors: 박종후
Original assignee: 숭실대학교 산학협력단
Priority date: 2016-10-24
Filing date: 2017-06-02
Publication date: 2018-05-03
Also published as: KR20180044616A

Abstract

The present invention relates to a variable inductor device for power conversion. The present invention provides a variable inductor device for power conversion, the variable inductor device comprising: a magnetic core; an inductor coil which is disposed in a power converter while being wound around the magnetic core and being moveable along a lengthwise direction of the magnetic core with reference to the location of the magnetic core; a controller for detecting a predetermined electrical parameter from the inductor coil or the power converter and then generating displacement information required for following an input target parameter, by using an error between the detected parameter and the target parameter; and an actuator for changing the location of the inductor coil on the basis of the displacement information fed back from the controller. According to the present invention, during variable control of inductance, the location of the coil instead of the magnetic core may be moved to minimize power consumption of the actuator and to optimize system performance, and a control value for following a desired parameter may be fed back to the actuator to automatically control the movement location of the coil and the inductance resulting therefrom.

Description

Variable Inductor Device for Power Conversion

The present invention relates to a variable inductor device for power conversion, and more particularly, to a variable inductor device for power conversion capable of variable control of inductance.

In general, an inductor is a coil that induces a voltage in proportion to the amount of change in current. Inductance is a property that disturbs the flow of current due to a change in the magnetic field occurring in or around the coil.

Inductors used in power conversion circuits such as DC-DC converters, DC-AC inverters, etc. mainly have a function of current smoothing, current suppression, energy storage, and high frequency removal of voltage and current due to semiconductor switching elements. . Most inductors used in power conversion circuits have a fixed inductance value. As a result, due to changes in the surrounding environment or the circuit, it cannot properly respond to the newly required inductance value.

As an alternative, a variable inductor can be used. The variable inductor mainly has a structure including a coil and a core. Conventional variable inductors change the position of the core or generate additional magnetic force in the core to vary the inductance value using the magnetic saturation of the coil.

However, the method of moving the core has a disadvantage in that the power consumption of the driving actuator required for the movement of the core is large because the weight of the core is heavy, and in the case of using an additional magnetic force, energy loss caused by magnetic saturation is caused. have.

Background art of the present invention is disclosed in US Patent No. 05999077 (published on December 7, 1999).

It is an object of the present invention to provide a variable inductor device for power conversion that can minimize power consumption and optimize system performance by varying the position of the inductor coil relative to the magnetic core.

The present invention is a magnetic core, a coil wound around the magnetic core is disposed in a power converter (Power Converter), the inductor coil movable along the longitudinal direction of the magnetic core relative to the position of the magnetic core to enable inductance variable And a controller for detecting a predetermined electrical parameter from the inductor coil or the power converter and generating displacement information required for following the target parameter by using an error between the detected parameter and the input target parameter. Provided is a variable inductor device for power conversion including an actuator for varying the position of the inductor coil based on the feedback of the displacement information.

Here, the electrical parameter may include at least one of voltage, current, and phase detected from the inductor coil or the power converter.

In addition, the magnetic core may be implemented in a rod shape having a straight longitudinal direction. Here, the inductor coil may be wound in whole or in part with respect to the length direction of the magnetic core.

In addition, the magnetic core may be implemented in a circular arc shape having a curved longitudinal direction and a gap between both ends. Here, the inductor coil may be wound around a portion of the magnetic core in the longitudinal direction.

In addition, the inductor coil may be detached toward one side of the magnetic medium outside the one end of the magnetic core during the movement, the inductance may vary depending on the degree of departure.

In addition, the magnetic core includes a first core and a second core forming a circular, polygonal, or straight length direction as both ends or one end thereof contact each other, and the first and second cores respectively have permeability. It may be formed of different materials. Here, the inductor coil may be wound around a portion of the magnetic core in the longitudinal direction.

In addition, the inductor coil may have one end portion separated from the first core toward the second core or from the second core toward the first core during the movement, and the inductance may vary according to the degree of departure. Can be.

According to the variable inductor device for power conversion according to the present invention, by moving the position of the coil instead of the magnetic core in the variable control of the inductance, it is possible to minimize the power consumption of the actuator, optimize the performance of the system, and follow the desired parameters By feeding back a control value from the controller to the actuator, there is an advantage in that it is possible to automatically control the moving position of the coil and the variable inductance accordingly.

1 is a view showing a variable inductor device for power conversion according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a state in which an inductor coil moves with reference to a magnetic core in FIG. 1.

3 is a view showing another form of the inductor coil shown in FIG.

4 and 5 are diagrams showing another form of the magnetic core applicable to the embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable inductor device for power conversion, and in implementing a variable inductor in a power converter, driving power of an actuator as the inductance is controlled by changing the position of the winding instead of the position of the core. In this paper, we propose a technique that can easily change the inductance by automatically controlling the position of the winding using a negative feedback controller.

1 is a view showing a variable inductor device for power conversion according to an embodiment of the present invention. Referring to FIG. 1, the variable inductor device 100 includes a magnetic core 110, an inductor coil 120, a controller 130, and an actuator 140.

The magnetic core 110 is wound around the inductor coil 120. The magnetic core 110 may be a variety of known materials used in the inductor device.

The inductor coil 120 is disposed on an outer surface of the magnetic core 110, and has a form in which the inductor coil 120 is wound in a spring shape from one end to the other end to be continuously wound. Lead terminals may be formed at both ends of the inductor coil 120. Obviously, the inductor coil 120 may be implemented in a more compact form than that shown in FIG. 1.

The magnetic core 110 and the inductor coil 120 form one inductor element and are used as an inductor element included in the power converter 10. The power converter 10 typically requires an inductor device for various purposes, and the embodiment of the present invention implements the inductor device in the form of a variable inductor.

In the embodiment of the present invention, the inductor coil 120 has a form that can be moved in parallel along the longitudinal direction of the magnetic core 110 on the basis of the position of the magnetic core 110, through which the inductance is variable.

Here, in order to further facilitate the movement of the inductor coil 120 and reduce friction with the magnetic core 110, the inner surface of the inductor coil 120 and the outer surface of the magnetic core 110 may be implemented to be spaced apart from each other by a predetermined distance. Can be. Of course, additionally, auxiliary means (gap holding means) for maintaining the gap between each other may be further provided.

FIG. 2 is a diagram illustrating a state in which an inductor coil moves with reference to a magnetic core in FIG. 1. As shown in FIG. 2, when the inductor coil 120 moves up (or falls) with respect to the magnetic core 110, a portion of the upper (or lower) portion of the inductor coil 120 moves outside the magnetic core 110. As it exits, the inside of the part that is out of the gap is filled with the air medium instead of the core.

Here, the magnetic permeability of the magnetic core and the magnetic permeability of the air is different, as shown in Figure 2 when the position of the inductor coil 120 is changed relative to the magnetic core 110, with respect to the vertical length direction of the inductor coil 120, The proportion of the two materials with different permeability (core and air medium) will be different, resulting in variable inductance values.

Controller 130 detects certain electrical parameters from inductor coil 120 or power converter 10. The controller 130 may be directly or indirectly connected to the power converter 10 or the inductor coil 120 to detect various electrical parameters.

The electrical parameter detected by the power converter 10 or the inductor coil 120 may correspond to an element associated with an inductance value. Embodiments of the present invention may include at least one of a voltage, a current, and a phase observed in a predetermined portion of the power converter 10 or the inductor coil 120. In the case of the power converter 10, a predetermined region of interest may be set in an internal circuit to observe electrical parameters. Of course, the inductor coil 120 also corresponds to some circuit elements of the power converter 10 and the electrical parameters may be used at any point in the power converter 10.

The controller 130 calculates an error by comparing the currently detected parameter with a target parameter input from the outside, and generates displacement information required for following the target parameter using the calculated error. Here, the target parameter may include at least one of voltage, current, and phase required to obtain a predetermined inductance.

The controller 130 sets the target parameter as a reference value and causes the currently measured electrical parameters to follow the reference. The controller 130 calculates the mutual error in real time and generates displacement information for canceling the error. Here, of course, the displacement information includes distance and direction information that the inductor coil 120 should move.

The actuator 140 changes the position of the inductor coil 120 based on the displacement information fed back from the controller 130. Here, the controller 130 may continuously provide the feedback information to the actuator 140 until the error is less than the set value while continuously measuring the error value even after the position variation of the inductor coil 120. The controller 130 and the actuator 140 may be implemented outside of the power converter 10 or integrally implemented therein to form a system.

As described above, the embodiment of the present invention can ultimately control the inductance by controlling the position of the actuator 140 with a feedback controller (negative feedback controller). In addition, since the position of the coil 120 is changed instead of the core 110, the driving power of the actuator 140 may be minimized than when the heavy weight core 110 is moved.

In an embodiment of the present invention, the actuator 140 may be connected to the inductor coil 120 in a fixed or adhesive manner. In addition, the actuator 140 may be driven by a voltage source or a current source, and both magnetic and piezoelectric methods may be used.

3 is a view showing another form of the inductor coil shown in FIG. In the case of FIG. 1, the inductor coil 120 is wound around the entire length of the magnetic core 110. Of course, as shown in FIG. 3, the inductor coil 220 may be implemented to be wound around a portion of the magnetic core 210. In the case of FIG. 3 in which the inductor coil 220 is wound around a portion of the magnetic core 210, the inductance may be changed when the position of the inductor coil 220 changes within the length of the magnetic core 210, and the inductor coil may change. Inductance may change even when a portion of the 220 is out of the magnetic core 210.

Meanwhile, in the case of FIG. 1, the magnetic core 100 is implemented in a rod shape having a straight length direction, but the present invention is not limited thereto.

4 and 5 are diagrams showing another form of the magnetic core applicable to the embodiment of the present invention. In the case of Figure 4, the magnetic core is implemented in an arc shape, Figure 5 is implemented in an annular shape.

First, the magnetic core 310 shown in FIG. 4 is implemented in a circular arc shape having voids between both ends. Unlike the previous FIG. 1, the magnetic core 310 has a curved longitudinal direction. Have The inductor coil 320 is wound around a portion of the magnetic core 310 in the longitudinal direction.

Therefore, in FIG. 1, if the inductor coil 120 moves in one dimension, the inductor coil 320 may move in two dimensions along the shape of the core in FIG. 4. Of course, in the case of the present invention, it is possible to implement the shape of the magnetic core 310 in the form of three-dimensional movement of the inductor coil 320.

In FIG. 4, the inductance is changed as the inductor coil 320 moves, and the inductance may be changed even when a part of the inductor coil 320 is separated from the gap portion of the magnetic core 310.

As described above, in each of the examples shown in FIGS. 1 to 4, each inductor coil has a structure in which one end thereof is detachable toward the air medium outside one end of the magnetic core during movement, Accordingly, the inductance may vary.

Next, the magnetic core 410 illustrated in FIG. 5 has a structure including a first core 411 and a second core 412 having an arc shape. The first core 411 and the second core 412 form a circular longitudinal direction as both ends are in contact with each other. In addition, the first and

second cores

411 and 412 may be formed of materials having different permeability. The inductor coil 420 is wound around a portion of the magnetic core 410 in the longitudinal direction.

In the case of FIG. 5, the two zones are formed of materials having different permeability with respect to the longitudinal direction of the core 410 to obtain a similar effect as described above. Here, the ratio of the two zones can be the same or different.

In this structure, one end of the inductor coil 420 may move away from the first core 411 toward the second core 412 or vice versa when moved, and the inductance may vary according to the degree of departure. have.

Of course, the magnetic core 410 shown in FIG. 5 may be implemented in a polygonal shape instead of a circular shape. In the polygonal structure, the first and second cores have a structure in which both ends are in contact with each other, and each of the first and second cores may be embodied in at least one angle instead of an arc shape.

In addition, the magnetic core may be implemented in a straight line. When the ends of the rod-shaped first cores and the second cores are connected to each other, the magnetic cores may have a straight line as a whole. In this case, the first and second cores are also made of materials having different permeability.

As described above, in the embodiment of the present invention, the core may be implemented as a one-dimensional linear core, or may be implemented as a shape in which a two-dimensional or three-dimensional movement of the coil is possible. Also, in the case of an actuator, a linear or circular actuator may be used depending on the shape of the core.

In addition, embodiments of the present invention can be applied to a plurality of coils. According to the exemplary embodiment of the present invention, by changing the inductance of the inductor in the power converter, and controlling the optimum inductance according to the operating point, it is possible to minimize the size, cost and power conversion loss of the device.

In conclusion, according to the variable inductor device for power conversion according to the present invention, by moving the position of the coil instead of the magnetic core in the variable control of the inductance, it is possible to minimize the power consumption of the actuator and optimize the performance of the system, desired parameters By feeding back a control value for controlling the actuator from the controller to the actuator, there is an advantage in that it can automatically control the moving position of the coil and the variable inductance accordingly.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims

core;

An inductor coil disposed in a power converter in a form wound around the magnetic core and movable along a length direction of the magnetic core based on a position of the magnetic core to enable inductance variation;

A controller for detecting a predetermined electrical parameter from the inductor coil or the power converter and generating displacement information required for following the target parameter using an error between the detected parameter and the input target parameter; And

And an actuator configured to vary the position of the inductor coil based on the displacement information fed back from the controller.
The method according to claim 1,

The electrical parameter is,

And at least one of voltage, current, and phase detected from the inductor coil or the power converter.
The method according to claim 1,

The magnetic core,

A variable inductor device for power conversion implemented in a rod shape having a straight longitudinal direction.
The method according to claim 3,

The inductor coil,

A variable inductor device for power conversion wound around all or a portion of the magnetic core in the longitudinal direction.
The method according to claim 1,

The magnetic core,

A variable inductor device for power conversion implemented in a circular arc shape having a curved longitudinal direction and a gap between both ends.
The method according to claim 5,

The inductor coil,

A variable inductor device for power conversion wound around a portion of the magnetic core in the longitudinal direction.
The method according to claim 3 or 5,

The inductor coil,

The one end is detachable toward the air medium outside the one end of the magnetic core during the movement, the variable inductor device for power conversion in which the inductance is variable according to the degree of departure.
The method according to claim 1,

The magnetic core,

A first core and a second core that form a circular, polygonal or straight length direction as both ends or one end thereof contact each other,

The first and second cores are each variable power inductor device formed of a material having a different permeability.
The method according to claim 8,

The inductor coil,

A variable inductor device for power conversion wound around a portion of the magnetic core in the longitudinal direction.
The method according to claim 8,

The inductor coil,

The one end is detachable from the first core toward the second core or from the second core toward the first core during the movement, wherein the inductance is variable according to the degree of departure.