JPS6126298B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention centrally monitors the on/off status of sectional switches (hereinafter referred to as switches) installed on power distribution lines in a power distribution control room of an electric power company, etc., and also switches the switches when necessary. This invention relates to a remote monitoring and control device slave station (hereinafter referred to as a slave station) that uses a pilot wire in the transmission path and uses a frequency allocation method to configure a remote monitoring and control device for turning on and off by remote control. .

This type of conventional device uses a frequency different from that of the switch ON/OFF status reply signal as the slave station selection signal in order to confirm the completion of the slave station selection operation while monitoring the ON/OFF status of the switch to be controlled. However, in order to eliminate these drawbacks, the present invention has a system in which the slave station completes the slave station selection operation. The switch on/off state reply signal is temporarily interrupted to notify the master station.

Figure 1 shows a general connection diagram of a general switch, a pilot wire, and a slave station. In the figure, 1 is the switch, 2 is its main contact, and 3 and 3' are the main contacts 2 and 2. Moving auxiliary normally open contact and auxiliary normally closed contact, 4 is a closing electromagnet, 5 and 6 are switch 1
An operation transformer whose primary side is connected to the power supply side and load side power distribution lines 7 and 8 connected to the main contactor 2 of the slave station 9 supplies operation power to the slave station 9. P
1 to P10 are introduced and connected to the slave station 9 via pilot wires which are signal transmission paths. The auxiliary normally open contact 3 of the main contactor 2 is connected to the terminals Vc and Va of the slave station 9, and the auxiliary normally closed contact 3' is connected to the terminals Vc and Vb of the slave station 9. Both terminals of the charging electromagnet 4 are connected to terminals B and C of the slave station 9, the secondary side of the operation transformer 5 is connected to terminals A and B of the slave station 9, and the secondary side of the operation transformer 6 is connected to the terminal B of the slave station 9. , D, respectively.

To explain the operation of the device configured as above, the slave station 9 is supplied with an operating voltage by the operating transformer 5 or 6, and the pilot wires P1 to
According to the signal applied to P10, the switch 1 is opened or closed, and the on/off state of the switch 1 is sent back to a remote monitoring and control device master station (hereinafter referred to as the master station) (not shown). Due to the operation of the control circuit within the slave station 9. Child station 9
When it outputs an output between terminals B and C, the closing electromagnet 4 is energized, the switch 1 is closed, and the main contact 2 and auxiliary contacts 3 and 3' are operated. At this time, the slave station 9 confirms the closed state of the switch 1 based on the conduction state between the terminals Va and Vc or the open state between the terminals Vb and Vc.

Furthermore, when slave station 9 stops outputting between terminals B and C, switch 1 opens; however, at this time, terminals Va and Vc
The slave station 9 confirms the open state of the switch 1 based on the open state between the terminals Vb and Vc or the conductive state between the terminals Vb and Vc. The pilot wires P1, P2, P3, and P4 are signal lines used when controlling the switch 1, and no signals are applied during monitoring (at all times). During monitoring, multiple frequency signals are constantly applied from the master station between the pilot wires P5 and P6, and the slave station 9 selects these signals and extracts one wave assigned to the slave station 9, regardless of whether the switch 1 is turned on. For example, pilot wire P7, P
If the switch 1 is off during the period of 8, the frequency signal is returned between the pilot wires P9 and P10. During control, a control signal is applied between the pilot wires P3 and P4, so that the slave station 9 can be controlled to turn on or off. After this, pilot wire P1,
When the switch on/off control signal is applied between P2, the slave station 9 controls the switch 1 to close or open.

FIG. 2 shows a conventional example of the slave station 9. In the figure, 1
0 and 11 are matching transformers for impedance matching provided at the receiving and transmitting ends of the pilot wires for signal reception and return, and a filter 12 and an auxiliary contact 3 of the switch 1 are connected between the matching transformers 10 and 11. Connecting them together constitutes an on/off status return circuit for the switch 1.

Further, 13 and 14 are matching transformers provided at the receiving and transmitting ends of the control and signal return pilot wires, and 15 is a filter having a different natural frequency from the filter 12, which receives the signal through the matching transformer 13. 16 is an amplifier that amplifies the output of the filter 15; 17 is a switching circuit that outputs only when the output frequency signal of the filter 16 is applied above a certain level; and 18 is operated by the output signal of the switching circuit 17. relay, 19,2
0 is a normally open contact of the relay 18, and a contact 19 sends the output of the amplifier 16 through the matching transformer 14 to the pilot wires P7 and P8. 21 is a control circuit connected between pilot wires P1 and P2 via contact 20, and outputs an output between terminals B and C to close or open switch 1 when a positive or negative DC voltage is applied. It is.

To explain the operation of the device configured as above, during monitoring, pilot wires P5, P
A plurality of frequency signals including the natural frequency of the filter 12 are applied only between the matching transformer 10, the filter 12, the auxiliary contact 3, and the frequency signal assigned to the slave station 9 when the switch 1 is in the ON state. The signal is sent back through the matching transformer 11 between the pilot wires P7 and P8 to indicate the on state. If the switch 1 is in the off state, the matching transformer 10,
Since the auxiliary contact 3 is open, the natural frequency signal of the filter 12 that has passed through the filter 12 is not returned between the pilot wires P7 and P8. During control, in order to detect the on/off state of the switch 1 at the master station, a plurality of frequency signals including the natural frequency of the filter 12 are applied between the pilot wires P5 and P6, and at the same time, a plurality of frequency signals including the natural frequency of the filter 12 are applied between the pilot wires P3 and P4. Only one wave of a signal having a natural frequency of a filter 15 different from that of the filter 12 is applied as a slave station selection signal. The natural frequency signal of the filter 15 passes through the matching transformer 13 and the filter 15 to the amplifier 1.
6, the switching circuit 17
The relay 18 is operated by the operation. relay 1
8 operates, the output of the amplifier 16 passes through the contact 19 and the matching transformer 14 to the pilot wire P.
The natural frequency signal of the filter 15 is returned between P7 and P8. At this time, the contact 20 is simultaneously closed by the operation of the relay 18, and the pilot wire P1,
P2 and the control circuit 21 are connected, and the slave station 9 enters the station selection completion state. Here, station selection means slave station selection. The master station confirms the completion of station selection by receiving the response of the unique frequency signal from the filter 15.
After this, if a positive DC voltage is applied between the pilot wires P1 and P2, the control circuit 21 outputs an output between the terminals BC and closes the switch 1, and if a negative DC voltage is applied, the control circuit 21 stops the output between terminals BC and opens switch 1.

A slave station with such a configuration requires two different natural frequency signals for monitoring and station selection for each slave station, and is therefore limited by the frequency range or channel number allocation of the master station. If the number of frequency channels of a station is n, there is a drawback that only n/2 slave stations can be operated for each master station.

In view of these points, the present invention uses one frequency signal for monitoring and control for one slave station,
Furthermore, even when the switch is off, a reply is sent to the master station through the pilot wire, thereby providing a remote monitoring and control device that allows slave stations to be installed up to the limit of the number of frequency channels possessed by the master station. .

The present invention will be explained below. FIG. 3 shows an embodiment of the present invention of a slave station. In the figure, 22 is a matching transformer for impedance matching connected between pilot wires P5 and P6, and a filter 23 is connected to the output side of this matching transformer 22. Connected to the output side of the filter 23 through a parallel circuit of the normally closed contact 24 of the relay 32 (described later) and the normally open contact 25 of the relay 34 (described later), and then connected to the auxiliary contacts 3 and 3' of the switch 1, and the auxiliary contact 3 to the input side of the matching transformer 26, and through the auxiliary contact 3' to the input side of the matching transformer 27.
The other output side of the filter 23 is connected to the input sides of matching transformers 26 and 27, respectively. The output sides of matching transformers 26, 27 are connected to pilot wires P7, P8 and P9, P10, respectively. Further, from the output side of the matching transformer 22, a filter 28 having the same natural frequency as the filter 23 is connected, and an amplifier 2 that amplifies the output of the filter 28.
9. A switching circuit 30 that outputs an output only when the output frequency signal of the amplifier 29 is applied at a certain level or higher; A short-time timer 31 that operates when the switching circuit 30 outputs an output is connected in sequence, and the output of the timer 31 is The side is connected to the normally closed contact 24 as described above.
, to the relay 32 which also has the short timer 3
3 to a relay 34 having a normally open contact 25 as described above. Also, pilot wire P
3. Connect P4 to the power terminal of the amplifier 29. 3
5 is a relay 34 between pilot wires P1 and P2
This is a control circuit that is connected through the normally open contact 36 of the switch 1 and outputs an output between terminals B and C to close or open the switch 1 when a positive or negative DC voltage is applied. The above amplifier 29, switching circuit 3
0, the relay 34, and the contact 36 are collectively referred to as a station selection circuit. In this case, the timers 31 and 33 are connected in cascade and operate in sequence.
There is no problem even if two timers are connected in parallel as long as they are adjusted in time.

To explain the operation of the device configured as above, during monitoring, pilot wires P3 and P
Since no DC voltage is applied between the amplifiers 4 and 4, the amplifier 29 does not operate. Therefore, since both the relays 32 and 34 are inoperative, when a frequency signal is applied between the pilot wires P5 and P6 and the switch 1 is in the ON state, the natural frequency signal of the filter 23 is transferred to the matching transformer 22, filter 23, Contact points 24, 3,
It is returned to between the pilot wires P7 and P8 via the matching transformer 26, and if the switch 1 is in the OFF state, the matching transformer 22, the filter 23,
The signal is returned through the contacts 24, 3' and the matching transformer 27 between the pilot wires P9, P10.
During control, one of the natural frequencies of the filter built into the controlled slave station is applied between pilot wires P5 and P6.
At the same time or after a short delay, a DC voltage is applied between the pilot wires P3 and P4.

Figures 4a and 4b show time charts when the switch is in the on state and when the switch is in the off state, respectively. First, when the switch 1 is in the on state, the matching transformer 2
2. Between pilot wires P7 and P8 via filter 23, contacts 24, 3, and matching transformer 26; when switch 1 is in the OFF state, matching transformer 22, filter 23, contacts 24, 3', and matching transformer. 27 to pilot wire P9, P
A switch ON/OFF state reply signal is sent back to each of the 10 times. During control, pilot wires P3 and P4
Since a DC voltage is applied between them, the amplifier 29 becomes operational, and the signal that has passed through the matching transformer 22 and the filter 28 is amplified by the amplifier 29, and furthermore, the output of the switching circuit 30 causes the timer 3 to be activated.
1 works. If the set time of the timer 31 is T1, the relay 32 is activated after the time T1 has elapsed. Until now, the pilot wire P has passed through the contact 24.
The signal that was being sent back between 7 and P8 or between P9 and P10 is stopped because the contact 24 is opened by the operation of the relay 32. Furthermore, the relay 33 operates simultaneously with the operation of the relay 32. If the set time of the timer 33 is T2, then the relay 3 is activated after T2 time has elapsed.
4 works. Contact 25 is activated by the operation of relay 34.
is closed and the switch 1 is on, the pilot wire P passes through the matching transformer 22, filter 23, contacts 25, 3, and matching transformer 26.
7, P8, when switch 1 is in the off state, matching transformer 22, filter 23, contact 25,
3', the ON/OFF status reply signal is sent back to the pilot wires P9 and P10 via the matching transformer 27. The operation of the relay 34 simultaneously connects the pilot wires P1 and P2 to the control circuit 35 through the contacts 36, thereby forming a switch on/off control circuit. The master station indirectly confirms the selection of the slave station by detecting that the reply signal is temporarily interrupted as shown in the time chart of FIG.

The DC voltage applied between the pilot wires P3 and P4 is commonly applied to each slave station, but the second reason is that the natural frequency signal of the filter of the slave station is applied between the pilot wires P5 and P6. Only slave stations that satisfy the following conditions are selected and controlled. By using this DC voltage signal, it is possible to monitor and select a slave station using one natural frequency, and the number of usable channels of the master station can be greatly increased.

FIG. 5 shows an embodiment of the control circuit 35, in which a relay 3 is connected between pilot wires P1 and P2.
The input terminals 101 and 102 of the control circuit 35 are connected to the input terminals 101 and 102 of the control circuit 35 through the normally open contact 36 of No. The circuits are connected, and a diode 41 in a direction opposite to that of the diode 37 is connected in parallel with the relay 38, and a diode 42 in a direction opposite to the diode 39 is connected in parallel with the relay 40. diode 4
1 and 42 are diodes for overvoltage protection of the relays 38 and 40. Reference numeral 45 denotes an on/off control circuit, and when the relay 38 operates, its normally open contact 43 closes and maintains itself, outputting an output between terminals B and C. Next, when the relay 40 operates, its normally closed contact 44 opens, releases self-holding, and stops output between terminals B and C.

To explain the operation of the device configured as above, a DC voltage is applied between the pilot wires P1 and P2 while the contact 36 is operating.
When the polarity is positive potential of pilot wire P1 with respect to P2, pilot wire P1, contact 3
6. Current flows through the diode 37, the relay 38, and the pilot wire P2, and the relay 38 operates. Further, when the pilot wire P1 has a negative potential with respect to P2, a current flows through the pilot wire P2, the relay 40, the diode 39, the contact 36, and the pilot wire P1, and the relay 40 operates. According to the operation of the relay 38 or 40, the switch operating voltage is outputted or stopped between the terminals B and C by the on/off control circuit 45. In addition, although the display method for temporarily interrupting the switch ON/OFF status reply signal has been explained above, it is not limited to temporary interruption, but can also be used to display multiple response interruptions or intermittent signals (flicker).
Various methods can be used, such as using .

As described above, the present invention enables a slave station to be selected when a DC signal and a frequency signal unique to the slave station are simultaneously received, and also signals the completion of the selection operation by sending an ON/OFF state reply signal of the sectional switch. Since the display is made by giving a temporary signal change to the signal, it is possible to monitor and control the switch by assigning one type of natural frequency to each slave station, and the frequency owned by the master station can be displayed. It is now possible to install slave stations up to the maximum number of channels, reducing the number of master stations,
This has the effect of saving space in the electrical room. In addition, even during control, it is possible to confirm the completion of the station selection of the slave station using the switch ON/OFF status reply signal, so the ON/OFF status of the controlled switch can always be grasped, preventing blind operation of distribution lines. Hazards can be eliminated. Furthermore, since a continuous signal is always returned even when the switch is off, it is possible to distinguish between failure conditions such as a defective slave station or disconnection of the pilot wire, and the off state of the switch. It is possible to obtain a remote monitoring and control device that can take prompt action even when an occurrence occurs.

[Brief explanation of the drawing]

Fig. 1 is a general connection diagram, Fig. 2 is a circuit diagram showing a conventional example, Fig. 3 is a circuit diagram showing an embodiment of the present invention, and Fig. 4 is a circuit diagram showing a conventional example.
The figure is a time chart, in which a is a diagram showing when the switch is in the ON state, b is a diagram when the switch is in the OFF state, and FIG. 5 is an explanatory diagram of the control circuit. 1... Switch, 3, 3'... Auxiliary contact of switch,
5, 6...operation transformer, 9...slave station, 22, 26,
27... Matching transformer, 23, 28... Filter, 29... Amplifier, 30... Switching circuit, 3
1, 33...Timer, 32, 34...Relay, 35
...Control circuit, P1 to P10...Pilot wire.

Claims (1)

[Scope of Claims] 1. In a remote monitoring and control device for centrally monitoring the on/off state of a sectional switch installed on a distribution line and for turning on/off the switch by remote control as necessary, during monitoring: A first filter that receives a monitoring frequency signal, selects a pre-assigned unique frequency, and returns a status display signal according to the on/off state of the sectional switch, which has the same unique frequency as the first filter. and a second filter that outputs when receiving the station selection signal of the unique frequency, and a control that is activated when the output of the second filter and the station selection DC signal are received at the same time and closes or opens the sectional switch. A remote monitoring and control device comprising: a station selection circuit that selects a circuit to be in a drivable state. 2. An amplifier is provided in the station selection circuit, and the amplifier outputs when both the frequency signal passed through the second filter and the DC voltage signal given from a separate circuit are applied. A remote monitoring and control device according to claim 1, characterized in that: 3. In a remote monitoring and control device that centrally monitors the on/off status of sectional switches installed on distribution lines and turns on/off the switches by remote control when necessary, a monitoring frequency signal is received at the time of monitoring. A first filter that selects the assigned unique frequency and returns a status display signal according to the on/off state of the sectional switch, which has the same unique frequency as the first filter; A second filter that outputs when a station selection signal is received; a control circuit that is activated when the output of the second filter and a station selection DC signal are received at the same time, and selects a control circuit that closes or opens the sectional switch to a drivable state. a selection operation completion display circuit that is inserted into a status display signal return circuit of a sectional switch and causes a temporary signal change to an on/off status response signal when the station selection circuit is activated. A remote monitoring and control device. 4. The selection operation completion display circuit sequentially activates the first and second timer circuits according to the output of the station selection circuit,
Consisting of a first relay circuit that changes the status display return signal of the sectional switch by the operation of the first time limit circuit, and a second relay circuit that causes the same return signal to be restored by the operation of the second time limit circuit. A remote monitoring and control device according to claim 3, characterized in that: