JP2024513339A - Method and apparatus for protecting electrical components from transient electromagnetic disturbances transmitted on parallel power lines - Google Patents

Abstract

Preventing signals induced by harmful EMI on power lines within a group of multiple adjacent parallel power lines in phase in a power system from reaching electrical components connected to one of the multiple power lines Apparatus for, the apparatus comprising at least one conductive impedance transition element having a disk-like structure including a plurality of holes for receiving a plurality of adjacent power lines in phase, each disk-like structure having a plurality of holes. having an outer diameter larger than the diameters of all of the parallel power lines, intentionally creating an impedance mismatch between the conductive impedance transition element and adjacent portions of the plurality of power lines. The impedance mismatch causes the conductive impedance transition element to reflect high frequency components of signals induced by harmful EMI onto multiple power lines, where the high frequency components are reflected and dissipated as heat. [Selection diagram] Figure 30

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority and benefit from U.S. patent application Ser. is a continuation-in-part of pending U.S. patent application Ser.

The present invention relates to a method and apparatus for protecting electronic equipment (electrical components (EC)) from harmful EMI, including transient electromagnetic disturbances such as electromagnetic pulses that can be generated naturally or artificially.
DEFINITIONS Component: An individual electrical or electronic element, or a plurality of such elements connected in a defined circuit or system.

Conductive Impedance Transition Element (CITE): A conductive element that is coupled to a conductor and whose diameter increases rapidly with respect to the conductor.

Damped Resonator: Two CITE elements or a cluster of CITE elements spaced apart on a conductor. The high frequency components of the electromagnetic signal are reflected back and forth between the CITE elements, and the reflection continues until the signal is dissipated as heat. The spacing between CITE elements is selected such that electromagnetic signals in the selected frequency bands do not collide and are added via constructive interference.

Electromagnetic Attack: A scenario in which harmful EMI signals are intentionally applied to some electrical or electronic equipment or system with the purpose of causing damage, disruption, or disruption in that system.

Electromagnetic interference (EMI): Electromagnetic radiation, which is undesirable when received by an electrical system because it can interfere with transmitted signals or equipment coupled to the system. EMI is defined herein as a broad term encompassing numerous subtypes defined below.

Electromagnetic Pulse (EMP): A harmful transient burst of electromagnetic radiation with a rapid rise time, typically less than 5 nanoseconds, that can generate potentially damaging current and voltage surges (and thus (can be considered a subset). Typical EMP intensity is on the order of tens of thousands of volts/meter. EMP is caused by a non-nuclear source (NNEMP, rise time typically less than 5 nanoseconds) that produces sudden fluctuations in the electromagnetic field, such as a nuclear explosion (NEMP, rise time typically less than 5 nanoseconds) or a coronal mass ejection. It is possible.

Electromagnetic Threat: A situation in which harmful, intentional electromagnetic signals may be used against electrical or electronic equipment or systems with the purpose of damaging, disrupting, or disrupting the system.

Anomalous Electromagnetic Pulse: A class of EMP previously defined in US 8,300,378 that encompasses all of the various electromagnetic threats described herein. Abnormal EMPs can be the result of transient pulses (NEMPs) resulting from nuclear explosions, non-nuclear electromagnetic pulses (NNEMPs) strong enough to reach and render power system components inoperable, or coronal mass ejections from solar storms. This includes geomagnetically induced currents (GICs) generated as a result.

Harmful EMI: Electromagnetic interference that, when experienced by an electrical system, can damage or render inoperable electrical equipment coupled to that system, such as, but not limited to, generators, electronic circuit boards, and transformers. becomes more likely to occur. This interference can be pulsed or continuous radiation.

High Altitude Electromagnetic Pulse (HEMP): This is also a subset of NEMP. HEMP occurs when a nuclear weapon detonates above the Earth's surface (outside the atmosphere), producing gamma rays that interact with the atmosphere and create a powerful electromagnetic energy field. Although this electromagnetic energy field is harmless to humans as it is radiated outward, circuits can be overloaded with effects similar to but much more quickly damaging than a lightning strike.

High permeability: High permeability is defined herein as a magnetic permeability greater than or equal to 1×10 ⁻³ μ (H/m; absolute permeability) (>1000 μ/μ0 (relative permeability)).

Intentional Electromagnetic Interference (IEMI): Electromagnetic interference that is intentionally (artificially) generated to adversely affect a targeted electrical system. This interference can be pulsed or continuous radiation.

Narrow Bandwidth EM Signal: An EM signal that has a bandwidth of 25 percent or less of the center frequency.

Nuclear Electromagnetic Interference (NEMI): Electrical interference produced by the detonation of a nuclear device with an initial rise time of less than 3 nanoseconds. NEMI includes fast rise time electromagnetic pulses (defined below) and slow rise time, long duration radiation. This is commonly known as electromagnetic pulse (EMP) (see above).

Phase Line: Two or more conductors placed adjacent to each other and carrying the same phase of a single-phase or multiphase power line.

Power Line: An electric power generation, transmission, or distribution system that includes an electric power grid that includes multiple synchronized generation sources. More specifically, a power line may include a "three-phase line" having three separate conductors, each conductor carrying a power signal in a phase-shifted relationship with the other conductors. The fourth conductor may be neutral.

Radio Frequency (RF): Electromagnetic radiation and signals in the radio portion of the spectrum, ranging from a few kilohertz to a few terahertz.

Source Region Electromagnetic Pulse (SREMP): A subset of the Nuclear Electromagnetic Pulse (NEMP). SREMPs are produced by low-altitude (intraatmospheric) nuclear explosions. The effective net vertical electron flow is formed by the asymmetric deposition of electrons in the atmosphere and on the ground, and the formation and decay of this current emit pulses of electromagnetic radiation in a direction perpendicular to the current. The asymmetry caused by low-altitude explosions means that some of the electrons ejected downward are trapped in the upper millimeters of the Earth's surface, while others can travel upwards and outwards and travel long distances through the atmosphere, becoming ionized. and occurs to cause charge separation. In high-altitude explosions, weaker asymmetries may exist due to atmospheric density gradients.

System Generated EMP (SGEMP): SGEMP is a special class of EMP signals that are generated as a result of reflected energy within the equipment enclosure. Usually associated with and found within missiles, but can occur elsewhere as well. This is unique in that it is a secondary form of EMP release.

Ultra-high bandwidth EM signal: An EM signal with a bandwidth greater than or equal to 75 percent of the signal's center frequency.

Note that NEMP, HEMP, SREMP, SGEMP, etc. are all electromagnetic pulses produced by the explosion of a nuclear device (fission, fusion, thermonuclear fusion). Both are characterized by very fast rise times, typically less than 5 nanoseconds, and in some cases rise times can be in the sub-nanosecond range. All these EMP types, as well as the non-nuclear EMP class (NNEMP), generate pulses that are typically represented by very wide RF bandwidths ranging from a few kilohertz to a few gigahertz. Additionally, note that the signal level at any individual frequency across this portion of the spectrum is not uniform, but that the majority of the energy is located below about 200 MHz. These boundaries are not fixed and are determined by several parameters present at the moment of the pulse's occurrence.

It is well known that certain events can generate electromagnetic radiation that can have extremely devastating effects on power infrastructure. The term used herein for this broad category of electromagnetic radiation is "harmful electromagnetic interference (EMI)." In light of concerns regarding the proliferation of nuclear weapons and similar destructive technologies, research has been conducted to investigate the effects of the powerful bursts of harmful EMI emitted by nuclear explosions (NEMI). Research shows that a nuclear explosion produces a burst of electromagnetic pulse (EMP) with a very fast rise time (on the order of less than 5 nanoseconds), followed by a slower, longer-lasting portion of the signal, which It can last for a long time, sometimes up to several minutes. One of the main factors that determines the final shape of the EMP pulse produced by a nucleus is the altitude at which the nucleus detonates. Typical EMP intensity is on the order of tens of thousands of volts/meter. In comparison, nearby radar is at 200 volts/meter, communications equipment is at 10 volts/meter, and a typical metropolitan environment is on the order of 0.01 volts/meter. It should also be noted that Federal Communications Commission (FCC) guidelines require a limit of 0.5 volts/meter at the edge of the property line at a transmission site for this type of radiation.

Characteristics of EMP that pose a threat to electrical equipment include very fast rise times, very short pulse widths, and electric field amplitudes that produce signals with a wide frequency spectrum. There are three basic mechanisms for EM coupling to conducting structures: electrical induction, which is the basic mechanism for linear conductors, magnetic induction, which is the primary mechanism when conducting structures form a closed loop, and grounding (i.e., physical There is signal transmission via planets. Equipment that can be affected by functional damage due to electrical transients includes active electronic equipment, passive electronic components, semiconductor equipment, squib and ignition devices, meters, as well as power systems, cables, grid switching and distribution elements. is included. Operational disruptions and failures can be expected in digital processing systems, memory units, guidance systems, and power distribution systems. Failure mechanisms include dielectric breakdown, thermal effects and interconnection, switching, transformer and generator failures.

The spectrum and energy distribution of any type of nuclear EMP depends primarily on the height at which the explosion occurs in the atmosphere. Explosions that occur below 40 km from the Earth's surface are called atmospheric explosions and produce source region electromagnetic pulses (SREMPs). On the other hand, explosions that occur more than 40 km above the Earth's surface are called ex-atmospheric explosions and generate high-altitude electromagnetic pulses (HEMP). SREMPs are produced by the collision of photons from gamma rays with molecules in the atmosphere. These high-energy photons eject electrons from surrounding air molecules, creating ionized air molecules. This enormous charge separation generates powerful electric fields that can reach hundreds of thousands of volts/meter, and large associated magnetic fields that can reach 5000 ampere turns/meter. FIG. 19A is a graph over time of an exemplary EMP waveform produced by an exemplary 100 kiloton atmospheric explosion. As shown in Figure 19A, the beginning of the SREMP waveform (E1) is very strong, rising to a maximum value that can reach 250 KV/meter in about 1 ns and falling to about 10 KV/meter within 10 ns. It's a pulse. In the scenario identified above, in the second part of the waveform (E2), the electric field remains approximately constant at 10 KV/meter, lasting from the 10 nanosecond mark until about 100 μs after the explosion. In the third part of the waveform (E3) starting about 100 μs after the detonation, the electric field drops from 10 KV/meter to about zero by the 1 millisecond mark. FIG. 19B is a graph of relative energy versus frequency of the SREMP waveform. As shown, the frequency components of the SREMP waveform are in the frequency range below 1 MHz, and the majority of the spectral components are below 10 kHz. Note that the exact field strength, pulse rise time, and duration depend on a combination of multiple factors, such as device geometry, device yield, explosion height, and atmospheric conditions at the time of the explosion.

In contrast, HEMP is produced by gamma photons absorbed by atmospheric molecules at altitudes above 40 kilometers. This absorption causes the electrons to be deflected by the Earth's magnetic field into a spiral path around the magnetic field lines, emitting electromagnetic energy. FIG. 20A is a graph over time of an EMI waveform produced by an exemplary exo-atmospheric explosion. As shown, the HEMP waveform is significantly different from the SREMP waveform. For devices in the 5 kiloton to 1 megaton range, this electron radiation energy produces large and variable electric fields in the range of tens of kilovolts/meter and associated magnetic fields in the range of 10 to 300 ampere turns/meter. The duration of some of the HEMP waveforms can be longer than SREMP, lasting several seconds in some cases. As mentioned above, the duration of a particular portion of the waveform depends on many factors, such as the geometry of the device, the yield of the device, the height of the explosion, and the atmospheric conditions at the time of the explosion. FIG. 20B is a schematic graph of relative energy versus frequency of the HEMP waveform. As shown, approximately 90 percent of the energy is contained in the 100 KHz to 10 MHz range.

EMP Lightning Protection As discussed above, the apparatus and methods disclosed herein provide protection from harmful EMI, including fast rise time electromagnetic pulses (EMP) as well as relatively slow lightning strikes. For example, EMP (SREMP) originating from the outer reaches of the atmosphere has a fast rise time (typically sub-nanoseconds) and a short pulse duration (less than 500 nanoseconds). This EMP has significant electric field strengths, typically in the range of 10 KV/meter to 500 KV/meter, but not limited to. Power line electrical pulses produced by lightning behave similarly to SREMP pulses, but have slower rise times (typically about 20 nanoseconds) and longer pulse widths than EMP produced by nuclear or other human means. have As a result, low-Q damped resonators tend to be slightly less effective at suppressing transient induced signals from lightning than they are at suppressing transient induced signals from SREMP or non-nuclear sources. However, by adjusting the Q factor of the damped resonator in various embodiments and configurations, very short EMP It is possible to target (SREMP) or longer pulse EMP (eg lightning).

Traditional Protection Schemes Note that in most electromagnetic attack scenarios, more than a single pulse is used in the attack. As a result, in order for a protection scheme to be viable, it must be able to withstand multiple consecutive electromagnetic attacks, or even constant electromagnetic attacks, in order for such a protection scheme to be considered a viable protection measure. Must be able to do it. Some protection schemes are one-shot or potentially one-off, and therefore not truly suitable for protection services, despite their current widespread use.

As mentioned above, in addition to the harmful EMI generated by nuclear offerings (SREMP and HEMP), electrical and electronic equipment can also be affected by non-nuclear electromagnetic pulses, intentional electromagnetic bursts, coronal mass ejections (solar storms) and thunderstorms, etc. may be damaged by other events. Certain measures are taken to protect electrical systems from harmful EMI. For example, conventional systems and devices for suppressing harmful EMI such as EMP and lightning include, but are not limited to, electron tube protectors, metal oxide varistors and other solid state devices, spark gaps, and inductors. Not done.

Electron Tube Protection Device: The inventors of the present application have previously identified a protection measure utilizing high speed, high power cold cathode field emission electron tubes as a preferred means of protecting electrical and electronic equipment from damage from any of the aforementioned electromagnetic threats. Developed in This protective cold cathode field emission electron tube is described in US Pat. No. 8,300,378 by Birnbach, "Method and apparatus for protecting power systems from extraordinary electromagnetic pulse ses”. Testing of this class of electron tube devices has shown them to be suitable for protection service in repetitive pulse applications with pulse repetition rates in excess of 500 kilohertz.

Metal oxide varistors (MOVs): MOVs are, but are not limited to, solid state devices that exhibit very high impedance (typically 10 MΩ to 100 MΩ) at rest. When a voltage above some predetermined threshold is applied across the MOV, the MOV changes its internal impedance to a very low impedance state. This allows MOVs to be used to shunt overvoltages around critical circuit elements. The rate at which this impedance change occurs is a function of the specific design and material content of the MOV. A significant limitation of the MOV device is that since the MOV device is a semiconductor, it cannot be repaired if a failure occurs in the crystal structure of the substrate, and cannot self-repair. The aforementioned types of failures are the main failure modes of MOVs. As a result, MOVs cannot be relied upon to provide protection against multiple overvoltage situations. Despite this limitation, MOVs are currently the primary surge suppression method used in public utilities.

Additionally, most MOVs do not have fast enough rise times (typically about 20 nanoseconds) to help suppress EMP from nuclear explosions (NEMPs), so when specifying MOVs, especially the E1 portion of the SREMP It is necessary to pay attention to the fast rise time part of HEMP. Even MOVs with fast reaction times adapted to fast rise times (approximately 2 to 5 nanosecond rise times) are typically too slow to be effective for all E1 pulses, which have sub-nanosecond rise times. Too much. This speed difference allows a catastrophically large amount of energy to pass before protection action occurs, resulting in failure of the protected device and possibly the protection device (MOV). Therefore, MOV is generally ineffective against NEMP.

There are several MOVs on the market that claim to be suitable for applications that protect against pulses greater than 5,000 amps even though the diameter of the connecting wire is less than 0.125 inch (1/8 inch). If the pulse is short enough and lasts less than 1 nanosecond, the connecting wire may not evaporate, but in a real-world electromagnetic attack scenario, the wire would evaporate and render the device useless. It will be apparent to those skilled in the art that the use of such devices is insufficient to provide protection against real world electromagnetic threats.

Other Semiconductor Devices: Note that there are various other semiconductor devices in use or under development for transient suppression applications. An example of this is a gallium nitride avalanche diode. It is a fast rise time switching diode with sufficiently robust parameters, and when several are used together in series or parallel depending on the specific application, the speed of the group can be increased by the interconnection and the required balanced network. The resulting parasitic inductance and capacitance result in slower speeds than the individual devices. All related semiconductor devices are susceptible to failure due to damage to the crystal structure associated with piezoelectric effects. This class of semiconductor devices is susceptible to the same failure modes as MOV devices, as described above.

Spark Gap: A spark gap is a form of fast switch that is sometimes used to protect against harmful EMI. Wire spark gaps to shunt overvoltages around sensitive components. The threshold voltage is determined by the spacing of the spark gap electrodes. The problem with spark gaps is getting them to trigger reliably at some predetermined voltage. A further problem is that once ignited, the contact surfaces of the spark gap deteriorate due to corrosion, causing changes in electrode spacing such that subsequent ignition events typically do not ignite at the same voltage as when the spark gap was new. Spark gaps require very high maintenance and their use is generally limited to laboratory pulsed power experiments. Another form of spark gap used only in the power distribution and transmission industry is a set of specially spaced curved rods, often referred to as "horns." Although the rise time is too slow for protection against fast rise time EMP, horns have been shown to be a simple approach for lightning protection and are widely used. The main disadvantage of horns is that they are easily damaged and need to be replaced frequently.

Inductor: When connected in series with a circuit, it can suppress high-speed transient signals. The problem with using series-connected inductors as a protection device is that the tolerances on the diameter of the inductor's conductor are very tight in relation to electrical insulation requirements and the ability to handle a certain amount of current without overheating. be. Generally, series inductors alone do not adequately suppress harmful EMI signals. An inductor's ability to withstand multiple repetitive pulses is a function of its design, particularly its insulation and thermal rating. Inductors consume energy and are typically used only in substations where surplus energy is readily available.

Therefore, there is a need for a method and apparatus that can reliably and efficiently overcome the aforementioned drawbacks and protect electronic equipment from harmful EMI.

The present disclosure provides that an electrical signal induced by harmful EMI on one or more power lines in a group of in-phase, adjacent parallel power lines in a power generation, transmission, and distribution system is transmitted to one of the plurality of parallel power lines. Provides a device for preventing access to electrical components connected to the device. The apparatus includes at least one conductive impedance transition element sized to receive and surround one of a plurality of adjacent in-phase power lines spaced apart from each other. including a disc-like structure having a plurality of holes, each disc-like structure having an outer diameter greater than the diameter of all of the plurality of parallel power lines, and providing impedance between the conductive impedance transition element and adjacent portions of the plurality of power lines. Deliberately create inconsistencies. Due to the impedance mismatch, the conductive impedance transition element reflects high frequency components of the signal induced onto the power lines by harmful EMI, and the high frequency components are reflected and dissipated as heat.

The present disclosure further provides a method for protecting components coupled to power lines of a group of equiphase parallel power lines of a power generation, transmission, and distribution system from harmful EMI. The method is implemented by attaching at least one conductive impedance transition element (CITE) having a diameter greater than the power line diameter to all power lines in equal phase at a location between the extended length of the power line and the element. , including intentionally creating an impedance mismatch. Due to the difference in diameter between the CITE and the power line, an impedance mismatch is intentionally induced between two or more conductive impedance transition elements and adjacent portions of the power line, and this impedance mismatch causes harmful EMI to interfere with the power line. High frequency components of the induced signal are reflected and dissipated by damped resonators formed between pairs of conductive impedance transition elements.

The magnitude of the impedance mismatch is frequency dependent, allowing the low frequency components of the induced transient electromagnetic signal to pass through multiple conductive impedance transition elements, while allowing the high frequency components of the induced transient electromagnetic signal to pass through multiple impedance transitions. reflected from the element.

To increase the efficiency of the conductive impedance transition elements, one or more of the plurality of conductive impedance transition elements may be constructed of or include portions of ferrite material. This ferrite material can be incorporated as a separate disk unit or integrated into a conductive disk element.

Note that one or more CITEs may be constructed of partially conductive or semiconductive materials such as carbon, graphite, etc. This allows the disk to absorb a portion of the incident energy. The absorbent CITEs may be used individually, in equally spaced sets, unevenly spaced sets, and in other configurations, as will be understood by those skilled in the art.

Further features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings in which like reference numerals refer to like elements. The drawings and portions thereof are illustrative and are not necessarily drawn to scale.

1 is a prior art schematic diagram of an electrical component (EC) connected to a power line (104) and susceptible to damage by transient electromagnetic interference signals (14); FIG. Not to scale having an electrical component (P.C.) protected from the destructive consequences of transient electromagnetic interference signals by at least one illustrated conductive impedance transition element (CITE; 106, 107) according to the present disclosure FIG. 2 is a schematic diagram of a power line. 2 is a schematic diagram of another embodiment in which a power line is protected by two CITEs (125) according to the present disclosure. FIG. This is a modification of the rectangular portion surrounded by the dotted line of the configuration in FIG. 3. FIG. 3 is a schematic diagram of another embodiment in which a power line is protected by three CITEs (178, 179) according to the present disclosure. 2 is a schematic diagram of another embodiment in which a CITE according to the present disclosure is used on a power line having a first protected component (100) and a second protected component (102). FIG. Similar to FIG. 6, showing a more general position of a CITE protecting a component on the left and a more general position of a CITE protecting a component on the right. FIG. 3 is a schematic diagram of another embodiment in which CITEs are arranged in three groups (235) along a power line. 1 is a single-sided plan view of a first embodiment of a conductive impedance transition element (CITE) according to the present disclosure; FIG. FIG. 7 is a plan view of the upper component of the CITE pivoted relative to the lower element about the hinge element, showing the first embodiment in a partially open state to allow attachment to a power conductor; FIG. 3 is a hinge end view of the first embodiment of the CITE. FIG. 2 is a perspective view of a first embodiment of CITE partially open; FIG. 3 is a perspective view of the lower component of the first embodiment of the CITE. FIG. 2 is a perspective view of the upper component of the first embodiment of CITE; 12 is a longitudinal cross-sectional view of the first embodiment of the CITE along axis 15-15 of FIG. 11; FIG. FIG. 4 is a single-sided plan view of another embodiment of a CITE according to the present disclosure. FIG. 2 is a perspective view of another embodiment of a conductive impedance transition element (CITE) according to the present disclosure. FIG. 4 is a plan view of another embodiment of a CITE having an elliptical cross-sectional shape. FIG. 4 is a plan view of another embodiment of a CITE having a polygonal cross-sectional shape. FIG. 4 is a plan view of another embodiment of a CITE having an asymmetric cross-sectional shape. FIG. 3 is a side cross-sectional view of an embodiment of a CITE with a mu-metal coating. 1 is a graph of an EMI waveform produced by an exemplary atmospheric explosion (SREMP) over time; (From Sandia National Laboratory, hereinafter referred to as "Sandia"). 2 is a graph of relative energy versus frequency of the SREMP waveform. (From Sandia). 1 is a graph of an EMI waveform produced by an exemplary extra-atmospheric (HEMP) explosion over time; (From Sandia). 2 is a graph of relative energy versus frequency of the HEMP waveform. (From Sandia). FIG. 3 is a perspective view of another embodiment of a conductive impedance transition element (CITE) formed as a ferrite bead in accordance with the present disclosure. A and B are longitudinal cross-sectional plan views of a CITE illustrating one embodiment of a method of assembling a CITE according to the present disclosure. FIG. 4 is a perspective view of an alternative embodiment of a CITE having a spherical shape. FIG. 2 is a front plan view of a CITE having a transparent peripheral portion filled with fluorescent gas. FIG. 3 shows an embodiment of a CITE having a central portion formed of different materials, each of which is an absorbent material such as graphene (A), a metal such as aluminum (B), and a ferrite material (C). FIG. 3 is a perspective view of a first side of another embodiment of a CITE according to the present disclosure having a metallic central portion; FIG. 7 is a perspective view of a second side of another embodiment of a CITE according to the present disclosure having an absorbent central portion. 1 is an axial cross-sectional view of an underground coaxial power cable having semiconductor layers with differential impedance along the length of the cable; FIG. FIG. 27B is a vertical cross-sectional view of the underground coaxial power cable shown in FIG. 27A. FIG. 7 is a side view of another embodiment of a CITE with rabbets for securing the upper and lower components of the CITE. 28B is a front plan view of the embodiment shown in FIG. 28A. FIG. FIG. 3 is a front plan view of an embodiment of a CITE adapted for parallel phase lines. FIG. 29B is an enlarged view of the central portion of the CITE shown in FIG. 29A. FIG. 29B is a perspective view of the CITE shown in FIG. 29A. FIG. 4 is a front plan view from another perspective of an embodiment of a CITE adapted for three-phase line; FIG. 3 is a side cross-sectional view of an embodiment of a CITE with a mu-metal coating.

The apparatus (systems) and methods disclosed herein are configured to protect electronic equipment, electrical components, and their systems from harmful EMI, including transient electromagnetic pulses (EMP).

As previously mentioned, EMP first came to prominence in connection with nuclear explosions. However, in recent years, it has become possible to generate EMP signals by electrical means (man-made weapons and simulators) that are comparable or even superior to those produced by nuclear explosions. Electromagnetic pulses of concern are typically in the range of, but not limited to, 10 KV/meter to 500 KV/meter or greater. The apparatus and methods disclosed herein protect electrical infrastructure from harmful EMI, including EMP arising from nuclear (NEMP) and non-nuclear (NNEMP) sources.

Deliberately Created Impedance Mismatch The disclosed apparatus (system) and method provide a means for creating an intentional impedance mismatch along a power line of a specified type so that a significant portion of the incoming harmful EMI is reflected. This harmful EMI can be in the form of EMP or interference signals. As used herein, a "power line" may be a power line of a power generation, transmission, or distribution system having a power grid that includes multiple synchronized generation sources. More specifically, a power line may include a "three-phase line" having three separate conductors, each conductor carrying a power signal in a phase-shifted relationship with the other conductors. The fourth conductor may be neutral. However, the systems and methods are generally applicable to the full range of phases used in power distribution systems, typically ranging from 1 to potentially 6 or more. The number of phases in the system does not affect the use of CITE technology, other than imposing the constraint that every phase, including neutral, must be equipped with one or more CITE devices or sets of such devices. . Reflecting a significant portion of harmful EMI signals may prevent electrical components from being damaged or rendered inoperable by the signals. Intentional frequency-dependent impedance mismatching is achieved by incorporating conductive impedance transition elements (CITEs) into power lines. A CITE can be thought of as a conductive attachment to a power line. The conductive attachment (CITE) may have the same cross-sectional shape as the power line, but the diameter will be several times larger than the power line diameter.

For example, consider the following total low-frequency inductance of an element with a circular cross section.

式中：
Ｌ_ｄｃは、ナノヘンリー（ｎＨまたは１０^－９Ｈ）を単位とする「低周波」または直流インダクタンスである。
ｌは素子または構造の長さ（ｃｍ）である。
ｒは素子または構造の半径（ｃｍ）である。

In the formula:
L _dc is the "low frequency" or direct current inductance in nanohenries (nH or 10 ^-9 H).
l is the length of the element or structure (cm).
r is the radius of the element or structure (cm).

(E.B.ROSA, "THE SELF AND MUTUAL INDUTUCTANCES OF LINEAR CONDUCTORS", Bulretin of the Bureau OF Standards, Vol.4, 301, 301, 301, 301. After the page). The reactance (i.e., a type of impedance) of an inductor is:
X _L =2πfL
From this equation, it can be seen that a change in the radius of the element causes a change in inductance (L), which in turn causes a proportional change in impedance (X _L ). "f" here is the frequency of the signal input to the inductor. In other words, if the presence of a CITE on a power line intentionally changes the variable r (radius of the power line) to r + x (where x represents the positive diameter change of the CITE with respect to r), then the CITE and the original A corresponding impedance intentional mismatch occurs between adjacent lengths of power line having a value of r. The above equation further shows that the impedance mismatch due to the difference in L is multiplied by the frequency value, and the higher the frequency, the greater the mismatch.

As one non-limiting example, if the power line includes a 1 inch diameter wire, the CITE may be configured as a 15 to 20 inch diameter disk. This embodiment is suitable for use in conventional power line settings where multiple power lines are typically placed side by side or overlapping each other with sufficient distance between the power lines. In particular, there are standards well known to those skilled in the art that define the distance that each power line should be separated from other power lines. It will be appreciated that because the CITE has a greater width (diameter) than the power line, the CITE extends outward from the power line toward the adjacent power line. To avoid arcing or other adverse effects due to the proximity of two conductors, sufficient distance must be maintained between the outer edge of a CITE and the adjacent power line or the perimeter of a CITE on an adjacent power line. be. Additional tolerances are also added to account for this phenomenon, as power lines can swing away from tethering and shorten the distance between adjacent lines. In some implementations, when the power lines are approximately 18 inches apart, the perimeter of the CITE is located a predetermined distance from adjacent power lines, such as approximately 6 to 12 inches. Note that increasing the distances separating individual lines in a power transmission system to allow for the installation of CITE hardware is a relatively simple matter.

Apart from considerations regarding the spacing between power lines, the diameter of the CITE also depends on the voltage level of the power lines. The higher the voltage used on the power line, the larger the diameter of the CITE attached to the power line must be.

As discussed herein, exemplary implementations of CITEs include arrangements of two or more CITEs coupled together as a unit and placed along a power line. Overall system efficiency may be based, at least in part, on the number of CITEs or groups of CITEs arranged in a predetermined manner along the power line and the spacing of the CITEs and groups of CITEs.

The impedance mismatch creates standing waves along the transmission line, and the voltage standing wave ratio (VSWR) is the voltage amplitude (minimum) of the partial standing wave at the antinode along the line; Defined as the ratio of the voltage amplitude (maximum) at the node. VSWR is a measure of the match (or mismatch) of the source and load impedances to the characteristic impedance of the power transmission line. High VSWR caused by an intentional mismatch in impedance between a CITE or group of CITEs and the power line causes reflection of high frequency components (in the MHz to GHz range) of incoming harmful EMI signals (e.g. EMP), but , the much lower fundamental frequency components (e.g., 50 to 400 Hz) of the current signal powering the power line are less affected. Reflection of high frequency components of transient signals can cause (1) electrical components, including magnetic windings, connected to power lines at voltages higher than that component's design voltage, such as thermal or insulation damage to transformers, generators, and motors; and/or (2) its high frequency components reaching and rendering inoperable switchgear components positioned to interrupt power line current. This is done to prevent the destructive consequences of Note that other failure mechanisms are also possible.

Effects of Destructive and Constructive Interference It is noted that it is possible to intentionally create a situation in which there is destructive or constructive interference of reflected transient signals in the power lines mentioned above. It is important to consider this point when designing a CITE system. Additionally, it is desirable to optimize the CITE system to intentionally create destructive interference of high frequency components, such that the high frequency components are able to cancel themselves independently of the normal operation of the CITE system.

To ensure destructive interference, it is necessary that the spacing of the CITEs at both ends of the power line is not large enough to cause constructive interference. For installations where the protected lines may be de-energized, a simple test can be performed to determine the optimal spacing.

In this test, a direct injection pulse source of appropriate rise time, pulse width, and amplitude is capacitively coupled to the power line after installation of the CITE structure. A high speed oscilloscope with a minimum instantaneous bandwidth of 1 GHz is coupled to one opposite line of the CITE structure. Inject a pulse and observe the waveform. The spacing is appropriate if the amplitude of the pulse is small compared to the pulse sampled from the injection side of the power line. If the pulse is large, one set of CITE structures needs to be moved until the minimum pulse size is observed. This test is also the method by which power lines are certified to verify proper operation of the CITE structure.

FIG. 1 is a schematic diagram, not to scale, of a system in which an electrical component (EC) (electrical or electronic equipment) 10 is connected to a power line 104 of a power generation, transmission and distribution system according to the prior art. Power lines 104 are shown shaded to indicate that they are conductive. External harmful electromagnetic signals 12 (harmful EMI), such as electromagnetic pulses (EMP), induce electromagnetic signals as pulses 14 on power lines 104 and are directed toward electrical components (EC) 10 . If the magnitude of the voltage pulse 14 reaching the electrical component (E.C.) 10 is too high due to one or more of the failure mechanisms described above, the electrical component (E.C.) 10 becomes inoperable.

FIG. 2 is a schematic diagram, not to scale, of a protected component 100 (denoted as “P.C.”), a power line 104, and a single conductive impedance transition element (CITE) 106. CITE 106 introduces an intentionally created frequency-dependent impedance mismatch along power line 104 as a means or technique to protect protected component (P.C.) 100 from harmful EMI effects. . A representative CITE 106 is shown schematically, and more detailed embodiments are described below and illustrated in subsequent figures. CITE 106 is electrically conductive (e.g., formed or coated with a metal such as aluminum, copper, stainless steel, ferrite, some combination thereof, or other electrically conductive material) and extends along the length of power line 104. and has a first side 107 facing away from the protected component (P.C.) 100. Generally, CITEs are structured such that one side of the element (referred to as the "first" side) maximizes the diameter ratio between the element and the power line. During installation, the first side of the CITE is installed facing away from the component to be protected. A sharp impedance mismatch exists between the first side 107 of the CITE 106 and the axially adjacent portion of the power line 104 . Note that a single CITE does not reflect 100% of unwanted high frequency components. Achieving this requires a more complex structure, as shown in FIGS. 3-8, and will be explained below. Note that FIGS. 2-5 refer to one end of a power line that includes a single protected component. Additionally, note that although the signals are shown spatially offset from the power lines for clarity, all signals travel on the conductors of the power lines.

Potentially harmful EMI signals 108 are induced (and in some cases injected) onto power line 104 by external harmful EMI 109 (eg, EMP) impacting power line 104 . Signal 108 is also referred to herein as "transient induced signal 108." Due to the intentional impedance mismatch introduced by the presence of the CITE 106 along the power line 104, the first side 107 of the CITE 106 directs the first portion 110 of the transient induced signal 108 to the protected component (P.C.). Reflect it away from 100. Reflective portion 110 is reversed in polarity compared to transient induced signal 108 due to the reflection described above. A smaller amplitude second portion 112 of the transient induction signal 108 is transmitted toward the protected component 100 . The first portion 110 that is transmitted away from the protected component is much larger (in amplitude) than the second portion, the ratio being a function of the degree of impedance mismatch. It should be appreciated that FIG. 2 is simplified (as are similar figures) with respect to the depiction of the transient electromagnetic interference signal and the depiction of the transmitted and reflected portions of the transient electromagnetic interference signal. For example, in FIG. 2, the transient guidance signal 108 and the reflected first portion of the transient guidance signal 110 appear to travel along separate paths shown separated by a vertical distance. However, these signals 108, 110 actually travel in opposite directions along overlapping paths that include power line 104. Additionally, only a small portion of the representative transmitted and reflected portions of the transient electromagnetic interference signal 108 are shown in FIG. 2 (and similar figures) for ease of illustration. Note that while the configuration of FIG. 2 is feasible and operable, it is not a preferred embodiment and is provided here primarily for illustrative purposes.

The design and placement of CITE 106 (and other CITEs) on power line 104 ensures that the voltage applied across protected component (P.C.) 100 avoids the destructive consequences of rendering that component inoperable. The objective is to ensure that the As discussed above, frequency-dependent impedance mismatch (according to CITE 106) reduces the voltage on power line 104 at the fundamental frequency of the current powering the power line away from protected component (P.C.) 100. Reflections are also avoided. This fundamental frequency may typically be, for example, 50, 60, or 400Hz.

One useful guideline for determining the maximum threshold voltage of the portion 112 of the transient inductive signal 108 transmitted to the protected component (P.C.) 100 is to The Basic Insulation Level (BIL) is a cross-border standard that is used worldwide. As is known, the equipment insulation of the system must be designed to withstand a certain minimum voltage before impulse (e.g. lightning impulse) overvoltages can be discharged through surge protection devices, etc. Therefore, the operating voltage level of the surge protector must be lower than the minimum withstand voltage level of the equipment. This minimum voltage rating is defined as the electrical equipment's BIL or basic insulation level. In many cases, the BIL is 6 to 7 times higher than the operating voltage level of the surge protector to ensure that the electrical equipment is protected. Note that the multiple of BIL depends on the operating voltage and decreases as the operating voltage increases.

Accordingly, one or more CITEs may be used to ensure that the portion 112 passing through the CITE(s) to the protected equipment (P.C.) 100 is determined by the BIL rating (or some set standard or threshold) of that equipment. ) is placed sufficiently close to the protected equipment (P.C.) 100 such that the

Additionally, as described herein, protected component (P.C.) 100 may take any number of different forms across a wide range of applications. For example, the protected component (P.C.) 100 may be in the form of a dwelling or a subcomponent thereof, or may be in the form of industrial power equipment such as a substation or a generator.

FIG. 3 shows another embodiment of a power line 104 where two CITEs 120, 122 are coupled. Each of the CITEs 120, 122 has a first side facing away from the protected component (P.C.) 100 and a second side facing towards the protected component (P.C.) 100. . A first side of CITE 120 and a first side of CITE 122 face each other across a portion of power line 104 to form a damped resonator 125 for dissipating the energy of the transient induced signal. A transient induced signal 126 is induced onto the power line 104 by external harmful EMI 127. A portion of the transient induced signal 126 passes to the left through the CITE 122 as a transmission portion 128. Another portion of the transient induced signal is reflected from the second side of CITE 122 as reflected portion 134. A portion of transmit portion 128 that passes through CITE 122 is reflected to the right from a first side of CITE 120 as reflective portion 130 . A portion of reflective portion 130 passes through CITE 122 as transmitting portion 131 . Another portion of transmission section 128 passes to the left through CITE 120 as transmission section 132. The transmission portion of the signal from the reception of the harmful EMI 127 to the protected component 100 via the inductive signal 126 and transmission portions 128, 132 is surrounded by a dashed box 150.

A portion of the reflective portion 130 is reflected to the left from the first side of the CITE 122 as a further reflective portion 136 . A portion of reflective portion 136 passes to the left through CITE 120 as transmitting portion 140. Another portion of reflective portion 136 is reflected to the right from the first side of CITE 120 as a further reflective portion 138 . When a signal is reflected, the further reflected portion is attenuated compared to the incident portion. For example, reflective portion 138 is attenuated compared to reflective portion 136. A portion of reflective portion 138 passes to the right through CITE 122 as transmitting portion 142. of the induced signal, starting from a portion of the external harmful EMI 127, including the induced signal on the power line 126, a portion 128 of the signal 126 initially transmitted through the CITE 122, and a portion 132 of the signal 128 transmitted through the CITE 120. The main transmitted components are surrounded by a dashed rectangular box 150. The terms "left" and "right" are used only for convenience in describing the system shown in FIG. 3 and the relative placement of components and relative directions of travel of the various signals. It will be understood.

As described herein, CITEs 120, 122 may be spaced apart from each other by a predetermined distance, the value of which depends on several operating parameters, such as the type of power line 104. As described below, the CITEs may be constructed to provide internal spacers or guides that automatically position the CITEs at a desired distance apart from each other.

From FIG. 3 and the previous paragraph, it can be seen that the initial transmitted portion causes a cascade of further reflected portions, specifically, the transmitted portion 128 gives rise to a reflected portion 130 which gives rise to a further reflected portion 136, which in turn gives rise to a reflected portion 130. It should be appreciated that portion 136 creates an additional reflective portion 138. FIG. 3 schematically depicts each of the reflective sections with successive decreases in intensity. As a result, CITEs 120 and 122 form a damped resonator 125 for harmlessly dissipating the energy of transient induced signals caused by exposure to harmful EMI.

In FIG. 3, signals 131, 134, and 142 travel from CITE 122 to the right along power line 104 where their energy is harmlessly dissipated as heat within the power line. Within the damped resonator 125, some damped resonant reflections of the transient induced signal 126 are also harmlessly dissipated as heat within the power line 104. The voltage on each of portions 132 and 140 directed from CITE 120 to protected component 100 is kept sufficiently low to avoid inoperability and/or damage to protected component 100. It should be understood that the CITE spacing allows for constructive or destructive interference. However, it will be clear to those skilled in the art that constructive interference at the frequencies of interest should be avoided (see discussion of constructive and destructive interference above).

In the embodiment shown in FIG. 3, external EMI induces signals to the right side of both CITEs 120, 122. FIG. 4 is a schematic diagram of another scenario in which harmful EMI attacks a portion of the power line between CITEs 120, 122. FIG. 4 shows the transmission portion within dashed box 150a as a basis for comparison with box 150 of FIG. As shown, in FIG. 4, unlike FIG. 3, the harmful EMI shown is received on the portion of the power line between CITEs 120 and 122. A transient electromagnetic signal 160 is induced onto power line 104 by harmful EMI 162, and a transmission portion 165 of the signal passes through CITE 120 to an electrical component (not shown in FIG. 4).

It is generally desirable to keep the length of the power line 104 between the protected component (P.C.) 100 and the first CITE (i.e., 120) as short as practical. Since the probability of influence from external harmful EMI is proportional to the length of the exposed power line, this limits the length of the aforementioned power line 104 from being exposed to transient electromagnetic signals (inductive signals) and As a result, the possibility that this length will be affected by external harmful EMI is limited. As an example, if a power line extends between a first transformer and a second transformer, a first set of CITEs is placed proximate the first transformer and a second set of CITEs is placed proximate the first transformer. one or more, preferably a plurality of CITEs, such that both sets of CITEs protect the first and second transformers in the manner described herein. must be placed at both ends of the power line. Of course, it will be appreciated that instead of a transformer, the end of the power line may be connected to any protected electrical component, such as the exemplary ones described herein or others.

FIG. 5 is a schematic diagram of another embodiment of the present disclosure in which three CITEs are coupled to a power line 104 to protect electrical components from transient induced signals resulting from transient electromagnetic interference. In this embodiment, CITEs 170, 172, 174 form two damped resonators, a first resonator 178 between CITEs 170 and 172, and a second resonator 179 between CITEs 172 and 174.

In FIG. 5, the same rules as above apply, and the CITEs 170, 172, 174 have a first side facing away from the protected component (P.C.) 100 and a protected component (P.C.) 100. and a second side face facing in the direction.

In FIG. 5, external harmful EMI 182 induces or injects signal 180 onto power line 104. In FIG. A portion of signal 180 is reflected off the first side of CITE 174 to the right as reflected portion 184 . A further portion of the transient electromagnetic (inductive or injected) signal 180 is transmitted to the left through the CITE 174 as a transmission portion 186. A portion of transmit portion 186 then reaches the first side of CITE 172 and is reflected back to the right side as reflective portion 188. Another portion of transmission portion 186 passes to the left through CITE 172 as transmission portion 187. A portion of the transmission portion 187 is further transmitted as a transmission signal 198 via the CITE 170 . It is further noted that with respect to amplitude, transmit portion 186 has a larger amplitude than transmit portion 187, which in turn has a larger amplitude than portion 198. Another portion of transmit portion 187 is reflected to the right by CITE 170 as reflective portion 195 . When reflected portion 188 reaches the second side of CITE 174, the first portion of the signal is transmitted as signal 190 and the second portion is reflected to the left as signal 192. A first portion of signal 192 to the left is transmitted through CITE 172 as signal 194 and a second portion of signal 192 is reflected off the first side of CITE 172 as signal 196. When signal 194 reaches the first side of CITE 170, a first portion of the signal is reflected as signal 200 and a second portion is transmitted through CITE 170 as transmission portion 202. Furthermore, when the signal 196 reaches the second side of the CITE 174, a portion of the signal is transmitted through the CITE 174 as a transmission portion 197.

The voltage on each of sections 198 and 202 is the final transmission section that is kept sufficiently low to avoid rendering protected component (P.C.) 100 inoperable. Transmission portions 184 , 190 , 197 are directed to the right from CITE 122 and dissipate that energy as heat along power line 104 .

In FIG. 5, the use of two damped resonators 178 and 179 allows more energy to be dissipated in the transient electromagnetic interference signal compared to the use of a single damped resonator 125 shown in FIG. However, this is due to the increased number of passes of reflected and transmitted signals between CITEs and increased heat dissipation along the power line. Accordingly, the use of multiple pairs of damped resonators may help minimize any portion of transient induced signals reaching the protected component 100. It will be appreciated that although the CITE structure may function as a heat sink, it is not intended to function as a heat sink itself. Rather, heat is expected to be dissipated by the power line 104 itself by a radiative process.

FIG. 6 is a schematic diagram of another embodiment in which a CITE according to the present disclosure is used on a power line having a first protected component 201 and a second protected component 203 at the far right. Thus, in contrast to FIGS. 2-5, FIGS. 6-8 show opposite ends of the power line, each with a respective protected component 201, 203. In the exemplary embodiment of FIG. 6, the first and second protected components are transformers. It should be understood that they can be other components (as defined above) as well. In FIG. 6, variable CITE element 230 represents a variable number (1 to N) of CITEs and CITE groups associated with protected component 201, and variable CITE element 232 represents a variable number of CITEs and CITE groups associated with protected component 203. Represents a variable n (1 to N). Additionally, the variable CITE elements 230 are shown separately on the right to indicate the individual elements (1 through N) of the variable CITE. Each of elements 230, 232 includes a number of adjacent damped resonators equal to the number of CITEs in the element minus one (n-1). For example, if three CITEs numbered 1, 2, and 3 are placed in series on a power line, there will be one damped resonator between CITEs 1 and 2, and one damped resonator between CITEs 2 and 3. Another damped resonator will be present. In the example shown in FIG. 6, resonator 235-1 is located between exemplary variable CITE elements CITE1 and 2, and resonator 235-2 is located between CITE2 and 3.

FIG. 7 is a schematic diagram of another embodiment similar to FIG. 6, including more locations for installing variable CITE elements that include one or more CITEs. For example, elements 240, 242, 244, 246, 248, 250, 252, 254 are coupled to power line 104 between protected components 100, 102. Again, each of variable CITE elements 240-254 may include 1 to N CITEs. FIG. 7 has a legend indicating that each variable CITE element 240-252 includes a number of adjacent damped resonators equal to the number of CITEs minus one (n-1). In the example shown in FIG. 7, resonator 235-3 appears between CITE1 and 2 of the exemplary variable CITE element, and resonator 235-4 appears between CITE2 and 3. The multiple CITEs that may be combined in the arrangement shown in FIG. 7 may provide multiple damped resonators to dissipate any signals induced by harmful EMI. For example, if variable CITE elements 240 and 242 located close to each other on a power line each include three CITEs, the total number of CITEs in the general location of elements 240, 242 would be six CITEs, with five CITEs between them. This will provide a damped resonator.

FIG. 8 is a schematic diagram of another embodiment in which CITEs are arranged in three groups along a power line 104. CITEs within a group are placed relatively close to each other (eg, between about 1 centimeter and 10,000 centimeters). This interval is hereinafter referred to as the intra-group interval. CITEs 260, 261, and 262 form the first group. CITEs 265, 266, and 267 form the second group. CITEs 270, 271, and 272 form a third group. CITE 275, 276, 277 form the fourth group. Each of the aforementioned groups of three CITEs may be separated from adjacent groups of three CITEs by a greater inter-group distance compared to the intra-group spacing. Intragroup spacing and intergroup distance are, as known to those skilled in the art, the fraction of the speed of light determined by the actual voltage compared to the voltage level required to achieve relativistic speed. is chosen to avoid producing constructive interference, which is determined by the speed of the induced signal on the power line. Note that the speed of light in a vacuum is approximately 1 foot per nanosecond. For power transmission lines of the type contemplated herein (eg, line 104), the speed of electromagnetic waves slows down by about 1 foot per 1.25 to 7 nanoseconds, depending on many physical considerations. Selecting the spacing of the damped resonators between each CITE based on the slowing down of the electromagnetic waves on the transmission line provides the optimal distance of the damped resonators between each CITE. In some embodiments, the spacing between resonators is about 800 feet to about 1200 feet. However, it will be understood that this range is merely exemplary in nature and not restrictive. Pulse propagation in this type of transmission line is well known and explained in textbooks on electromagnetic pulse theory.

FIG. 8 further shows that within the groups (i.e., 235-5 and 235-6 in the first group, 235-8 and 235-9 in the second group, 235-11 and 235-12 in the third group, 235-14 and 235-15) of the fourth group, as well as adjacent damped resonators between the groups (ie, 235-7, 235-10, 235-13).

A pair of CITEs of a damped resonator may be nested within another pair of CITEs of another damped resonator. For example, in FIG. 8, a first group of CITEs 262 and a second group of CITEs 265 define a resonator 235-7 therebetween, whereas a first group of CITEs 261 and a second group of CITEs 266 define a resonator 235-7 between them. It can be thought of as defining a large resonator 235-15 containing 235-7. By nesting CITEs in the manner described above, the degree of attenuation of transient induced signals is increased. This provides a convenient way to design the system. Take the maximum amplitude of the induced signal that the system is designed to protect and divide it by the damping coefficient for each nested pair of damped resonators' CITE to get the number of nested sets required .

Comparison with Conventional Low-Pass Filters Furthermore, the CITE of the present disclosure has useful characteristics compared to conventional low-pass filters. Electrically, the CITE of the present disclosure can be described as a low-Q low-pass filter. The Q factor is the ratio of reactance to resistance, which describes how damped an oscillator or resonator is, and characterizes the bandwidth of the resonator relative to the center frequency. A higher Q value indicates a lower rate of energy loss compared to the stored energy in the resonator, and the vibrations die out more slowly. Typically, filters are designed to have as high a Q value as possible, but the present invention provides an optimal configuration for dissipating the energy captured by the filter, especially for low Q values. Optimized. Furthermore, the CITE of the present invention is distinguished from conventional low-pass filters in that the CITE has a non-resonant design, operates achromatically, and has a unique and unique frequency response curve. It can be seen that while conventional filters are designed to absorb energy internally as heat, CITE is designed to reflect some of the unwanted energy.

Conventional low-pass filters typically use inductors, capacitors, and resistors to form various types of resonant circuits. By using various combinations of these types of components, you can build filters for almost any transfer function. The problem with this approach is that in typical power transmission and distribution systems operating with conventional AC voltages and currents at 50 to 60 hertz, the individual components are very large, cumbersome, and expensive. The present invention solves this problem by avoiding the use of inductors, capacitors, or resistors and instead replacing them with highly mismatched conductive impedance transition elements (CITEs). The CITE of the present disclosure provides selective impedance impedance, as opposed to the use of tuned resonant electronic circuits comprised of any combination of inductors, capacitors, and/or resistors that simply absorb unwanted portions of the signal. It is distinguished from traditional low-pass filter designs because it uses matching to generate reflections of unwanted portions of the signal.

The CITE of the present invention provides a more achromatic frequency response in that frequencies below about 1 megahertz pass unhindered and higher frequencies are selectively attenuated. There is no need to change component values as in conventional filter designs, and the higher the frequency, the higher the attenuation coefficient. Using multiple damped resonators further increases the attenuation of high frequency components. The design method described herein provides an approximately step function frequency response.

Note that low-pass filters have not historically been used for lightning suppression due to their large size and associated component cost.

A system with a low "Q", ie, a low quality factor (Q<1/2), is said to be overdamped. Such a system does not tolerate vibration well, but when it departs from the equilibrium steady-state output, it returns to the equilibrium steady-state output by exponential decay, approaching the steady-state value asymptotically. It has an impulse response that is the sum of two decaying exponential functions with different decay rates. As the quality factor decreases, the slower decay modes become stronger compared to the faster modes and dominate the system response, resulting in a slower system. A second order low pass filter with a very low quality factor has an approximately first order step response. The output of the system responds to the step input by slowly rising toward an asymptote.

As applied to the present invention in connection with the E1 pulse, a low A filter with a Q value is desirable. Since the pulse width of the E1 pulse is very short, typically less than 500 nanoseconds, it is desirable to use multiple damped resonators to further reduce the Q factor of the device.

CITE Embodiments As described herein, one of the components of the present system is an impedance transition element (CITE), typically arranged in sets of at least two CITEs.

Thus, the conductive impedance transition element (CITE) forming one side of the damped resonator can be implemented as a conductive disk with a larger diameter than the power line it surrounds, and the conductive disk is electrically coupled to the power line. Ru. As previously mentioned, the resulting diameter difference between the CITE and the adjacent portion of the power line causes transient electromagnetic (inductive) signals as a result of the ratio of impedance mismatch between the CITE and the adjacent portion of the power line. A structure is created that exhibits high VSWR for high frequencies.

An exemplary embodiment of CITE and portions thereof according to the present disclosure will be described in connection with FIGS. 9-15. FIG. 9 is a plan view of one side of the CITE 300. CITE 300 is generally disk-shaped and has an opening in the shape of a central hole 302 . CITE 300 is shown in FIG. 9 with first (e.g., upper) portion 305 and second (e.g., lower) portion 310 in an open position in which the two portions 305, 310 are at least partially spaced apart from each other. It is formed from a first portion 305 and a second portion 310 joined by a hinge element 315 for movement between a closed position and a closed position.

As shown in FIG. 9, CITE 300 has an outer peripheral portion that may have a toroidal shape as shown, a middle portion, and a central portion in which a central hole 302 is formed. Since CITE 300 is defined by first portion 305 and second portion 310, each of these portions has a peripheral portion, a middle portion, and a central portion. The outer peripheral portion therefore includes rounded edges intended to eliminate and/or control corona discharge.

In the illustrated embodiment, the top component has a peripheral portion 312 of increased width and the bottom component has a corresponding peripheral portion 313 of increased width. In one implementation, perimeter portion 312 is approximately 1/2 of a torus, and perimeter portion 313 is likewise approximately half a torus, such that when the two portions 312, 313 are combined, they extend along the perimeter of CITE 300. to define an almost toroidal shape. In other words, these portions 312, 313 have rounded surfaces. Note that the inner surfaces of 312 and 313 may be textured or even spike-shaped to perforate and increase electrical contact with the power conductors contained in these elements (Fig. 9 to 11, but shown in FIGS. 12 to 15).

The first portion 305 has an intermediate portion 314 that is recessed relative to the outer circumferential portion 312 and the second portion 310 has a corresponding intermediate portion 315 that is recessed relative to the outer circumferential portion 313. Compared to the toroidal shape of the outer circumferential portion, the intermediate portions 312, 314 may be planar in shape and generally have a semicircular shape.

The first portion 305 further includes a protruding fastening hub 316 (extending out of the page in the illustration of FIG. 9) located on the second side of the CITE facing the protected component; It includes a corresponding protruding fastening hub 317 similarly located on the second side of the CITE. As shown, the fastening hubs 316, 317 form a lip around the central hole 302. The fastening hub is used to securely couple the CITE to the power line and to securely secure the upper portion 305 and lower portion 310 to each other, as described further below with reference to FIGS. 10-12. . In the view shown in FIG. 9, the upper component 305 is installed on the lower component.

As shown in FIG. 10, via hinge element 315, upper component 305 may pivot counterclockwise away from lower component 310. When pivoted, a gap or space opens between the upper component 305 and the lower component 310. As shown, this gap opening similarly provides access to a central opening defined between fastening hubs 316, 317 that receives power lines (cables) around which the CITE is disposed. Similarly, FIG. 10 shows clearance holes 307 and threaded holes 308 through the foot portions 321, 327 of fastening hubs 316 and 317, respectively. Returning again to FIG. 9, when the upper and lower parts are joined (unpivoted), the bore holes 307, 308 coincide, forming a continuous hole into which a fastening element such as a screw or bolt can be inserted, and the CITE Secure the top and bottom together. An exemplary screw head 303 is shown in FIG. 9 to represent such a fastening element. In some embodiments, portions 321, 327 may include additional bore holes to accept additional screws or bolts to further ensure a tight coupling between the upper and lower fastening hubs of the CITE. . Also, rivets may be used, in which case no screw elements are required. Further shown in FIG. 12 is an angled contact surface 328 of the lower component that seats against a complementary contact surface (not shown) of the upper component 305.

In some embodiments, the fastening hubs 316, 317 are located on one side of the CITE 300 (i.e., projecting outward perpendicularly in one direction to the plane of the disk) when multiple CITEs 300 are coupled in series. , two adjacent CITEs 300 may be arranged such that the protruding fastening hubs 316, 317 contact or are in close proximity to opposite sides of the adjacent CITEs 300, so that the fastening hubs may function as spacers. Thus, when two adjacent CITEs 300 are pressed together into contact, the fastening hub portions 316, 317 may determine the distance between the two adjacent CITEs 300. The length of the fastening hubs 316, 317 may be used to define the distance (gap) between two adjacent CITEs 300 in embodiments where groups of CITEs are grouped into one unit. Accordingly, the transmitted transient inductive signal traveling from the first CITE 300 toward the electrical component to be protected is transmitted a predetermined set distance (defined as the length of the protruding inner portions 316, 317) from the first CITE 300. A second CITE 300 is encountered at the same location. In this manner, a series of CITEs 300 may be placed at controlled spacing along the power line. Although it is envisioned that the spacing between series-adjacent CITEs 300 may be uniform, there may be at least a first distance between two adjacent CITEs 300 and a different second distance between two other adjacent CITEs 300. It will also be appreciated that the spacing may be non-uniform. The uneven spacing of CITEs 300 can serve to provide multiple destructive interference conditions along power line 104. Since the incoming harmful EMI can contain different spectral components, the presence of non-uniform spacing ensures destructive interference over different frequency ranges.

In some embodiments, the body of CITE 300 is made from lightweight materials such as plastic or fiberglass. In order to make a CITE mainly composed of such materials, which are themselves insulating, conductive, a conductive coating of, for example, copper, nickel, iron, or mu-metal can be applied by electroplating (with or without electric current). applied to the peripheral portion using techniques known to those skilled in the art, including but not limited to) and vacuum deposition. Metal flakes or particles may be injected into the material making up the body of the CITE during formation to enhance the adhesion of the conductive coating to the outer peripheral portion of the CITE. Preferably, particles of the same composition as the coating to be applied (eg iron or nickel) are used. Alternatively, in a less preferred embodiment (due to its weight), the entire body of the CITE may be constructed from a conductive material such as copper, nickel, iron, or mu-metal, or a combination thereof.

As discussed further below, the performance of the CITE can be improved by increasing the magnetic permeability of the middle portion of the CITE 314, and the middle portion can be coated with a material having high magnetic permeability. In preferred embodiments, the intermediate portion may be coated or plated with mu metal or high purity iron. In another embodiment, the intermediate may be coated with a ferrite material.

FIG. 11 is a hinge end view of the CITE shown in FIG. 10 with the upper and lower components 305, 310 pivoted away from the seated position. In this view, the bottom surface 322 of the top component has a jagged contour and the top surface 324 of the bottom component can have a complementary jagged contour adapted to cooperatively engage the bottom surface of the top component. I understand. However, surfaces 322, 324 do not engage flush, leaving an inwardly extending notch 325 within the CITE.

FIG. 12 is a perspective view of CITE 300 in a slightly pivoted position to more clearly show fastening hubs 316, 317. The fastening hub 316 includes a semi-circular lip portion 319 and a rectangular “foot” portion 321 of the foot. Similarly, fastening hub 317 includes a semicircular lip portion 323 and a rectangular foot portion 327. The "foot" portions 321a, 327a of each fastening hub have a fastening mechanism that is different from that shown in FIGS. 9 and 10. In this embodiment, the bottom surface of the foot portion 321a (of the fastening hub 316) has the ability to flex and snap into place against corresponding teeth disposed within the receptacle 345 of the foot portion 327b of the fastening hub 317. The ratchet element 343 includes flexible teeth with a ratchet element 343. The manufacturing methods and material properties used in this ratcheting fastener are known to those skilled in the art. When the CITE is closed and ratchet element 343 enters receptacle 345, upper portion 305 and lower portion 310 are locked together in position. Also shown in FIG. 12 is an angled contact surface 328 of the lower component that seats against a complementary contact surface (not shown) of the upper component 305.

The inner surface of the semicircular portions 319, 323 of the fastening hub includes sharp cutting elements 341 (identified collectively). The cutting element is adapted to cut into the outer surface of the power line when the CITE is attached and the fastening hubs 316, 317 are closed around the power line. Cutting into the power line ensures a stable and secure conductive connection between the CITE and the power line. Cutting element 341 may be formed into a spike-like pyramid shape as shown, or other shapes that support the functional purpose of the cutting element known to those skilled in the art. The number and size of individual cutting elements used may be varied based on the known characteristics of the power line.

To prevent arcing, a conductive paste is applied to all joints within the CITE and the interface between the CITE and the power line. For example, when installed on power lines, Cool Amp ConductoLube Co., of Lake Oswego, Oregon, is used. A conductive paste such as ConductoLube manufactured by ConductoLube, or the like, may be applied to the surface 328 and all other interfaces between the upper component 305 and the lower component 310. In the illustrated embodiment, a conductive paste is also applied to the hinge surfaces 322, 324 to also prevent arcing at the hinge elements. Once the CITE is installed around the power line and the power line is placed within the center hole 302 of the CITE, a conductive paste is applied around the edges of the center hole to create a uniform conductive connection between the CITE and the power line. Can be secured.

FIG. 13 is a perspective view of the lower component 310 of the CITE, and FIG. 14 is a perspective view of the upper component 310. The component diagrams of FIGS. 13 and 14 more clearly show the sloped contact surfaces 328, 329 where the upper and lower components are connected. Both surfaces 328, 329 are discontinuous, broken in the middle, and provided with a central hole 302. FIG. 15 is a longitudinal cross-sectional view taken along axis 15-15 of FIG. Figure 15 shows that most of the outer portions 312, 313, other than the respective hinge elements 315 of the upper and lower components, are hollow, which helps reduce the weight and cost of the CITE.

Thus, the structure of CITE 300 allows the structure to be easily opened to receive the cable, which is then captured by sealing the top component 305 and bottom component 310, thereby ensuring that the CITE 300 is securely attached to the cable. be combined.

In another embodiment of the CITE 1300 shown in FIGS. 28A and 28B, the top component of the CITE has a tongue element 355 projecting from the bottom surface of the component, similar to the top component of the embodiment shown in FIGS. 9-16. . The lower component includes a complementary groove 357 sized to securely receive the tongue element with close tolerances to achieve reliable electrical contact. The tongue and groove pair, along with the fastening hub, serve to secure the upper and lower components together after attaching the CITE to the power line.

FIG. 16 is a perspective view of another embodiment of a CITE according to the present disclosure. CITE 600 includes an upper portion 605 and a lower portion 610 that are not attached to hinge elements. In the illustrated embodiment, the fastening hub 616 of the portion 605 has a semi-circular lip 621 forming a lip around a central hole through the cite 602 and two feet 623, 624 located on either side of the semi-circular lip 621. including. Similarly, fastening hub 617 of section 610 includes a semicircular lip 631 disposed around central hole 602 and two feet 633, 634. The upper foot 623 connects to the lower foot 633 and the upper foot 624 connects to the lower foot 634 to secure the upper and lower parts together. In a preferred embodiment, matching threaded bore holes are drilled in portions 623/633 and 624/634 to allow screws, bolts, rivets or similar fastening elements to pass through the matching portions for secure coupling. When attached to power lines, a conductive paste is applied across the interface between the top and bottom to prevent arcing in the gaps between the parts.

On the other hand, in the embodiments shown in FIGS. 9-16, the cross-sectional shape of the CITE is circular, whereas the one or more CITEs used may be elliptical, polygonal, and non-uniform (e.g., asymmetric and/or may have other shapes, including (irregular). In all such embodiments, the cross-sectional dimension of the CITE is larger than the diameter of the power line to which it is attached, creating an intentional impedance mismatch, similar to the case with circular CITEs.

Use of CITE Elements for Signaling Purposes The CITE of the embodiments shown in FIGS. It may be usefully adapted to signal the presence of power lines. In one implementation of the CITE 1000 shown in FIG. 24, the walls of the outer "torus" portion 1010 may be made, at least in part, of a transparent material, such as plastic or fiberglass. Because the torus section is hollow, it can be filled with a gas such as neon that fluoresces in the presence of a high electric field. Fluorescent radiation, e.g. 1015, is shown emanating from a peripheral portion 1010. When a CITE containing such a transparent (or partially transparent) gas-filled torus is attached to a high-voltage power line, the electric field generated by the power line causes the gas to fluoresce. This fluorescence makes the CITE visible from a distance and signals the presence of the high-voltage power line to which it is attached.

Note that the normal components of gas discharge luminescence need to be present. A getter pump is therefore desirable to maintain the purity of the fluorescent gas, preferably a noble gas such as neon or argon.

Additional CITE Embodiments FIG. 17 shows an alternative embodiment of an impedance transition element (CITE) labeled 500. Like all CITEs described herein, CITE 500 is electrically conductive and makes electrically conductive contact with and surrounds power line 104 . CITE 500 has a generally flat surface 505 shown on the right and a conical surface 510 that slopes to the left from surface 510. The flat surface 505 as the first reflective surface exhibits a sudden change in impedance compared to the impedance of the adjacent part of the power line 104 (to the right of the surface 505) due to the sudden change in diameter. The left conical surface exhibits a more gradual change in impedance compared to the impedance of the adjacent portion of power line 104 (to the left of flat surface 510). Therefore, flat surface 505 is used to reflect transient electromagnetic interference signals. Similar to the previous embodiment, CITE 500 functions as a result of having a much larger diameter compared to the power line dimensions.

18A-18C illustrate embodiments of CITEs with different cross-sectional shapes. FIG. 18A shows an embodiment of CITE 701 having an upper portion 705 and a lower portion 710 that have an oval cross-sectional shape when assembled. FIG. 18B shows an embodiment of CITE 711 having an upper portion 715 and a lower portion 720 that have a polygonal (hexagonal in this case) shape when assembled, and FIG. 18C shows an embodiment of a CITE 711 that has an asymmetric cross-sectional shape when assembled. 7 shows an embodiment of a CITE 712 having an upper portion 725 and a lower portion 730. In the illustrated embodiment, CITEs 701, 711, and 721 are otherwise structurally similar to the embodiment illustrated in FIG. (including similar fastening hubs).

As mentioned above, it is practical to form CITEs from lightweight elements such as fiberglass or plastic and coat them with materials that are electrically conductive and have high magnetic permeability. In a preferred embodiment, the outer "torus" portion of the CITE may be coated with a conductive metal such as copper, nickel, high purity iron or mu-metal using electroplating or vacuum deposition. The middle part of the CITE can be plated with mu-metal, which has very high magnetic permeability. The central section has a smaller surface area than the outer torus sections, which reduces the volume of applied mu-metal or high-purity iron, significantly increasing magnetic permeability while reducing overall cost. In some embodiments, mu-metal or iron is coated on only one side of the CITE, while in other embodiments both sides are coated. With the addition of mu-metal or iron, a much smaller CITE structure (ie, smaller diameter) can be used to obtain a similar degree of E1 pulse attenuation.

Additionally, the performance of the magnetic shield can be improved by constructing the shield with alternating layers of high and low permeability materials. The degree of improvement depends on many factors including the relative permeability of the material used, thickness, spacing, etc. In an additional embodiment, CITE adds a symmetrically placed layer of mu-metal or high-purity iron on either side of it, creating a "sandwich" structure with a high-low-high (HLH) permeability cross-section. It can be constructed by Figure 32 shows a side embodiment with such a "sandwich" structure. As shown, the CITE 1400 includes a first mu metal or high purity iron layer 1410 coated on the surface of the first side of the CITE, and a second mu metal layer 1410 coated on the surface of the second side of the CITE. or a high purity iron layer 1420. Although additional layers can be added, for practical purposes a three layer CITE design is preferred.

In other embodiments, it is practical to form the CITE entirely or partially from ferrite components. The use of ferrite has many advantages, such as reduced physical size and lower Q-factor, but increases cost. FIG. 21 shows another embodiment of a conductive impedance transition element (CITE) in the form of a ferrite bead placed coaxially on the power line 104. The CITE570 ferrite bead's shape and electromagnetic properties make it highly effective against high frequency signals, attenuating relatively high frequency signals induced by external harmful EMI on power lines, as well as radio frequency interference (RFI) electronic noise. A relatively high impedance can be obtained. Energy from these energy sources is either reflected along the power line 104 toward the inductive signal source or dissipated along the power line as low-level heat. Only in extreme cases does the fever become noticeable. Note that ferrite not only reflects some of the energy, but also absorbs it.

CITE typically does not dissipate energy, but instead creates a reactance that impedes the flow of relatively high frequency transient electromagnetic interference signals. This reactance is commonly referred to simply as impedance, but impedance can be any combination of resistance and reactance. Ferrite concentrates the magnetic field, increases impedance and therefore reactance, and interferes with or "cancels out" high frequency signals. Ferrite beads are typically manufactured in a segmented configuration that facilitates attachment to existing power lines.

If the ferrite component is so designed, additional losses may occur in the form of resistive heating of the ferrite itself. The Q value of an inductor is the ratio of reactance to resistance at a particular frequency. When a ferrite inductor has a low Q value, it has a relatively high resistance and is therefore susceptible to resistance heating. Depending on the application, the resistive loss characteristics of ferrite may or may not be desirable. The design of ferrite CITE, which uses ferrite beads to improve noise filtering (in addition to protecting electrical components from transient electromagnetic interference signals), also depends on the specific characteristics of the circuit containing the ferrite CITE and the frequency ranges it blocks. need to be considered. Different ferrite materials have different frequency characteristics. Those skilled in the art will appreciate that manufacturer's documentation can assist in selecting the most effective material for a frequency range. Note that ferrite structures consisting of two or more different ferrite compositions may be utilized to optimize both the reflection and absorption properties of the CITE. Various methods of combining two or more ferrite components will be known to those skilled in the art.

As known to those skilled in the art, the magnetic permeability of ferrite depends on the particular ferrite mixture used. Generally, the magnetic permeability of ferrite ranges from 1500 to 3000 (relative). Materials with substantially higher magnetic permeability are used, such as mu-metal (75% to 80% nickel, balance dependent on the specific alloy), which has a magnetic permeability in the range of 80,000 to 100,000 on the same relative scale. In this case, the size of the CITE can be reduced while having at least comparable permeability properties. Therefore, as mentioned above, with the addition of mu-metal, a much smaller CITE structure can be used to obtain the same degree of E1 pulse attenuation. In some embodiments, the reduced size CITE may include a layer of mu-metal coated on the surface of one side of the CITE.

In embodiments using mu-metal or high-purity iron, it is necessary to form a conductive bond between the mu-metal or high-purity iron and the aluminum. This can be accomplished by many means including, but not limited to, conductive epoxy bonding, soldering, brazing, pressure (friction) bonding, and the like.

Additionally, it is desirable to extend the mu-metal or high-purity iron from one side of the CITE across the centerline so that it overlaps and electrically connects with the mu-metal or high-purity iron on the opposite side of the device. This ensures that the magnetic properties are continuous rings of magnetic properties rather than rings with gaps. If a design with a gap is used, the gap must be wide enough to prevent arcing. The size of that gap is determined by the operating voltage at which the CITE is designed to operate.

It should be noted that, as known to those skilled in the art, for optimal operation, the mu-metal or high-purity iron requires hydrogen firing and annealing after production.

It is important to note that regardless of the shape of the conductive impedance transition element (CITE), multiple CITE pairs may be used to increase the attenuation of reflected transient electromagnetic interference signals. This plurality of pairs of impedance transition elements constitutes a preferred embodiment of the invention. Additionally, it is noted that the impedance transition elements are designed and formed consistent with proper high voltage engineering practices to prevent or minimize the formation of arcs, corona discharges, and electrical shorts. . These shapes are well known to those skilled in the high voltage art.

Conductive impedance transition elements (CITEs) have a simple physical structure that can be manufactured in a variety of ways. These methods include machining, casting, die casting, injection molding, forging, stamping, lost wax casting, powder metallurgy and sintering, 3D additive manufacturing, water jet profiling, laser profiling, etc., and combinations of these methods. including but not limited to. Additionally, the CITE can be assembled from components such as a disk containing an anti-corona ring attached to the outer periphery and a centrally attached clamping mechanism. The particular method(s) selected will be routine to those skilled in the art and will typically be based on the most cost-effective method(s) for manufacturing the required number of devices over a given period of time; , based on the manufacturing processes available to the manufacturer.

In many implementations, the CITE is assembled from an upper component and a lower component, each manufactured separately. In other embodiments, CITEs may be manufactured in other ways, including from longitudinal sections. 22A and 22B are plan views showing how to assemble a CITE from two longitudinal sections. FIG. 22A shows a front view of the disc-shaped first portion 805. The front surface of the illustrated portion defines a "plane of cross-section." The first portion has a slot 808 extending centrally from the outer periphery of the disk. The diameter of slot 808 is set such that power line 804 is received within the slot as shown. A removable bracket 815 is shown positioned below the inner end of central slot 808 of portion 805. The bracket includes clearance holes for receiving threaded elements 817, 818, such as screws or bolts. The back of the section 805 cab includes additional fastening elements (e.g., holes) for receiving fasteners such as screws or bolts that extend laterally, perpendicular to the plane of the section (not shown in FIG. 22A). include.

FIG. 22B is a rear view of the complementary disc-shaped second portion 820. The second part 820 is designed to fit into part 805 for assembling the CITE. Second portion 820 includes a slot 822 shaped similarly to slot 808 of portion 805 for receiving power line 804 . A bracket 825, complementary to top bracket 815, is shown above the inner end of slot 822. Bracket 825 includes threaded holes 827, 828 adapted to receive threaded elements 817, 818 of complementary bracket 815 of the first portion. In this manner, the first portion may be secured to the second portion with brackets 815, 825 that fit tightly around power line 804. Furthermore, the surface of the second part may include threaded holes, such as 831, 832, for receiving additional fastening elements. In this way, each section is further fixed relative to the plane of the section via complementary brackets 815, 825 that secure the first and second sections in the plane of the section. They can be fastened to each other via additional fastening elements that fasten along the lateral direction.

As shown in FIG. 23, in another embodiment, CITE 900 is formed in the shape of a sphere 905 having a diameter greater than the diameter of power line 904. Although this is not the preferred form for CITE, the sphere also provides an impedance mismatch that causes reflection of incoming harmful EMI.

Furthermore, the CITE of the present invention includes a simple structure for clamping to existing power lines. They have no active electronic circuitry and contain no internal components that can be damaged or degraded in virtually any operational scenario.

Furthermore, as a function of their physically simple design, impedance transition elements can be easily mass-produced. Therefore, the cost of a pair of CITEs forming a damped resonator is a fraction of the cost of other solutions. Additionally, CITE can be designed to be easily installed on live power lines, significantly reducing installation time and cost compared to other technologies. The savings will be particularly significant since the power supply via the power line will not be interrupted.

Absorber Element The CITE element described above is electrically conductive and does not absorb incident harmful EMI energy. In the embodiments shown in FIGS. 2-8, the energy of the incoming EMI is dissipated as heat along the power lines. One or more absorber elements are installed on the power line in conjunction with or in addition to the CITE element to increase the dissipation rate and reduce the amount of energy that the power line needs to dissipate per unit time. obtain. The absorber element may be formed in a similar manner to CITE, but made from a resistive or semi-resistive (or semi-conducting) material such as graphene. Resistive materials are designed to absorb energy from incoming harmful EMI and convert electromagnetic energy into heat. The heat thus generated is dissipated into the environment over time by radiation or conduction cooling. One or more absorber elements may be added at regular or irregular intervals along the power line. In one example where groups of CITEs are assembled together, absorber elements may be added to or placed adjacent to each assembly. Those skilled in the art will readily understand that this is only one example and that absorber elements may be added in various numbers and configurations depending on the purpose of providing additional heat dissipation capacity.

The absorber element may be a separate standalone element, or in some embodiments the absorber element may be integrated as part of a CITE element. A combination of separate and integrated absorber elements can also be used. Figures 25A to 25C show disk elements in which the central portion of the disk is made of different materials. In FIG. 25A, the central portion 1025 is made from a resistive or semiconducting material, such as graphene, which acts as an absorber element. In FIG. 25B, central portion 1035 is made from a metal such as aluminum. This embodiment is similar to CITE described above with reference to FIGS. 9-16. FIG. 25C shows a disk element in which the central portion 1045 is made from a ferritic material that can function as both a reflector and absorber of incoming harmful EMI.

Another embodiment of an integrated CITE/absorber element is shown in FIGS. 26A and 26B. In this embodiment, one side of CITE 1105 includes a conductive central portion 1115 and the opposite side of CITE 1110 includes an absorbent material (resistive or semiconductive) in its central portion 1120 element. The CITE assembly incorporates a variety of conductive, absorbent, and ferritic materials in the array of CITEs (as shown in Figure 8) to achieve maximum suppression of unwanted high frequency components of the incident signal. Note that it can be configured in combination.

In-Phase Adjacent Power Cable Embodiments Many high-voltage power line installations have multiple sets of parallel phase lines. In such installations, the multiple phases of each set of power lines are placed at a distance from each other, typically measured in feet, while in-phase parallel power lines are placed at a distance, typically measured in inches. and are placed very close to each other. In other words, the interphase conductor spacing is an order of magnitude larger than the in-phase conductor spacing. This is due to the fact that adjacent power lines in phase are at the same voltage, so they can be spaced fairly close together. Actual spacing will vary depending on power line characteristics, such as diameter and other factors. In some embodiments, the distance between adjacent sets of in-phase power lines may be, for example, 2 inches to 36 inches apart, and more typically 6 inches to 12 inches apart. Generally, all parallel power lines have the same diameter.

FIG. 29A shows an example of a CITE specifically adapted to provide protection against harmful EMI to two adjacent parallel power lines that are in phase. Those skilled in the art will appreciate that the illustrated embodiment can be extended to installations having more than two separate sets of adjacent parallel power lines (an example of which is shown in FIG. 31 and described below). explain). In the embodiment shown in FIG. 29A, the power lines are shown horizontally adjacent to each other. Although this is one possible arrangement, adjacent power lines may be set at any angle or orientation relative to each other as long as they remain parallel and not too close to other phase power lines. Returning to FIG. 29A, CITE 1150 includes an upper portion 1155 and a lower portion 1160. The upper portion 1155 includes an upper central hub 1157 and the lower portion 1160 includes a lower central hub 1162. In the illustrated embodiment, the upper central hub portion 1157 includes two arcuate semi-cylindrical notches and the lower central hub portion 1162 includes a complementary arcuate semi-cylindrical notch. As can be seen, when the top 1155 and bottom 1160 are assembled, the notches in the top and bottom central hubs combine to form two central holes 1171, 1172 that can receive adjacent parallel power lines. Cutting elements, e.g. 1174, 1175, are arranged on the inner surface of the holes 1171, 1172.

FIG. 29B shows an enlarged view of the upper and lower central hubs 157, 162 and central holes 1171, 1172. In FIG. 29B, the closest distance (D) between central holes 1171, 1172 is shown. As mentioned above, the distance (D) is determined by the power line installation and can range from 2 inches to 36 inches. Therefore, the hub area of CITE 1150 for multiple adjacent power lines is typically larger than the CITE embodiment for a single power line. To accommodate larger hubs, the diameter of the CITE may be increased accordingly. As with other embodiments, CITE 1150 may be made using metals such as aluminum or copper. The CITE may include ferrite materials and, in some embodiments, may include absorber elements as described above.

FIG. 30 is a perspective view of CITE 1150 for two-phase lines. FIG. 30 shows the CITE in a slightly open position, in which the CITE can be installed in parallel power lines by inserting the parallel power lines into the central holes 1171, 1172. This view also clearly shows the ratchet locking mechanism for securing the top 1155 and bottom 1160 of the CITE to each other. In the illustrated embodiment, the locking mechanism includes a ratchet element 1180 that includes teeth and a corresponding receptacle 1182 that includes a corresponding profile adapted to reliably receive the ratchet element. Note that the design aspects described above and adapted for a single power line shown in FIGS. 9-28E may also be adapted for attachment to multiple adjacent parallel power lines in phase. For example, a multi-line compatible CITE may include a hinge and may use a different locking mechanism than that shown in FIG. 30.

FIG. 31 is another front plan view of an embodiment of the CITE 1200 adapted for three-phase line, shown without the central hub and cutting element. CITE 1200 includes an upper portion 1205 and a lower portion 1210. Both the upper and lower portions are preferably semi-circular in shape as shown, including an arcuate outer periphery and a flat chamfered edge (as shown in Figure 12). The top 1205 includes two arcuate notches 1207 emerging from the planar edge. In this exemplary embodiment, the bottom portion 1210 is not an exact mirror image of the top portion. In particular, the bottom planar edge is modified by a central polygonal notch 1212 with a wide side of the planar edge and a narrow side towards the outer periphery of the bottom. In the illustrated embodiment, the polygonal notch is trapezoidal, but the polygonal notch can be formed into other shapes, asymmetrical or symmetrical. The narrow edge of the polygonal notch further includes a central arcuate notch 1214. The lower polygonal notch 1212 has a correspondingly shaped polygonal insert 1220 with a wide edge located on the flat edge of the lower part and a narrow edge located on the narrow edge of the lower polygonal notch. Blocked. The wide portion of the polygonal insert 1220 has two more arcuate notches that mate in alignment with the respective actuation notches 1207 and 1209 on the top. An arcuate notch 1226 on the narrow edge of the polygonal insert mates in alignment with an arcuate notch 1214 on the bottom. The polygonal insert 1220 and the top and bottom edge mechanical surfaces can be machined using a tongue and groove mechanism or other mating elements, with the polygonal insert positioned within the polygonal notch 1212. and fixed in place, preventing any movement of the insert along the axis of the power line conductor. It is also noted that the polygonal insert and associated notch may be on the top rather than the bottom.

As can be discerned, the corresponding arcuate notches 1207/1222, 1209/1224, and 1226/1214 form holes in which in-phase power lines may be installed. During installation of the CITE 1200, power lines may be attached to the bottom notch 1214. A polygonal insert 1220 may then be placed over this power line. Additional power lines can be placed on the notches 1222, 1224 of the insert, and the top can be placed on top of the additional power lines. These parts may be secured using the fasteners described in the embodiments above. Additionally, the arcuate notch may include a cutting element as described above. A conductive paste should be used to seal the edges joining the polygonal insert 1220 to the bottom part 1210 of the CITE. In certain embodiments (not shown in FIG. 31), the top and bottom of the CITE may be hinged (eg, as shown in FIG. 10).

Impedance Mismatch in Underground Power Cables The embodiments described above relate to exposed above-ground power lines. Especially in large metropolitan areas, a significant number of power lines run underground rather than being exposed. It may be useful to provide impedance mismatching elements in underground cables to provide protection for electrical and electronic components attached thereto. 27A and 27B are axial and longitudinal cross-sectional views, respectively, of a coaxial power cable 1200 with periodic changes in impedance in accordance with the present disclosure. The cable includes a core 1205 with one or more conductive wires, a semiconducting layer 1210 surrounding the core, a conductive shield layer 1215, and an insulating layer 1220 surrounding the shield layer. As shown in FIG. 27B, the semiconductor layer 110 has a periodic change in capacitance corresponding to a periodic change (differential) in impedance. For example, regions 1232 and 1234 have a higher resistance compared to their respective adjacent regions 1233 and 1235.

Adjacent regions of differential impedance create mismatched interfaces of impedance against which received harmful EMI is reflected in a manner similar to how inductive signals along terrestrial power lines are reflected by CITE elements.

Note that there are several ways to achieve variations in the impedance of the semiconductor layer. These include, but are not limited to, variations in the conductivity of the composition of the semiconductor layer, variations in the thickness of the semiconductor layer, and other variations apparent to those skilled in the art of manufacturing coaxial type cables.

As will be apparent to those skilled in the art, the CITE described herein may be used in conjunction with, but not limited to, other protection measures used by power companies to protect against harmful EMI, such as vacuum tube devices. Not limited.

The claims should not be limited by the preferred embodiments and examples described herein, but are to be given the broadest interpretation consistent with the description as a whole. It will be apparent to those skilled in the art that there are many possible variations that fall within the scope of this specification.

Claims (23)

An electrical signal induced by harmful EMI on one or more power lines in a group of a plurality of contiguous parallel power lines in phase within a power generation, transmission, and distribution system connects to one of said plurality of parallel power lines. A device for preventing access to an electrical component that is
at least one conductive impedance transition element, the at least one conductive impedance element having a plurality of spaced apart holes sized to receive and surround one of the plurality of adjacent power lines of the in-phase. a disk-like structure having an outer diameter greater than a diameter of all of the plurality of parallel power lines, and wherein the disk-like structure has an outer diameter greater than the diameter of all of the plurality of parallel power lines, and the disk-like structure has an impedance between the conductive impedance transition element and adjacent portions of the plurality of power lines. Intentionally creating inconsistencies;
the impedance mismatch causes the at least one conductive impedance transition element to reflect high frequency components of signals induced onto the plurality of power lines by harmful EMI;
The device, wherein the high frequency components are reflected and dissipated as heat. 2. The apparatus of claim 1, wherein the at least one conductive transition element includes two central holes for receiving two adjacent parallel power lines. The magnitude of the impedance mismatch is frequency dependent and reflects the unwanted high frequency spectral components of the induced transient electromagnetic signal from the at least one conductive impedance transition element. 2. The apparatus of claim 1, wherein low frequency spectral components of an electromagnetic signal are allowed to pass through the at least one conductive impedance transition element. 2. The apparatus of claim 1, wherein one or more of the at least one conductive impedance transition element is comprised in whole or in part of a ferrite material. 5. The apparatus of claim 4, wherein one or more of the at least one conductive impedance transition element is comprised of two or more different ferrite materials. 2. The apparatus of claim 1, wherein the ratio of the outer diameter of the at least one conductive impedance transition element to the diameter of the plurality of power lines is within a range of about 1.5:1 to 100:1. 7. The apparatus of claim 6, wherein the ratio of the diameter of the at least one conductive impedance transition element to the diameter of the plurality of power lines is preferably within a range of about 2:1 to 80:1. Each of the at least one conductive impedance transition element includes a first section and a second section, each of the first part and the second section includes a plurality of fastening hubs, each of the fastening hubs having a notch for receiving the power line, when the fastening hubs of the first and second sections are attached to the power line. 2. The apparatus of claim 1, wherein the first and second parts are fastened together to secure them together. the fastening hub of the at least one electrically conductive impedance transition element has an inner surface supporting a cutting element adapted to cut into the plurality of power lines, thereby securing the electrically conductive impedance transition element to the power lines; 9. Apparatus according to claim 8. The plurality of fastening hubs of the first and second sections each include a plurality of semi-cylindrical sections and a foot section, and the foot section of the first section is a ratchet. the foot portion of the second section has a receptacle having features matching the ratchet element, and the first and second sections are secured to each other. 9. The device according to claim 8, which allows. A method for protecting components coupled to power lines of a group of equiphase parallel power lines of a power generation, transmission, and distribution system from harmful EMI, the method comprising:
by attaching at least one conductive impedance transition element (CITE) having a diameter greater than the diameter of the power line to all of the equal phase power lines at a location between the extended length of the power line and the component; Including intentionally creating an impedance mismatch;
The diameter difference between the CITE and the power line intentionally causes an impedance mismatch between the two or more conductive impedance transition elements and adjacent portions of the power line, the impedance mismatch comprising: The method wherein high frequency components of signals induced in the power line by the harmful EMI are reflected and dissipated by damped resonators formed between pairs of the plurality of conductive impedance transition elements. the ratio of the diameter of the at least one conductive impedance transition element to the diameter of the power line to which the at least one conductive impedance transition element is attached is within a range of about 1.5:1 to 100:1. 12. The method of claim 11. The ratio of the diameter of the at least one electrically conductive impedance transition element to the diameter of the power line to which the at least one electrically conductive impedance transition element is attached is preferably within the range of about 2:1 to 80:1. 13. The method according to claim 12. 12. The method of claim 11, wherein the at least one conductive impedance transition element is formed in the shape of a disk. 12. The method of claim 11, wherein the at least one conductive impedance transition element comprises a plurality of conductive impedance transition elements arranged in at least one pair forming a damped resonator. An electrical signal induced by harmful EMI on one or more power lines in a group of a plurality of contiguous parallel power lines in phase within a power generation, transmission, and distribution system connects to one of said plurality of parallel power lines. A device for preventing access to an electrical component that is
at least one conductive impedance transition element, the at least one conductive impedance transition element comprising a disk-shaped structure including an upper part and a lower part, at least one of the upper part and the lower part being connected to the in-phase plurality of adjacent a notch for receiving an insert, the disk-like structure including a further notch for receiving a power line, the disk-like structure providing an impedance discontinuity between the at least one conductive impedance transition element and adjacent portions of the plurality of power lines; having an outer diameter greater than the diameters of all of the plurality of parallel power lines to intentionally create alignment;
the impedance mismatch causes the at least one conductive impedance transition element to reflect high frequency components of signals induced onto the plurality of power lines by harmful EMI;
The device, wherein the high frequency components are reflected and dissipated as heat. 17. The insert of claim 16, wherein the insert is polygonal in shape and the notch in the insert matches a corresponding notch in one of the top and bottom of the at least one conductive impedance transition element. Device. the disc-like structure of the conductive impedance transition element has a radially outer portion having a first thickness and a radially intermediate portion having a second thickness less than the first thickness; 2. The device of claim 1, wherein the structure is constructed from one of plastic and fiberglass materials. 19. The apparatus of claim 18, wherein the outer portion of the conductive impedance transition element is coated with a conductive material. 19. The apparatus of claim 18, wherein the electrically conductive material includes at least one of copper and nickel. 19. The apparatus of claim 18, wherein the intermediate portion of the conductive impedance transition element is coated with a high magnetic permeability material. 22. The apparatus of claim 21, wherein the high permeability material is mu metal. 22. The apparatus of claim 21, wherein the high permeability material is high purity iron.

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