KR102129578B1 - Current compensation device - Google Patents

Abstract

The present invention provides a current compensation device which actively compensates for a first current inputted in a common mode to each of at least two large current paths connected to a first device. The current compensation device comprises: at least two high current paths transmitting a second current supplied by a second device to a first device; a sensing unit sensing a first current on the high current path to generate an output signal corresponding to the first current; an amplification unit amplifying the output signal of the sensing unit to generate an amplification current; a compensation unit generating a compensation current based on the amplification current and allowing the compensation current to flow through each of the at least two large current paths; and a disturbance protection unit limiting an applied voltage to a voltage of a threshold voltage or less when the voltage of a predetermined threshold voltage or greater is applied to at least one of an input terminal of the amplification unit to which the sensing unit and the amplification unit are connected and an output terminal of the amplification unit to which the sensing unit and the compensation unit are connected.

Description

CURRENT COMPENSATION DEVICE

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

Generally, electrical appliances such as household appliances, industrial electrical appliances, and electric vehicles emit noise during operation. For example, noise may be emitted through the power line due to the switching operation of the power converter in the electronic device. Leaving such noise is not only harmful to the human body, but also causes malfunctions or malfunctions in peripheral parts and other electronic devices. As such, the electromagnetic interference that an electronic device exerts on other devices is referred to as electromagnetic interference (EMI), and, among other things, noise transmitted through wires and substrate wiring is called conductive emission (CE) noise.

In order to ensure that electronic devices operate without causing damage to peripheral parts and other devices, EMI noise emissions are strictly regulated in all electronic products. Accordingly, most electronic products essentially include a current compensation device (eg, an EMI filter) that reduces the EMI noise current in order to satisfy the regulation on the amount of noise emission. For example, in white appliances such as air conditioners, electric vehicles, aviation, and energy storage systems (ESS), an EMI filter is essentially included. Conventional EMI filters use a common mode choke (CM choke) to reduce common mode (CM) noise among conductive emission (CE) noise. The common mode (CM) choke is a passive filter, and serves to suppress the common mode noise current.

On the other hand, with the development of technology, as more and more high-power products are released, the need for high-power current compensation devices is increasing. However, in a high-power/high-current system, the common mode (CM) choke rapidly reduces noise reduction performance due to a magnetic saturation phenomenon. Therefore, in order to prevent magnetic saturation and maintain noise reduction performance in high-power/high-current systems, conventionally, the size of common mode chokes must be increased or increased, which increases the size and price of EMI filters for high-power products. There was a problem. In addition, if the current compensation device includes an active element, there is a problem that the active element may fail when a disturbance such as a lightning strike occurs.

The present invention has been devised to improve the above problems, and to provide an active current compensation device that reduces common mode noise by injecting a compensation current for a common mode (CM) noise current. In addition, it is intended to provide an active current compensation device that can be protected from disturbances such as lightning strikes when mounted on an electrical appliance. However, these problems are exemplary, and the scope of the present invention is not limited thereby.

According to an embodiment of the present invention, a current compensation device that actively compensates for a first current input in a common mode in each of at least two large current paths connected to a first device is supplied by a second device At least two or more large current paths to transfer the second current to the first device; A sensing unit configured to sense the first current on the large current path and generate an output signal corresponding to the first current; An amplifying unit that amplifies the output signal of the sensing unit to generate an amplifying current; A compensation unit generating a compensation current based on the amplification current and allowing the compensation current to flow through each of the at least two large current paths; And when a voltage equal to or greater than a predetermined threshold voltage is applied to at least one of an input terminal of the amplifying unit connected to the sensing unit and the amplifying unit, and an output terminal of the amplifying unit connected to the sensing unit and the compensating unit, the applied voltage is applied to the threshold voltage. Disturbance protection unit limited to the following voltage; may include.

According to an embodiment, the disturbance protection unit has a first impedance when a voltage less than the predetermined threshold voltage is applied to at least one of the input terminal and the output terminal, and at least one of the input terminal and the output terminal is the When a voltage higher than a predetermined threshold voltage is applied, it may have a second impedance lower than the first impedance.

According to an embodiment, when a voltage above the predetermined threshold voltage is applied to at least one of the input terminal and the output terminal, the disturbance protection unit may consume at least a part of power due to the voltage above the predetermined threshold voltage. .

According to an embodiment, the current compensation device may include: a first disturbance protection unit connected to the input terminal; And a second disturbance protection unit connected to the output terminal.

According to one embodiment, the sensing unit, the primary side disposed on the large current path; And a secondary transformer configured to output the output signal to the amplification unit. The sensing transformer includes a first transformer, and the first disturbance protection unit includes the secondary transformer based on the voltage applied to the at least two large current paths by the primary side. The voltage above the threshold voltage induced on the side may be limited to a voltage below the threshold voltage and transferred to the amplifying unit.

According to one embodiment, the compensation unit is a primary side disposed on a path connecting the output terminal of the amplification unit and the reference potential of the amplification unit; And a secondary side disposed on a path connecting the compensating capacitor portion and a reference potential of the current compensating device, wherein the second disturbance protection portion includes a voltage at which the secondary side is applied to the at least two large current paths. The voltage above the threshold voltage induced on the primary side may be limited to a voltage below the threshold voltage and transferred to the amplifying unit.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to various embodiments of the present invention made as described above, it is possible to provide a current compensation device in which the price, area, volume, and weight do not increase significantly even in a high-power system. Specifically, the active current compensation device according to various embodiments of the present disclosure can reduce the price, area, volume, and weight compared to a passive filter including a CM choke.

In addition, the current compensation device according to various embodiments of the present invention may provide an active current compensation device that can operate independently without parasitic in the CM choke.

In addition, the active current compensation device according to various embodiments of the present invention, by having an active circuit stage electrically isolated from the power line, it is possible to stably protect the elements included in the active circuit stage.

In addition, the active current compensation device according to various embodiments of the present invention may be protected from external overvoltage, such as a lightning strike.

Through this, the present invention can provide a current compensation device that can stably operate regardless of the characteristics of the surrounding electrical system, has versatility as an independent component, and can be commercialized as an independent module.

Of course, the scope of the present invention is not limited by these effects.

1 schematically shows a configuration of a system including a current compensation device 100 according to an embodiment of the present invention.
2 schematically shows a current compensation device 100A according to an embodiment of the present invention.
3 schematically shows a current compensation device 100A-1 according to an embodiment of the present invention.
4 schematically shows a current compensation device 100A-2 according to an embodiment of the present invention.
5 schematically shows a current compensation device 100B according to another embodiment of the present invention.
6 schematically illustrates a current compensation device 100C according to another embodiment of the present invention.
7 schematically shows a configuration of a current compensation device 100D according to another embodiment of the present invention.

The present invention can be applied to a variety of transformations and may have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description. Effects and features of the present invention and methods for achieving them will be clarified with reference to embodiments described below in detail with reference to the drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms.

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

In the following examples, terms such as first and second are not used in a limiting sense, but for the purpose of distinguishing one component from other components. In the following embodiments, singular expressions include plural expressions, unless the context clearly indicates otherwise. In the following embodiments, terms such as include or have means that the features or components described in the specification exist, and do not exclude the possibility that one or more other features or components may be added in advance. In the drawings, the size of components may be exaggerated or reduced for convenience of description. When an embodiment can be implemented differently, a specific process order may be performed differently from the described order. In the following embodiments, when a region, component, unit, unit, module, etc. is connected, a region, component, unit, unit, module as well as a region, component, unit, unit, and module are directly connected. This includes cases where other areas, components, parts, units, and modules are interposed and connected indirectly.

1 schematically shows a configuration of a system including a current compensation device 100 according to an embodiment of the present invention. The current compensator 100 is a first current (I11, I12) input to the common mode (Common Mode, CM) through the two or more large current paths (111, 112) from the first device 300 (eg, EMI noise Current).

Referring to FIG. 1, the current compensation device 100 may include a sensing unit 120, an amplification unit 130, a compensation unit 160, and a disturbance protection unit 133.

In the present specification, the first device 300 may be various types of devices that use power supplied by the second device 200. For example, the first device 300 may be a load driven using the power supplied by the second device 200. In addition, the first device 300 may be a load (eg, an electric vehicle) that stores energy using power supplied by the second device 200 and is driven using the stored energy. However, it is not limited thereto.

In the present specification, the second device 200 may be various types of devices 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 generates and supplies power, or may be a device (eg, an electric vehicle charging device) that supplies power produced by another device. Of course, the second device 200 may be a device that supplies stored energy. However, it is not limited thereto. A power conversion device may be located on the first device 300 side. For example, the first currents I11 and I12 may be input to the current compensation device 100 by the switching operation of the power conversion device. That is, the first device 300 side may correspond to a noise source, and the second device 200 side may correspond to a noise receiver.

The two or more large current paths 111 and 112 may be paths that transmit power supplied by the second device 200, that is, the second currents I21 and I22 to the first device 300, for example, power lines. have. For example, each of the two or more large current paths 111 and 112 may be a live line and a neutral line. At least a portion of the large current paths 111 and 112 may pass through the current compensation device 100. The second currents I21 and I22 may be alternating currents having frequencies in the second frequency band. The second frequency band may be, for example, 50 Hz to 60 Hz band.

Also, the two or more large current paths 111 and 112 may be a path in which noise generated in the first device 300, that is, the first currents I11 and I12 are transmitted to the second device 200. The first currents I11 and I12 may be input in a common mode for 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. Alternatively, the first currents I11 and I12 may be noise currents generated by a switching operation of the power conversion device of the first device 300. The first currents I11 and I12 may be currents having frequencies in the first frequency band. The first frequency band may be a higher frequency band than the second frequency band described above. The first frequency band may be, for example, 150KHz to 30MHz band.

Meanwhile, the two or more large current paths 111 and 112 may include two paths as illustrated in FIG. 1, or may include three paths or four paths as illustrated in FIG. 6. The number of large current paths 111 and 112 may vary depending on the type and/or type of power used by the first device 300 and/or the second device 200.

The sensing unit 120 may sense the first currents I11 and I12 on two or more large current paths 111 and 112 and generate output signals corresponding to the first currents I11 and I12. That is, the sensing unit 120 may mean a means for sensing the first currents I11 and I12 on the large current paths 111 and 112. At least a part of the large current paths 111 and 112 may pass through the sensing unit 120 for sensing the first currents I11 and I12, but an output signal generated by sensing is generated in the sensing unit 120. The portion can be insulated from the high current paths 111 and 112. For example, the sensing unit 120 may be implemented as a sensing transformer. The sensing transformer may sense the first currents I11 and I12 on the large current paths 111 and 112 while being insulated from the large current paths 111 and 112.

According to an embodiment, the sensing unit 120 may be differentially connected to the input terminal of the amplifying unit 130.

The amplifying unit 130 may be electrically connected to the sensing unit 120 to 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. The amplifying unit 130 may be implemented by various means, and may include active elements. In one embodiment, the amplification unit 130 may include an OP-AMP. For example, the amplification unit 130 may include a plurality of passive elements such as resistors and capacitors in addition to the OP-AMP. In another embodiment, the amplifying unit 130 may include a bipolar junction transistor (BJT). For example, the amplifying unit 130 may include a plurality of passive elements such as resistors and capacitors in addition to the BJT. However, the present invention is not limited thereto, and means for'amplifying' described in the present invention may be used without limitation as the amplifying unit 130 of the present invention. The reference potential (reference potential 2) of the amplifier 130 and the reference potential (reference potential 1) of the current compensation device 100 may be potentials that are distinguished from each other.

The amplifying unit 130 receives power from the first device 300 and/or the third device 400 separated from the second device 200, amplifies and amplifies the output signal output by the sensing unit 120 It can generate an electric current. In this case, the third device 400 may be a device that receives power from a power source independent of the first device 300 and the second device 200 and generates input power of the amplifying unit 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 of the amplifying unit 130.

The compensation unit 160 may generate a compensation current based on the output signal amplified by the amplifier 130. The output side of the compensator 160 may be connected to the large current paths 111 and 112 to flow the compensating currents IC1 and IC2 to the large current paths 111 and 112, but may be insulated from the amplifier 130. For example, the compensation unit 160 may include a compensation transformer for the insulation. For example, an output signal of the amplifying unit 130 flows to the primary side of the compensation transformer, and a compensation current based on the output signal may be generated to the secondary side of the compensation transformer. The compensation unit 160 injects the compensation currents IC1 and IC2 into the large current paths 111 and 112 through each of two or more large current paths 111 and 112 in order to cancel the first currents I11 and I12. ). The compensation currents IC1 and IC2 may have the same magnitude as the first currents I11 and I12 and may have opposite phases. That is, the sensing unit 120, the amplifying unit 130, and the compensating unit 160 may be designed such that the current gain ratio representing the compensating currents IC1 and IC2 compared to the first currents I11 and I12 is -1. have.

The disturbance protection unit 133 may protect the amplification unit 130 from disturbance. For example, the active elements included in the amplification unit 130 may be protected by the disturbance protection unit 133.

The current compensation device 100 may be mounted on an electric device, but in general, a situation in which the electric device operates may not be stable. That is, a disturbance signal, such as an overvoltage or an overcurrent, may enter the current compensation device 100 from the outside through the large current paths 111 and 112. For example, a pulse voltage of several kV may occur in at least one of the large current paths 111 and 112 due to a lightning strike or a lightning surge. The overvoltage/overcurrent as described above may be transmitted to the amplifying unit 130 through the sensing unit 120 or the compensation unit 160. The amplifying unit 130 may include various types of active elements, and thus is vulnerable to external disturbances, and malfunction or failure may occur due to overvoltage/overcurrent.

In various embodiments of the present invention, the current compensation device 100 primarily protects the amplification unit 130 from the above-described disturbance by having a structure in which the amplification unit 130 is insulated from the large current paths 111 and 112. can do. Through the current compensation device 100 insulated structure, it is possible to prevent the active element from being directly exposed to high voltage.

For more reliable protection from disturbances, the current compensation device 100 may include a disturbance protection unit 133. In one embodiment, the disturbance protection unit 133, the input terminal of the amplification unit 130 to which the sensing unit 120 and the amplification unit 130 is connected, and the amplification to which the sensing unit 120 and the compensation unit 160 are connected When a voltage above a predetermined threshold voltage is applied to at least one of the output terminals of the unit 130, the applied voltage may be limited to a voltage below the threshold voltage. For example, the disturbance protection unit 133, the amplification unit through the first disturbance protection unit 131 and the compensation unit 160 to block the overvoltage transmitted to the amplifier 130 through the sensing unit 120 A second disturbance protection unit 132 for blocking the overvoltage transmitted to the 130 may be included.

The first disturbance protection unit 131 may be connected to an input terminal of the amplification unit 130. According to an embodiment, the first disturbance protection unit 131 may be differentially connected to the input terminal of the amplification unit 130. The first disturbance protection unit 131 may be connected in parallel to the output terminal of the sensing unit 120.

The second disturbance protection unit 132 may be connected to the output terminal of the amplification unit 130. The second disturbance protection unit 132 may be connected in parallel to the input terminal of the compensation unit 160.

The first disturbance protection unit 131 and the second disturbance protection unit 132 may be insulated from the large current paths 111 and 112.

According to an embodiment, the first disturbance protection unit 131 has a first impedance when a voltage lower than a predetermined threshold voltage is applied to the input terminal of the amplifying unit 130 and is predetermined to the input terminal of the amplifying unit 130. When a voltage higher than or equal to the threshold voltage is applied, the second impedance may be lower than the first impedance. The first impedance is a very large value, and may be, for example, a value close to infinity. Likewise, the second disturbance protection unit 132 has a first impedance when a voltage lower than a predetermined threshold voltage is applied to the output terminal of the amplifying unit 130, and is higher than a predetermined threshold voltage to the output terminal of the amplifying unit 130. When a voltage is applied, it may have a second impedance lower than the first impedance.

According to an embodiment, when the voltage applied to the disturbance protection unit 133 is less than a specified voltage, the disturbance protection unit 133 does not flow current through the external disturbance protection unit due to an external overvoltage ( When the voltage applied to 133) is greater than or equal to a specified voltage, an amplifying unit 130 may be protected from passing over voltage (parallel) to prevent the overvoltage from being transmitted to the amplifying unit 130.

The current compensation device 100 may be a feedforward type compensation filter that compensates for noise input from the first device 300 side at a front end that is a power source side. That is, in the current compensation device 100, the sensing unit 120 may be disposed on the side of the first device 300 as a noise source, and the compensation unit 160 may be disposed on the side of the second device 200 as the power source. .

2 schematically shows a current compensation device 100A according to an embodiment of the present invention. The current compensating device 100A actively compensates for the first currents I11 and I12 (for example, noise currents) input in a common mode to each of the two large current paths 111A and 112A connected to the first device 300A. can do.

Referring to FIG. 2, the current compensation device 100A includes a sensing transformer 120A, an amplifier 130A, a compensation unit 160A, a first disturbance protection element 131A, and a second disturbance protection element 132A It may include. The compensation unit 160A may include a compensation transformer 140A and a compensation capacitor unit 150A.

In one embodiment, the above-described sensing unit 120 may include a sensing transformer (120A). In this case, the sensing transformer 120A may be a means for sensing the first currents I11 and I12 on the large current paths 111A and 112A while insulated from the large current paths 111A and 112A. The sensing transformer 120A may sense the first currents I11 and I12 which are noise currents input to the large current paths 111A and 112A (eg, power lines) from the first device 300A side.

The sensing transformer 120A may include a primary side 121A disposed on the large current paths 111A and 112A, and a secondary side 122A differentially connected to the input terminal of the amplifier 130A. have. The sensing transformer 120A is based on the magnetic flux density induced by the first currents I11 and I12 on the primary side 121A (e.g. primary winding) disposed on the large current paths 111A and 112A. An induced current can be generated on the secondary side 122A (eg, secondary winding). The primary side 121A of the sensing transformer 120A may be, for example, a winding in which a first large current path 111A and a second large current path 112A are wound on one core. However, the present invention is not limited thereto, and the primary side 121A of the sensing transformer 120A may have a form in which the first large current path 111A and the second large current path 112A pass through the core.

Specifically, the magnetic flux density induced by the first current I11 on the first large current path 111A (eg, live line) and the first current I12 on the second large current path 112A (eg neutral line). The magnetic flux density induced by may be configured to overlap (or reinforce) each other. At this time, the second currents I21 and I22 also flow on the large current paths 111A and 112A, and the magnetic flux density induced by the second current I21 on the first large current path 111A and the second large current path 112A. ), the magnetic flux densities induced by the first current I22 on the phase may be configured to cancel each other. In addition, for example, the sensing transformer 120A has a second magnetic flux density magnitude induced by the first currents I11 and I12 in a first frequency band (for example, a band having a range of 150KHz to 30MHz). It may be configured to be larger than the magnitude of the magnetic flux density induced by the second currents I21 and I22 of the band (for example, a band having a range of 50 Hz to 60 Hz).

In this way, the sensing transformer 120A is configured such that magnetic flux densities induced by the second currents I21 and I22 can cancel each other, so that only the first currents I11 and I12 are sensed. That is, the current induced to the secondary side 122A of the sensing transformer 120A may be a current in which the first currents I11 and I12 are converted at a constant rate.

For example, in the sensing transformer 120A, the turns ratio of the primary side 121A and the secondary side 122A is 1:N _sen, and the self-inductance of the primary side 121A of the sensing transformer 120A is L. _{Speaking of sen} , the secondary side 122A can have a self-inductance of N _sen ² L _sen . At this time, the current induced to the secondary side 122A is 1/N _sen times the first currents I11 and I12. For example, the primary side 121A and the secondary side 122A of the sensing transformer 120A may be combined with a coupling coefficient of k _sen .

The secondary side 122A of the sensing transformer 120A may be connected to the input terminal of the amplifier 130A. For example, the secondary side (122A) of the sensing transformer (120A) is differentially connected to the input terminal of the amplifier 130A, it is possible to supply an induced current to the amplifier 130A. Alternatively, depending on the configuration of the amplification section 130A, the secondary side 122A of the sensing transformer 120A is a path connecting the input terminal of the amplification section 130A and the reference potential (reference potential 2) of the amplification section 130A. It may be placed on. That is, one end of the secondary side 122A may be connected to the input terminal of the amplification unit 130A, and the other end of the secondary side 122A may be connected to the reference potential (reference potential 2) of the amplification unit 130A. .

The amplifying unit 130A may correspond to the amplifying unit 130 described above. The amplifier 130A can amplify the current sensed by the sensing transformer 120A and induced to the secondary side 122A. For example, the amplification unit 130A may amplify the magnitude of the induced current at a predetermined ratio, and/or adjust the phase.

The compensation unit 160A may correspond to the compensation unit 160 described above. The compensation unit 160A may include a compensation transformer 140A and a compensation capacitor unit 150A. The amplification current amplified by the amplification unit 130A described above flows to the primary side 141A of the compensation transformer 140A.

The compensation transformer 140A may be a means for isolating the amplifier 130A including the active element from the large current paths 111A and 112A. That is, while the compensation transformer 140A is insulated from the large current paths 111A and 112A, generating a compensation current (on the secondary side 142A) for injecting the large current paths 111A and 112A based on the amplified current. It may be a means for.

The compensation transformer 140A may include a primary side 141A differentially connected to the output terminal of the amplifier 130A, and a secondary side 142A connected to the large current paths 111A and 112A. have. The compensating transformer 140A induces a compensating current on the secondary side 142A (eg secondary winding) based on the magnetic flux density induced by the amplifying current flowing on the primary side 141A (eg primary winding). can do.

At this time, the secondary side 142A may be disposed 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 100A. That is, one end of the secondary side 142A is connected to the large current paths 111A and 112A through the compensation capacitor unit 150A, and the other end of the secondary side 142A is the reference potential of the current compensation device 100A. (Reference potential 1). On the other hand, the primary side 141A of the compensation transformer 140A, the amplifier 130A, and the secondary side 122A of the sensing transformer 120A are separated from the rest of the components of the current compensation device 100A. It can be connected to the potential (reference potential 2). The reference potential (reference potential 1) of the current compensation device 100A and the reference potential (reference potential 2) of the amplifier 130A may be divided.

As described above, the present invention uses a different reference potential from the rest of the components for the component generating the compensation current, and allows a component generating the compensation current to operate in an isolated state by using a separate power source. The reliability of the current compensation device 100A can be improved.

In the compensation transformer 140A, if the turns ratio of the primary side 141A and the secondary side 142A is 1:N _inj, and the self inductance of the primary side 141A of the compensation transformer 140A is L _inj , The secondary side 142A may have a self inductance of N _inj ² L _inj . At this time, the current induced to the secondary side 142A is 1/N _inj times the current flowing through the primary side 141A (that is, the amplification current). The primary side 141A and the secondary side 142A of the compensation transformer 140A may be combined with a coupling coefficient of k _inj .

The current converted through the compensation transformer 140A may be injected as compensation currents IC1 and IC2 into the large current paths 111A and 112A (eg, power lines) through the compensation capacitor unit 150A. Accordingly, the compensation currents IC1 and IC2 may have the same magnitude and opposite phases to the first currents I11 and I12 in order to cancel the first currents I11 and I12. Therefore, the magnitude of the current gain of the amplifier 130A can be designed to be N _sen N _inj .

The compensation capacitor unit 150A may provide a path through which the current generated by the compensation transformer 140A flows into each of the two large current paths 111A and 112A, as described above.

The compensation capacitor unit 150A has two Y-capacitors, one end of which is connected to the secondary side 142A of the compensation transformer 140A, and the other end of which is connected to the large current paths 111A and 112A. Y-cap). One end of each of the two Y-caps shares a node connected to the secondary side 142A of the compensation transformer 140A, and the opposite end of each of the two Y-caps is a first large current path 111A and a first 2 It may have a node connected to the high-current path (112A).

The compensation capacitor unit 150A may flow compensation currents IC1 and IC2 induced by the compensation transformer 140A to the power line. When the compensation currents IC1 and IC2 compensate (or cancel) the first currents I11 and I12, the current compensation device 100A can reduce noise.

Meanwhile, the compensation capacitor unit 150A may be configured such that the current IL1 flowing between the two large current paths 111A and 112A through the compensation capacitor is less than the first threshold size. In addition, the compensation capacitor unit 150A may be configured such that the current IL2 flowing between each of the two large current paths 111A and 112A and the reference potential 1 through the compensation capacitor is less than a second threshold size.

The current compensation device 100A can realize an isolated structure by using the compensation transformer 140A and the sensing transformer 120A.

The current compensation device 100A according to an embodiment of the present invention may not include a common mode (CM) choke. Since the CM choke functions as a passive filter, it must have a very large inductance to suppress leakage of the first currents I11 and I12 (for example, noise current). Therefore, the number of windings of the CM choke increases and the size of the core becomes very large. Unlike the CM choke, the sensing transformer 120A included in the current compensating device 100A according to an embodiment of the present invention is intended to sense the noise first currents I11 and I12, and therefore needs to have a large impedance There is no The sensing transformer 120A may have an impedance of a thousandth to a hundredth of the impedance of the CM choke. Therefore, the size of the sensing transformer 120A can be much smaller than the size of the CM choke. The current compensating device 100A according to an embodiment of the present invention can operate independently without parasitic on the CM choke. It goes without saying that the current compensating device 100A may operate in combination with a separate external CM choke independent of the current compensating device 100A.

The first disturbance protection element 131A and the second disturbance protection element 132A may be examples of the first disturbance protection unit 131 and the second disturbance protection unit 132 described above.

The first disturbance protection element 131A and the second disturbance protection element 132A may include a TVS (Transient Voltage Suppression) diode element. However, it is not limited thereto.

For example, an external overvoltage S such as a brain surge may occur in at least one of the large current paths 111A and 112A. For example, when an external overvoltage S occurs in the second large current path 112A as shown in FIG. 2, it is amplified in the form of magnetic energy through the first transmission path P1 or the second transmission path P2 ( 130A). The first transmission path P1 is a path through the sensing transformer 120A, and the second transmission path P2 represents a path through the compensation transformer 140A. Since the active elements of the amplifying unit 130A are vulnerable to external disturbance, a protection device is required.

The first disturbance protection element 131A may be connected in parallel to the secondary side 122A of the sensing transformer 120A in order to protect the amplifier 130A from overvoltage transmitted to the first transmission path P1. . The second disturbance protection element 132A may be connected in parallel to the primary side 141A of the compensation transformer 140A in order to protect the amplifier 130A from overvoltage transmitted to the second transmission path P2. . The first disturbance protection element 131A and the second disturbance protection element 132A may be insulated from the large current paths 111A and 112A.

The first and second disturbance protection elements 131A and 132A may include, for example, a TVS diode element. At this time, in order to minimize the performance reduction of the amplifier 130A due to the TVS diode element, a TVS diode element having a sufficiently low diode junction capacitance may be used. That is, the junction capacitance of the TVS diodes for the first and second disturbance protection elements 131A and 132A may be less than or equal to a specified value. For example, the junction capacity of the TVS diode may be several hundred pF or less. Further, even if the TVS diodes for the first and second disturbance protection elements 131A and 132A have a low junction capacity, their durability can be ensured due to the insulating structure.

The first and second disturbance protection elements 131A and 132A (eg, a TVS diode) may have a breakdown voltage. For example, when the voltage across the first disturbance protection element 131A is less than the breakdown voltage, current may not flow through the first disturbance protection element 131A. However, when a voltage equal to or higher than the breakdown voltage is applied to both ends of the first disturbance protection element 131A due to the external overvoltage S, the impedance of the first disturbance protection element 131A decreases and the first disturbance protection element 131A is turned on. Current can flow through. The second disturbance protection element 132A may operate similarly to the first disturbance protection element 131A. Therefore, the active elements included in the amplifier 130A may be protected from overvoltage.

The first and second disturbance protection elements 131A and 132A, when a voltage equal to or higher than a predetermined threshold voltage (eg, breakdown voltage) is applied to at least one of the input terminal and the output terminal of the amplifying unit 130A, It is possible to consume at least a portion of the power by voltage. At least a portion of the remaining power due to the voltage above the predetermined threshold voltage may be consumed by the remaining elements (eg, elements included in the amplifier 130A).

Due to the combination of the insulating structure and the first and second disturbance protection elements 131A and 132A, the current compensation device 100A can be used as an independent module in any system.

3 schematically shows a current compensation device 100A-1 according to an embodiment of the present invention. The current compensation device 100A-1 illustrated in FIG. 3 is an example of the current compensation device 100A illustrated in FIG. 2. The amplification unit 130A-1 included in the current compensation device 100A-1 is an example of the amplification unit 130A of the current compensation device 100A.

Referring to FIG. 3, the amplifying unit 130A-1 may include a first amplifying element for amplifying a positive signal and a second amplifying element for amplifying a negative signal. For example, the amplifying unit 130A-1 may be implemented as a push-pull amplifier utilizing an amplifying element including npn BJT and pnp BJT.

The induced current induced from the secondary side 122A by the sensing transformer 120A may be differentially input to the amplifying unit 130A-1. C _b and C _e can selectively couple only the AC signal.

The third device 400A supplies a DC low voltage V _DC based on the reference potential 2 to drive the amplifier 130A-1. C _DC is a decoupling capacitor for _DC to V _DC and may be connected in parallel to the third device 400A. C _DC can selectively couple only the AC signal between both collectors of npn BJT and pnp BJT.

In the amplification unit 130A-1, R _npn , R _pnp , R _bb , and R _e can adjust the operating point of the BJT. R _npn is a collector terminal of the npn BJT, a third device 400A terminal, and a base terminal of the npn BJT. R _bb can connect the base end of the npn BJT and the base end of the pnp BJT. R _pnp is a collector terminal of the pnp BJT, a reference potential 2, and a base terminal of the pnp BJT.

Meanwhile, in one embodiment, the secondary side 122A side of the sensing transformer 120A may be connected to the base and emitter ends of the two BJTs, and the primary side 141A side of the compensation transformer 140A is a collector of two BJTs And can be connected to the base. The amplifier 130A-1 may have a regression structure that injects the output current back to the base of the BJT. Due to the regression structure, the amplification unit 130A-1 can stably obtain a constant current gain for the operation of the current compensation device 100A-1.

In the case of a positive swing in which the input voltage of the amplifying unit 130A-1 due to noise is greater than 0, npn BJT may operate. At this time, the operating current may flow through the first path 601. In the case of a negative swing in which the input voltage of the amplifying unit 130A-1 due to noise is less than 0, the pnp BJT may operate. At this time, the operating current may flow through the second path 602.

는, 수학식 1과 같이 나타낼 수 있다. Meanwhile, the current gain of the BJT element itself

Can be expressed as Equation (1).

는 BJT 소자 자체가 가지는 전류 이득을 나타내고, I_sen은, 센싱 변압기(120A)에 의해 유도되는, 2차 측(122A)에 흐르는 전류이고, I_out,BJT는, 보상 변압기(140A)의 1차 측(141A)에 흐르는 전류이다. I_sen을

의 함수로 나타내면 수학식 2와 같다. In Equation 1,

Denotes the current gain of the BJT element itself, I _sen is the current flowing through the secondary side 122A, induced by the sensing transformer 120A, and I _{out, BJT} is the primary of the compensation transformer 140A It is a current flowing through the side 141A. I _sen

Equation 2 is expressed as a function of.

는 수학식 3과 같이 나타낼 수 있다. Therefore, the current gain of the amplifier 130A-1

Can be expressed as Equation 3.

는 1보다 매우 큰 값(예: 100 이상)을 가지므로,

는 -1로 근사될 수 있다. 따라서, 전류 보상 장치(100A-1)의 경우, N_senN_inj = 1을 만족하도록 설계함으로써, 보상 전류(IC1, IC2)로 제1전류(I11, I12)를 상쇄할 수 있다. 즉, 센싱 변압기(120A)의 1차 측(121A) 대 2차 측(122A)의 권선비와, 보상 변압기(140A)의 1차 측(141A) 대 2차 측(142A)의 권선비가 역수를 만족하도록 설계할 수 있다. BJT current gain

Has a value much greater than 1 (for example, 100 or more),

Can be approximated as -1. Therefore, in the case of the current compensation device 100A-1, by designing to satisfy N _sen N _inj = 1, it is possible to cancel the first currents I11 and I12 with the compensation currents IC1 and IC2. That is, the winding ratio of the primary side 121A to the secondary side 122A of the sensing transformer 120A and the primary side 141A to secondary side 142A of the compensation transformer 140A satisfy the reciprocal. Can be designed to

)를 다시 입력단으로 귀환시키는 피드백 구조를 가질 수 있다. 따라서, 증폭부(130A-1)는 전류 이득에 제한적인 대신, 안정적으로 전류 이득을 얻을 수 있다. The amplifying unit 130A-1 of the current compensating device 100A-1 includes an output current (

) Back to the input stage. Accordingly, the amplifier 130A-1 can stably obtain a current gain instead of being limited to the current gain.

The current compensator 100A-1 is connected in parallel to the secondary side 122A of the sensing transformer 120A to protect the amplifier 130A-1 from overvoltage transmitted through the sensing transformer 120A. A first disturbance protection element 131A may be included. In addition, in order to protect the amplifier 131A-1 from overvoltage transmitted through the compensation transformer 140A, the second disturbance protection element 132A is connected in parallel to the primary side 141A of the compensation transformer 140A. Can.

The first and second disturbance protection elements 131A and 132A may be implemented as, for example, TVS diode elements having a junction capacity of a specified value or less (eg, several hundred pF or less).

The first and second disturbance protection elements 131A and 132A (eg, a TVS diode) may have a breakdown voltage, and the breakdown voltage may be designed according to the operating voltage of the amplifier 130A-1. have.

4 schematically shows a current compensation device 100A-2 according to an embodiment of the present invention. The current compensation device 100A-2 illustrated in FIG. 4 is an example of the current compensation device 100A illustrated in FIG. 2. The amplification section 130A-2 included in the current compensation device 100A-2 is an example of the amplification section 130A of the current compensation device 100A.

Referring to FIG. 4 in comparison with FIG. 3, the amplifying unit 130A-2 according to an embodiment of the present invention includes, in addition to the first amplifying element and the second amplifying element, the first amplifying element and the second amplifying element. At least one impedance (Z1, Z2) for adjusting the amplification ratio may be further included. The first impedance Z1 and the second impedance Z2 may be implemented by using one or more of a resistor (R) element, a capacitor (C) element, or an inductor (L) element, respectively.

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 more accurately compensate the phase and magnitude of current compensation according to frequency.

The first stage of the first impedance Z1 may be connected to the primary side 141A of the compensation transformer 140A, and the second stage may be connected to the emitter stage of each of the two BJTs. In addition, the first terminal of the second impedance may be connected to the primary side 141A of the compensation transformer 140A, and the second terminal may be connected to the capacitor C _b of each base terminal of the BJT. have.

The amplification degree A _iamp of the amplifying unit 130A-2 according to an embodiment of the present invention may be adjusted according to at least one of the impedances Z1 and Z2. For example, when 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 with -n(n>1). . At this time, the design value of n can be tuned in consideration of the characteristic error of the device.

The current compensation device 100A-2 is also connected in parallel to the secondary side 122A of the sensing transformer 120A to protect the amplifier 130A-2, like the current compensation device 100A-1. A first disturbance protection element 131A may be included. In addition, in order to protect the amplifier 131A-2 from overvoltage transmitted through the compensation transformer 140A, the second disturbance protection element 132A is connected in parallel to the primary side 141A of the compensation transformer 140A. Can.

5 is a diagram schematically showing the configuration of a current compensation device 100B according to another embodiment of the present invention. Hereinafter, descriptions of contents overlapping with those described with reference to FIGS. 1 to 2 will be omitted.

Referring to FIG. 5, the current compensation device 100B may further include a decoupling capacitor unit 170B in the current compensation device 100A illustrated in FIG. 2. The decoupling capacitor unit 170B may be coupled to the amplifying unit 130A including an active circuit at the second device 200A side to prevent a portion of energy from moving. The decoupling capacitor unit 170B may be a means for the output impedance from the compensation unit 160A to the second device 200A to satisfy a predetermined condition. In other words, the decoupling capacitor unit 170B is a means for compensating current to be output to the second device 200A side along at least two large current paths 111A and 112A, and not returning to the current compensating device 100B side again. Can be

For example, in order for the active current compensation device 100A to maintain stable performance, the impedance of the output side of the current compensation device 100A (that is, the second device 200A side) is the impedance of the first device 300A) ( That is, it may have to be sufficiently smaller than the impedance Z _n of the noise source side).

However, the impedance Z _n on the side of the first device 300A and the impedance Z _line on the side of the second device 200A may be arbitrarily changed according to the surroundings of the power system and the filter. For example, in the case of household appliances, an outlet or a wall may be located on the side of the second device 200A, and their impedance (Z _line ) may have a random value. In addition, since the CM choke is located on the Z _line side, it is possible to configure the entire EMI filter together with the current compensation device 100A. Accordingly, the current compensation device 100B can be provided by combining the decoupling capacitor unit 170B with the current compensation device 100A so as to eliminate uncertainty due to the surrounding situation and operate independently in any situation.

The decoupling capacitor unit 170B prevents the output performance of the compensating current of the current compensating device 100B from significantly changing according to a change in the impedance value of the second device 200A, and thus serves as a current compensating device in various systems. Make it work.

The decoupling capacitor unit 170B may include at least two or more capacitors disposed on a path branched from each of at least two large current paths 111A and 112A connecting the second device 200A and the compensation capacitor unit 150A. It can contain.

The decoupling capacitor portion 170B may include two capacitors. One end of each of the two capacitors may be connected to a reference potential (reference potential 1) of the current compensating device 100B, and the opposite ends of each of the two capacitors may include a first large current path 111A and a second large current path 112A, respectively. ). The decoupling capacitor unit 170B may be connected to the power supply side (ie, the second device 200A side) of the current compensation device 100B, for example, in order to eliminate uncertainty on the side of the second device 200A. However, it is not limited thereto.

The impedance Z _Y of the decoupling capacitor unit 170B may be designed to have a sufficiently small value in a first frequency band that is a target of noise reduction. For example, the impedance Z _Y of the decoupling capacitor unit 170B may satisfy Equation (4).

는, 감결합 커패시터부(170B) 로 인해 임의의 Z_line 값과 상관없이 설계된 Z_Y의 값을 가질 수 있다. 예를 들어 감결합 커패시터부(170B)의 임피던스 Z_Y는, 지정된 주파수 대역(예: 제1 주파수 대역) 내에서 지정된 값보다 작은 값을 가지도록 설계될 수 있다. 감결합 커패시터부(170B)의 임피던스(Z_Y)가 노이즈 저감의 대상이 되는 제1 주파수 대역에서 충분히 작은 값을 가짐으로써, 전류 보상 장치(100B)가 제2 장치(200A) 측 임피던스(Z_line)에 상관없이 정상적으로 동작할 수 있다. Referring to Equation 4, the impedance viewed from the current compensation device 100B toward the second device 200A

, May have a value of Z _Y designed regardless of an arbitrary Z _line value due to the decoupling capacitor portion 170B. For example, the impedance Z _Y of the decoupling capacitor unit 170B may be designed to have a value smaller than a specified value within a designated frequency band (eg, a first frequency band). The impedance (Z _Y ) of the decoupling capacitor portion 170B has a sufficiently small value in the first frequency band, which is the target of noise reduction, so that the current compensating device 100B has the impedance (Z _line ) on the side of the second device 200A. ).

According to various embodiments of the present invention, due to the combination of the insulating structure, the first and second disturbance protection elements 131A and 132A, and the decoupling capacitor portion 170B, the current compensation device 100B can be used in any system. It can be used as an independent module.

6 is a diagram schematically showing the configuration of a current compensation device 100C according to another embodiment of the present invention. Hereinafter, descriptions of contents overlapping with those described with reference to FIGS. 1 to 5 will be omitted.

Referring to FIG. 6, the current compensation device 100C actively receives the first currents I11, I12, and I13 input in a common mode to each of the large current paths 111C, 112C, and 113C connected to the first device 300C. Can compensate.

To this end, the current compensation device 100C according to another embodiment of the present invention includes three large current paths 111C, 112C, and 113C, a sensing transformer 120C, an amplifier 130C, a compensation transformer 140C, and a compensation capacitor The unit 150C may include a first disturbance protection element 131A, a second disturbance protection element 132A, and a decoupling capacitor portion 170C.

Looking in contrast to the current compensation devices 100A and 100B according to the embodiment described with reference to FIGS. 2 to 5, the current compensation device 100C according to the embodiment shown in FIG. 6 includes three large current paths 111C, 112C, and 113C ), and thus there is a difference between the sensing transformer 120C and the compensation capacitor unit 150C. Therefore, hereinafter, the current compensation device 100C will be described based on the above-described differences.

The current compensator 100C may include a first large current path 111C, a second large current path 112C, and a third large current path 113C, which are separated from each other. According to an embodiment, the first large current path 111C may be an R phase, the second large current path 112C may be an S phase, and the third large current path 113C 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 111C, the second large current path 112C, and the third large current path 113C.

The primary side 121C of the sensing transformer 120C is disposed on each of the first large current path 111C, the second large current path 112C, and the third large current path 113C, so that the induced current is on the secondary side 122C. You can create The magnetic flux density generated in the sensing transformer 120C by the first currents I11, I12, and I13 on the three large current paths 111C, 112C, and 113C may be reinforced with each other.

Meanwhile, in the current compensation device 100C, the amplifying unit 130C may be implemented as, for example, the amplifying unit 130A-1, but is not limited thereto.

Meanwhile, in the compensation capacitor unit 150C, compensation currents IC1, IC2, and IC3 generated by the compensation transformer flow through the first large current path 111C, the second large current path 112C, and the third large current path 113C, respectively. You can provide a route.

The current compensator 100C according to this embodiment may be used to compensate (or cancel) the first currents I11, I12, and I13 moving from the load of the three-phase three-wire power system to the power source.

The current compensating device 100C may further include a decoupling capacitor unit 170C on the output side (ie, the second device 200C side). The decoupling capacitor portion 170C may include three Y-capacitors (Y-caps). One end of each of the three Y-caps may be connected to the first large current path 111C, the second large current path 112C, and the third large current path 113C, respectively. The opposite ends of the three Y-caps may be connected to a reference potential (reference potential 1) of the current compensation device 100C.

The impedance Z _Y of the decoupling capacitor unit 170C may be designed to have a value smaller than a specified value in a first frequency band targeted for noise reduction. Due to the coupling of the decoupling capacitor portion 170C, the current compensation device 100C can be used as an independent module in any system (eg, a three-phase three-wire system).

7 is a diagram schematically showing the configuration of a current compensation device 100D according to another embodiment of the present invention. Hereinafter, descriptions of contents overlapping with those described with reference to FIGS. 1 to 6 will be omitted.

Referring to FIG. 7, the current compensation device 100D may actively compensate for the first currents I11 and I12 input in a common mode to the large current paths 111D and 112D connected to the first device 300D.

To this end, the current compensation device 100D according to the embodiment includes a large current path 111D, 112D, a sensing transformer 120D, an amplification unit 130D, a compensation transformer 140D, a compensation capacitor unit 150D, and a first disturbance protection The device 131D may include a second disturbance protection device 132D.

Looking in contrast to the current compensation devices 100A and 100B according to the embodiment described with reference to FIGS. 2 to 5, the current compensation device 100D according to the embodiment shown in FIG. 7 is a second device 200D side (example : It indicates a feedback type CSCC current compensation device 100D that senses a common mode noise current going to the power source and compensates with a current at the first device 300D side (eg, noise source side). That is, in the current compensation device 100D, the sensing transformer 120D may be disposed on the second device 200D side, and the compensation capacitor unit 150D may be disposed on the first device 300D side.

The current compensation device according to various embodiments of the present disclosure can stably operate regardless of the characteristics of the electrical system to be mounted. Therefore, the current compensation device does not need to be custom designed through repeated tests for each circuit or system, and may have versatility as an independent component. The current compensation device can be commercialized as an independent module.

In addition, the current compensation device according to various embodiments of the present invention can operate independently without parasitic on the CM choke, and can reduce the area, volume, and weight compared to the passive filter including the CM choke.

In addition, the current compensation device according to various embodiments, unlike the CM choke, although used for high power, the degree of increase in size or the degree of increase in price is negligible. Specifically, a passive filter including a CM choke is rapidly increased in size, price, and weight to be used in a high-power system due to the magnetic saturation phenomenon. However, the amplification unit 130A-1 included in the current compensation device is not greatly affected by the change in the amount of power. In the current compensation device, the volume increase rate of the sensing transformer 120A according to the increase in the amount of power may be much smaller than the volume (eg, size and/or number) increase rate of the CM choke. Therefore, the current compensation device according to various embodiments may be more advantageous in terms of price, volume, and weight than a passive filter in a high power system.

In addition, since the current compensation device according to various embodiments of the present disclosure is electrically insulated from a large current path (for example, a power line), elements included in the amplifying unit 130A can be protected from electrical overstress (EOS). . For example, since the amplifying unit 130A according to various embodiments of the present invention is insulated from a power line, a DC low voltage (eg, a third device 400, within 15V) used in a control board can be used. Therefore, the amplifier 130A does not require a separate power conversion circuit. In addition, the current compensation device according to various embodiments of the present invention, regardless of the reference potential (reference potential 1) of the power supply (for example, the second device 200), is rated to configure the amplifier 130A Devices with low voltage can be used.

The specific implementations described in the present invention are exemplary embodiments, and do not limit the scope of the present invention in any way. For brevity of the specification, descriptions of conventional electronic configurations, control systems, software, and other functional aspects of the systems may be omitted. In addition, the connection or connection members of the lines between the components shown in the drawings are illustrative examples of functional connections and/or physical or circuit connections, and in the actual device, alternative or additional various functional connections, physical It can be represented as a connection, or circuit connections. In addition, unless specifically mentioned, 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 is not limited to the above-described embodiments, and should not be determined, and the scope of the spirit of the present invention, as well as the claims to be described later, as well as all ranges that are equivalent to or equivalently changed from the claims Would belong to

Claims (5)

In the current compensation device to actively compensate for the first current input in a common mode (Common Mode) in each of the at least two or more large current paths connected to the first device,
At least two or more large current paths for transferring a second current supplied by a second device to the first device;
A sensing unit configured to sense the first current on the large current path and generate an output signal corresponding to the first current;
An amplifying unit that amplifies the output signal of the sensing unit to generate an amplifying current;
A compensation unit generating a compensation current based on the amplification current and allowing the compensation current to flow through each of the at least two large current paths; And
It includes; a first disturbance protection unit connected in parallel to the output terminal of the sensing unit generating the output signal, and a second disturbance protection unit connected in parallel to the input terminal of the compensation unit.
The first disturbance protection unit and the second disturbance protection unit include a TVS (Transient Voltage Suppression) diode element,
A current compensation device having a junction capacitance of the TVS diode device of several hundred pF or less. The method according to claim 1,
The first disturbance protection unit and the second disturbance protection unit,
When a voltage lower than a predetermined threshold voltage is applied to the output terminal of the sensing unit and the input terminal of the compensation unit, the first impedance has a voltage,
A current compensation device having a second impedance lower than the first impedance when a voltage equal to or greater than the predetermined threshold voltage is applied to the output terminal of the sensing unit and the input terminal of the compensation unit. delete The method according to claim 1,
The sensing unit
A primary side disposed on the large current path; And
And a sensing transformer including a secondary side outputting the output signal to the amplifying unit.
The first disturbance protection unit
A current compensating device in which the primary side limits a voltage above a threshold voltage induced on the secondary side to a voltage below the threshold voltage to the amplifying unit based on the voltage applied to the at least two large current paths. The method according to claim 1,
The compensation unit
A primary side disposed on a path connecting the output terminal of the amplification unit and the reference potential of the amplification unit; And
Included in the compensation unit and the secondary side disposed on the path connecting the reference potential of the compensation capacitor unit and the current compensation device connected to the high-current path; includes,
The second disturbance protection unit
The second side of the current compensation device, based on the voltage applied to the at least two large current paths, limits the voltage above the threshold voltage induced on the primary side to a voltage below the threshold voltage and delivers it to the amplifying unit.

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