JPS61142919A - Low voltage power failure-free switchgear - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (A) [Industrial Application Field] In recent years, information equipment, computers, robots, and other O'A and FAfi devices have been widely introduced into households and factories, and with this, power consumption has increased. Instantaneous voltage drops and power outages in the grid can cause equipment malfunctions and defective products, so it is important to improve the quality of power distribution (
Stable voltage and frequency, low distortion, uninterrupted power supply, etc.) are now strongly required.

The present invention also applies in the case of replacing a pole transformer, etc.
This invention relates to a low-voltage uninterruptible switching device that switches the load on the transformer in parallel to the secondary side of an adjacent pole transformer, etc., thereby enabling completely uninterruptible work.

(B) [Prior art] Conventionally, when replacing a pole-mounted transformer, the work was done through a power outage, or the load on the transformer was temporarily cut off and switched to the secondary side of the pole-mounted transformer in the pond. There was some construction going on.

In other words, during the construction work, the power is cut off for customers whose load is on the transformer, or the load is temporarily switched to the pole-mounted transformer in the pond, but in this case, the load is transferred before and after the construction work. When switching back to the pole-mounted transformer in the pond, the phase and voltage do not necessarily match, which necessitates a power outage switchover, which has the inconvenience of causing inconvenience to customers.

As mentioned above, these power outages are becoming increasingly unacceptable due to the spread of information-related technologies such as value-added communication networks.

(C) [Problems to be solved by the invention] The present invention:
As mentioned above, there will be no work power outages or power outage switching due to power distribution-related work.

In other words, in the case of replacing a pole transformer, etc., the voltage and phase of the secondary load is calculated and displayed by the combiator to the secondary power supply of the pole transformer, and the voltage and phase are calculated and displayed, and the voltage and phase are adjusted according to the display. The present invention provides a low-voltage uninterruptible switching device that enables complete uninterrupted construction without any instantaneous power outage by switching in parallel.

(D) [Means to solve the problem] '1st
As shown in the figure, the midpoint 3 of any phase winding 2 of the load-side winding of a three-phase transformer 1 with the same voltage on both the power supply and load sides is set as the ground phase three-phase, and from any three-phase power supply, A three-phase transformer 1 that can generate a voltage and phase suitable for the existing lighting common load on the load side, and a power supply side 6 connected to the power supply terminal 4 of the three-phase transformer 1.
and an existing lighting common load side 8 connected to the load side terminal 5 via the switch 7, and a calculation detection unit 9 that uses a computer to calculate and display phase and voltage compatibility and open phase indications. and a closing mechanism 10 that closes the switch 7 when the power supply side 6 and the load side 8 are compatible, and by making the connection phase compatible according to the compatible phase display detected by the calculation detection section, it is possible to switch between different phases. This is a low-voltage uninterruptible switching device that allows you to easily switch and connect loads to a power source in parallel.

In addition, by inserting a breaker 11 into the power supply side 6 of the three-phase transformer 1 and opening it when changing the terminal connections, the power supply side 6 can be connected to the power supply side terminal 4 of the three-phase transformer 1.
Damage to the terminals due to the excitation current to the three-phase transformer 1 that occurs when connecting the terminals can be prevented.

Next, each member will be explained.

The three-phase transformer 1 is shown in Fig. 1 [As shown in this figure, the three-phase windings have the same number of turns for both the secondary and secondary windings, and the intermediate point 3 of either phase of the secondary side, that is, the load side winding 2 is The ground phase is three phases, the power supply side terminals 4 are each R-3-T phase, and the load side terminals 5 are each A
There are three phases: the -B-C phase and the ground phase, and these terminals have a structure that allows easy switching, such as a plug-in jack type, to facilitate phase matching.

The switch 7 is, for example, an electromagnetic switch, and has a structure in which it is operated by ON/OFF control from the switch operation section 16 of the calculation detection section 9.

As shown in FIG.
6 voltage dividers 13 that divide the potential for the three phases of '-T phase and A-B-C phase on the load side 8, for example, an auto-transformer, and a wave/form storage unit 14 that stores the divided voltage waveform. A microcomputer 15 calculates and detects the existence of an open phase and a compatible phase based on this waveform, a liquid phase display unit 12 displays the calculation detection results, and a switch operating unit 1 that closes the switch 7 when the voltage and phase are compatible.
6, and a power supply circuit 17 serving as a power supply for these.

Next, the input mechanism 10 operates the switch operating section 16.
The switch 7 is composed of an electromagnetic switch, etc., which operates under N-OFF control.

(E) [Effect of the invention] The secondary side of a pole-mounted transformer on a distribution line is generally used for common lighting, as shown in Figure 2, where the connection is between a and b and grounded to form a three-phase connection. Many methods are used.

However, in order to balance the loads on each phase of the distribution line, the high voltage side of the transformer is
It is used in connection with V and changing the phase order as appropriate.

Therefore, when replacing a transformer to increase its capacity, etc., the phase order on the secondary side of each transformer is not necessarily the same. Therefore, when carrying out work during a power outage or transferring the load of that transformer to a pole transformer adjacent to the work load, parallel switching is not possible, so the work must be carried out after switching to a power outage.

In the present invention, even if the phase of the secondary side of an adjacent pole transformer is different from the phase of the transformer concerned, the load of the transformer can be applied without interruption by parallel switching to this transformer. A low-voltage uninterruptible switching device that has a low-voltage uninterruptible switching device can calculate and display the compatible phase, and according to the display, you can easily match the phases by switching the connection wires from the adjacent transformer connected to this device, and display the phase compatibility. If this is confirmed and the switch 7 is turned on using the switch operation unit 16, the load can be switched in parallel to the secondary side of the adjacent pole transformer without interruption.

As a phase matching means, U-V-W, V-W-U%W-U- are used for the high voltage side connection in the lighting common connection on the secondary side of the pole transformer shown in Figure 2.
There are three types of V, and the phase relationship of each phase on the secondary side of the pole transformer in each case is shown as a-b-c shown by the solid line in Figure 3, and a'-b shown by the thick line. '-c', and a''-b''-c'' shown by chain lines.

From this figure, it is seen that e'-a''-1,l or b''-c'' has the same phase and the same voltage as a-b-c.
-a'''.

This principle is applied to the three-phase transformer 1 of the present invention, in which the phases a-b-c on the load side are not changed, and the phases on the power source side are a-b-c, c'-a'-b. ',b
7-c''-a'' can be handled.

That is, in the case of Fig. 4, the load side a - b - c, the power supply side a
-b and c are both in the same phase, and of course parallel connection is possible. Next, in the case of FIG. 5 as well, the power supply side c'-a'-b' has the same phase as the load side abc, and parallel connection is possible. Furthermore, in the case of FIG. 6 as well, the phases b"-c"-a" on the power supply side are the same as those on the load side a-b-c, making parallel connection possible.

In this way, even in the case of adjacent power supplies with different phases, by making the connections shown in Fig. 4, Fig. 5, or Fig. 6, you can connect the loads in parallel on the load side a-b-c without interruption. It is something that can make it possible.

Next, as shown in FIG.
The potentials of T and load sides A, B, and C relative to the ground-phase E are divided by a voltage divider 13, for example, an autotransformer, and the six divided voltage waveforms are A/D converted and simultaneously stored in the waveform storage unit 1.
4 to be memorized. The microcomputer 15 subtracts the stored instantaneous values of the voltage waveforms of each phase on the power supply side and the load side to obtain the instantaneous voltage value between each phase.
The phase open voltage (effective value) and phase are calculated from each instantaneous voltage value.

Then, from this calculation result, a connection change message for the phase that is missing and a compatible phase and the voltage between each phase are calculated and displayed on the liquid crystal display section 12.

Next, the closing mechanism 10 switches the phase order on the power supply side according to the compatible phase display of the calculation detection unit 9, and after confirming the compatible display displayed on the liquid crystal display unit 12, switches the switch using the switch operation unit 16. 7 to connect the load in parallel to the power supply side.

If you then disconnect the secondary side or secondary load side lead-in line of the transformer being replaced, the load will be switched in parallel to the adjacent pole transformer without any power outages.

After replacing the pole-mounted transformer, check that the wiring of the new transformer after replacement is the same as that of the transformer before replacement, connect the load-side lead-in wires as before, and open switch 7. The load will then be switched to the new transformer without interruption. Then, remove this device.

To check whether the wiring of the new transformer after replacement is the same as that of the transformer before replacement, prepare the calculation detection part of this device separately, and connect it to the secondary side of the new transformer. You can ensure safety by placing the lead wire in an open position and checking the phase order before connecting.

As described above, the low-voltage uninterruptible switching device of the present invention transfers the load to the secondary side of an adjacent pole transformer in parallel without any interruption, even if the phases are different. It has an excellent function that allows switching and switching back to completely uninterrupted load supply even during work.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the configuration of the present invention, Fig. 2 is a lighting common connection diagram of a pole transformer, Fig. 3 is a phase angle explanatory diagram in the same lighting common connection, and Figs. 4, 5, and 5. FIG. 6 is an explanatory diagram of the power supply side phase relative to the load side of the three-phase transformer according to the present invention. 1 is a three-phase transformer, 2 is the load side winding, 3 is the load side winding 2
, 4 is the power supply side terminal, 5 is the load side terminal, 6 is the power supply side, 7 is the switch, 8 is the load side, 9 is the calculation detection section, 10 is the closing mechanism, 11 is the breaker, 12 is the liquid crystal display 13 is a voltage divider, 14 is a waveform storage unit, 15 is a microcomputer, 16 is a switch operation unit, and 17 is a power supply circuit.

Claims (1)

[Scope of Claims] The midpoint of any phase winding of the load side winding of a three-phase transformer with the same voltage on both the power supply and load sides is set as the ground phase, and the existing lighting common load is connected to the existing lighting common load from any three-phase power supply. A three-phase transformer that can generate a voltage and phase compatible with A calculation detection unit that uses a computer to calculate and display voltage and phase compatibility indications and open phase indications with the load side of the existing lighting common use connected to the load side, and when the power supply side and load side are compatible, the above switch is activated. It consists of a closing mechanism that makes it possible to easily switch and connect loads in parallel to power supplies with different phases by matching the phases of the connections according to the compatible phase display detected by the calculation detection unit. Low voltage uninterruptible switching device.