JPS6123885Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a block filter for power line transport.

FIG. 1 shows a schematic block diagram of a power line carrier control system. In the figure, reference numeral 1 denotes a commercial power source, and to this commercial power source 1 there is a power line 3 for supplying carrier control signals and power via a block filter section 2.
is connected. A transmitter 4 and a receiver 5 are connected to the power line 3 after the block filter section 2, and a control signal 6 transmitted from the transmitter 4 is connected to the power line 3.
is superimposed on the commercial power frequency 7 and received by the receiver 5 via the power line 3, and is controlled by the receiver 5. FIG. 2 shows the signal waveform on the power line 3, in which the control signal 6 is superimposed on the commercial power frequency 7 of 50 Hz or 60 Hz. By the way, in the power line transmission system as shown in FIG. 1, the block filter unit 2 is used to prevent the control signal 6 from leaking to other systems on the commercial power supply 1 side and causing adverse effects such as malfunction.
This prevents the control signal 6 issued from the block filter section 2 from flowing to the commercial power supply 1 side. FIG. 3 shows a circuit diagram of a conventional block filter used in the block filter section 2, which includes a parallel resonant filter 9a consisting of an inductance element 8a and a capacitor 10a, and an inductance element 8a.
b. A parallel resonance filter 9b consisting of a capacitor 10b is inserted and connected in series to each line of the power line 3, and a series resonance filter 13 consisting of an inductance element 11 and a capacitor 12 is inserted between each line of the power line 3 on the commercial power supply 1 side. The block filter section 2 is constructed by connecting the two. Figure 4a
shows the impedance characteristics of each parallel resonant filter 9a, 9b, where the horizontal axis shows the frequency and the vertical axis shows the magnitude of impedance Z.
In this case, impedance Z takes the maximum value Z ₀ at resonance frequency ₁ , and impedance Z becomes smaller as the distance from resonance frequency ₁ increases. Next, Figure 4b
shows the impedance characteristic of the series resonant filter 13, and in this case, the impedance Z has a minimum value _Z1 at the resonant frequency ₁ .

Now, if the resonance frequency ₁ is made to match the frequency of the control signal 6, if a signal source with a frequency _{of 1} and a voltage of V ₁ is connected from the right side of the block filter section 2, a signal will appear between the two power lines 3 on the commercial power supply 1 side. signal voltage
V ₂ can be expressed by the formula V ₂ = V ₁ · Z ₁ / (Z ₁ + 2Z ₀ ), and since the impedance Z ₀ is large and Z ₁ is a small value, the leakage voltage to the commercial power supply 1 side _V2
can be made smaller. Furthermore, each of the parallel resonant filters 9a and 9b has a low impedance Z with respect to the commercial power frequency 7 on the commercial power supply 1 side, and the series resonant filter 13 has a high impedance Z with respect to the commercial power frequency 7. It has no effect on voltage 7. FIG. 5 shows a schematic block diagram in which another system is added to the power line transfer control system shown in FIG.
A power line 3' is connected through the power line 3', and another transmitter 4' and a receiver 5' are connected to this power line 3'. In the system shown in FIG. 5, a control signal 6 emitted from a transmitter 4' passes through a power line 3 and is received by a receiver 5'. Furthermore, the control signal 6 from the transmitter 4' hardly leaks to the system on the left side of the block filter section 2' due to the action of the block filter section 2'. Next, considering the power line 3 to which the transmitter 4 and receiver 5 are connected, the series resonant filter 13 of the block filter section 2' is directly connected between the lines at the non-power side end of this connection section. Therefore, the impedance Z for the control signal 6 between the lines at the non-power side end of the power line 3 becomes the low impedance _Z1 described above. Therefore transmitter 4
When the control signal 6 is transmitted, the impedance between the lines is very small, so the control signal 6 is largely absorbed and attenuated, so that the receiver 5 cannot receive the control signal 6. Figure 6 shows single-phase 3-wire
A conventional block filter section 2 used for a 200V power line 3 is shown, and each of the three power lines 3 is equipped with a parallel resonance filter 9a consisting of an inductance element 8a and a capacitor 10a, and a parallel resonance filter 9b consisting of an inductance element 8b and a capacitor 10b. ,
Parallel resonant filters 9c each comprising an inductance element 8c and a capacitor 10c are inserted and connected in series, and a series resonant filter comprising an inductance element 11a and a capacitor 12a is inserted between the power line 3, which is a neutral line, and each power line 3, which is a live line. 13a, an inductance element 11b, and a series resonant filter 13b consisting of a capacitor 12b, and further connect two live power lines 3 to the load side (and the commercial power supply 1 side).
Another series resonant filter 18 consisting of an inductance element 16 and a capacitor 17 is connected as a bypass for the control signal 6. In this conventional example, as well as the conventional example shown in FIG. 3, the impedance Zi to the control signal 6 when looking at the block filter section 2 from the commercial power supply 1 side is low, so two sets of filters are used as in the system shown in FIG. The above problem occurs because it is impossible to connect the systems and operate each system independently due to the attenuation of the control signal 6.

In this way, in any of the conventional block filters, when looking at the block filter section from the commercial power source, a series resonant filter is connected between the two power lines, and its resonant frequency matches the frequency of the control signal. There is. Therefore, when looking at the block filter from the commercial power supply side, the impedance to the control signal is extremely low, and it is impossible to use a power line carrier control system using control signals of the same frequency on the commercial power supply side of the block filter. There were flaws.

This invention was created in view of the above-mentioned drawbacks.
Its purpose is to be used in power line carrier control systems that use general power lines as signal lines. To provide a single-phase three-wire power line carrier block filter with improved impedance characteristics for control signals when viewed from the commercial power supply side, assuming that a similar power line carrier control system is used in other systems. It is in.

The present invention will be explained below with reference to examples. FIG. 7 shows a circuit diagram of an example used in a single-phase two-wire power line 3, which is the basis of the present invention.
Parallel resonant filter 9b consisting of capacitor 10b
are inserted and connected in series to each line of the power line 3, and a series resonant filter 13 consisting of an inductance element 11 and a capacitor 12 is connected between the power lines 3 on the commercial power supply 1 side of the power line 3. A parallel circuit of an inductance element 14 and a resistor 15 is inserted and connected in series to one of the power lines 3 on the side, thereby forming the block filter section 2. Here, each parallel resonance filter 9a, 9b
It is also assumed that the resonant frequency of the series resonant filter 13 matches the frequency of the control signal 6.

If a control signal source with a frequency of ₁ is connected to the opposite side of the commercial power supply 1, the impedance Z of each parallel resonant filter 9a, 9b will be
As shown in figure a, it takes a large value of Z ₀ . On the other hand, the impedance Z of the series resonant filter 13 is shown in Fig. 4b.
Take a small value Z ₁ like . Therefore, when looking at the block filter section 2 from the control signal source, since there are parallel resonance filters 9a and 9b on the control signal source side, the impedance Z to the control signal 6 is large, and the control signal 6 leaks to the commercial power supply 1 side. At the same time, the partially leaked control signal 6 is filtered through a series resonant filter 13 whose impedance Z is low relative to the control signal 6.
This ensures that the control signal 6 is not leaked to the commercial power supply 1 side.

Next, when the block filter section 2 is viewed from the commercial power supply 1 side, the control signal 6 of the series resonant filter 13 is
The impedance Z with respect to the frequency takes a small value of Z ₁ as shown in FIG. 8a, but since the inductance element 14 is inserted in series in one line of the power line 3, Impedance Z ₂ is added, and the impedance seen from the commercial power supply 1 side becomes Z ₃ which is larger than the impedance Z ₁ for the control signal 6 of the series resonant filter 13 described above, as shown in FIG. 8c. If two such block filter sections 2 are used to divide the power line 3 as shown in FIG.
A series resonant filter 13 is connected between the power lines 3 at the non-power supply side end via an inductance element 14, and as a result, the impedance _Z2 of the inductance element 14 is added to the control connected to the separated section. This eliminates the situation where the control signal 6 from the signal source is absorbed and attenuated by the series resonant filter 13 as in the conventional case. moreover,
By connecting the resistor 15 in parallel to the inductance element 14, the value of the impedance seen from the commercial power supply 1 side at the resonance point at the frequency ₂ lower than the frequency ₁ of the control signal 6 shown in FIG.
Z ₄ can be made larger. Therefore, if the block filter section 2 of the present invention is used in place of the block filter sections 2 and 2' of the circuit shown in FIG. 5, the frequency of the control signal ₆ of the transmitter 4' in FIG. When the frequency of the control signal 6 of the transmitter 4 is set to ₂ , the transmission of the control signal 6 from the transmitter 4' to the receiver 5' and the transmission of the control signal 6 from the transmitter 4 to the receiver 5' interfere with each other. The control signal 6 is not attenuated.

By the way, the reason why the power line 3 is divided by the block filter sections 2, 2' as shown in FIG. 5 is because if a plurality of transmitters operate and transmit at the same time, there is a possibility that the control signals 6 will collide with each other and cause interference. Further, even when the frequencies of the control signals 6 of the transmitters 4 and 4' are both set to ₁ , the transmission of the control signals 6 from the transmitter 4' to the receiver 5' can be performed without mutual interference, and the control signals 6 can be transmitted from the transmitter 4' to the receiver 5'. Since it is not attenuated, the control signal 6 of the same frequency can be used in a plurality of control systems.

FIG. 9 shows a circuit diagram of an embodiment of the present invention which uses the basic example described above and corresponds to the conventional example shown in FIG. A parallel circuit with an inductance element 14 is inserted in series, and the impedance to the control signal 6 when looking at the block filter section 2 from the commercial power supply 1 side is sufficiently high as in the case of Fig. 7, and as shown in Fig. 5. A single-phase three-wire block filter with little signal attenuation can also be realized when configuring the system shown in FIG.

FIG. 10 shows an application example of the present invention configuring a single-phase three-wire block filter, in which a parallel circuit consisting of resistors 15a, 15b and inductance elements 14a, 14b is connected to two live power lines 3, respectively. When inserted in series, the impedance to the control signal 6 when viewed from the block filter section 2 is higher than from the commercial power supply 1 side, and in this application example, the impedance between the live power lines 3 is also increased. have

In the present invention, a parallel circuit of an inductance element and a resistor configured as described above and set to complete the impedance seen from the commercial power supply side is connected to the single-phase three-wire circuit from the connection position of the series resonant filter to the commercial power supply side. Since it is inserted in series only to the power line, which is a power line, there is no influence on the commercial power supply side due to leakage of control signals used in the power line transport system, and there is no adverse effect on the control signals of similar systems on the commercial power supply side. It has the advantage of being able to operate a power line transport control system without having to do so.
Furthermore, as described above, since the parallel circuit of the inductance element and the resistor is inserted only in the neutral wire, there is an advantage that the number of constituent elements is small and the cost is low.

[Brief explanation of the drawing]

Figure 1 is a schematic block diagram of a basic power line carrier system, Figure 2 is a waveform diagram of the power supply commercial frequency in the same control signal carrier state as above, Figure 3 is a circuit diagram of a conventional example,
Figures 4a and b are explanatory diagrams of the same operation as above, Figure 5 is a schematic block diagram of a power line transport system using two sets of systems as above, Figure 6 is a circuit diagram of another conventional example, and Figure 7 is A circuit diagram of a basic example of the present invention, Figures 8a, b, and c are explanatory diagrams of the same operation as above, Figure 9 is a circuit diagram of an embodiment of the invention, and Figure 10 is a circuit diagram of an applied example of the invention. 1 is a commercial power supply, 2 and 2' are block filter sections, 3 is a power line, 9a, 9b, 9c are parallel resonance filters, 13, 13a, 13b are series resonance filters, 14 is an inductance element, and 15 is a resistor. .

Claims (1)

[Scope of utility model registration request] Using a parallel resonant filter and a series resonant filter that resonate with the frequency superimposed on the power line, the parallel resonant filters are inserted and connected in series to each line of the power line, and the connection position of the parallel resonant filter is connected to the commercial power supply side. A block filter section formed by connecting the above series resonance filter between power lines is inserted into the power line so as to divide the power line into at least two sections, and each section of the power line is equipped with a transmitter and a receiver for transmitting the power line. In the power line carrying block filter that is connected to A power line carrying block filter characterized in that it is inserted in series only in a three-wire neutral power line.