KR102636667B1 - Current compensation device - Google Patents

Abstract

Embodiments of the present invention are a current compensation device that actively compensates for the first current input in common mode from one device in various types of power systems, but balances noise between power lines with a more simplified circuit configuration. It's about.

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 products, or electric vehicles emit noise while operating. 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 appliances such as air conditioners, electric vehicles, aviation, and energy storage systems (ESS), 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.

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 seeks to provide a current compensation device with improved noise removal rate by balancing noise in one or more large current paths, and in particular, to provide a current compensation device that balances noise with a more simplified structure.

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 from the first device according to an embodiment of the present invention is to compensate for the second current supplied by the second device to the first device. At least two high current paths passing through; a first balancing unit that adjusts balancing of the first current between the at least two large current paths; a sensing unit that detects a first current whose balance is adjusted by the first balancing unit on the at least two large current paths and generates an output signal corresponding to the detection result; an amplifier that amplifies the output signal and generates an amplified output signal; a compensation unit that generates a compensation current based on the amplified output signal; a compensation capacitor unit providing a path through which the compensation current flows to a reference high current path, which is one of the at least two high current paths; and a second balancing unit that distributes the compensation current provided to the reference large current path to the at least two large current paths.

The second balancing unit adjusts the balancing of the composite currents in the at least two or more large current paths, and the composite current is a current in which the compensation current is added to the first current for which the balancing is adjusted in each of the at least two or more large current paths. It can be.

The current compensation device according to an embodiment of the present invention may further include an output impedance adjustment unit that adjusts the output impedance from the compensation unit to the second device.

The output impedance adjusting unit includes a first capacitor that provides a path through which current flows between the reference large current path and the reference potential of the compensation unit, and the second balancing unit includes a current flowing between the reference large current path and each of the remaining large current paths. It may include one or more second capacitors that provide a flow path.

The output impedance may be a composite impedance obtained by connecting the first impedance of the first capacitor and the second capacitor in series and the impedance of the second device in parallel.

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.

Specifically, the current compensation device according to various embodiments may have reduced 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.

Additionally, the current compensation device according to various embodiments of the present invention can be protected from external overvoltage.

Additionally, the current compensation device according to various embodiments of the present invention can improve the noise removal rate by balancing noise in one or more large current paths.

In addition, the current compensation device according to various embodiments of the present invention can reduce manufacturing costs and improve productivity by balancing noise on large currents with a more simplified structure.

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.
Figure 2 is a diagram schematically showing the configuration of a current compensation device (100A) used in a three-phase, four-wire system according to an embodiment of the present invention.
FIG. 3 is a diagram for explaining the configuration and operation of the first balancing unit 160A according to an embodiment.
Figure 4 shows the process in which the compensation current (IC) generated by the compensation unit 140 is distributed to the large current paths 111A, 112A, 113A, and 114A through the compensation capacitor unit 150A and the second balancing unit 170A. This is a drawing for explanation.
FIG. 5 is a diagram illustrating a process in which the second balancing unit 170A adjusts the balancing of the synthesized current according to an embodiment.
Figure 6 is a diagram for explaining the process of adjusting the output impedance (Zeq31, Zeq32, Zeq33, Zeq34) by the second balancing unit (170A) and the output impedance adjusting unit (180A).
Figure 7 is a diagram schematically showing the configuration of a current compensation device 100B used in a three-phase, three-wire system according to another embodiment of the present invention.

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 device input in common mode to each of at least two large current paths 111, 112, 113, and 114 connected to the first device 300. 1 Current (I11, I12, I13, I14) 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, 112, 113, and 114, a sensing unit 120, an amplifying unit 130, a compensating unit 140, It may include a compensation capacitor unit 150, a first balancing unit 160, a second balancing unit 170, and an output impedance adjusting unit 180.

Two or more large current paths (111, 112, 113, 114) connect the second currents (I21, I22, I23, I24) supplied by the second device 200 within the current compensation device 100 to the first device 300. ), which may be a transmission path, for example, a power line.

According to one embodiment, the two or more high current paths 111, 112, 113, and 114 may be R lines, S lines, T lines, and N lines, respectively, in a three-phase, four-wire power system as shown in FIG. 2. Of course, the two or more high current paths 111, 112, 113, and 114 may be R lines, S lines, and T lines, respectively, in a three-phase, three-wire power system as shown in FIG. 7. As such, in the present invention, the quantity of two or more high current paths 111, 112, 113, and 114 can be set in various ways depending on the configuration of the power system used.

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, 112, 113, and 114 connects the power supplied by the second device 200, that is, the second currents I21, I22, I23, and I24, to the first device 300. ) may be a path to be transmitted to.

According to one embodiment, the second currents I21, I22, I23, and I24 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, 112, 113, and 114 is configured to prevent noise generated in the first device 300, that is, at least a portion of the first currents I11, I12, I13, and I14, from the second device 200. It may be a delivery route. At this time, the first currents (I11, I12, I13, and I14) may be input in common mode to each of the two or more large current paths (111, 112, 113, and 114).

The first currents I11, I12, I13, and I14 may be currents unintentionally generated in the first device 300 for various reasons. For example, the first currents (I11, I12, I13, I14) are generated by virtual capacitance between the first device 300 and the surrounding environment, or by internal switching of the first device 300. It may be a generated noise current.

The first currents I11, I12, I13, and I14 may be currents having a frequency in the first frequency band. At this time, the first frequency band may be 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.

The first balancing unit 160 may adjust the balancing of the first currents I11, I12, I13, and I14 between the large current paths 111, 112, 113, and 114.

In the present invention, 'adjusting balancing' may mean adjusting the physical quantity of each adjustment target so that the difference in physical quantity between the balancing adjustment targets is reduced. Accordingly, the first balancing unit 160 can reduce the size difference between the first currents I11, I12, I13, and I14 flowing in each of the large current paths 111, 112, 113, and 114. For example, the magnitude of the first current I11 of the first large current path 111 is 1, the magnitude of the first current I12 of the second large current path 112 is 3, and the magnitude of the first current I12 of the third large current path 113 is 3. Let us assume that the magnitude of the first current (I13) is 1.5, and the magnitude of the first current (I14) of the fourth large current path 114 is 2.5. According to the above-described assumption, the first balancing unit 160 sets the magnitude of the first current (I11) to 2.01, the magnitude of the first current (I12) to 2.02, and the magnitude of the first current (I13) to 1.99. The magnitude of the first current (I14) can be adjusted to 1.98.

In this way, the present invention equalizes the distribution of the first currents (I11, I12, I13, I14), which are noise currents, on each large current path, so that noise removal by the remaining components of the current compensation device 100 can be performed more efficiently. Let it happen.

According to one embodiment, the first balancing unit 160 may be configured to include a high-current path connection portion that allows only current in the first frequency band to flow between the high-current paths 111, 112, 113, and 114. At this time, the high current path connection part may be implemented, for example, as a capacitor having a capacitance that conducts only current in the first frequency band.

The sensing unit 120 is electrically connected to the large current paths 111, 112, 113, and 114 and detects the first current whose balance is adjusted on two or more large current paths 111, 112, 113, and 114, and responds to the detection result. A corresponding output signal can be generated. In other words, the sensing unit 120 may mean a means for detecting the first current (or the first current with adjusted balancing) on the large current paths 111, 112, 113, and 114.

According to one embodiment, the sensing unit 120 may be implemented as a sensing transformer. At this time, the sensing transformer is a means for detecting the first current (I11, I12, I13, I14) on the high current path (111, 112, 113, 114) in a state insulated from the high current path (111, 112, 113, 114). You can.

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 is electrically connected to the sensing unit 120 and can amplify the output signal output by the sensing unit 120 to generate an amplified output signal.

In the present invention, 'amplification' by the amplification unit 130 may mean adjusting the size and/or phase of the amplification target.

By the amplification of the amplification unit 130, the current compensation device 100 generates a compensation current (IC) that has the same magnitude and opposite phase as the balanced first current, and generates a compensation current (IC) that is the same in size and opposite in phase as the balanced first current. 114) Phase balancing may compensate for the adjusted first current. In this case, ‘compensation’ can mean ‘removal’ or ‘reduction’.

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 amplifier 130 may include a Bipolar Junction Transistor (BJT). In another embodiment, the amplifier 130 may include a plurality of passive elements such as resistors and capacitors in addition to the BJT. However, the above implementation method of the amplifying unit 130 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 130 of the present invention. You can.

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. You can. 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.

The compensation unit 140 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 (IC) generated by the compensation unit 140 flows to the reference large current path 114. At this time, the reference large current path 114 means any one of the large current paths 111, 112, 113, and 114, and depending on selection, any one of the remaining large current paths 111, 112, and 113 may correspond to the reference large current path. there is.

According to one embodiment, the compensation capacitor unit 150 may be implemented as a capacitor that provides a path through which the compensation current (IC) generated by the compensation unit 140 flows to the reference high current path 114. At this time, the compensation capacitor unit 150 may include a capacitor connecting the reference potential (reference potential 1) of the current compensation device 100 and the reference high current path 114.

The second balancing unit 170 may distribute the compensation current (IC) provided to the reference large current path 114 to two or more large current paths 111, 112, 113, and 114. For example, if the size of the compensation current (IC) provided to the large current path 114 is 8, the second balancing unit 170 provides a compensation current of size 2 to each of the four large current paths 111, 112, 113, and 114. The compensation current (IC) can be distributed to flow.

Meanwhile, the second balancing unit 170 can adjust the balancing of the composite currents on the large current paths 111, 112, 113, and 114. At this time, the composite current may mean a current obtained by adding the distributed compensation current to the first current whose balancing is adjusted by the first balancing unit. As described above, 'adjusting balancing' in the present invention may mean adjusting the physical quantity of each adjustment target so that the difference in physical quantity between the balancing adjustment targets is reduced. Accordingly, the second balancing unit 170 can reduce the size difference between the composite currents flowing in each of the large current paths 111, 112, 113, and 114. For example, the magnitude of the composite current of the first large current path 111 is 0.01, the magnitude of the composite current of the second large current path 112 is 0.02, and the magnitude of the composite current of the third large current path 113 is -0.01. , Let us assume that the magnitude of the composite current of the fourth large current path 114 is -0.02. Under the above-described assumption, the second balancing unit 170 can adjust the magnitude of the composite current in all high current paths 111, 112, 113, and 114 to 0.

In this way, the present invention can more completely block the first current transmitted to the second device 200 by once again evening out and reducing the distribution of the minute first currents remaining after current compensation by the compensator 140. there is.

According to one embodiment, the second balancing unit 170 may be configured to include a high-current path connection portion that allows only current in the first frequency band to flow between the high-current paths 111, 112, 113, and 114. At this time, the high current path connection part may be implemented, for example, as a capacitor having a capacitance that conducts only current in the first frequency band.

The second balancing unit 170 may adjust the output impedance from the compensating unit 140 to the second device 200 together with the output impedance adjusting unit 180, which will be described later.

The output impedance adjusting unit 180, together with the above-described second balancing unit 170, can adjust the output impedance from the compensating unit 140 to the second device 200. For example, the impedance adjusting unit 180 reduces the output impedance seen from the compensating unit 140 toward the second device 200, thereby preventing the compensation current (IC) from flowing in the reverse direction (i.e. toward the compensating unit 140). You can. In one embodiment, the output impedance adjuster 180 may be implemented as a capacitor with a predetermined capacitance.

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, 112, 113, and 114 and actively compensating for them, and despite the miniaturization of the device 100, high current , can be applied to high voltage and/or high power systems. Additionally, the current compensation device 100 itself can be miniaturized as the second balancing unit 170 performs various roles.

Hereinafter, a current compensation device 100 according to various embodiments will be described with reference to FIGS. 2 to 7 together with FIG. 1 .

Figure 2 is a diagram schematically showing the configuration of a current compensation device (100A) used in a three-phase, four-wire system according to an embodiment of the present invention.

The current compensation device (100A) according to an embodiment of the present invention is connected to the first device (the first device is connected to P4 to P7) in common mode in each of the four high current paths (111A, 112A, 113A, and 114A). The input first current (I11, I12, I13, I14) can be actively compensated.

For this purpose, the current compensation device (100A) according to an embodiment of the present invention includes four large current paths (111A, 112A, 113A, 114A), a sensing transformer (120A), an amplifier (130A), a compensation transformer (140A), and a compensation transformer (140A). It may include a capacitor unit (150A), a first balancing unit (160A), a second balancing unit (170A), and an output impedance adjusting unit (180A).

Additionally, the current compensation device 100A may include terminals P1 to P11 connected to external devices. At this time, the terminal P1 is a terminal connected to the reference potential 1, the terminal P2 is a terminal connected to the reference potential 2, and the terminal P3 is connected to a third device that supplies power to the amplification unit 130A. terminals, the terminals P4 to P7 may be terminals connected to the first device, and the terminals P8 to P11 may be terminals connected to the second device.

FIG. 3 is a diagram for explaining the configuration and operation of the first balancing unit 160A according to an embodiment.

The first balancing unit 160A adjusts the balancing of the first currents (I11, I12, I13, and I14) between the large current paths (111A, 112A, 113A, and 114A) to produce the balanced first current (I11', I12', I13', I14') can be generated.

In one embodiment, the first balancing unit 160 has high current paths (111A, 112A, 113A) corresponding to the R line, S line, and T line, respectively, as shown in FIG. 3, and a high current path (114A) corresponding to the N line. ) may be implemented to include capacitors (161A, 162A, 163A) connecting.

The capacitance of the capacitors 161A, 162A, and 163A constituting the first balancing unit 160A may be determined so that only the current in the first frequency band to which the frequency of the first current belongs selectively flows. For example, when the first frequency band is 150khz to 30Mhz, the capacitance of the capacitors 161A, 162A, and 163A constituting the balancing unit 160A are each determined to be 30uF, so that the capacitors 161A, 162A, and 163A are shorted in the corresponding frequency band. It can be made to operate like a (Short) circuit. Accordingly, the balancing of the first current between the high current paths (111A, 112A, 113A, 114A) through the capacitors (161A, 162A, 163A) can be adjusted.

For example, if the size of the first current (I11) on the first large current path (111A) is relatively larger than the size of the first currents (I12, I13, and I14) on the remaining large current paths (112A, 113A, and 114A), the first current Can be transmitted to the fourth large current path (114A) through the capacitor (161A) and to the remaining large current paths (112A, 113A) through the capacitors (162A, 163A).

Meanwhile, in order to distribute (or balance) the first current in an equal size among the large current paths (111A, 112A, 113A, 114A), a first balancing unit (160A) is installed for each large current path (111A, 112A, 113A, 114A). The difference between the impedances (Zeq11, Zeq12, Zeq13, and Zeq14) when viewed may be less than a predetermined critical impedance difference.

In one embodiment, the first balancing unit 160A may reduce the difference between the voltages of each of the high current paths 111A, 112A, 113A, and 114A in the first frequency band to less than a predetermined threshold voltage difference. As described above, in the first frequency band, the capacitors 161A, 162A, and 163A operate like a short circuit, so the high current paths 111A, 112A, 113A, and 114A are supplied by the first balancing unit 160A, respectively. The difference between the voltages may be reduced below a predetermined threshold voltage difference. In other words, the difference between the voltages of the nodes (N1, N2, N3, N4) on each high current path (111A, 112A, 113A, 114A) may be reduced to below a predetermined threshold voltage difference.

In this way, the present invention generates balanced first currents (I11', I12', I13', and I14') and transfers them to other components of the current compensation device (100A), thereby enabling efficient removal of noise. there is.

In one embodiment, the above-described sensing unit 120 may be implemented as a sensing transformer 120A. At this time, the sensing transformer (120A) is insulated from the large current paths (111A, 112A, 113A, 114A) and the first current (I11', I12', I13) with the balance adjusted on the large current paths (111A, 112A, 113A, 114A). It may be a means to detect ', I14').

The sensing transformer (120A) is provided on the primary side (121A) disposed on the large current path (111A, 112A, 113A, 114A), and the balanced first current (I11', I12', I13', I14') is adjusted. A first induced current may be generated in the secondary side 122A based on the first magnetic flux density induced by . At this time, the secondary side 122A of the sensing transformer 120A may be differentially connected to the input terminal of the amplifier 130A, which will be described later.

In one embodiment, the first winding (121A) and the second winding (122A) of the sensing transformer (120A) may be wound around the transformer core in consideration of the direction of generation of magnetic flux and/or magnetic flux density.

For example, the first magnetic flux densities induced by the first currents (I11', I12', I13', and I14') whose balance is adjusted on the first side (121A) of the sensing transformer (120A) can overlap each other ( or to reinforce each other), and the first current (I11', I12', I13', I14) is configured and balanced on the secondary side (122A) insulated from the large current path (111A, 112A, 113A, 114A) ') can generate a first induced current corresponding to ').

Meanwhile, the number of windings on the high current path (111A, 112A, 113A, 114A) side (or primary side (121A)) and secondary side (122A) depends on the requirements of the system in which the current compensation device (100A) is used. It can be determined appropriately. For example, both the high current path (111A, 112A, 113A, 114A) side (or primary (121A)) winding and the secondary (122A) winding may be wound on the transformer core only once. In this case, the sensing transformer 120A is configured such that the high current path (111A, 112A, 113A, 114A) side (or primary side (121A)) winding and secondary side (122A) winding only pass through the central hole of the core. It can be configured. However, this is an example and the spirit of the present invention is not limited thereto.

Meanwhile, the sensing transformer (120A) has a second magnetic flux density induced by the second currents (I21, I22, I23, I24) flowing in each of the two or more large current paths (111A, 112A, 113A, and 114A) according to a predetermined magnetic flux density condition. It can be configured to be satisfactory.

For example, the sensing transformer 120A may be configured so that the second magnetic flux density induced by the second currents I21, I22, I23, and I24 satisfies a predetermined magnetic flux density condition. At this time, the predetermined magnetic flux density conditions may be conditions that cancel each other out.

In other words, the sensing transformer 120A is configured so that the second induced current induced by the second currents I21, I22, I23, and I24 flowing in each of the two or more large current paths 111A, 112A, 113A, and 114A is a predetermined second current. It can be configured to satisfy induced current conditions. At this time, the predetermined second induced current condition may be a condition in which the size of the second induced current is less than a predetermined threshold size.

In this way, the sensing transformer 120A is configured so that the second magnetic flux densities induced by the second currents I21, I22, I23, and I24 cancel each other, and the balanced first currents I11' and I12' are adjusted. , I13', and I14') can only be detected.

The sensing transformer 120A is a first frequency band (e.g., a band ranging from 150 KHz to 30 MHz) induced by the first currents (I11', I12', I13', and I14') whose balancing is adjusted. The magnitude of the magnetic flux density is configured to be greater than the magnitude of the second magnetic flux density induced by the second currents (I21, I22, I23, I24) in the second frequency band (for example, a band ranging from 50 Hz to 60 Hz). You can.

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 fact that the sensing unit 120 is implemented with the sensing transformer 120A is an example, and the spirit of the present invention is not limited thereto. Therefore, the first currents (I11, I12, I13, I14) input in common mode on the high current paths (111A, 112A, 113A, 114A) or the first currents (I11', I12', I13', I14' with balancing adjusted) ) can be used without limitation as the sensing unit (120A).

The amplifier 130 may amplify the output signal output from 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.

Due to the amplification of the amplification unit 130A, the current compensation device 100A generates a compensation current that is equal in size and opposite in phase to the balanced first currents (I11', I12', I13', and I14'). (IC) can be generated to compensate for the balanced first currents (I11', I12', I13', and I14') on the high current paths (111A, 112A, 113A, and 114A). At this time, 'same size' may mean that the sum of the sizes of the first currents (I11', I12', I13', and I14') and the size of the compensation current (IC) are the same or can be considered the same.

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.

For example, the sensing transformer (120A) converts the balanced first current (I11', I12', I13', I14') with a size of 1 into a first induced current with a size of 1/F1, and the compensation unit 140 ) is implemented as a compensation transformer (140A) that converts an amplification current with a size of 1 into a compensation current with a size of 1/F2, the amplification unit 130A generates an amplification current that is F1xF2 times the size of the first induced current. You can. 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 amplifier 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 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.

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 (IC) based on the output signal amplified by the above-described amplifier 130.

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-described high-current paths 111A, 112A, 113A, and 114A, and is installed on the high-current path 111A, 112A, 113A, and 114A (or the second path described later) based on the amplification current. It may be a means for generating a compensation current (on the car side 142A).

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 primary side (141A) of the compensation transformer (140A), the amplifier unit (130A), and the secondary side (122A) of the sensing transformer (120A) are distinguished from the remaining components of the current compensation device (100A). It can be connected to the 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.

The compensation capacitor unit 150 may provide a path through which the compensation current (IC) generated by the compensation unit 140 flows to the reference large current path 114. At this time, the reference large current path 114 refers to one of the large current paths 111, 112, 113, and 114. Depending on selection, the remaining large current paths 111, 112, and 113 may also become the reference large current paths.

In one embodiment, the compensation capacitor unit 150 may be implemented as a compensation capacitor unit 150A that provides a path through which the current generated by the compensation transformer 140A flows to the reference high current path 114A.

Figure 4 shows the process in which the compensation current (IC) generated by the compensation unit 140 is distributed to the large current paths 111A, 112A, 113A, and 114A through the compensation capacitor unit 150A and the second balancing unit 170A. This is a drawing for explanation.

As described above, the compensation capacitor unit 150A may provide a path through which the compensation current generated by the compensation unit 140A flows to the reference high current path 114A. Meanwhile, the compensation current delivered to the reference large current path 114A may be distributed to each large current path 111A, 112A, 113A, and 114A through the second balancing unit 170A.

For example, the compensation current transmitted to the reference large current path 114A may be transmitted to the first high current path 111A through the first capacitor 171A of the second balancing unit 170A (see path W1). Similarly, , Compensation current may be transmitted to each of the second large current path (112A) and the third large current path (113A) through the second capacitor (172A) and the third capacitor (173A). (Refer to paths W2 and W3) Meanwhile, the compensation current remaining after being delivered to the high current paths 111A, 112A, and 113A may remain in the fourth high current path (or the reference high current path 114A). (see path W4)

The compensation current provided to each of the four large current paths (111A, 112A, 113A, 114A) is the balanced first current (I11', I12', I13', I14) on each large current path (111A, 112A, 113A, 114A). '), the balanced first currents (I11', I12', I13', and I14') can be prevented from being transmitted to the second device (200A). At this time, the balanced first current (I11', I12', I13', I14') and the compensation current have the same (or can be viewed as the same) magnitude and are opposite in phase (or in phase corresponding to the opposite). It could be electric current.

In one embodiment, the compensation capacitor unit 150A is configured so that the current flowing between the reference high current path 114A and the reference potential (reference potential 1) of the current compensation device 100A through the compensation capacitor satisfies a predetermined second condition. It can be configured. At this time, the predetermined second current condition may be a condition in which the size of the current is less than the predetermined second threshold size.

As described above, the second balancing unit 170 not only distributes the compensation current provided by the compensation capacitor unit 150A to each large current path 111A, 112A, 113A, and 114A, but also adjusts the balancing of the composite currents to achieve balancing. A controlled synthetic current can be generated. At this time, the composite current may mean a current obtained by adding the distributed compensation current to the first currents (I11', I12', I13', and I14') whose balancing was adjusted by the first balancing unit (160A).

FIG. 5 is a diagram illustrating a process in which the second balancing unit 170A adjusts the balancing of the synthesized current according to an embodiment.

In one embodiment, the second balancing unit 170A includes high current paths 111A, 112A, and 113A corresponding to the R, S, and T lines, respectively, and a high current path 114A corresponding to the N line, as shown in FIG. 5. ) can be implemented with capacitors (171A, 172A, 173A) connecting.

The capacitance of the capacitors 171A, 172A, and 173A constituting the second balancing unit 170A may be determined so that only the current in the first frequency band to which the frequency of the composite current belongs selectively flows, and a detailed description of this is given in This is replaced with an explanation of the balancing unit (160A).

In one embodiment, when the size of the composite current (I31) on the first large current path (111A) is relatively larger than the size of the composite currents (I32, I33, and I34) on the remaining large current paths (112A, 113A, and 114A), the composite current (I31) may be transmitted to the fourth high current path (114A) through the capacitor (171A) and then to the remaining high current paths (112A, 113A) through the capacitors (172A, 173A).

Meanwhile, in order to distribute (or balance) the composite current in an equal size between the large current paths (111A, 112A, 113A, 114A), the first balancing unit (170A) is looked at for each large current path (111A, 112A, 113A, 114A). The difference between the impedances (Zeq21, Zeq22, Zeq23, and Zeq24) when viewed may be less than a predetermined critical impedance difference.

In one embodiment, the second balancing unit 170A may reduce the difference between the voltages of each of the high current paths 111A, 112A, 113A, and 114A in the first frequency band to less than a predetermined threshold voltage difference. In the first frequency band, the capacitors (171A, 172A, 173A) operate like a short circuit, so the difference between the voltages of each of the large current paths (111A, 112A, 113A, 114A) is adjusted by the second balancing unit (170A). may decrease below a predetermined threshold voltage difference. In other words, the difference between the voltages of the nodes (N5, N6, N7, N8) on each high current path (111A, 112A, 113A, 114A) can be reduced below a predetermined threshold voltage difference.

In this way, the present invention can more completely block the first current transmitted to the second device by once again evening out and reducing the distribution of the minute first currents remaining after current compensation by the compensator 140A.

As a result, the current compensation device (100A) according to an embodiment of the present invention is a first current (I11, I12, I12, I13, I14) can be actively compensated to prevent malfunction or damage to the second device.

Meanwhile, in FIGS. 4 and 5 , for convenience of explanation, the process of distributing the compensation current and the process of balancing the composite current are described as separate processes, but the above-described processes can be performed simultaneously. In other words, the second balancing unit 170A distributes the compensation current to the high current paths 111A, 112A, 113A, and 114A, and at the same time adjusts the balancing of the composite currents generated by the compensation current, resulting in the high current path 111A, The first current (I11, I12, I13, I14) of 112A, 113A, 114A) can be removed or reduced.

In one embodiment, the second balancing unit 170A may adjust the output impedance from the compensating unit 140A to the second device together with the output impedance adjusting unit 180A, which will be described later.

Figure 6 is a diagram for explaining the process of adjusting the output impedance (Zeq31, Zeq32, Zeq33, Zeq34) by the second balancing unit (170A) and the output impedance adjusting unit (180A).

In one embodiment, the output impedance adjusting unit 180A includes a capacitor 181A that provides a path through which current flows between the reference high current path 114A and the reference potential of the compensating unit 140A, as shown in FIG. 6. can do.

In addition, as described above, the second balancing unit 170A includes capacitors 171A, 172A, and 173A that provide paths through which current flows between the reference large current path 114A and the remaining large current paths 111A, 112A, and 113A, respectively. It can be included.

In one embodiment, the output impedances (Zeq31, Zeq32, Zeq33, Zeq34) from the compensation unit (140A) to the second device are the impedances of the capacitor (181A) and the capacitors (171A, 172A, 173A) connected in series, respectively. It can be a composite impedance that connects the impedances of 2 devices (Zeq41, Zeq42, Zeq43, Zeq44) in parallel. For example, in the first large current path (111A), the output impedance (Zeq31) may be a composite impedance obtained by connecting the impedance of the capacitor (181A) and the capacitor (171A) in series and the impedance (Zeq41) of the second device in parallel. there is.

In this way, the second balancing unit 170A and the output impedance adjusting unit 180A act as an impedance connected in parallel with the impedances (Zeq41, Zeq42, Zeq43, Zeq44) of the second device, and the compensation unit 140A 2 By reducing the output impedance (Zeq31, Zeq32, Zeq33, Zeq34) seen on the device side, current compensation by the compensation current is smoothly achieved even with the impedance (Zeq41, Zeq42, Zeq43, Zeq44) of the second device of various sizes.

Figure 7 is a diagram schematically showing the configuration of a current compensation device 100B used in a three-phase, three-wire system according to another embodiment of the present invention. Hereinafter, descriptions of content that overlaps with the content described with reference to FIGS. 1 to 6 will be omitted.

The current compensation device 100B according to another embodiment of the present invention provides first currents I11, I12, and I13 input in common mode to each of the three large current paths 111B, 112B, and 113B connected to the first device. You can actively compensate.

To this end, 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 amplification unit (130B), a compensation transformer (140B), and a compensation capacitor unit. It may include (150B), a first balancing unit (160B), a second balancing unit (170B), and an output impedance adjusting unit (180B).

In contrast to the current compensation device 100A according to the embodiment described in FIGS. 2 to 4, the current compensation device 100B according to the embodiment shown in FIG. 5 has three large current paths 111B, 112B, and 113B. It includes, and accordingly, there are differences in the sensing transformer (120B), the compensation capacitor unit (150B), the first balancing unit (160B), the second balancing unit (170B), and the output impedance adjusting unit (180B). 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 includes three distinct large current paths, that is, a first large current path (111B), a second large current path (112B), and a third large current path (113B). can do.

According to one embodiment, the first high current path 111B may be an R line, the second high current path 112B may be an S line, and the third high current path 113B may be a T line 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 balancing unit 160B adjusts the balancing of the first currents (I11, I12, and I13) between the large current paths (111B, 112B, and 113B), so that the balanced first currents (I11', I12', and I13) are adjusted. ') can be created.

In one embodiment, the first balancing unit 160B has one end connected to each of the high current paths 111B, 112B, and 113B corresponding to the R line, S line, and T line, as shown in FIG. 5, and the other end is common. It can be implemented with a connected capacitor. For example, if the size of the first current (I11) on the first large current path (111B) is relatively larger than the size of the first currents (I12, I13) on the remaining large current paths (112B, 113B), the first current (I11) is It can be transmitted to the remaining large current paths 112B and 113B through the capacitor 161B and capacitors 162B and 163B.

The first side (121B) of the sensing transformer (120B) is disposed in each of the first large current path (111B), the second large current path (112B), and the third large current path (113B) to generate the first induced current. . The magnetic flux densities generated in the sensing transformer 120B by the balanced first currents I11', I12', and I13' on the three large current paths 111B, 112B, and 113B can be mutually reinforced. Since the process of generating the first induced current by the balanced first currents (I11', I12', and I13') is described in FIG. 2, detailed description thereof will be omitted.

The compensation capacitor unit 150B may provide a path through which the compensation current (IC) generated by the compensation transformer flows to the third high current path 113B, which is a reference high current path. At this time, the reference large current path (113B) refers to one of the high current paths (111B, 112B, and 113B), and depending on selection, the remaining large current paths (111B, 112B) may also become the reference high current path.

In one embodiment, the compensation capacitor unit 150B may be implemented as a capacitor 151B as shown in FIG. 7.

The second balancing unit 170B may distribute the compensation current delivered to the reference large current path 113B to each large current path 111B, 112B, and 113B.

In one embodiment, the second balancing unit 170B includes capacitors 171B and 172B, one end of which is connected to each of the high current paths 111B, 112B, and 113B corresponding to the R line, S line, and T line, and the other end of which is commonly connected. , 173B).

In one embodiment, the compensation current transmitted to the reference large current path 113B may be transmitted to the first large current path 111B through the first capacitor 171B of the second balancing unit 170B. Similarly, compensation current may be transmitted to each of the second high current path 112B and the third high current path 113B through the second capacitor 172B and the third capacitor 173B.

The compensation current provided to each of the three large current paths (111B, 112B, 113B) cancels the balanced first current (I11', I12', I13) on each large current path (111B, 112B, 113B), so that the balancing is It is possible to prevent the adjusted first currents (I11', I12', and I13) from being transmitted to the second device (200A). At this time, the balanced first currents (I11', I12', and I13) and the compensation current may be currents of the same (or considered to be the same) magnitude and opposite in phase (or in phase corresponding to the opposite). .

In one embodiment, the compensation capacitor unit 150B is configured so that the current flowing between the reference high current path 113B and the reference potential (reference potential 1) of the current compensation device 100B through the compensation capacitor satisfies a predetermined second condition. It can be configured. At this time, the predetermined second current condition may be a condition in which the size of the current is less than the predetermined second threshold size.

As described above, the second balancing unit 170B not only distributes the compensation current provided by the compensation capacitor unit 150B to each large current path 111B, 112B, and 113B, but also adjusts the balancing of the composite currents to adjust the balancing. A synthetic current can be generated. At this time, the composite current may mean a current obtained by adding the distributed compensation current to the first currents (I11', I12', and I13') whose balancing was adjusted by the first balancing unit (160B).

The capacitance of the capacitors 171B, 172B, and 173B constituting the second balancing unit 170B may be determined so that only the current in the first frequency band to which the frequency of the synthesized current belongs selectively flows, and a detailed description of this is given in This is replaced with an explanation of the balancing unit 160B.

In one embodiment, the second balancing unit 170B, together with the output impedance adjusting unit 180B, may adjust the output impedance from the compensating unit 140B to the second device.

In one embodiment, the output impedance adjusting unit 180B may include a capacitor 181B that provides a path through which current flows between the reference high current path 113B and the reference potential of the compensating unit 140B.

The principle of adjusting the output impedance from the compensator 140B to the second device by the second balancing unit 170B and the output impedance adjusting unit 180B has been explained in detail in FIG. 6, so detailed description thereof will be omitted.

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.

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 scope of the patent claims described below as well as all scopes equivalent to or equivalently changed from the scope of the claims are within the scope of the spirit of the present invention. It will be said to belong to

100: Current compensation device
111, 112, 113, 114: High current path
120: Sensing unit
130: Amplification unit
140: Compensation unit
150: Compensation capacitor unit
160: First balancing unit
170: Second balancing unit
180: Output impedance adjustment unit
200: second device
300: first device
400: third device

Claims (5)

In a current compensation device that actively compensates for the first current input in common mode from the first device,
at least two high current paths for transferring a second current supplied by a second device to the first device;
a first balancing unit including a high-current path connection unit that allows only a first current in a first frequency band to flow, and controlling balancing of the first current between the at least two large current paths;
a sensing unit that detects a first current whose balance is adjusted by the first balancing unit on the at least two large current paths and generates an output signal corresponding to the detection result;
an amplifier that amplifies the output signal and generates an amplified output signal;
a compensation unit that generates a compensation current based on the amplified output signal;
a compensation capacitor unit providing a path through which the compensation current flows to a reference high current path, which is one of the at least two high current paths; and
A current compensation device comprising; a second balancing unit distributing the compensation current provided to the reference large current path to the at least two large current paths. According to paragraph 1,
A current compensation device wherein the high current path connecting portion is implemented with at least one capacitor having a capacitance that conducts only the first current in the first frequency band. According to paragraph 2,
The current compensation device is used in a three-phase, four-wire system, wherein the at least two high current paths are four high current paths corresponding to the R line, S line, T line, and N line,
The high current path connection unit includes capacitors connecting each of the high current paths corresponding to the R, S, and T lines and the high current path corresponding to the N line. According to paragraph 2,
The current compensation device is used in a three-phase, three-wire system, wherein the at least two high current paths are three high current paths corresponding to the R line, S line, and T line,
The high-current path connection unit includes capacitors with one end connected to each of the high-current paths corresponding to the R line, S line, and T line and the other end commonly connected. According to paragraph 1,
The first current is a current having a frequency of a first frequency band, and the first frequency band is a higher band than the second frequency band of the second current.