JPH0552090B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a single-phase three-wire block filter that is used by being inserted into a power line on which a carrier signal is superimposed, such as in a power line carrier monitoring and control device.

Recently, the development of home automation that combines various electronic devices has been progressing, but there is a method that uses a single-phase 3-wire power line for electric lights installed indoors as the wiring for transmitting signals.
In a single-phase three-wire power line carrier monitoring and control device, a block filter is provided at the boundary between indoors and outdoors to block carrier waves carrying signals from leaking from the indoor power line to the outdoors.

[Conventional technology]

In conventional single carrier block filters used in power line carrier monitoring and control equipment, the inductor is formed by combining three U-shaped magnetic cores so as not to form a closed magnetic path in the power inductor magnetic core on which commercial current is superimposed. and the center frequency is 125kHz,
This block filter was configured as a single-carrier block filter that eliminates a band over 165 kHz, but this block filter cannot cover a wide range when using the spread spectrum method (hereinafter referred to as SS method), which is another method for power line carrier monitoring and control equipment. The conventional carrier frequency is
There is a problem in that a block filter that is symmetrical at 125kHz and 165kHz is not usable.

[Problems to be solved by the present invention]

The present invention is a block filter connected to a power line connected to a power line carrier monitoring and control device using the SS method, and which secures the necessary attenuation amount at the power line carrier signal frequency using the SS method, and which is similar to the conventional single carrier method. The purpose of the present invention is to provide a small, lightweight, and inexpensive block filter for power line carrier monitoring and control equipment that can provide the necessary attenuation even at carrier signal frequencies of 125 kHz and 165 kHz.

[Means for solving problems]

In order to achieve this object, the present invention adopts a block filter circuit system of a normal mode low-pass filter for single-phase three-wire system, and a power inductor on which a commercial power supply current is superimposed can be used. To prevent magnetic saturation, a toroidal powder magnetic core made of metal magnetic material is used, and two power inductors wound around this are inserted in series on both live wire sides, for a total of four. A cascaded two-stage inverted L-type low-pass filter is constructed between both live wires and the neutral wire by the capacitor connected between the wire and the neutral wire.
Connect a capacitor between both live wires on the indoor terminal side,
A varistor is connected between the live wire and the neutral wire on the output terminal side to form a block filter for an SS type power line transport monitoring and control device.

〔Example〕

An embodiment of the present invention will be described in detail below.

An embodiment of a circuit constituting a block filter according to the present invention is shown in FIG. The power inductor is connected to both live wires of a single-phase three-wire system. This power inductor is composed of toroidal powder magnetic cores, and uses a total of four magnetic cores, and is assembled by winding wires around the magnetic cores whose surfaces have been electrically insulated in advance.

By using a power inductor using this powder magnetic core, the inductance value is such that the attenuation characteristics do not deteriorate within the pre-designed rated current value range even when a commercial frequency power supply current is superimposed. It is. FIG. 1 shows a low-pass filter type normal mode block filter according to the present invention. Power inductor L1 is copper wire 2.3mm
The magnetic core is made of molybdenum permalloy powder core (hereinafter referred to as TM core) with a magnetic permeability of 125 and has an inductance of approximately 100 μH, and has damping characteristics in the low frequency range. It was a good filter. In addition, for one inductor L2, a copper wire of 2.3 mmφ is used, and a powder magnetic core (hereinafter referred to as SN core) whose main component is iron with a magnetic permeability of 60 is used.
An inductor with an inductance of approximately 8μH was used to construct a high-frequency filter. That is, two of the above-described power inductors are used for each of the two live wires, and a total of four power inductors are connected in series to both live wires, and an inductor L1 using a TM core and an inductor L2 using an SN core are connected in cascade. In addition, inductor L1 using TM core and inductor L2 using SN core
Both live wires and the neutral wire in between are connected with a 2.2 μF film capacitor C1, and a 2.2 μF film capacitor is also used on the output terminal side of the inductor L2 using the SN core. The inductance of power inductor L1 is 120 to 65 μH, and the inductance of L2 is 13 to 6 μH. The capacitor C2 that connects both live wires on the indoor terminal side (input terminal side) is
A 500PF one is used, and C2 serves to propagate the signal to both live wires if a signal is applied to either terminal of the neutral wire or both live wires. A 250V AC varistor VA is used on the outdoor terminal side (output terminal side) to prevent surge voltage from entering indoors from outdoors. A varistor is an element that has the characteristic that when a voltage higher than the rated voltage is applied to both terminals, the resistance value between both terminals decreases rapidly, and works to block and absorb surge voltages entering indoors from outdoors. FIG. 2 shows the attenuation characteristics of a block filter for a power line carrier monitoring and control device using the SS method according to an embodiment of the present invention. It exhibits high attenuation characteristics of more than 70db in a wide frequency band ranging from 200 to 500kHz, and
A block filter with an attenuation characteristic of 40 db or more at Hz, which fully satisfies the required performance, was obtained.

[Comparison with conventional technology]

The block filter according to the present invention can also be used in conventional single carrier type (125kHz, 165kHz) systems, or
It can also be used for the SS method, and is extremely small, lightweight, and inexpensive.

〔Effect of the invention〕

As described above, according to the present invention, a TM with high magnetic permeability is used in the inductor on which the commercial power supply current is superimposed.
An inductor using a core, an inductor using an SN core with good frequency characteristics in the high frequency range, and a capacitor connected between the inductor and the neutral wire to form an inverted L-type low-pass filter and connected in two stages vertically. A block filter is constructed by inserting an interphase crossover capacitor on the indoor terminal side and connecting a surge voltage absorbing varistor on the outdoor terminal side.
The block filter of the present invention is small, lightweight, and can be used for both single-phase three-wire single conveyance type and SS type.
We were able to provide an inexpensive block filter.

In the embodiment according to the present invention, the two inductors connected in series on the live line side were constructed using a molybdenum permalloy powder magnetic core and a powder magnetic core mainly composed of iron. Instead of an inductor, use a sendust powder magnetic core with high magnetic permeability, or a magnetic core with air gaps in the magnetic path of a toroidal magnetic core using iron-based or cobalt-based amorphous thin strips, and use a magnetic core with a magnetic permeability value similar to that of molybdenum permalloy pressure. Any powder magnetic core equivalent to a powder magnetic core may be used. For a powder magnetic core mainly composed of iron, a powder magnetic core of silicon, aluminum, or an iron alloy, or a magnetic core obtained by inserting a gap in an iron-based amorphous ribbon magnetic core may be used.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a block filter according to the present invention. FIG. 2 is a diagram showing the attenuation characteristics of the block filter according to the embodiment constructed from the circuit diagram shown in FIG. 1. L1...Inductor using a molybdenum permalloy powder magnetic core. L2...Inductor using a powder magnetic core whose main component is iron. C1...Capacitor (film capacitor). C2... Capacitor. V.A.
...Barista.

Claims (1)

[Claims] 1. In a normal mode block filter for single-phase three-wire system, the cascade-connected inductor inserted into two live wires has a powder magnetic core with high permeability made of a metal magnetic material with high magnetic permeability characteristics, or an air gap in the magnetic path. An inductor in which a wire is wound around an annular magnetic core made of a metal magnetic material, and an inductor in which a wire is wound around a powder magnetic core made of a metal magnetic material with low magnetic permeability or an annular magnetic core made of a metal magnetic material with an air gap in the magnetic path. A single-phase three-wire system characterized by having two stages of inverted L-shaped low-pass filters connected in cascade between the neutral wire and the neutral wire via a capacitor, and a capacitor connected between the live wires on the indoor output terminal side. Block filter for expressions.