JPH0615297Y2 - Transformer tap switching control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tap switching control circuit for a transformer having an improved tap switching mechanism in a system in which a plurality of transformers are operated in parallel.

In recent years, multiple electric power transformers have been placed and operated in parallel. In this case, the control circuit of the main board sends a tap "up" or "down" command to the slave board to control it. It is transmitted to a circuit to control tap switching for all the units at the same time.

As a conventional tap switching control circuit, for example, the one shown in FIGS. 1 and 2 is used.

The circuit shown in Fig. 1 is a control circuit 1 for the main board in the case of passing voltage contacts.
And the control circuits 2 and 3 of the slave board are connected in parallel between the common power source PN. When the contacts 10r are closed by the "up" command of the tap, the operation auxiliary relay coil 11R of the control circuit 1 of the main panel, the operation auxiliary relay coil 21R of the control circuits 2 and 3 of the secondary panel, which are respectively connected to the electric operation mechanism, 31R is excited, and a "raise" command is issued from here to the electric operation mechanism of the tap changer attached to each transformer. As for the command for "lowering" the taps, the operation auxiliary relay coils 11L, 21L, 31L are excited by closing the contacts 10, and the "up" or "lowering" of the taps is completed for all the units at the same time.

Fig. 2 shows the case of passing the non-voltage contact, which is controlled by a separate power source. The control circuit 1 of the main board is controlled by the "up" command of the tap.
When the contact 10r provided in the above is closed, the operation auxiliary relay coil 11R that outputs a signal to the electric operation mechanism is excited. When this is excited, the contact 11r provided in the control circuit 2 of the slave board
Is closed, the operation auxiliary relay coil 21R is excited, and taps are switched. At the same time, the contact 11r provided in the control circuit 3 of the slave board is closed, and the operation auxiliary relay coil 3 is closed.
1R is excited to switch taps. In the case of a tap "down" command, contact 11, operation auxiliary relay coil 11L, contact 11, operation auxiliary relay coil 21
A signal is transmitted to L and the operation auxiliary relay coil 31L, and the taps are “raised” or “lowered” for all the units. In this structure, each of the control circuits 1, 2 and 3 is used as a separate power source, and the contacts are connected without voltage.

However, in the conventional tap switching control circuit, any of the control circuits 1, 2 and 3 can be used as the control circuit 1 of the main panel which can issue the command of "up" or "down" of the tap. Is provided in each control circuit.
Therefore, when n transformers are operated in parallel, the unit parallel circuits shown in FIGS. 1 and 2 are actually n × (n−1) connection circuits, which complicates the design and wiring. Moreover, circuit design cannot be done unless the number of transformers to be operated in parallel is decided, and when the number of transformers is increased or decreased, the change design and work become troublesome, and it is usually applicable only to parallel operation of several units. Was the reality.

The present invention has been made in view of such a point in the case of passing a non-voltage contact, and it suffices to increase the number of unitized control circuits according to the number of transformers operating in parallel, the design is easy and the wiring is simple. It is an object of the present invention to provide a tap switching control circuit for a transformer, which is effective especially in the case of a large number of parallel-operated units, and which can easily cope with a facility change to increase or decrease the number of transformers. Is.

An embodiment of the present invention will be described in detail below with reference to FIG.

FIG. 3 shows an embodiment in which three transformers are operated in parallel, and three unitized control circuits 1, 2 and 3 form a loop between control power sources PN of different power sources. It is connected.

The control circuit 1 of the main board is an operation auxiliary relay coil 11 for issuing a tap "up" command to the electric operation mechanism between the control power sources PN.
R and a coil 11L that issues a "down" command are connected in parallel. Further, between the control power source PN, the switch 13 opened on the main panel side and the coil 12R and the coil 12L of the reception / transmission auxiliary relay are connected in parallel via the reception circuit 14. The coil 12 that is excited by the "up" command
One contact 12r 'of R is the coil 11 of the operation auxiliary relay.
While being connected in series with R, another contact 12r is attached to a receiving circuit 24 provided in the control circuit 2 of the slave board.

Similarly, one contact 12 'of the coil 12L of the auxiliary transmission / reception relay that is excited by the "down" command is connected in series with the coil 11L of the operation auxiliary relay, and the other contact 12 is connected to the control circuit 2 of the slave board. It is attached to the receiving circuit 24 provided.

Further, the coil 11R of the operation auxiliary relay, the contact 11r of the coil 11L, and the contact 11 are also the receiving circuit 2 of the control circuit 2 on the slave side.
It is attached to 4.

That is, the receiving circuit 24 includes the contacts 11r, 1L of the coils 11R, 11L of the operation auxiliary relays and the coils 12R, 12L of the auxiliary transmission / reception auxiliary relays which constitute the control circuit 1 of the main board.
It is composed of 1, 12r and 12. Contact 1
1r is connected in series with the closed switch 15 and between the closed switch 23 and the coil 22R of the reception / transmission auxiliary relay. The other contacts 12r, 11, 12
Are respectively connected in parallel with the contacts 11r and are connected to the receiving circuit 24.
Are configured.

Therefore, the receiving circuit 14 provided in the control circuit 1 of the main board includes the contacts 31r and 31 of the operation auxiliary relay coils 31R and 31L of the control circuit 3 of the slave board connected adjacently to the front and the reception / transmission auxiliary relay coil 32R. , 32L of contacts 32r and 32 are connected in parallel, and the switch 35 is opened.

1R is an operation switch for "up" command provided in parallel with the contact 12r ', and 1L is an operation switch for "down" command provided in parallel with the contact 12'.

That is, the control circuit 1 of the main board is used as a unit control circuit, three of these are connected in parallel, and the other two are used as the control circuits 2 and 3 of the slave board. However, the switch 13 is opened on the main board side, the switches 23 and 33 are closed, the switch 15 provided at the contact point connected to the main board is closed, and the other switches 25 and 35 are open. Only different.

In the figure, 2R, 2L, 3R and 3L are operation switches, 21R and 21L are coils of operation auxiliary relays, and 21
r and 21 are contacts thereof, 22R and 22L are coils of the receiving and transmitting auxiliary relays, 22r, 22r ', 22 and 22' are contacts thereof, and 32r 'and 32' are contacts of coils 32R and 32L of the receiving and transmitting operation relay. .

Next, the operation of the tap switching control circuit will be described.

First, when issuing a tap "raise" command, the operation switch 1
When R is turned on, the coil 11R of the operation assisting relay is self-held, the electric operation mechanism issues a "raise" command to raise the tap, and the contact 11r of the receiving circuit 24 provided in the control circuit 2 of the slave board. Close. In this case, switch 2
Since coils 3 and 15 are set to the closed state, they are brought into conduction and the coil 22R of the auxiliary transmission / reception relay is excited. As a result, the contacts 22r 'and 22r are also closed.
By closing the contact 22r ', the coil 2 of the operation auxiliary relay
When 1R is excited, a "raise" command is issued to the electric operation mechanism to "raise" the tap connected to the control circuit 2 of the slave board.

By the excitation of the coils 21R and 22R, the control circuit 3 of the slave board
The contacts 21r and 22r provided in the receiving circuit 34 are closed. At this time, the switch 33 is in the closed state and the switch 25 is in the open state, so that the current is the switch 33 and the contact 22r.
The coil 32R of the reception / transmission auxiliary relay is excited through this. As a result, the contact 32r 'is closed, the coil 31R of the operation auxiliary relay is excited, the "up" command is issued to the electric operation mechanism, and the "up" of the tap connected to the control circuit 3 of the slave board is issued. Is done.

By the excitation of the coils 31R and 32R, 31r and 32r provided in the receiving circuit 14 of the control circuit 1 of the main board are closed, but the switches 13 and 35 are opened and thus do not operate.

Further, when the "down" command of the tap is issued, the operation switch 1L provided in the control circuit 1 of the main board is put in and the operation auxiliary relay coil 11L is excited to issue a command to the electric operating mechanism to make the tap. "Lowering" is performed. Thereafter, the contact 11, the coil 22L, the contact 22 ', and the coil 21L operate in the same manner as described above, and the second tap is lowered. Further, contact 22, coil 32L, contact 32 'coil 31
The operation is terminated when L operates and the third tap is lowered, and the loop is sequentially looped back to the control circuit 3 of the main board.

Further, when the control circuit 2 of the slave board is operated as the main board and the command of "up" or "down" of the tap is issued from here, the switches 15 and 23 are opened, the switches 25 and 33 are closed, and the switch 13 is opened. Can be changed by changing the closed state and the switch 35 to the open state.

Although the above tap switching control circuits are shown to be operated by separate power supplies, respectively, they can be operated by a common power supply.

As described above, according to the present invention, it suffices to add a control circuit unitized according to the number of parallel operation units and connect them in a loop, which simplifies the design and simplifies the wiring. It is possible to obtain a tap switching control circuit for a transformer, which is effective when the number of transformers is large and can easily cope with equipment changes for increasing or decreasing the number of transformers.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a conventional tap switching control circuit for a transformer according to a common power supply system, FIG. 2 is a circuit diagram showing a conventional tap switching control circuit for a transformer according to another power supply system, and FIG. 3 is the present invention. FIG. 3 is a circuit diagram showing a tap switching control circuit for a transformer according to an embodiment of the present invention. 1, 2, 3 ... Control circuit 1R, 1L, 2R, 2L, 3R, 3L ... Operation switch 10r, 10 ... Contact 11R, 11L, 21R, 21L, 31R, 31L.
Coil of operation auxiliary relay 11r, 11, 21r, 21, 31r, 31 ...
Contact points 12R, 12L, 22R, 22L, 32R, 32L ...
Transmission / reception auxiliary relay coils 12r, 12r ', 12, 12', 22r, 22
r ', 22, 22', 32r, 32r ', 32,
32 '... Contact 13, 23, 33 ... Switch 14, 24, 34 ... Receiving circuit 15, 25, 35 ... Switch

Claims (1)

[Scope of utility model registration request] 1. An operation auxiliary relay coil for issuing a command for raising or lowering a tap to an electric operation mechanism, a contact connected to an operation auxiliary relay coil provided in an adjacent preceding control circuit, and a preceding control circuit. A receiving circuit that consists of a contact that is connected to an auxiliary transmission / reception auxiliary relay coil that is provided, and a reception / transmission auxiliary relay coil that is connected to this receiving circuit and that receives and excites a signal to raise or lower the tap, and this reception / transmission auxiliary relay coil. A tap switching control circuit for a transformer, characterized in that a plurality of control circuits each having a contact for energizing the operation auxiliary relay coil which is closed by excitation of a relay coil are connected in a loop.