JPH0550213B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fail safe device in an automatic breaker breaker closing device.

Generally, a protective relay device includes a so-called main detection means for detecting a short circuit or a ground fault, and a so-called failsafe means for detecting a failure of the relay device itself. Both of these means usually use two series of devices with the same configuration, one being used as the main detection means and the other as a fail-safe means. For this reason,
Using fail-safe means has the disadvantage of increasing the price of the entire device, and without using fail-safe means, incorrect information may be generated in the event of a failure of the relay device itself, such as the failure to trip the disconnector. Since the tripping information would be sent out at any time, there was a risk that the reliability of the device would decrease.

The present invention eliminates the above-mentioned drawbacks, simplifies the circuit, fully exhibits the fail-safe function, and provides a fail-safe device for an automatic disconnector closing device, which can improve the reliability of the device. With the goal.

Before explaining one embodiment of the present invention with reference to the drawings, first, a short-circuit current suppression measure using a double busbar will be described with reference to FIG. In Figure 1, during normal operation, as shown in "Pattern 1", the busbar connection and disconnection BCB and line switch LS ₁
is open, and bank BA ₁ and bus line BU ₁ are open.
It is assumed that power is supplied to the bank BA ₃ through the mustard cutter CB ₁ and CB ₃ , and that power is supplied to the bus line _{BU 2} via the mustard cutter CB ₂ of the bank BA 2. In addition, in FIG. 1, LS ₂ is a line switch. Here, if an accident occurs in bank BA ₂ during normal times in "Pattern 1" and, for example, transformer protection relay RY ₁ breaks the secondary side disconnector CB ₂ , then the second bus line BU ₂ becomes no voltage. At this time, the means to automatically turn on the busbar contactor disconnector BCB and line switch LS ₁ to relieve the supply problem is the one after turning on in "Pattern 1" in FIG. 1.

In addition, in "Pattern 2" in Figure 1, overload detection relay RY ₂ installed in bank BA ₂ operates and cuts off the load if the load on bank BA ₂ increases any further. The diagram after "Pattern 2" shows that the bus line contactor disconnector BCB and line switch LS ₁ are automatically turned on in order to relieve the overload.

Furthermore, in "Pattern 3" in Fig. 1, an accident occurs in bank BA ₂ , causing the breaker CB ₂ to rupture, and the load on bank BA ₂ of bus BU ₂ is transferred to bank BA ₄ .
If bank BA ₄ becomes overloaded when moving to
The diagram after turning on "Pattern 3" shows the automatic turning on of the bus-bar contactor disconnector BCB and line switch LS ₁ to relieve an overload in the same way as described above.

If any of banks BA ₁ to _{BA 3} becomes overloaded while the busbar connection or disconnector BCB is open as described above, or if busbars BU ₁ and BU ₂ become non-voltage, an overload occurs. In order to relieve the load and supply problems, the busbar contactor and disconnector BCB are automatically turned on, and this automatic closing device will be described below with reference to FIG. 2. Note that FIG. 2 is for actually carrying out "Pattern 1" to "Pattern 3" in FIG. 1.

FIG. 2 is a block diagram showing an embodiment of the present invention. In FIG. a digital input section 22 to which operating signals of the transformer protection relay RY ₁ and overload detection relay RY ₂ shown in FIG. 1 are input;
Analog input section 23 receives the load status of each bank, and μ determines whether the bus connection, disconnection, or line switch shown in FIG. 1 should be turned on.
- A digital output section 25 that sends out a signal to turn on the CPU 24 and the aforementioned shield disconnector or line switch.
It consists of Note that the analog input section 23
are the current-voltage converter 23a and the multiplexer 2
3b and an analog/digital converter 23c. In addition, the A and B bus voltages described below are also connected to the analog input section 2 via the transducer TD.
3 is input.

The output of the central processing unit 21 is sent to the auxiliary relay section 2.
6. This auxiliary relay section 26 sends out a closing command signal to the closing circuit of the busbar connection, disconnector, or line switch. 27 and 28 are relay parts that detect the non-voltage of the A and B bus lines, and 29 is a synchronization confirmation device 29 that confirms synchronization of the A and B bus line voltages when connecting the bus or turning on a disconnector. The output and the outputs of the relay sections 27 and 28 are supplied to the digital input section 22. 30 is a fail-safe circuit whose details are shown in FIG. 3, and the signal supplied to the digital input section 22 is applied to the input of this fail-safe circuit 30. The output of this failsafe circuit 30 is the auxiliary relay section 2
6.

The fail-safe circuit 30 is constructed as shown in FIG. In Fig. 3, X is a relay that operates in the event of a bank fault, and Y is a relay that operates in the event of an overload.One end of both relays It is connected to the supply terminal 32, and the other end is connected to the DC negative electrode bus N. P is a DC positive electrode bus. FS ₁ is a fail-safe first relay, and this first relay FS ₁ has two windings F ₁ and F ₂ .

One end of the winding F ₁ of the first relay FS1 is connected to the DC positive bus P through a series circuit of the normally open contact AXa ₂ , which is closed when the device is in use, and the normally open contact Xa ₁ of the relay is connected to the DC negative bus N via the switching contact TS of the first relay FS1. Further, one end of the winding _F2 of the first relay FS1 is connected to the DC positive electrode bus P via the timer contact Ta, and the other end is connected to the DC negative electrode bus N via the switching contact TS. T is a timer relay, one end of which is directly connected to the DC positive bus P through the normally open contact FS1a ₁ of the first relay FS1, and the other end directly connected to the DC negative bus N. FS2 is the second fail-safe relay.
One end has a normally open contact AXa ₂ that closes when the device is in use.
The other end of the relay Y is directly connected to the DC positive bus P through the normally open contact Ya ₂ of the relay Y, and the other end is directly connected to the DC negative bus N. Normally open contacts Xa ₂ and Xa ₂ of the relays X and Y and the first and second fail-safe relays FS1 and FS
One end of the normally open contacts FS1a ₂ and FS2a ₁ of 2 is connected to the DC positive electrode bus P, and the other end is connected to the central processing unit 21.
It is connected to the digital input section 22 of. Said first,
Normally open contacts FS1a ₃ , FS of second relay FS1, FS2
2a ₂ are connected in parallel. This contact FS1a ₃ , FS2
Outputs 30a and 30b of the parallel circuit _a2 are input to an auxiliary relay section 26 shown in FIG.

In FIG. 4, the outputs 30a and 30b are input to input terminals 26a and 26b. The input terminal 26b is connected to the contact CPa, which is closed by the command output 25a sent from the digital output section 25 of the central processing unit 21, and the first and second relays FS1,
The normally open contacts of FS2 are connected to one side of a closing circuit (not shown) such as a disconnector or line switch through the parallel circuits of FS1a ₄ and FS2a ₃ in sequence. In addition, the input terminal 26b is the normally closed contact of the inspection relay.
It is connected to the other of the input circuits (not shown) via RYb.

Next, the operation of the above embodiment will be described. Digital input section 22 of the automatic disconnector closing device shown in Fig. 2
For example, suppose that a bank fault signal (operating signal of transformer protection relay RY ₁ shown in FIG. 1) is input. This accident signal activates relay X shown in FIG. At this time, if _the normally open contact AXa ₁ is closed, the first
Relay FS1 is activated. As a result of this operation, the switching contact TS is switched to the right side in the figure, and the timer relay T starts operating by closing the normally open contact _FS1a1 of the first relay FS1. The operating time of this timer relay T is set to the sum of the supply hindrance relief time and the margin time after the bank accident. Since the contact Ta is closed by the operation of the timer relay T, the first relay FS1 is maintained in its operating state. This causes each normally open contact of the first relay FS1 to
FS1a ₁ to _{FS1a 4} remain closed for the predetermined time (time determined by the timer). During this closing time, the .mu.-CPU 24 of the central processing unit 21 performs calculations for relief from the supply failure, and if relief is possible, a relief command output 25a is sent from the digital output section 25. With this output 25a,
The contact CPa shown in FIG. 4 is closed, and the relief command signal is applied to the busbar connection and disconnection closing circuit via the normally open contact _FS1a4 . By this, the first
In the event of an accident like "Pattern 1" shown in the figure, power can be supplied from the Otsu bus.

Furthermore, in the case of overload relief, relay Y is activated to operate second relay FS2, and the same calculation as described above is performed to perform relief.

Although the above-mentioned operation is based on a normal accident, suppose that an abnormality occurs in the central processing unit 21 and the relief output 25a is sent from the digital output section 25. At this time, the output 25a closes the contact CPa shown in FIG. 4, but the first and second relays FS1 and FS of the fail-safe circuit 30
2 do not operate, so their contacts FS1a ₃ ,
FS1a ₄ , FS2a _{2 and} FS2a ₃ remain open, and no command output is sent to the closing circuit.
Therefore, the occurrence of erroneous injection due to internal failure can be prevented. In addition, failure monitoring of the fail-safe circuit 30 is performed by comparing normally open contacts Xa ₂ and FS1a ₂ and normally open contacts Ya ₂
A comparison of FS2a ₁ and μ-CPU of central processing unit 21
24, and the first
This can be done by checking the operating time of relay FS1.

As described above, according to the present invention, the first circuit is turned on for a predetermined period of time after the occurrence of a bank accident to relieve a supply failure, and the second circuit is turned on when a bank is overloaded to relieve an overload. A closing command is supplied to the connecting circuit breaker by taking the AND of the logical sum output of the ON operation of both the first and second circuits and the closing command output of the bus connecting circuit breaker. As a result, a fail-safe circuit can be obtained with a simple configuration, and the function of the circuit can be sufficiently exhibited, and erroneous input can be prevented, so that the reliability of the device can be improved.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram for describing short-circuit current suppression measures when using a double busbar, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 extracts the main part of Fig. 2. Fig. 4 is a block diagram of the auxiliary relay section. 21... Central processing unit, 22... Digital input section, 23... Analog input section, 24... μ-
CPU, 25...Digital output section, 26...Auxiliary relay section, 27, 28...Relay section, 29...Synchronization confirmation device, 30...Fail safe circuit,
Y...Relay, FS1, FS2...First and second relays, FS1a ₄ , FS2a ₃ ...Normally open contact, CPa...Contact.

Claims (1)

[Claims] 1 When one of the busbars connected to the busbar contactor or disconnector becomes non-voltage or one of the banks connected to the busbar becomes overloaded, the busbar contactor or disconnector is automatically turned on. In the device for relieving a supply hindrance or overload, the first circuit is turned on for a predetermined period of time after the occurrence of a bank accident to relieve the supply hindrance, and the first circuit is turned on at the time of a bank overload for overload relief. and a second circuit that performs a logical product, the logical product of the ON operation of both the first and second circuits and the closing command output of the bus connection or disconnector are taken, and when the logical product output is sent out. 1. A fail-safe device for an automatic breaker disconnection device, characterized in that only a closing command is supplied to the breaker.