JP2005123751A - Electric noise filter and electric noise eliminating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a large power noise filter with a high current capacity and a high withstanding voltage for effectively attenuating electric noises with high frequencies. <P>SOLUTION: The electric noise filter is configured by arranging a circuit element with an impedance different from a characteristic impedance of a transmission line between a main conductor of a sub conductor missing part and a sub conductor or between the main conductor of the sub conductor missing part of the transmission line and a third conductor or by annularly providing a magnetic body to the transmission line, the transmission line being configured with the main conductor and the sub conductor coaxially coated on the main conductor via an insulator, the sub conductor being divided into a plurality of conductors at a prescribed uniform interval or by two kinds or more of lengths, the adjacent sub conductors being interconnected by the third conductor, or part of the removed sub conductors through the division being left and used for the interconnection in place of the third conductor. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrical noise power from the device or the device, such as an electronic device or an electric device with electrical discharge, and the like. In particular, the present invention relates to an electrical noise filter and an electrical noise removal method for preventing electric noise from propagating to the outside, and in particular, an electrical noise filter and an electrical noise removal method applied to a high voltage, large current distribution system. It is about.

A conventional electrical noise filter is an inductive element such as an individual coil or transformer, or an electrostatic capacity element such as an individual capacitor, or a combination of these individual inductive element and electrostatic capacity element, or around an electric wire. It has been composed of inductive elements made of magnetic material.
However, each inductive element such as a coil or a transformer is an electric winding, whether it is an air core or a magnetic core, and resonates with the parasitic capacitance between the electric windings and the inductance of the inducting element. A circuit is configured, and an individual capacitive element such as a capacitor is also a resonance circuit by an inductance parasitic on a lead wire for connecting an electrode of the capacitive element to an external electric circuit and a capacitance of the capacitive element. Therefore, the effect of the electrical noise filter composed of individual inductive elements or capacitive elements is limited to a frequency region near the resonance frequency.
In particular, an inductive element used for a high-power noise filter inserted into a high-voltage, high-current power line must use a thick conductor in order to pass a large current. The resonance frequency of the is reduced. In order to realize a large withstand voltage, the capacitance element must also increase the thickness of the dielectric disposed between the electrodes, and to obtain the same capacitance, the electrode area must be increased. Therefore, the capacitance element increases in volume almost in proportion to the square of the withstand voltage. A capacitive element having a large volume requires a longer lead line, and the resonance frequency of the capacitive element is lowered by an increase in inductance of the lead line.
As described above, it has been difficult to realize a large current capacity, high withstand voltage, high power noise filter that attenuates high frequency electrical noise using individual inductive elements and capacitive elements.
Further, in the noise filter in which a magnetic material is provided around the electric wire, the permeability of the magnetic material starts to decrease from several MHz and decreases to nearly 1 at several GHz. For this reason, it has the disadvantage that the effect is reduced against high frequency electrical noise.

  On the other hand, if an inductive element with a small inductance and a capacitive element with a small capacitance are used, the filter can be operated up to a high frequency. However, in order to ensure the attenuation amount of electrical noise, a large number of such inductive and capacitive elements must be connected in series. For example, assuming that the inductive elements and the capacitive elements provided concentrated in one place are dispersedly arranged in 10 places, the inductance of each dielectric element is reduced to 1/10 of the concentrated time and the capacitance of each capacitive element is set. When ten electric circuits that are reduced to 1/10 of the concentration are connected in series, the total inductance and capacitance of the electric circuits are the same as when the electric circuits are concentrated. However, such an electric circuit is a so-called LC distributed constant circuit, and becomes a lossless delay circuit in which the phase of the transmission signal is delayed but the amplitude of the voltage / current does not change. Therefore, an electric circuit in which a large number of inductive elements having small inductances and electrostatic capacitance elements having small capacitances are arranged uniformly does not function as a noise filter.

  The problem to be solved by the present invention is to provide a high-power noise filter with a large current capacity and a high withstand voltage that effectively attenuates high-frequency electrical noise.

The present inventor has solved the above problems by the following means.
(1) In a transmission line composed of a main conductor and a sub-conductor that is coaxially covered with the main conductor via an insulator, the sub-conductor is divided into a plurality at predetermined equal intervals and further adjacent to each other. An electrical noise filter characterized in that each sub-conductor is connected by a third conductor, or a part of the sub-conductor missing by division is left and connected in place of the third conductor.
(2) In a transmission line composed of a main conductor and a sub-conductor that is coaxially covered with the main conductor via an insulator, the sub-conductor is divided into at least two types of lengths, and each adjacent conductor An electrical noise filter characterized in that the sub-conductors are connected by a third conductor, or a part of the sub-conductor missing by division is left and connected in place of the third conductor.

(3) In a transmission line composed of a main conductor and a sub-conductor that is coaxially covered with the main conductor via an insulator, the sub-conductor is divided into a plurality at predetermined equal intervals and further adjacent The sub-conductors connected to each other are connected by a third conductor, or a part of the sub-conductor lacking by division is left and connected in place of the third conductor, and further, the sub-conductor lacking portion of the transmission line is led. A circuit element having an impedance different from the characteristic impedance of the transmission line is disposed between the body and the sub-conductor, or the main conductor and the third conductor of the sub-conductor lacking portion of the transmission line. Noise filter.
(4) In a transmission line composed of a main conductor and a sub-conductor coated coaxially with the main conductor via an insulator, the sub-conductor is divided into at least two types of lengths and further adjacent Each sub-conductor is connected by a third conductor, or a part of the sub-conductor which is lacked by division is left and connected in place of the third conductor, and the main conductor of the sub-conductor lacking portion of the transmission line is also connected. And a circuit element having an impedance different from the characteristic impedance of the transmission line between the main conductor and the third conductor of the sub conductor or the sub conductor lacking portion of the transmission line. Noise filter.

(5) The electrical noise filter as described in (3) or (4) above, wherein the circuit element is at least one capacitance element.
(6) The electrical noise filter as described in (3) or (4) above, wherein the circuit element is obtained by connecting at least one capacitance element and one resistance element in series.

(7) In a transmission line composed of a main conductor and a sub-conductor that is coaxially covered with an insulator through an insulator, the sub-conductor is divided into a plurality at predetermined equal intervals, and A part of the sub-conductor that is missing from the main conductor in the part lacking the conductor is connected with a third conductor between the adjacent sub-conductors, or is divided by replacing the third conductor. Is an electrical noise filter characterized by being connected and left behind.
(8) In a transmission line composed of a main conductor and a sub conductor that is coaxially coated on the main conductor via an insulator, the sub conductor is divided into at least two lengths, and the sub conductor A magnetic material is wrapped around the main conductor of the portion lacking, and the adjacent sub-conductors are connected by the third conductor, or a part of the sub-conductor missing by the division is replaced with the third conductor. An electrical noise filter characterized by being left and connected.

(9) In a transmission line composed of a main conductor and a sub conductor that is coaxially covered with an insulator through the main conductor, a constant interval, or two or more types of intervals, on the outer periphery of a part of the sub conductor An electrical noise filter characterized by comprising a magnetic material.
(10) In a transmission line composed of a main conductor and a sub-conductor that is coaxially coated on the main conductor via an insulator, the sub-conductor is divided into a plurality at predetermined equal intervals, and A magnetic body is wrapped around the outer periphery of a part of the sub-conductor and the main conductor of the part lacking the sub-conductor, and the adjacent sub-conductors are connected by the third conductor, or replaced with the third conductor. An electrical noise filter characterized in that a part of the sub-conductor missing due to the division is left and connected.
(11) In a transmission line composed of a main conductor and a subconductor that is coaxially covered with an insulator through an insulator, the subconductor is divided into at least two types of lengths, and the subconductor Magnetic material is wrapped around the outer periphery of part of the conductor and the main conductor in the part lacking the sub-conductor, and each adjacent sub-conductor is connected by a third conductor, or divided in place of the third conductor An electrical noise filter characterized in that a part of the sub-conductor missing is left and connected.

  (12) A series connection circuit of a low frequency blocking electrostatic capacitance element and a resistance element having a value close to the characteristic impedance of the transmission line is connected between the main conductor and the sub conductor at the end of the transmission line. The electrical noise filter according to any one of (1) to (10) above.

  (13) At least part of a single-phase or three-phase power transmission line extending from a power source including noise to a load, or a single-phase or three-phase distribution line for supplying power to the power source, (12) An electric noise removing method comprising the electric noise filter according to any one of (12).

The electrical noise filter according to any one of claims 1 to 8, wherein the sub-conductor of the transmission line formed of the main conductor and the sub-conductor coated coaxially with an insulator interposed between them has a predetermined equal interval, or two or more types. It is divided into a plurality of lengths, and adjacent sub-conductors are connected by a third conductor, or a part of the sub-conductors missing by the division is left and connected instead of the third conductor. Based on the structure, an impedance different from the characteristic impedance of the transmission line is provided between the main conductor and the sub conductor of the sub conductor lacking part of the transmission line, or between the main conductor and the third conductor of the sub conductor lacking part of the transmission line. It is possible to attenuate electrical noise in the high frequency range of several MHz or more with a relatively simple structure by connecting circuit elements or by attaching a magnetic material to the main conductor of the sub conductor lacking part of the transmission line. And hundreds of amps and thousands of volts Cormorant can be used as an electrical noise filter of large current capacity.
According to the ninth aspect of the present invention, an electric noise filter can be configured more easily and inexpensively because it is only necessary to wrap the magnetic body outside the sub conductor without dividing the sub conductor.
Furthermore, the electrical noise filter of the present invention configured in a straight line shape can be easily replaced with a distribution line of an existing facility, and the power distribution system itself can be formed as an electrical noise filter.

Embodiments and operations of the present invention will be described with reference to a configuration diagram of an example, an equivalent circuit diagram, and an analysis result graph. FIGS. 1 to 17 are diagrams mainly for explaining and analyzing the basic configuration of the present invention and its operation principle, and FIGS. 18 to 26 are the present invention applicable to high voltage and large current devices. FIG. 27 is a diagram showing a method for preventing electrical noise using the electrical noise filter of the present invention.
FIG. 1 is a perspective view of an embodiment of an electrical noise filter in which a capacitive element is added between a main conductor and a sub conductor of a sub conductor lacking portion of a transmission line in which the sub conductor is equally divided into four parts, and FIG. FIG. 3 is an equivalent circuit diagram of the electrical noise filter embodiment shown in FIG. 1, and FIG. 4 is a calculation result by the electronic circuit analysis program of the equivalent circuit of FIG. FIG. 5 is an equivalent circuit diagram in the case where a capacitance element and a resistance element that are terminated and matched are added to the equivalent circuit of FIG. 3, and FIG. 6 is a calculation result by the electronic circuit analysis program of the equivalent circuit of FIG. 7 is an equivalent circuit diagram when a series resistance is added to the capacitive element added between the main conductor and the sub-conductor in the equivalent circuit of FIG. 5, and FIG. 8 is an electronic circuit of the equivalent circuit of FIG. It is a transfer characteristic as a calculation result by an analysis program.
9 shows the transfer characteristic as a result of calculation by the analysis program of the equivalent circuit shown in FIG. 7 when the sub-conductor is divided into four by two types, and FIG. 10 shows the transfer characteristic around 300 MHz in FIGS. It is an enlarged comparison figure.

FIG. 11 is a perspective view of an embodiment of an electrical noise filter in which a magnetic material is wrapped around a main conductor of a sub conductor lacking portion of a transmission line in which the sub conductor is divided into four parts, and FIG. 12 is an equivalent circuit diagram of the embodiment shown in FIG. FIG. 13 shows transfer characteristics as a result of calculation by the electronic circuit analysis program of the equivalent circuit shown in FIG. 12, and FIG. 14 shows a case where a capacitance element and a resistance element that are terminal matched to the equivalent circuit shown in FIG. 12 are added. FIG. 15 is a transmission characteristic as a result of calculation by the electronic circuit analysis program of the equivalent circuit shown in FIG.
FIG. 16 is a perspective view of an embodiment of an electrical noise filter in which a magnetic material is provided in places around a transmission line in which a main conductor is coaxially covered with an auxiliary conductor via an insulator, and FIG. 17 is an embodiment shown in FIG. FIG.

18 is a development view of the capacitive element of the electrical noise filter embodiment shown in FIG. 1, and FIG. 19 is an embodiment in which the electrical noise filter embodiment of FIG. 1 is configured as a three-phase electrical noise filter. FIG. 20 is a perspective view of an example in which the electrical noise filter of FIG. 11 is configured as a three-phase electrical noise filter.
21 is an equivalent circuit diagram of an electrical noise filter in which a capacitive element is connected between two main conductors of two transmission lines, and FIG. 22 is a single-phase two-wire system for the electrical noise filter shown in FIG. And by changing one of the magnetic bodies wrapped around the main conductor of the part lacking the sub-conductor to be wrapped around the two main conductors, between the main conductors. FIG. 23 is an equivalent circuit diagram of the electrical noise filter shown in FIG. 22. FIG. 23 is a perspective view of an embodiment of the electrical noise filter in which mutual induction is introduced.
FIG. 24 is a cross-sectional view of a portion where a short ring is applied to a magnetic body wrapped around the main conductor.
Further, FIG. 25 is a perspective view of an embodiment in which a magnetic material is mounted outside the sub conductor of the electrical noise filter shown in FIG.

26 is a perspective view of an embodiment in which the electrical noise filter shown in FIGS. 1 and 11 is configured in a folded shape (however, a capacitance element and a resistance element connected between the main conductor and the sub conductor of the sub conductor lacking portion) 27 is a perspective view of an embodiment in which the electrical noise filter shown in FIG. 1 and FIG. 11 is formed in a winding type (however, the illustration of the magnetic material to be wrapped around the sub-conductor lacking portion is omitted). It is.
FIG. 28 is a diagram showing a circuit configuration example of a noise removal method using the electrical noise filter of the present invention.

  In the perspective view and the sectional view of the embodiment, 1, 1 ', 1 "are different electric noise filters, 2, 2' is a main conductor, 3 is a sub conductor, 3a, 3b, 3c, 3d, 3e are divided. 5a, 5b and 5c are circuit elements, 6a, 6a ', 6b, 6c, 6c', 6d, 6e, 6f and 6g are magnetic bodies, and 7 is between the sub conductors. A third conductor to be connected, 8 is a sub-conductor terminal, 9 is a short ring, 10 is a conductor connecting between the sub-conductors at the opposite positions of two or three electrical noise filters, 51 is a connection terminal to the main conductor, 52 is a connection terminal to the sub conductor, 53 is a resistance element, 54 is a main conductor side electrode of the capacitance element, 55 is a sub conductor side electrode of the capacitance element, and 56 is an insulator It is.

  In the equivalent circuit diagram, 21a, 21b, 21c, 21d, 21a ′, 21b ′, 21c ′, 21d ′ are the transmission lines 22a, 22b, 22a, 22b, 22c and 22d are capacitive elements, 23a, 23b and 23c are resistance elements, 24a, 24b and 24c are induction elements, 25a, 25b and 25c are internal resistances of the induction elements, and 26a, 26b, 26c and 26d are mutual induction elements. , 27 is a terminal matching capacitance element, 28 is a terminal matching resistance element, 29 is an input terminal, and 30 is an output terminal.

  Furthermore, in the figure which shows the circuit structural example of the noise removal method using this invention Example, 41 is a noise source, 42 is a load, 43a, 43b, 43c is a power line, 44a, 44b, 44c, 44d is the electrical of this invention It is a noise filter.

The first basic structure of the electrical noise filter according to the present invention is such that, as seen in the cross-sectional view of FIG. 2, the subconductor 3 is coaxially coated around the main conductor 2 with an insulator 4 interposed therebetween, and As shown in the embodiment of FIG. 1, the transmission line 1 is divided into a plurality of pieces (four pieces in FIG. 1), and the main conductor 2 in the transmission line 1 where the sub-conductor 3 is missing. It consists of circuit elements 5a, 5b, and 5c having impedances different from the characteristic impedance of the transmission line respectively disposed between the divided sub-conductors 3a and 3b, 3b and 3c, 3c and 3d.
The operation of the embodiment shown in FIG. 1 will be described with reference to FIGS. In addition, in each equivalent circuit diagram of FIG. 3, FIG. 5, FIG. 7, etc., for convenience of explanation, the transmission line 1 shown in FIG. 1 is divided for each divided portion of the sub-conductor 3, and the transmission lines 21a, 21b, The transmission lines 21a, 21b, 21c, and 21d are connected in series, and the capacitance elements 22a, 22b, and 22c and the resistance elements 23a, 23b, and 23c are connected to the respective connection points. .
In the equivalent circuit shown in FIG. 3, when the characteristic impedances Zc of the transmission lines 21a, 21b, 21c, and 21d are 50Ω, the delay time T is 5 ns, and the capacitances of the capacitive elements 22a, 22b, and 22c are 50 nF. FIG. 4 shows the result of calculating the transfer characteristics of the equivalent circuit of FIG. 3 in the frequency region from 100 kHz to 1 GHz by an electronic circuit analysis program manufactured by Oracle.

When a circuit element having an impedance Zp different from the characteristic impedance Zc of the transmission line is connected to both ends of the transmission line having an arbitrary characteristic impedance Zc to form a mismatched terminal, the high-frequency current and high-frequency voltage applied to the input terminal are After propagating through the transmission line, it is reflected at the output end and returns to the input end. Therefore, when a plurality of mismatched terminated transmission lines are connected as shown in FIG. 3, the high-frequency current and high-frequency voltage applied to the input terminal 29 are reflected at each connection point. The amount of high-frequency current waves and voltage waves transmitted is generally reduced.
As can be seen from FIG. 4, this is clear from the fact that the transmission amount becomes a negative value at a frequency of 10 MHz or more and the transmission amount of the high-frequency current and high-frequency voltage is reduced. Noise is reduced. On the other hand, the transmission amount shows a large positive value exceeding 26, 25 dB at 1.78 MHz, 4.5 MHz, 6.8 MHz, and 8.3 MHz, and electrical noise at this frequency is amplified. .

The equivalent circuit shown in FIG. 5 is an equivalent circuit when the terminal matching capacitance element 27 and the terminal matching resistance element 28 are connected between the output terminals 30 of the equivalent circuit of FIG. FIG. 6 shows the circuit constants of the equivalent circuit, the characteristic impedances Zc of the transmission lines 21a, 21b, 21c and 21d are 50Ω, the delay time T per meter is 5 ns, and the capacitance elements 22a, 22b and 22c. The transfer characteristics in the frequency region from 100 kHz to 1 GHz of the equivalent circuit of FIG. 5 when the capacitance of each capacitance of 50 nF, the capacitance of the low-frequency high-voltage blocking electrostatic capacitance element 27 is 50 nF, and the termination matching resistor 28 is 50Ω are described above. The result calculated by the electronic circuit analysis program is shown.
As can be seen from FIG. 6, the peak of the transmission amount between 1.78 MHz and 8.3 MHz is reduced by at least 5 dB from the value exceeding 26, 25 dB in FIG. 4, but the electrical noise of this frequency is amplified. There is no change in being done.

The peak of the transmission amount showing positive values at 1.78 MHz and 4.5 MHz shown in FIGS. 4 and 6 is caused by adding resistors 23a, 23b, and 23c to the capacitive elements 22a, 22b, and 22c as shown in FIG. It can be mitigated by connecting in series. In the circuit shown in FIG. 7, the value Zp of the resistors 23a, 23b and 23c is calculated by the electronic circuit analysis program as 5Ω which is 1/10 of the characteristic impedance Zc = 50Ω of the transmission lines 21a, 21b, 21c and 21d. Is shown in FIG.
When the calculation results shown in FIG. 8 are compared with the calculation results shown in FIGS. 4 and 6, the following two features can be seen in FIG. In other words, the first point is that the transmission amount in the low frequency band of 1 MHz or less has increased to 3.4 dB, but the transmission amount was within the frequency range of 1 to 10 MHz seen in FIGS. In addition to the disappearance of the positive peak, the transmission amount shows a negative value in this frequency range, and the second point is that the minimum value of the transmission amount at a frequency of 10 MHz or more, which is -150 to -250 dB, The minimum value increases to about -61 dB, and the minimum value is substantially constant from about 50 MHz to about 600 MHz.
Although the transmission amount of electrical noise within the frequency range of 1 MHz to 10 MHz is greatly reduced by the first feature, the minimum value of the transmission amount at a frequency of 10 MHz or more is increased by -61 dB by the second feature. The value of -61 dB is sufficiently good as the performance of the electric noise filter in the frequency domain.
The transmission amount of -61 dB is

Is introduced into the transmission amount G at each connection point given by the characteristic impedance Zc = 50Ω and series resistance value Zp = 5Ω of the transmission lines 21a, 21b, 21c, 21d used in the calculation of the electric circuit analysis program. The value of the,
G = 5 / (50 + 5)
That is, a value when -20.8 dB is considered to have been repeated at three connection points,
20.8 dB × 3 = −62.5 dB
Very close to. Therefore, the minimum value of the transmission amount can be further reduced by increasing the number of transmission lines connected.

  In FIGS. 4, 6, and 8, there are peaks at which the transmission amount is 0 dB at discrete frequencies every 100 MHz such as 100 MHz, 200 MHz, 300 MHz, and 400 MHz. These frequencies are caused by a reflection phenomenon determined by the delay time T of the transmission lines 21a, 21b, 21c, and 21d shown in FIG. In other words, it corresponds to the standing wave observed in the vibration phenomenon of the string, and the waves of 1/2 wavelength, 1/4 wavelength, 1/6 wavelength, etc. exist stably between the connection points of the vibration node. To occur. Therefore, when the delay time of each of the transmission lines 21a, 21b, 21c, and 21d is T seconds, the vibration frequency (hereinafter referred to as resonance frequency) fp with the transmission line connection point as a node is given by the equation shown in Equation 2. Note that n in the formula 2 is an arbitrary positive integer.

Here, since the delay time T of the transmission lines 21a, 21b, 21c, and 21d is calculated as 5 ns as described above, the resonance frequency fp obtained from Equation 2 is fp = n / (2 × 5 × 10 ⁻⁹ ) = 100n × 10 ⁶
That is, the minimum is 100 MHz, which is a frequency that is an integral multiple thereof, but the calculation results shown in FIGS. 4, 6, and 8 agree well with it.
In a transmission line that shows a small transmission amount at a frequency other than the vicinity of the specific frequency as shown in FIG. 8, electrical noise in which the power spectrum spreads flatly in a wide frequency band, such as thermal noise, is reduced. However, for electrical noise having a fixed period such as switching noise, if the reciprocal of the period and the resonance frequency fp coincide with each other, the effect of reducing the electrical noise is reduced. become.

As described above, the resonance frequency fp is determined by the delay time T of the transmission lines 21a, 21b, 21c, and 21d. Therefore, when divided by the sub-conductor 3 different lengths in Figure 1, becomes a different value as the transmission lines 21a, 21b, 21c, 21d delay time of T, respectively T _a, T _b, T _c, T _d, each resonant frequency fp be fp _a, fp _b, fp _c, is distributed as such fp _d, the resonance frequencies fp _a, fp _b, fp _c, the amount transferred in fp _d also carried a sub-conductor 3 was equally divided The amount of transmission at the resonance frequency fp in the case of Example 1 can be reduced.
In the equivalent circuit shown in FIG. 7, the delay times T _a and T _c of the transmission lines 21a and 21c are set to 4.5 ns, which is 90% of the delay time T = 5 ns in the first embodiment, and the delay times of the transmission lines 21b and 21d. FIG. 9 shows the result of calculating the transfer characteristics in the vicinity of 100 kHz to 1000 MHz by the electric circuit analysis program when T _b and T _d are set to 5.5 ns which is 110% of the delay time T = 5 ns in the first embodiment. .
As is clear from the comparison between FIG. 8 and FIG. 9, the peak where the amount of transmission that appears every 100 MHz, such as 100 MHz, 200 MHz, 300 MHz, and 400 MHz, seen in the calculation result of FIG. 8 disappears. Further, the maximum transmission amount at 10 MHz or more is also reduced to -20 dB or less.

FIG. 10 shows an enlarged view of the transfer characteristics around 300 MHz in FIGS.
The subconductor 3 is divided into equal lengths, and the calculation results when the delay time T of each transmission line 21a, 21b, 21c, 21d is 5 ns are broken lines, and the subconductor 3 is divided into two types of lengths. The calculation results when the delay times of the transmission lines 21a and 21c are 4.5 ns and the delay times of the transmission lines 21b and 21d are 5.5 ns are indicated by solid lines. The broken line shows a steep peak where the transmission amount becomes 0 dB at 300 MHz, whereas the solid line shows a moderate peak where the transmission amount is 21 dB or less in two places of 272 MHz and 333 MHz. The frequencies 272 MHz and 333 MHz correspond to the reciprocals of the delay times 5.5 ns and 4.5 ns, respectively.
As a result, as can be seen from FIG. 9, the transmission noise can be reduced to -20 dB or less in a high frequency band of several MHz or more, and the electrical noise that is also effective for electrical noise having a fixed period such as switching noise. A circuit configuration applicable as a filter is possible.

  Until now, the example which forms the mismatch of the connection point between transmission lines with a capacitive element was demonstrated. However, the same effect can be obtained even if the mismatch of the connection points between the transmission lines is formed by the inductive element. Therefore, as a second basic structure of the electrical noise filter according to the present invention, as shown in FIG. 11, the sub conductor 3 is coaxially covered around the main conductor 2 via the insulator 4, and the sub-filter is arranged. Magnetic bodies 6a, 6b, and 6c are mounted on the transmission line in which the conductor 3 is divided into a plurality (four in FIG. 11) and the main conductor 2 in the transmission line where the sub-conductor is absent. An electrical noise filter 1 ′ in which the divided subconductors 3 a, 3 b, 3 c, 3 d are connected by a third conductor 7 can be given.

FIG. 12 shows an equivalent circuit of the electrical noise filter 1 ′ having the structure shown in FIG. In FIG. 12, the inductances of the magnetic bodies 6a, 6b, 6c as inductance elements 24a, 24b, 24c are 3.5 μH, and the internal resistances 25a, 25b, 25c of the induction elements 24a, 24b, 24c are the resistance values of the magnetic elements 6a, 6b, 6c. 200Ω which is a value simulating that the magnetic permeability of the bodies 6a, 6b and 6c decreases in inverse proportion to the frequency at 5 MHz or more, and the characteristic impedance of the transmission lines 21a, 21b, 21c and 21d is 50Ω, the transmission line 21a, FIG. 13 shows the calculation result by the electronic circuit analysis program when the delay time of 21c is 4.1 ns and the delay times of the transmission lines 21b and 21d are 5.9 ns.
As can be seen from FIG. 13, the transmission amount shows a good value of -20 dB or less in the frequency range of 30 MHz or more.
Those skilled in the art can easily understand that the inductance of 3.5 μH applied to the above analysis is a value that can be realized by mounting a magnetic body around one conductor.

  In this way, a plurality of transmission lines 21a, 21b, 21c, 21d,... Are connected in series, and are different from the characteristic impedance Zc of the transmission lines 21a, 21b, 21c, 21d,. When the impedance Zp is connected to form a mismatched state, the average transmission amount is lower than −20 dB over a wide frequency band, particularly in a high frequency range from several MHz to around 1 GHz, and an electrical noise filter having an effect in this frequency range Can be realized.

The equivalent circuit of FIG. 14 is an equivalent circuit when the terminal matching capacitance element 27 and the terminal matching resistance element 28 are connected between the output terminals 30 of the equivalent circuit of FIG. 12, and the equivalent circuit shown in FIG. FIG. 15 shows the result of calculation by the electronic circuit analysis program. The circuit constants of the respective elements used for the calculation are the same as in the previous example.
As is clear from FIG. 15, the peak point having a value of 0 dB or more, as seen in FIG. 13, disappears.

  Further, even if a mutual inductive element is used between the connection points of the transmission lines 21a, 21b, 21c, and 21d, the same effect as in the case of the inductive element can be obtained. Therefore, as a third basic structure of the electrical noise filter according to the present invention, as shown in FIG. 16, the sub conductor 3 is coaxially covered with the main conductor 2 and the insulator 4 around the main conductor 2. In the transmission line thus formed, there is an electrical noise filter 1 ″ in which a magnetic material is provided around the outer periphery of a part of the sub-conductor 2 with a constant interval or two or more types of intervals. 16 shows an equivalent circuit of the electrical noise filter 1 ″ shown in FIG.

  An embodiment in which the above three basic structures of the electrical noise filter according to the present invention are applied to an electrical noise filter having a large current capacity and a high withstand voltage will be described below.

As a first embodiment, an example in which the first basic structure of the electrical noise filter of the present invention shown in FIG. 1 is applied to an electrical noise filter having a withstand voltage of 2000 V and a current capacity of 600 A will be described with reference to FIG. The values of withstand voltage of 2000 V and current capacity of 600 A can drive four train motors.
The main conductor 2 in this embodiment is composed of a copper strip having a cross-sectional area of 300 mm ² , that is, a width of 50 mm and a thickness of 6 mm, in order to correspond to a main current of 600 A, and the main conductor 2 has a thickness of 50 μm. Subconductors 3a, 3b, 3c, and 3d made of copper foil having a thickness of 0.05 mm are wound around an insulator 4 in which two layers of polyimide resin films are wound and a transmission line 1 is realized. In this case, the gap between the main conductor 2 and the insulator 4 and between the insulator 4 and the sub-conductors 3a, 3b, 3c, and 3d reduces the electrostatic capacity. It is desirable that the subconductors 3a, 3b, 3c, and 3d are tightly wound so as to be sufficiently smaller than the thickness.
The polyimide resin film is a material having a withstand voltage of 10,000 V per 20 μm thickness in an ideal state, and the insulator 4 having a thickness of 100 μm has a sufficient margin for a required withstand voltage of 2000 V. Further, since only high-frequency current flows through the sub-conductors 3a, 3b, 3c, and 3d, the cross-sectional area can be selected smaller than that of the main conductor.

  The characteristic impedance Zc and the propagation velocity vc of the transmission line 1 are the cross-sectional structure shown in FIG. 2, the cross-sectional dimension of the main conductor 2 (50 mm × 6 mm), the thickness of the insulator 4 (100 μm), and the insulator From the capacitance Cp per unit length of the transmission line 1 calculated from the dielectric constant (in the case of polyimide resin 3) and the inductance Ls per unit length, they are given by the equations shown in Equations 3 and 4, respectively.

Since the capacitance Cp of the transmission line 1 in the above embodiment is 30 nF per meter and the inductance Ls is 25 nH per meter, substituting the above numerical values into the equations of Equations 3 and 4, respectively,
Zc = (25 × 10 ⁻⁹ / 30 × 10 ⁻⁹ ) ^1/2
= 0.913Ω
vc = 1 / (25 × 10 ⁻⁹ × 30 × 10 ⁻⁹ ) ^1/2
= 36.5 × 10 ⁶ m / sec.
In this embodiment, the lengths of the transmission lines 21a, 21b, 21c, 21d divided into four by the subconductors 3a, 3b, 3c, 3d are different within a range of plus or minus 10%, and the low attenuation peak due to standing waves is used. The average length is 0.75 m, and the total length of the main conductor 2 is 3 m. Therefore, under the condition of vc = 36.5 × 10 ⁶ m / sec, the lowest frequency of occurrence of reflection is about 24.3 MHz, and a performance that can reduce noise at a lower frequency than the examples shown in FIGS. 4 and 8 is obtained. It is done.

Further, in the electric circuit elements 5a, 5b and 5c of this embodiment shown in FIG. 1, the capacitance elements 22a, 22b and 22c in the equivalent circuit of FIG. 7 are 100 nF, and the capacitance elements 22a, 22b and 22c are in series. Since the resistance elements 23a, 23b, and 23c connected to are 0.05Ω, the impedance of the electric circuit elements 5a, 5b, and 5c at 24.3 MHz is 0.05Ω−0.066jΩ, and the absolute value thereof is 0.083Ω. Thus, the characteristic impedance Zc is 1/10 or less of 0.913Ω.
FIG. 18 is a structural development view of the electric circuit elements 5a, 5b, and 5c. In FIG. 18, 51 is a connection terminal to the main conductor, 52 is a connection terminal to the sub conductor, 53 is a resistance element, 54 is a main conductor side electrode of the capacitance element, 55 is a sub conductor side electrode of the capacitance element, Reference numeral 56 denotes an insulator.

  From the above description, it is clear that the configuration shown in FIG. 1 acts as an electrical noise filter.

As a second embodiment of the present invention, the second basic structure of the electric noise filter of the present invention shown in FIG. 11 is applied to an electric noise filter having a withstand voltage of 2000 V and a current capacity of 600 A, based on FIG. explain.
In FIG. 11, the magnetic bodies 6a, 6b, and 6c are wrapped around the main conductor 2 in the sub conductor lacking portion between the sub conductors 3a, 3b, 3c, and 3d, and the inductance of the main conductor 2 is increased only in this portion. . Moreover, the 3rd conductor 7 which electrically connects subconductor 3a, 3b, 3c, 3d is provided.

The material and dimensions of the main conductor 2, the insulator 4 and the subconductor 3 in this example are the same as those shown in Example 1, and the magnetic bodies 6a, 6b and 6c are 0.4 mm thick TDK stocks. It is composed of 10 layers of IVM04 type high frequency magnetic material manufactured by company. Since the magnetic material has a small initial permeability of 12, it does not cause magnetic saturation even for the low-frequency maximum current 600A of the main conductor 2. Further, it has an imaginary term having a relative permeability of 8 or more in a wide range from 100 MHz to 3 GHz. For this reason, the inductor exhibits a large impedance in a wide frequency range.
In the present embodiment shown in FIG. 11, the magnetic bodies 6a, 6b, 6c are made of the magnetic material having a total thickness of 4 mm and a width of 40 mm, and therefore have an inductance of 42 nH. Therefore, at a frequency of 24.3 MHz, the impedance is 6.5Ω, reflection occurs at the connection point of the transmission lines 21a, 21b, 21c, and 21d, and the filter operates as an electrical noise filter.

  FIG. 19 is a perspective view of an embodiment in which three electrical noise filters 1 of Embodiment 1 shown in FIG. The corresponding subconductors of each electrical noise filter are connected by subconductor short-circuit conductors 10a, 10b, 10c, and 10d, respectively.

  FIG. 20 shows a perspective view of an embodiment in which three electrical noise filters 1 ′ of the embodiment 2 shown in FIG. 11 are arranged for a three-phase power source. The sub-conductors corresponding to each of the electrical noise filters are connected to each other by sub-conductor short-circuit conductors 10a, 10b, 10c, and 10d as in the third embodiment.

FIG. 21 is an equivalent circuit diagram of an embodiment in which two electrical noise filters of the first embodiment are arranged and applied to a single-phase power supply, and a capacitance element 22d is connected between the main conductors in a portion lacking the subconductor. This causes reflection. Capacitance elements 22a and 22a 'connected between the main conductor and the sub conductor are also connected between the main conductors via the ground in the same manner, and here again, reflection occurs and acts as an electric noise filter. doing.
Similarly, the same effect occurs when applied to a three-phase power source.

FIG. 22 shows an embodiment in which the electric noise filter 1 ′ shown in FIG. 11 is introduced with two power lines. The sub-conductors 3a and 3b of the two electric noise filters 1 ′, Magnetic bodies 6a, 6c, 6a ', 6c' are mounted on the main conductors 2, 2 'in the sub-conductor lacking part between 3c and 3d, and the sub-conductor lacking part between the sub-conductors 6b and 6c in the central part A magnetic body 6d that introduces mutual induction between the two main conductors 2 is provided around the outer periphery of the two main conductors 2 and 2 '. FIG. 23 shows an equivalent circuit thereof. In the present embodiment, the introduction of the mutual induction is described as one place, but the introduction is not rejected at a plurality of places.
Also, in the case of the three-phase three-wire system, mutual induction between the three wires is performed by mounting one magnetic body 6d around the three main conductors 2 as in the case of the single-phase two-wire system. It is possible to introduce.
Further, as shown in FIG. 24, a short ring 9 is formed by winding a conductor around a magnetic body 6d introduced with mutual induction, and a noise voltage is induced in the short ring to cause energy loss, so that electrical It is also preferable to enhance the effect as a noise filter.

  FIG. 25 shows an embodiment in which magnetic bodies 6d, 6e, 6f and 6g are mounted outside the sub conductors 3a, 3b, 3c and 3d of the electrical noise filter 1 'shown in FIG.

Each embodiment of the electrical noise filter 1, 1 ′, 1 ″ according to the present invention has been described in a straight line, but in the case where the length (distance) necessary for installation cannot be obtained, FIG. Even with the folding type shown in FIG. 5 and the spiral type shown in FIG. 27, the transmission characteristics equivalent to the above-described transmission characteristics can be obtained.
In FIG. 26 and FIG. 27, the circuit elements 5a, 5b, and 5c or the magnetic bodies 6a, 6b, and 6c in which the sub-conductor lacking portion is mounted are not shown.

In addition, the electrical noise filter of the present invention described so far in the embodiment is divided into a plurality of sub-conductors that are coaxially covered with one main conductor via an insulator, and further adjacent sub-conductors. Basically, the conductor is connected by a third conductor, or a part of the subconductor that is missing due to the division is left and connected in place of the third conductor. An electric noise filter having a configuration in which a plurality of main conductors are introduced in parallel and a plurality of main conductors are bundled and a sub conductor is covered with an insulator around the outer periphery may be used. Alternatively, an electrical noise filter may be used in which a plurality of short transmission lines covered with one sub-conductor are connected in cascade via an insulator, and circuit elements having different characteristic impedances can be easily introduced into the connection portion.
Furthermore, it is also preferable to increase the electrical noise removal effect by cascading a plurality of electrical noise filters shown in the embodiments of the present application.

FIG. 28 shows a specific example of a noise removal method in which the electrical noise filter of the present invention is introduced into a three-phase power line.
FIG. 28A is an example in which an electrical noise filter 44a is connected to the power line 43a from the noise source 41 to the load 42. FIG.
FIG. 28B shows an electrical noise filter between the noise source 41 and the power line 43b connected to the external power line 43c so that the electrical noise from the noise source 41 does not flow outside via the power line 43. In addition, FIG. 28C shows an example in which an external power line 43 is connected to prevent electrical noise from other noise sources (not shown) from entering the load 42 via the external power line 43c. This is an example in which electrical noise filters 44c and 44d are connected.
These can be used as a noise removal method for a distribution system inside a train or a distribution system inside a building in a casing of an electronic (information) device.

The perspective view of the Example of the electrical noise filter which added the electrostatic capacitance element between the main conductor and subconductor of the subconductor lack part of the transmission line which divided the subconductor into 4 equally A-A 'sectional view of the electrical noise filter embodiment shown in FIG. 1 is an equivalent circuit diagram of the electrical noise filter embodiment shown in FIG. Transfer characteristics of the equivalent circuit of Fig. 3 as a result of calculation by an electronic circuit analysis program 3 is an equivalent circuit diagram in the case where a capacitance element and a resistance element that are terminated and matched are added to the equivalent circuit of FIG. Transfer characteristics of the equivalent circuit of FIG. 5 as a result of calculation by an electronic circuit analysis program 5 is an equivalent circuit diagram when a series resistance is added to the capacitive element added between the main conductor and the sub-conductor in the equivalent circuit of FIG. Transfer characteristics of the equivalent circuit of FIG. 7 as a result of calculation by an electronic circuit analysis program Transfer characteristics as a result of calculation by the analysis program of the equivalent circuit shown in Fig. 7 when the sub-conductor is divided into four parts of two lengths Fig. 8 and Fig. 9 are enlarged comparison diagrams of transfer characteristics around 300MHz. The perspective view of the Example of the electrical noise filter which wrapped the magnetic body in the main conductor of the subconductor lack part of the transmission line which divided the subconductor into 4 parts Equivalent circuit diagram of the embodiment shown in FIG. Transfer characteristics as a result of calculation by the electronic circuit analysis program of the equivalent circuit shown in FIG. 12 is an equivalent circuit diagram when a capacitance element and a resistance element that are terminal matched are added to the equivalent circuit shown in FIG. Transfer characteristics as a result of calculation by the electronic circuit analysis program of the equivalent circuit shown in FIG. The perspective view of the Example of the electrical noise filter which surrounded the magnetic body in the part of the transmission line which coat | covered the subconductor coaxially through the insulator on the main conductor Equivalent circuit diagram of the embodiment shown in FIG. FIG. 1 is an exploded view of the capacitive element of the electrical noise filter embodiment shown in FIG. The perspective view of the Example which comprised the electrical noise filter Example of FIG. 1 as an electrical noise filter for three phases The perspective view of the Example which comprised the electrical noise filter of FIG. 11 as an electrical noise filter for three phases. Equivalent circuit diagram of an electrical noise filter with a capacitive element connected between two main conductors of a two-phase transmission line The electrical noise filter shown in FIG. 11 is configured for a single-phase two-wire system, and one of the magnetic bodies wrapped around the main conductor in the portion lacking the sub-conductor is disposed around the two main conductors. The perspective view of the Example of the electrical noise filter which introduced the mutual induction between the main conductors by changing so that it might be wrapped in 22 is an equivalent circuit diagram of the electrical noise filter shown in FIG. Sectional view of the location where the short ring is applied to the magnetic material wrapped around the main conductor FIG. 11 is a perspective view of an embodiment in which a magnetic material is provided outside the sub conductor of the electrical noise filter shown in FIG. FIG. 1 and FIG. 11 are perspective views of an embodiment in which the electrical noise filter is configured as a folded type (however, the capacitance element and the resistance element connected between the main conductor and the sub conductor in the sub conductor lacking portion are illustrated. (Omitted) FIG. 1 is a perspective view of an embodiment in which the electrical noise filter shown in FIG. Circuit configuration example of noise elimination method using electrical noise filter of the present invention

Explanation of symbols

1, 1 ', 1 ": Electrical noise filter 2, 2': Main conductor 3: Sub conductors 3a, 3b, 3c, 3d, 3e are divided sub conductors 4: Insulators 5a, 5b, 5c are Circuit elements 6a, 6a ', 6b, 6c, 6c', 6d, 6e, 6f, 6g: Magnetic body 7: Third conductor connecting the sub conductors 8: Sub conductor terminal 9: Short ring 10a, 10b, 10c 10d: Subconductor short-circuit conductors 21a, 21b, 21c, 21d, 21a ', 21b', 21c ', 21d': Transmission lines 22a, 22a 'divided at the introduction point of impedance mismatch such as subconductor division , 22b, 22c, 22d: Capacitance elements 23a, 23b, 23c: Resistance elements 24a, 24b, 24c: Inductive elements 25a, 25b, 25c: Inductive element internal resistances 26a, 26b, 26c, 26d: Mutual induction Child 27: Capacitance element for termination matching 28: Resistance element for termination matching 29: Input terminal 30: Output terminal 41: Noise source 42: Load 43a, 43b, 43c: Power lines 44a, 43b, 43c, 43d: Electrical noise filter 51: Connection terminal to main conductor
52: Connection terminal to sub conductor 53: Resistance element 54: Main conductor side electrode of capacitance element,
55: Sub-conductor side electrode of capacitance element
56: Insulator

Claims (13)

  In a transmission line composed of a main conductor and a sub-conductor that is coaxially coated on the main conductor via an insulator, the sub-conductor is divided into a plurality at predetermined equal intervals, and each adjacent sub-conductor is further divided An electrical noise filter characterized in that a part of a sub-conductor which is connected by a third conductor or is replaced by a third conductor is left behind and connected.   In a transmission line composed of a main conductor and a sub-conductor coated coaxially with an insulator through an insulator, the sub-conductor is divided into at least two types of lengths, and further between adjacent sub-conductors Are connected by a third conductor, or a part of a sub-conductor that is missing due to division is left and connected in place of the third conductor.   In a transmission line composed of a main conductor and a sub-conductor that is coaxially covered with an insulator through the main conductor, the sub-conductor is divided into a plurality at predetermined equal intervals, and each adjacent sub-conductor is further divided. The conductors are connected by the third conductor, or a part of the sub-conductor that is missing by the division is left and connected in place of the third conductor, and the main conductor of the sub-conductor lacking portion of the transmission line is also connected to the conductor. An electrical noise filter comprising a sub-conductor or a circuit element having an impedance different from the characteristic impedance of the transmission line between the main conductor and the third conductor of the sub-conductor lacking portion of the transmission line .   In a transmission line composed of a main conductor and a sub-conductor that is coaxially coated with the main conductor via an insulator, the sub-conductor is divided into at least two lengths, and each adjacent sub-conductor is further divided A part of the sub-conductor which is connected by the third conductor or is replaced by the third conductor is left and connected, and the main conductor and the sub-conductor in the sub-conductor lacking part of the transmission line are also left and connected. An electrical noise filter comprising a conductor or a circuit element having an impedance different from the characteristic impedance of the transmission line between a main conductor and a third conductor of a sub conductor lacking portion of the transmission line.   The electrical noise filter according to claim 3 or 4, wherein the circuit element is at least one capacitance element.   5. The electrical noise filter according to claim 3, wherein the circuit element is formed by connecting at least one capacitance element and one resistance element in series.   In a transmission line composed of a main conductor and a sub-conductor that is coaxially covered with an insulator through the main conductor, the sub-conductor is divided into a plurality of predetermined equal intervals, and the sub-conductor is absent. A magnetic material is wrapped around the main conductor of the portion, and adjacent subconductors are connected by a third conductor, or a part of the subconductor missing by division is left in place of the third conductor, An electrical noise filter characterized by being connected.   In a transmission line composed of a main conductor and a sub-conductor that is coaxially coated on the main conductor via an insulator, the sub-conductor is divided into at least two lengths and lacks the sub-conductor. A magnetic material is wrapped around the main conductor of the part, and adjacent sub-conductors are connected by a third conductor, or a part of the sub-conductor that is missing due to division is left and connected instead of the third conductor. An electrical noise filter characterized by being made.   In a transmission line composed of a main conductor and a sub conductor that is coaxially coated on the main conductor with an insulator interposed therebetween, a magnetic body having a constant interval or two or more types of intervals on the outer periphery of a part of the sub conductor An electrical noise filter characterized by comprising:   In a transmission line composed of a main conductor and a sub-conductor that is coaxially covered with an insulator through an insulator, the sub-conductor is divided into a plurality at predetermined equal intervals, and one of the sub-conductors Magnetic material is wrapped around the outer periphery of the part and the main conductor in the part lacking the sub-conductor, and the adjacent sub-conductors are connected by a third conductor, or are replaced by the third conductor and missing by division. An electrical noise filter, wherein a part of the sub-conductor is left and connected.   In a transmission line composed of a main conductor and a sub-conductor that is coaxially coated with the main conductor through an insulator, the sub-conductor is divided into at least two lengths, and one of the sub-conductors. Magnetic material is wrapped around the outer periphery of the part and the main conductor in the part lacking the sub-conductor, and the adjacent sub-conductors are connected by a third conductor, or are replaced by the third conductor and missing by division. An electrical noise filter, wherein a part of the sub-conductor is left and connected.   A series connection circuit of a capacitance element for blocking low frequency and a resistance element having a value close to the characteristic impedance of the transmission line is connected between a main conductor and a sub conductor at the end of the transmission line. Item 11. The electrical noise filter according to any one of Items 1 to 10. A single-phase or three-phase power transmission line extending from a power source including noise to a load, or at least a part of a single-phase or three-phase distribution line supplying power to the power source, according to any one of claims 1 to 12. An electrical noise removal method comprising the electrical noise filter according to item 1.