KR102636646B1 - Current compensation device - Google Patents

Abstract

Embodiments of the present invention relate to a current compensation device that minimizes the influence on other devices by actively compensating a first current input from one device in a common mode in various types of power systems. The current compensation device of the present invention has at least two high current paths and through openings for transmitting the second current supplied by the second device to the first device, at least two or more high current paths are inserted into the through openings, and at least two or more high current paths are inserted into the through openings. A sensing unit that detects the first current in the above large current path and generates an output signal corresponding to the first current, an amplifier unit that amplifies the output signal and generates an amplified signal, and a compensation unit that generates a compensation current based on the amplified signal. and a compensation capacitor unit that provides a path through which the compensation current flows to each of at least two high current paths.

Description

Current compensation device {CURRENT COMPENSATION DEVICE}

Embodiments of the present invention relate to a current compensation device that actively compensates for a current input in common mode on two or more high current paths connecting two devices.

In general, electrical devices such as home appliances, industrial electrical appliances, or electric vehicles emit noise during operation. For example, noise may be generated due to switching operations inside electrical devices. This noise is not only harmful to the human body, but also causes malfunction or failure of other connected electronic devices.

The electromagnetic interference that electronic devices cause to other devices is called EMI (Electromagnetic Interference), and in particular, noise transmitted via wires and board wiring is called conducted emission (CE) noise.

In order to ensure that electronic devices operate without causing malfunctions in surrounding components and other devices, the amount of EMI noise emissions from all electronic products is strictly regulated. Therefore, most electronic products necessarily include a current compensation device such as an EMI filter to reduce EMI noise in order to satisfy regulations on noise emissions.

For example, in white goods such as air conditioners, electric vehicles, aviation, energy storage systems (ESS), etc., a current compensation device is essential. A conventional current compensation device uses a common mode choke (CM choke) to reduce common mode (CM) noise among conducted emission (CE) noise.

Meanwhile, as high-power products are released, the needs for current compensation devices for high-power systems are increasing. However, in high-power/high-current systems, the noise reduction performance of common mode (CM) chokes rapidly deteriorates due to magnetic saturation. Therefore, in order to prevent magnetic saturation and maintain noise reduction performance in high-power/high-current systems, conventionally it is necessary to increase the size or number of common mode chokes, which greatly increases the size and price of current compensation devices for high-power products. A problem arose.

In particular, in high-power/high-current systems, a thick copper plate in the form of a bus bar is used as the path (or winding) through which the current flows. In this case, it is limited to winding the winding several times around the sensing unit that detects the current flowing in the winding to actively remove noise. Additionally, when a thick copper plate is wound multiple times, the size of the sensing unit increases and the overall size of the current compensation device increases significantly.

The present invention is intended to improve the above problems and provide an active current compensation device that reduces common mode (CM) noise.

In addition, the present invention is intended to improve the above problems, and to provide an active current compensation device with reduced size of the sensing unit and increased productivity.

However, these tasks are illustrative and do not limit the scope of the present invention.

A current compensation device that actively compensates for the first current input in common mode to each of at least two large current paths connected to the first device according to an embodiment of the present invention is supplied by the second device. at least two high current paths for delivering a second current to the first device; A sensing unit that has a through opening, wherein the at least two large current paths are inserted into the through openings, and detects the first current on the at least two large current paths to generate an output signal corresponding to the first current; an amplifier that amplifies the output signal to generate an amplified signal; a compensation unit that generates a compensation current based on the amplified signal; and a compensation capacitor unit providing a path through which the compensation current flows to each of the at least two high current paths.

In addition, the sensing unit may be configured with a sensing transformer including a core having the through opening and generating the output signal based on the magnetic flux density generated by the first current on the at least two large current paths. .

Additionally, the core has a clamp structure that can be opened and closed, and each of the at least two high current paths can be inserted into the core in an open state.

Additionally, the amplification unit includes a first amplification element that amplifies a positive signal; a second amplifying element that amplifies a negative signal; and at least one impedance that adjusts the amplification ratio of the first amplification element and the second amplification element.

In addition, each of the first amplification element and the second amplification element includes a bipolar junction transistor (BJT), and the at least one impedance is connected to an emitter terminal of the BJT of the first amplification element and the second amplification element. a first impedance (Z1); And a second impedance (Z2) connected to the base terminal of the BJT of the first amplifying element and the second amplifying element; wherein the first impedance (Z1) and the second impedance (Z2) are connected to the sensing unit and The amplification ratio of the first amplification element and the second amplification element may be adjusted based on the current amplification degree of the compensator.

In addition, when the current amplification of the sensing unit is 1/F1 and the current amplification of the compensating unit is 1/F2, the first impedance (Z1) and the second impedance (Z2) have a current amplification of the amplification unit of F1*F2. The amplification ratio of the first amplification element and the second amplification element can be adjusted so that .

Other aspects, features and advantages other than those described above will become apparent from the detailed description, claims and drawings for carrying out the invention below.

According to various embodiments of the present invention as described above, it is possible to provide a current compensation device in which the price, area, volume, and weight do not significantly increase even in a high power system.

The current compensation device according to various embodiments of the present invention can be reduced in price, area, volume, and weight compared to a passive compensation device including a CM choke.

Additionally, the current compensation device according to various embodiments of the present invention can provide an active current compensation device that can operate independently without being parasitic on the CM choke.

Additionally, the current compensation device according to various embodiments of the present invention can stably protect elements included in the active circuit stage by having an active circuit stage that is electrically insulated from the power line.

In particular, according to the present invention, by simply passing the winding through the core without the need to wind the winding (or high-current path) around the core (or sensing transformer), the number of times (or number of turns) the winding passes through the core can be greatly reduced, and thus The size of the sensing unit can be greatly reduced. In particular, in a three-phase, four-wire power system, the size of the sensing unit can be reduced more dramatically.

According to the present invention, the productivity of products using high power/high current systems can be dramatically increased by greatly reducing the number of times the winding passes through the core.

According to the present invention, the risk of magnetic saturation is greatly reduced as the number of turns and inductance on the power line side are reduced, and the amount of increase in core size due to increase in power can also be greatly reduced.

The above-described effects are listed as examples, and the effects of the present invention are not limited thereto.

Figure 1 is a diagram schematically showing the configuration of a system including a current compensation device 100 according to an embodiment of the present invention.
FIG. 2 is a diagram schematically showing the configuration of a current compensation device 100A used in a second line system according to an embodiment of the present invention.
3A and 3B are diagrams for explaining the operation of the sensing unit 120 according to an embodiment of the present invention when implemented with a sensing transformer 120A.
FIGS. 4A and 4B are diagrams to explain that the sensing unit 120 according to an embodiment of the present invention is implemented as a sensing transformer 120A in which a large current path is wound once.
FIGS. 5A and 5B are diagrams to explain that the amplifier 130A according to an embodiment of the present invention is implemented with a Bipolar Junction Transistor (BJT) and a plurality of passive elements.
Figures 6a and 6b are diagrams for explaining a feedback amplifier whose amplification degree can be freely designed according to an embodiment of the present invention.
FIG. 7 is a diagram for explaining currents IL1 and IL2 flowing through the compensation capacitor unit 150A.
Figure 8 is a diagram schematically showing the configuration of a current compensation device 100B according to another embodiment of the present invention.
Figure 9 is a diagram schematically showing the configuration of a current compensation device 100C according to another embodiment of the present invention.
FIG. 10 is a diagram schematically showing the configuration of a system in which the current compensation device 100B according to the embodiment shown in FIG. 8 is used.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, identical or corresponding components will be assigned the same reference numerals and redundant description thereof will be omitted. .

In the following embodiments, terms such as first and second are used not in a limiting sense but for the purpose of distinguishing one component from another component. In the following examples, singular terms include plural terms unless the context clearly dictates otherwise. In the following embodiments, terms such as include or have mean that the features or components described in the specification exist, and do not exclude in advance the possibility of adding one or more other features or components. In the drawings, the sizes of components may be exaggerated or reduced for convenience of explanation. For example, the size and shape of each component shown in the drawings are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to what is shown.

Figure 1 is a diagram schematically showing the configuration of a system including a current compensation device 100 according to an embodiment of the present invention.

The current compensation device 100 according to an embodiment of the present invention is a first current (I11) input in common mode to each of at least two large current paths 111 and 112 connected to the first device 300. , I12) can be actively compensated. To this end, the current compensation device 100 according to an embodiment of the present invention includes at least two large current paths 111 and 112, a sensing unit 120, an amplification unit 130, a compensation unit 140, and a compensation capacitor unit ( 150) may be included.

The two or more large current paths 111 and 112 may be paths for transferring the second currents I21 and I22 supplied by the second device 200 within the current compensation device 100 to the first device 300. For example, it may be a power line. According to one embodiment, each of the two or more high current paths 111 and 112 may be a live line and a neutral line. For example, the high current paths 111 and 112 may be implemented through thick copper plates in high voltage/high power systems (eg, electric vehicles).

In this specification, the second device 200 may be a device of various types for supplying power to the first device 300 in the form of current and/or voltage. For example, the second device 200 may be a device that produces and supplies power, or it may be a device that supplies power generated by another device (for example, an electric vehicle charging device). Of course, the second device 200 may be a device that supplies stored energy. However, this is an example and the spirit of the present invention is not limited thereto.

In this specification, the first device 300 may be a device of various types that uses power supplied by the above-described second device 200. For example, the first device 300 may be a load driven using power supplied by the second device 200. Additionally, the first device 300 stores energy using power supplied by the second device 200 and may be a load (eg, an electric vehicle) driven using the stored energy. However, this is an example and the spirit of the present invention is not limited thereto.

As described above, each of the two or more large current paths 111 and 112 may be a path for transmitting the power supplied by the second device 200, that is, the second currents I21 and I22, to the first device 300. According to one embodiment, the second currents I21 and I22 may be alternating currents having a frequency in the second frequency band. At this time, the second frequency band may be, for example, a band ranging from 50Hz to 60Hz.

In addition, each of the two or more large current paths 111 and 112 may be a path through which at least a portion of the noise generated in the first device 300, that is, the first currents I11 and I12, is transmitted to the second device 200. At this time, the first currents I11 and I12 may be input in common mode to each of the two or more large current paths 111 and 112.

The first currents I11 and I12 may be currents unintentionally generated in the first device 300 due to various causes. For example, the first currents I11 and I12 may be noise currents generated by virtual capacitance between the first device 300 and the surrounding environment.

The first currents I11 and I12 may be currents having a frequency in the first frequency band. At this time, the first frequency band may have a higher frequency band than the above-described second frequency band, for example, it may be a band ranging from 150 KHz to 30 MHz.

Meanwhile, the two or more large current paths 111 and 112 may include two paths as shown in FIG. 1, or may include three paths or four paths as shown in FIGS. 8 and 9. . The number of high current paths 111 and 112 may vary depending on the type and/or type of power source used by the first device 300 and/or the second device 200.

Meanwhile, the sensing unit 120 may detect the first currents I11 and I12 on the two or more large current paths 111 and 112 and generate output signals corresponding to the first currents I11 and I12. In other words, the sensing unit 120 may mean a means for detecting the first currents I11 and I12 on the large current paths 111 and 112.

According to one embodiment, the sensing unit 120 may have a through opening through which at least two high current paths are inserted. The sensing unit 120 may detect the first current on two or more inserted large current paths and generate an output signal corresponding to the sensed first current.

In one embodiment, the sensing unit 120 may be implemented as a sensing transformer including a core that has a through opening and generates an output signal based on the magnetic flux density generated by the first current on at least two high current paths. there is. At this time, the core has a clamp structure that can be opened and closed, and can be implemented so that each of at least two high current paths is inserted inside in the open state.

In the present invention, 'clamp structure' may mean a structure configured to allow the outer portion of the core to be opened and closed. For example, the outer portion of the core of the clamp structure may be configured to allow the high current paths 111 and 112 to be inserted into the through opening in an open state. Thereafter, the outer portion of the open core may be closed to prevent the inserted high current paths 111 and 112 from escaping.

However, the description of the sensing unit 120 as described above is illustrative, and the spirit of the present invention is not limited thereto. Therefore, a current sensing means that is combined with a path (or conductor) in the form of 'insertion' of the path (or conductor) through which the current to be sensed flows can be used without limitation as the sensing unit 120 of the present invention.

According to one embodiment, the sensing unit 120 may be differentially connected to the input terminal of the amplifying unit 130, which will be described later.

The amplification unit 130 may amplify the output signal output from the sensing unit 120 to generate an amplified signal. In the present invention, 'amplification' by the amplification unit 130 may mean adjusting the size and/or phase of the amplification target.

By amplification by the amplification unit 130, the current compensation device 100 generates compensation currents (IC1, IC2) that are the same in size and opposite in phase as the first currents (I11, I12), thereby generating the high current paths (111, 112). ) can compensate for the first currents (I11, I12) of the phase.

The amplifier 130 may be implemented by various means. In one embodiment, the amplifier 130 may include OP-AMP. In another embodiment, the amplifier 130 may include a plurality of passive elements such as a resistor and a capacitor in addition to the OP-AMP. In another embodiment, the amplifying unit 130 may include at least one amplifying element including a bipolar junction transistor (BJT) and a passive element (eg, a resistor, a capacitor, etc.). For example, the amplifier 130 of the present invention may include a push-pull amplifier in which an npn type BJT and a pnp type BJT are connected in series.

According to one embodiment of the present invention, the amplification unit 130 may include at least one impedance for adjusting the amplification ratio of the amplification element. However, the above implementation method of the amplifying unit 130 is exemplary and the spirit of the present invention is not limited thereto, and the means for 'amplification' described in the present invention can be used without limitation as the amplifying unit 130 of the present invention. You can. A detailed description of the amplifying unit 130 will be described later with reference to FIGS. 6A and 6B.

Meanwhile, the amplification unit 130 receives power from the third device 400, which is distinct from the first device 300 and/or the second device 200, and amplifies the output signal output from the sensing unit to generate an amplification current. can be created. At this time, the third device 400 may be a device that receives power from a power source unrelated to the first device 300 and the second device 200 and generates input power to the amplifier 130. Optionally, the third device 400 may be a device that receives power from any one of the first device 300 and the second device 200 to generate input power for the amplifier 130, for example. For example, the third device 400 may be a device that applies direct current power. .

The compensation unit 140 is electrically connected to the amplification unit 130 and may generate a compensation current based on the output signal amplified by the amplification unit 130 described above.

The compensation unit 140 may be electrically connected to a path connecting the output terminal of the amplifier unit 130 and the reference potential (reference potential 2) of the amplifier unit 130 to generate a compensation current. The compensation unit 140 may be electrically connected to a path connecting the compensation capacitor unit 150 and the reference potential (reference potential 1) of the current compensation device 100. The reference potential of the amplifier 130 (reference potential 2) and the reference potential of the current compensation device 100 (reference potential 1) may be different potentials.

The compensation capacitor unit 150 may provide a path through which the compensation current generated by the compensation unit 140 flows to each of two or more high current paths.

According to one embodiment, the compensation capacitor unit 150 may be implemented as a compensation capacitor unit 150 that provides a path through which the current generated by the compensation unit 140 flows to each of two or more large current paths 111 and 112. there is. At this time, the compensation capacitor unit 150 may include at least two or more compensation capacitors connecting the reference potential (reference potential 1) of the current compensation device 100 and each of the two or more large current paths 111 and 112.

The current compensation device 100 configured as described above is capable of detecting currents under specific conditions on two or more large current paths 111 and 112 and actively compensating for them, and despite the miniaturization of the device 100, high current, high voltage and/or Alternatively, it can be applied to high power systems.

Hereinafter, a current compensation device 100 according to various embodiments will be described with reference to FIGS. 2 to 10 together with FIG. 1 .

FIG. 2 is a diagram schematically showing the configuration of a current compensation device 100A used in a second line system according to an embodiment of the present invention.

The current compensation device (100A) according to an embodiment of the present invention actively compensates for the first current (I11, I12) input in common mode to each of the two large current paths (111A, 112A) connected to the first device (300A). can be compensated with

To this end, the current compensation device (100A) according to an embodiment of the present invention includes two large current paths (111A, 112A), a sensing transformer (120A), an amplification unit (130A), a compensation transformer (140A), and a compensation capacitor unit (150A). ) may include.

In one embodiment, the above-described sensing unit 120 may include a sensing transformer 120A. At this time, the sensing transformer 120A may be a means for detecting the first currents I11 and I12 on the high current paths 111A and 112A while being insulated from the high current paths 111A and 112A.

The sensing transformer (120A) is located on the first side (121A) disposed on the large current path (111A, 112A) on the second side (121A) based on the first magnetic flux density induced by the first current (I11, I12). The first induced current can be generated at 122A). At this time, the second secondary side 122A of the sensing transformer 120A may be differentially connected to the input terminal of the amplifier 130, which will be described later.

3A and 3B are diagrams for explaining the operation of the sensing unit 120 according to an embodiment of the present invention when implemented with a sensing transformer 120A.

In particular, FIG. 3A is a diagram to explain the principle by which the sensing transformer 120A generates the first induced current ID1.

For convenience of explanation, the description will be made on the assumption that the first secondary side 121A and the second secondary side 122A of the sensing transformer 120A are configured as shown in FIG. 3A. In other words, the explanation will be made on the premise that the high current path (111A, 112A) and the secondary side (122A) winding are wound around the core (123A) of the sensing transformer (120A) in consideration of the direction of generation of magnetic flux and/or magnetic flux density.

As the first current I11 is input to the high current path 111A, magnetic flux density B11 may be induced in the core 123A. Similarly, as the first current I12 is input to the large current path 112A, magnetic flux density B12 may be induced in the core 123A.

A first induced current ID1 may be induced in the winding of the second secondary side 122A by the induced magnetic flux densities B11 and B12.

In this way, the sensing transformer 120A is configured so that the first magnetic flux densities B11 and B12 induced by the first currents I11 and I12 overlap (or reinforce each other), so that two or more large current paths A first induced current (ID1) corresponding to the first current (I11, I12) may be generated in the second side (122A) insulated from (111A, 112A).

Meanwhile, the sensing transformer 120A may be configured so that the second magnetic flux density induced by the second currents I21 and I22 flowing in each of the two or more large current paths 111A and 112A satisfies a predetermined magnetic flux density condition.

FIG. 3B is a diagram for explaining the second magnetic flux densities B21 and B22 induced in the sensing transformer 120A by the second currents I21 and I22.

As in FIG. 3A, the description will be made on the assumption that the first secondary side 121A and the second secondary side 122A of the sensing transformer 120A are configured as shown in FIG. 3B. In other words, the explanation assumes that two or more large current paths (111A, 112A) and a secondary side (122A) winding are wound around the core (123A) of the sensing transformer (120A), taking into account the direction of generation of magnetic flux and/or magnetic flux density. do.

As the second current I21 is input to the large current path 111A, magnetic flux density B21 may be induced in the core 123A. Similarly, as the second current I22 is input (or output) to the large current path 112A, magnetic flux density B22 may be induced in the core 123A.

The sensing transformer 120A is configured so that the second magnetic flux densities B21 and B22 induced by the second currents I21 and I22 (flowing in each of the two or more large current paths 111A and 112A) satisfy a predetermined magnetic flux density condition. It can be configured. At this time, the predetermined magnetic flux density conditions may be conditions that cancel each other out, as shown in FIG. 3B.

In other words, the sensing transformer 120A ensures that the second induced current ID2 induced by the second currents I21 and I22 flowing in each of the two or more large current paths 111A and 112A satisfies a predetermined second induced current condition. It can be configured to do so. At this time, the predetermined second induced current condition may be a condition in which the size of the second induced current ID2 is less than a predetermined threshold size.

In this way, the sensing transformer (120A) is configured so that the second magnetic flux densities (B21, B22) induced by the second currents (I21, I22) cancel each other, so that only the first currents (I11, I12) are sensed. You can.

The sensing transformer (120A) has a size of the first magnetic flux density (B11, B12) induced by the first current (I11, I12) of the first frequency band (for example, a band ranging from 150 KHz to 30 MHz) is second. It may be configured to be larger than the size of the second magnetic flux densities B21 and B22 induced by the second currents I21 and I22 in the frequency band (for example, a band ranging from 50 Hz to 60 Hz).

In the present invention, 'configuring' component A to do B may mean that the design parameters of component A are set to be appropriate for B. For example, the fact that the sensing transformer (120A) is configured to have a large magnetic flux induced by current in a specific frequency band is determined by factors such as the size of the sensing transformer (120A), the diameter of the core, the number of turns, the size of the inductance, and the size of the mutual inductance. This may mean that the parameters are appropriately set so that the magnitude of magnetic flux induced by current in a specific frequency band is strong.

The second secondary side 122A of the sensing transformer 120A is differentially connected to the input terminal of the amplifier 130A, as shown in FIG. 2, in order to supply the first induced current to the amplifier 130A. You can. In addition, depending on the configuration of the amplification unit 130A, the second side 122A of the sensing transformer 120A is a path connecting the input terminal of the amplification unit 130A and the reference potential (reference potential 2) of the amplification unit 130A. It may also be placed on a table.

Meanwhile, as described above, the sensing unit 120 is implemented as a sensing transformer 120A as an example, and the spirit of the present invention is not limited thereto. Therefore, a means capable of detecting only the first currents (I11, I12) input in common mode on the high current paths (111A, 112A) can be used without limitation as the sensing unit 120.

However, this is an example and the spirit of the present invention is not limited thereto. That is, the number of large current paths 111A, 112A and secondary side 122A windings wound around the core 123A can be appropriately determined according to the requirements of the system in which the current compensation device 100A is used.

According to one embodiment of the present invention, the sensing transformer (120A) has a through opening and may include a core that generates an output signal based on the magnetic flux density generated by the first current on at least two high current paths. . At this time, the core has a clamp structure that can be opened and closed, and in the open state, each of at least two high current paths 111A and 112A can be inserted inside.

FIGS. 4A and 4B are diagrams for explaining a sensing transformer 120A including a core 123A having an open/closeable clamp structure.

Referring to FIG. 4A, the sensing unit 120 may be implemented as a sensing transformer 120A including a core 123A of a clamp structure. As shown, high current paths 111A and 112A may be inserted into the opening of the sensing transformer 120A.

Hereinafter, it is assumed that the high current path (111A, 112A) and the secondary side (122A) winding are inserted (or wound) into the core (123A) of the sensing transformer (120A) in consideration of the direction of generation of magnetic flux and/or magnetic flux density. It is explained as follows.

As the first current I11 is input to the high current path 111A, magnetic flux density B11 may be induced in the core 123A. Similarly, as the first current I12 is input to the large current path 112A, magnetic flux density B12 may be induced in the core 123A. A first induced current ID1 may be induced in the winding of the second secondary side 122A by the induced magnetic flux densities B11 and B12.

In this way, the sensing transformer 120A is configured so that the first magnetic flux densities B11 and B12 induced by the first currents I11 and I12 overlap (or reinforce each other), so that two or more large current paths A first induced current (ID1) corresponding to the first current (I11, I12) may be generated in the second side (122A) insulated from (111A, 112A).

Meanwhile, the sensing transformer 120A may be configured so that the second magnetic flux density induced by the second currents I21 and I22 flowing in each of the two or more large current paths 111A and 112A satisfies a predetermined magnetic flux density condition.

Figure 4b shows that when the high current path (111A, 112A) is wound once on the first side (121A) of the sensing transformer (120A) of the present invention, the second current (I21, I22) is induced in the sensing transformer (120A). This is a diagram to explain the second magnetic flux density (B21, B22).

Referring to FIG. 4B, the sensing unit 120 may be implemented as a sensing transformer 120A including a core 123A of a clamp structure. As in FIG. 4A , high current paths 111A and 112A may be inserted into the opening of the sensing transformer 120A, as shown.

As in FIG. 3B, the sensing transformer 120A is configured so that the second induced current ID2 induced by the second currents I21 and I22 flowing in each of the two or more large current paths 111A and 112A meets a predetermined second induced current condition. It can be configured to be satisfactory. At this time, the predetermined second induced current condition may be a condition in which the size of the second induced current ID2 is less than a predetermined threshold size.

In this way, the sensing transformer (120A) is configured so that the second magnetic flux densities (B21, B22) induced by the second currents (I21, I22) cancel each other, so that only the first currents (I11, I12) are sensed. You can.

However, this is an example and the spirit of the present invention is not limited thereto.

In the sensing transformer 120A according to an embodiment of the present invention, both the high current path 111A and 112A and the secondary winding 122A may be inserted into the core 123A. In this case, the sensing transformer 120A may be configured in such a way that the high current paths 111A, 112A and the secondary winding 122A only pass through the opening of the core 123A.

According to the embodiment of the present invention disclosed in FIGS. 4A and 4B, the core 123A may have a clamp structure in which one portion of the core 123A can be opened and closed to allow the high current paths 111A and 112A to pass through or insert into the central opening.

The clamp-type core (123A) of the present invention can be configured to allow the large current paths (111A, 112A) to pass through the central through opening in an open state, and after the large current paths (111A, 112A) are inserted, the core (123A) ) can be closed. However, this is only an example, and the core 123A may be implemented in various shapes through which the high current paths 111A and 112A can be inserted into the through opening. For example, the core 123A may be implemented in a square shape in addition to a circular shape as shown in FIGS. 4A and 4B.

As such, the present invention is configured to simply insert (or simply pass through) the high current paths 111A and 112A into the core 123A, and the sensing unit 120 winds the high current paths 111A and 112A around the core 123A several times. Compared to , its size can be dramatically reduced.

In particular, in high-power/high-current systems, materials that are difficult to process, such as thick copper conductors, are used as the high-current paths (111A, 112A), so the high-current paths (111A, 112A) are simply inserted into the core (123A). Productivity and assembly efficiency of products using high power/high current systems can be improved.

The amplification unit 130A may amplify the output signal output by the above-described sensing unit 120 and generate an amplified output signal.

In one embodiment, the amplifier 130 may be implemented as an amplifier 130A that generates an amplified current by amplifying the first induced current generated by the sensing transformer 120A.

In the present invention, 'amplification' by the amplification unit 130 may mean adjusting the size and/or phase of the amplification target. For example, the amplification unit 130A may change the phase of the first induced current by 180 degrees and increase the size by K times (K>=1) to generate the amplification current.

By the amplification of the amplification unit 130A, the current compensation device 100A generates compensation currents IC1 and IC2 that are the same in size and opposite in phase as the first currents I11 and I12, thereby forming the large current path 111A. , 112A), the first currents (I11, I12) can be compensated.

The amplification unit 130A may generate an amplification current by considering the transformation ratio of the above-described sensing transformer 120A and the transformation ratio of the compensation unit 140 described later. That is, the amplification unit 130A calculates the current amplification according to the transformation ratio of the sensing transformer 120A included in the sensing unit 120 and the current amplification according to the transformation ratio of the compensation transformer 140A included in the compensation unit 140. You can set the amplification level based on the amplification level.

Specifically, the sensing transformer 120A converts the first currents I11 and I12 with a magnitude of 1 into a first induced current with a magnitude of 1/F1, and the compensation unit 140 converts the amplification current with a magnitude of 1 into a first induced current with a magnitude of 1. When implemented with a compensation transformer (140A) that converts to a compensation current of 1/F2, the amplification unit (130A) considers the current amplification degree of the sensing transformer (120A) and the current amplification degree of the compensation transformer (140A) to generate the first induced current. It is possible to generate an amplification current that is F1xF2 times. At this time, the amplification unit 130A may generate the amplification current so that the phase of the amplification current is opposite to the phase of the first induced current.

The amplification unit 130A may be implemented by various means. For example, the amplification unit 130A may include OP-AMP. Optionally, the amplification unit 130A may include a plurality of passive elements such as resistors and capacitors in addition to the OP-AMP. Additionally, the amplifier 130A may include a Bipolar Junction Transistor (BJT). Optionally, the amplification unit 130A may include a plurality of passive elements and additional impedance in addition to the BJT. However, the above implementation method of the amplifying unit 130A is illustrative and the spirit of the present invention is not limited thereto, and the means for 'amplification' described in the present invention can be used without limitation as the amplifying unit 130A of the present invention. You can.

FIGS. 5A and 5B are diagrams to explain that the amplifier 130A according to an embodiment of the present invention is implemented with a Bipolar Junction Transistor (BJT) and a plurality of passive elements.

Referring to FIG. 5A , the amplification unit 130A may include a first amplification element that amplifies a positive signal and a second amplification element that amplifies a negative signal. For example, the amplifier 130A may be implemented as a push-pull amplifier using an amplification element including an npn type BJT or a pnp type BJT.

Specifically, in the case of a positive swing where the voltage due to noise is greater than 0, an amplification element including an npn type BJT can operate. At this time, the operating current may flow through the npn type BJT path. In the case of negative swing where the voltage due to noise is less than 0, an amplification element including a pnp type BJT can operate. At this time, the operating current can flow through the pnp type BJT path.

The push-pull amplifier of the amplifier unit (130A) is an npn type BJT, a pnp type BJT, a capacitor (C _e ) at the emitter stage of each BJT, a capacitor (C _b ) at the base stage of each BJT, It may include the resistance of the collector stage of each BJT (R _npn , R _pnp ), the resistance of the emitter stage of the two BJTs (R _e ), and the resistance of the base stage of the two BJTs (R _bb ).

The first end of the capacitor (C _e ) of the emitter stage of each of the two BJTs is connected to the second side (122A) of the sensing transformer (120A), and the second end is connected to the emitter (emitter) of each BJT. It may be connected to a stage.

The resistance of the collector stage of each BJT (R _npn , R _pnp ), the resistance of the emitter stage of the two BJTs (R _e ), and the resistance of the base stage of the two BJTs (R _bb ) are each related to the DC operation of the BJT. It may be a configuration for designing a point.

The push-pull amplifier of the amplification unit 130A may further include C _DC , and C _DC may be a decoupling capacitor for the V _DC voltage from the third device 400, and an npn type BJT , Connected to the collector of a pnp type BJT, it is possible to selectively couple only AC signals.

According to one embodiment of the present invention, the push-pull amplifier may be implemented as a feedback system that re-inputs the amplified signal or amplified current to the base of the BJT included in the amplifying element.

Specifically, the amplification current generated by the amplification unit 130A induces a compensation current to the secondary side 142A based on the third magnetic flux density, and then passes through the first secondary side 141A of the compensation transformer 140A again. It may be input to the secondary side (122A) of the sensing transformer (120A). That is, as the amplification current is fed back to the secondary side (122A) of the sensing transformer (120A), the push-pull amplifier can stably obtain a constant current gain for active EMI filter operation.

Figure 5b is a simplified diagram of the amplifier of Figure 5a.

Referring to FIG. 5B, the induced current I _i generated on the second side 122A of the sensing transformer 120A may be the first induced current input to the amplifying unit 130A or an output signal including the first induced current. there is. Additionally, I _OBJT passing through the first side 141A of the compensation transformer 140A may be an amplified current or an amplified signal output from _the amplifier 130A.

β is the current gain of the BJT device itself, and when I _i is expressed as a function of I _OBJT , it is as in Equation 1.

Therefore, the amplification degree A _i,amp of the amplification unit 130A can be expressed as Equation 2.

Since the current gain β of the BJT has a value much larger than 1 (β>>1), A _i,amp can be approximated as -1.

Therefore, the current compensation device 100A is designed to satisfy N _sen N _inj = 1, so that the noise current can be offset with the compensation current. At this time, N _SEN may be the number of turns ratio or transformation ratio of the sensing transformer (120A), and N _INJ may be the number of turns ratio or transformation ratio of the compensation transformer (140A).

The amplifier of this embodiment returns the output current back to the input to form a feedback system, thereby achieving a more stable current gain.

6A and 6B are diagrams for explaining the amplification unit 130A according to another embodiment of the present invention.

Looking at FIG. 6A in contrast to FIG. 5A, the amplification unit 130A according to another embodiment of the present invention has an amplification ratio of the first amplification element and the second amplification element in addition to the above-described first amplification element and the second amplification element. It may include at least one impedance (Z1, Z2) that adjusts.

For example, the amplification unit 130A includes an npn type BJT, a pnp type BJT, a capacitor (C _e ) at the emitter stage of each BJT, a capacitor (C b ) at the base stage of each BJT, and a capacitor (C _b ) at the base stage of each BJT. It may include the resistance of the collector stage (R _npn , R _pnp ), the resistance of the emitter stage of the two BJTs (R _e ), and the resistance of the base stage of the two BJTs (R _bb ). The first end of the capacitor (C _e ) of the emitter stage of each of the two BJTs is connected to the second side (122A) of the sensing transformer (120A), and the second end is connected to the emitter (emitter) of each BJT. It may be connected to a stage. The resistance of the collector stage of each BJT (R _npn , R _pnp ), the resistance of the emitter stage of the two BJTs (R _e ), and the resistance of the base stage of the two BJTs (Rbb) are the DC operating points of each BJT. It may be a configuration for designing.

In contrast to the amplification unit 130A described in FIG. 5A, the amplifier of FIG. 6A may include at least one impedance (Z1, Z2) that adjusts the amplification ratio of the first amplification element and the second amplification element. The first impedance (Z1) and the second impedance (Z2) may each be implemented by using one or more resistor (R) elements, capacitor (C) elements, or inductor (L) elements in combination.

For example, the first impedance (Z1) and the second impedance (Z2) may be implemented in RC series or RLC series, respectively, and may be designed to compensate more precisely for the phase and magnitude of current compensation according to frequency.

The first end of the first impedance Z1 may be connected to the first secondary side 141A of the compensation transformer 140A, and the second end may be connected to the emitter terminal of each of the two BJTs. Additionally, the first end of the second impedance may be connected to the first secondary side (141A) of the compensation transformer (140A), and the second end may be connected to the capacitor (C _b ) of the base terminal of each BJT. there is.

The amplification degree (A _iamp ) of the amplifier (130A) according to another embodiment of the present invention may be adjusted according to the value of at least one impedance (Z1, Z2) described above. For example, if the first impedance (Z1) is R ₁ and the second impedance (Z2) is (n-1)R ₁ , the amplification degree (A _iamp ) may be designed to be -n (n>1). . At this time, the design value of n can be tuned by considering the characteristic error of the device.

Figure 6b is a simplified diagram of the amplifier of Figure 6a.

Referring to FIG. 6B, the first induced current I _i generated in the secondary side 122A of the sensing transformer 120A may be an input current input to the amplifier 130A. Additionally, I _OBJT may be an amplification current passing through the first secondary side 141A of the compensation transformer 140A, and I _OBJT may be an output current output from the amplification unit 130A.

The amplification degree A _i,amp of the amplifier 130A can be expressed as Equation 3.

(β>>1, Z2 >> rπ/β, Z1 = R _1, Z2 = (n-1) Z-1)

As shown in Equation 3, the amplifier of the present invention can be designed with current amplification (Ai,amp) = -n (n>1). According to the above example, the amplification (Ai,amp) can be designed as Nsen*Ninj, and precise tuning of the current amplification can be possible by setting Z1 and Z2 above considering the error.

In particular, when the current compensation device includes the sensing unit 120A of the clamp structure described in FIGS. 4A to 4B, the sensing gain of the first current is not large, so the sensing unit ( 120A) can compensate for the decrease in gain.

Meanwhile, as described above, the amplifier 130A may receive power from the third device 400A and amplify the first induced current to generate an amplified current.

The compensation unit 140 may generate a compensation current based on the output signal amplified by the amplification unit 130 described above.

In one embodiment, the compensation unit 140 may include a compensation transformer 140A. At this time, the compensation transformer 140A is insulated from the above-mentioned large current paths 111A and 112A, and provides compensation to the large current paths 111A and 112A (or to the secondary side 142A described later) based on the amplified current. It may be a means for generating electric current.

More specifically, the compensation transformer 140A is connected to the third magnetic flux density induced by the amplification current generated by the amplification unit 130A at the first primary side 141A differentially connected to the output terminal of the amplification unit 130A. Based on this, a compensation current can be generated in the secondary side (142A). At this time, the second secondary side 142A may be placed on a path connecting the compensation capacitor unit 150A, which will be described later, and the reference potential (reference potential 1) of the current compensation device.

Meanwhile, the first side 141A of the compensation transformer 140A, the amplifier 130A, and the second side 122A of the sensing transformer 120A are separated from the remaining components of the current compensation device 100A. It can be connected to the reference potential (reference potential 2).

As such, the present invention uses a different reference potential for the component that generates the compensation current from the remaining components and uses a separate power source, thereby allowing the component that generates the compensation current to operate in an insulated state. The reliability of the current compensation device (100A) can be improved.

In one embodiment, the compensation capacitor unit 150 is a compensation capacitor unit 150A that provides a path through which the current generated by the compensation transformer 140A flows to each of the two large current paths 111A and 112A, as described above. It can be implemented.

FIG. 7 is a diagram for explaining currents IL1 and IL2 flowing through the compensation capacitor unit 150A.

The compensation capacitor unit 150A may be configured so that the current IL1 flowing between the two large current paths 111A and 112A through the compensation capacitor satisfies a predetermined first current condition. At this time, the predetermined first current condition may be a condition in which the size of the current IL1 is less than the predetermined first threshold size.

In addition, the compensation capacitor unit 150A is configured such that the current Il2 flowing between each of the two large current paths 111A and 112A through the compensation capacitor and the reference potential (reference potential 1) of the current compensation device 100A is set to a predetermined second level. It can be configured to satisfy the conditions. At this time, the predetermined second current condition may be a condition in which the size of the current IL2 is less than the predetermined second threshold size.

The compensation current flowing to each of the two large current paths (111A, 112A) along the compensation capacitor unit (150A) cancels out the first currents (I11, I22) on the large current paths (111A, 112A), thereby generating the first currents (I11, I22). ) can be prevented from being transmitted to the second device (200A). At this time, the first currents I11 and I22 and the compensation current may be currents of the same magnitude and opposite phases.

Accordingly, the current compensation device 100A according to an embodiment of the present invention provides first currents I11 and I12 input in common mode to each of the two large current paths 111A and 112A connected to the first device 300A. By actively compensating, malfunction or damage to the second device 200A can be prevented.

Figure 8 is a diagram schematically showing the configuration of a current compensation device 100B according to another embodiment of the present invention. Hereinafter, descriptions of content that overlaps with the content described with reference to FIGS. 1 to 7 will be omitted.

The current compensation device 100B according to another embodiment of the present invention includes first currents I11, I12, and I13 input in common mode to each of the high current paths 111B, 112B, and 113B connected to the first device 300B. ) can be actively compensated.

For this purpose, the current compensation device (100B) according to another embodiment of the present invention includes three large current paths (111B, 112B, 113B), a sensing transformer (120B), an amplifier (130B), a compensation transformer (140B), and a compensation capacitor. It may include a unit 150B.

In contrast to the current compensation device 100A according to the embodiment described in FIGS. 2 to 7, the current compensation device 100B according to the embodiment shown in FIG. 8 has three large current paths 111B, 112B, and 113B. It includes, and accordingly, there is a difference between the sensing transformer (120B) and the compensation capacitor unit (150B). Therefore, the current compensation device 100B will be described below with a focus on the above-mentioned differences.

The current compensation device 100B according to another embodiment of the present invention may include a first large current path 111B, a second large current path 112B, and a third large current path 113B that are distinct from each other. According to one embodiment, the first high-current path 111B may be an R-phase power line, the second high-current path 112B may be an S-phase power line, and the third high-current path 113B may be a T-phase power line. The first currents I11, I12, and I13 may be input in a common mode to each of the first large current path 111B, the second large current path 112B, and the third large current path 113B.

The first secondary side (121B) of the sensing transformer (120B) according to another embodiment of the present invention is disposed in each of the first large current path (111B), the second large current path (112B), and the third large current path (113B). A first induced current may be generated. The magnetic flux densities generated in the sensing transformer 120B by the first currents I11, I12, and I13 on the three large current paths 111B, 112B, and 113B may reinforce each other. Since the process of generating the first induced current by the first currents I11, I12, and I13 is described in FIG. 3A, detailed description thereof will be omitted.

On the other hand, when the current compensation device 100B includes three large current paths 111B, 112B, and 113B as shown in FIG. 8, using a clamp-type sensing unit as shown in FIGS. 4A and 4B increases the sensing efficiency compared to using a conventional sensing transformer. The effect of reducing the size of the unit and the size of the current compensation device (100B) can be maximized.

Meanwhile, the compensation capacitor unit 150B according to another embodiment of the present invention allows the compensation currents (IC1, IC2, IC3) generated by the compensation transformer to flow through the first large current path 111B, the second large current path 112B, and A path flowing through each of the third large current paths 113B can be provided.

The current compensation device 100B according to this embodiment can be used to offset (or block) the first currents I11, I12, and I13 moving from the load to the power source in a three-phase, three-wire power system.

Figure 9 is a diagram schematically showing the configuration of a current compensation device 100C according to another embodiment of the present invention. Hereinafter, descriptions of content that overlaps with the content described with reference to FIGS. 1 to 8 will be omitted.

The current compensation device (100C) according to the embodiment is a first current (I11, I12, I13, I14) input in common mode to each of the high current paths (111C, 112C, 113C, and 114C) connected to the first device (300C). can be actively compensated.

To this end, the current compensation device (100C) according to the embodiment includes four large current paths (111C, 112C, 113C, 114C), a sensing transformer (120C), an amplification unit (130C), a compensation transformer (140C), and a compensation capacitor unit (150C). ) may include.

In contrast to the current compensation device 100A according to the embodiment described in FIGS. 2 to 7 and the current compensation device 100B according to the embodiment described in FIG. 5, the current compensation device according to the embodiment shown in FIG. 9 ( 100C) includes four large current paths (111C, 112C, 113C, 114C), and accordingly there is a difference in the sensing transformer (120C) and compensation capacitor section (150C). Therefore, the current compensation device 100C will be described below with a focus on the above-mentioned differences.

First, the current compensation device 100C according to the embodiment may include a first large current path 111C, a second large current path 112C, a third large current path 113C, and a fourth large current path 114C. You can. According to one embodiment, the first large current path (111C) is the R phase, the second large current path (112C) is the S phase, the third large current path (113C) is the T phase, and the fourth large current path (114C) is the It may be an N-phase power line. The first currents (I11, I12, I13, I14) include the first large current path (111C), the second large current path (112C), the third large current path (113C), and the fourth large current path (114C). ) can be input to each in common mode.

The first side (121C) of the sensing transformer (120C) according to the embodiment includes a first large current path (111C), a second large current path (112C), a third large current path (113C), and a fourth large current path (114C), respectively. It may be placed to generate a first induced current. The magnetic flux densities generated in the sensing transformer 120C by the first currents I11, I12, I13, and I14 on the four large current paths 111C, 112C, 113C, and 114C can be mutually reinforced. The process of generating the first induced current by the first currents I11, I12, I13, and I14 has been described in FIG. 4A, so detailed description thereof will be omitted.

Meanwhile, the compensation capacitor unit 150C according to the embodiment allows the compensation currents (IC1, IC2, IC3, IC4) generated by the compensation transformer to flow through the first large current path 111C, the second large current path 112C, and the third large current path. A path flowing through each of the path 113C and the fourth large current path 114C may be provided.

The current compensation device (100C) according to this embodiment can be used to offset (or block) the first current (I11, I12, I13, I14) moving from the load to the power source in a three-phase, four-wire power system. there is.

Even in this case, using a clamp-type sensing unit as shown in FIGS. 4A and 4B can further maximize the effect of reducing the size of the sensing unit and the size of the current compensation device (100C) compared to using a conventional sensing transformer.

FIG. 10 is a diagram schematically showing the configuration of a system in which the current compensation device 100B according to the embodiment shown in FIG. 8 is used.

The current compensation device 100B according to the embodiment may be used with one or more other compensation devices 500 on a high current path connecting the second device 200B and the first device 300B.

For example, the current compensation device 100B according to the embodiment may be used together with the compensation device 1 (510) that compensates for the first current input in common mode. At this time, compensation device 1 (510) may be implemented as an active element, similar to the compensation device (100B), or may be implemented as only a passive element.

Additionally, the current compensation device 100B according to the embodiment may be used together with the compensation device 2 520 that compensates for the third current input in differential mode. At this time, compensation device 2 (520) may also be implemented as an active element or may be implemented only as a passive element.

Additionally, the current compensation device 100B according to the embodiment may be used together with the compensation device n 530 that compensates for voltage. At this time, the compensation device n (530) may also be implemented as an active element or may be implemented only as a passive element.

Meanwhile, the type, quantity, and arrangement order of the compensation device 500 described in Figure 10 are exemplary and the spirit of the present invention is not limited thereto. Therefore, depending on the design of the system, various quantities and types of compensation devices may be further included in the system. Additionally, of course, the embodiment shown in FIG. 10 can be equally applied to all other embodiments of the present specification.

The specific implementations described in the present invention are examples and do not limit the scope of the present invention in any way. For the sake of brevity of the specification, descriptions of conventional electronic components, control systems, software, and other functional aspects of the systems may be omitted. In addition, the connections or connection members of lines between components shown in the drawings exemplify functional connections and/or physical or circuit connections, and in actual devices, various functional connections or physical connections may be replaced or added. Can be represented as connections, or circuit connections. Additionally, if there is no specific mention such as “essential,” “important,” etc., it may not be a necessary component for the application of the present invention.

Therefore, the spirit of the present invention should not be limited to the above-described embodiments, and the claims described below as well as all scopes equivalent to or equivalently changed from these claims fall within the scope of the spirit of the present invention. They will say they do it.

100: Current compensation device
111, 112: High current path
120: Sensing unit
130: Amplification unit
140: Compensation unit
150: Compensation capacitor unit
200: second device
300: first device

Claims (5)

In a current compensation device that actively compensates for the first current input in common mode to each of at least two large current paths connected to the first device,
at least two high current paths for transferring a second current supplied by a second device to the first device;
A sensing unit that has a through opening, wherein the at least two large current paths are inserted into the through openings, and detects the first current on the at least two large current paths to generate an output signal corresponding to the first current;
an amplifier that amplifies the output signal to generate an amplified signal;
a compensation unit that generates a compensation current based on the amplified signal; and
A compensation capacitor unit providing a path through which the compensation current flows to each of the at least two high current paths,
The amplification unit,
a first amplifying element that amplifies a positive signal;
a second amplifying element that amplifies a negative signal; and
It includes a first impedance (Z1) and a second impedance (Z2) that adjust the amplification ratio of the first amplification element and the second amplification element,
The first impedance (Z1) and the second impedance (Z2) adjust the amplification ratio of the first amplification element and the second amplification element based on the current amplification degree of the sensing unit and the compensation unit,
The amplification unit,
The first amplifying element is an npn type BJT (bipolar junction transistor),
The second amplifying element is a pnp type BJT (bipolar junction transistor),
Resistors (Rnpn, Rpnp) connected to collector terminals of BJTs of the first amplification element and the second amplification element;
A resistor (Re) connected between emitter terminals of the BJT of the first amplification element and the second amplification element;
a resistor (Rbb) disposed between base terminals of BJTs of the first and second amplifying elements;
A capacitor (Ce) connected to each emitter terminal of the BJT of the first amplification element and the second amplification element;
A capacitor (Cb) connected to each base terminal of the BJT of the first amplification element and the second amplification element; and
a decoupling capacitor (C _DC ) connected between collector terminals of a BJT of the first amplification element and the second amplification element;
Including a current compensation device. According to paragraph 1,
The sensing unit
a first side disposed on the at least two high current paths; and
a second side generating a first induced current based on a first magnetic flux density induced by the first current; It consists of a sensing transformer including,
The second side is differentially connected to the input terminal of the amplifier to input the first induced current as the output signal. According to paragraph 1,
The compensation department
a first secondary side connected to the first impedance and the second impedance; and
It consists of a compensation transformer including a secondary side that generates the compensation current based on the third magnetic flux density induced by the amplification signal,
The first side is differentially connected to the output terminal of the amplifier, and the second side is disposed on a path connecting the compensation capacitor section and the reference potential. According to paragraph 1,
When the current amplification of the sensing unit is 1/F1 and the current amplification of the compensating unit is 1/F2, the first impedance (Z1) and the second impedance (Z2) are adjusted so that the current amplification of the amplification unit is F1*F2. A current compensation device that adjusts the amplification ratio of the first amplification element and the second amplification element. delete