JPH03253012A - On-load tap change-over switch - Google Patents

Abstract

PURPOSE:To enable the fluctuation in voltage of the tertiary winding to be directly controlled by a method wherein movable contactors, fixed resistance contactors, a fixed main contactor and fixed resistance contactors are provided on a change-over switch while a tap selector movable contactor etc., is provided on a tap selector. CONSTITUTION:In case of change-over from a tap 64A to another tap 64B, firstly, change-over switching axles 57, 57' start to rapidly turn clockwise by spring force. Next, a movable contactor 59 of a tap selector 52 and a movable contactor 53 of change-over switch 51 are turned to open a fixed conductive contactor 74A. Next, fixed resistance contactors 55A, 55A' of said switch 51 are closed and then a fixed main contactor 54A is opened. Furthermore, when fixed resistance contactors 55B, 55B' are closed and the other contactors 55A, 55A' are opened, another contactor 54B is closed. When said contactors 55B, 55B' are opened in the final stage to close a fixed conductive contactor 74B of tap selector for stopping the switching step, the change-over to the tap 64B is finished. Through these procedures, the title on-load change-over switch can be rationalized into a device capable of directly controlling the fluctuation in voltage of the tertiary winding.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an on-load tap switching device, and particularly to a large capacity autotransformer equipped with a voltage regulating tap winding and a tertiary winding. The present invention relates to an on-load tap switching device provided in a tertiary winding in order to compensate for variations in tertiary winding induced voltage due to switching of taps on the power side.

[Conventional technology]

A conventional autotransformer has a series winding 1 and a shunt winding 2 connected in series, as shown in FIG. 6(a).
The tap winding 3 is connected to the side through the polarity changer 7, and the tap winding 3 is connected to the neutral point 8 side through the on-load tap changer 4, and the high voltage terminal 5 is connected from the high voltage side of the series winding 1. , and the low voltage terminals 6 are drawn out from the connection points of the series winding 1 and the shunt winding 2, respectively. Furthermore, each of these windings 1 to 3
A tertiary winding 9 is provided which is magnetically coupled to the tertiary winding 9.
The power factor is compensated by supplying power to other loads from the terminals 10 and 11, or by connecting a capacitor or an axle (not shown). Such a configuration is common in Japanese Patent Publication No. 61-57690.

However, in this configuration, the induced voltage in the series winding l and the shunt winding 2 can be made to a predetermined voltage by switching the taps of the tap winding 3, but in response to this tap switching, the induced voltage in the iron core Since the magnetic flux density of the tertiary winding 9 changes, the induced voltage in the tertiary winding 9 also changes each time. Furthermore, the terminal voltage of the tertiary winding 9 fluctuates due to connection/disconnection of the capacitor bank, etc.

Therefore, in such a case, there is a possibility that the tertiary winding 9 cannot perform power factor compensation or supply power to other loads.

Therefore, an example of a large-capacity autotransformer that has been proposed and used in the past in order to compensate for the voltage fluctuation of the secondary winding wA9 will be explained with reference to FIG. 6(b). 12 and 13 are excitation windings connected in parallel with the tertiary winding 9, and a tap winding 14 for indirectly adjusting the voltage of the tertiary winding 9 is magnetically coupled to the excitation winding 13. , the primary winding 1 of the series transformer via the tap changer 15
7 and to the other side of the primary winding 17 of the series transformer via a polarity switch 16.

Further, 18 forms the secondary side of the series transformer and is connected in series to the tertiary winding 9. and, respectively, series winding 1
9 The shunt winding 2 and the tertiary winding 9 form a transformer body 20, the tap winding 3 and the excitation winding 12 form a primary voltage regulator 21, and the excitation winding &! 13. The tap winding 14 and the primary and secondary windings 17 and 18 of the series transformer are
A tertiary voltage regulator 22 is formed. With this configuration, the primary winding 17 of the series transformer is excited by the tap winding 14 with an appropriate tap selected by switching the on-load tap switching device 15, and the secondary winding 18 of the series transformer is excited. By adjusting or subtracting the voltage to the tertiary winding 9, fluctuations in the tertiary winding voltage can be indirectly compensated for, and this is known in Japanese Patent Laid-Open No. 63-200509.

Here, the on-load tap switching device 15 generally has the structure shown in FIG. The structure is such that a tap selector 31 is connected to select the
The entire structure is suspended in four parts inside the transformer tank 39. In a large capacity container, this height dimension becomes large. 32 is a mechanism box that transmits the driving force of the switching switch 30 and the tap selector 31.

A wiring diagram of this on-load tap switching device 15 is shown in FIG. The tap winding 14 has a pair of tap selectors 15A, 15.
A cylindrical insulator 30 forming a switching switch 30 via B
are connected to fixed main contacts 34A and 34B arranged on the circumference of
B, 35B') are arranged between the fixed main contacts 34A and 34B, and the respective fixed main contacts 34A and fixed resistance contacts 35A, 35A' are arranged between the fixed main contacts 34B and the fixed resistance. Contactors 35B and 35B' are connected in parallel. A movable contact 33 can be selectively connected to the fixed main contacts 34A and 34B by rotating the switching operation shaft 37. In FIG. 8, the fixed main contact 34
The movable contact 34B is connected to the movable contact 33 to form an energizing path, but when the switching operation shaft 37 rotates counterclockwise, the movable contact 33 connects to the fixed main contact 34B.
Fixed resistance contacts 35B, 35B', 35A',
35A, and the fixed main contact 34A is switched one after another while making rolling contact, and the energization path is changed to the fixed main contact 3.
Transfer to 4A. Switching from the fixed main contact 34A to 34B can also be done by performing the above operation in the opposite direction, and the switching operation of the on-load tap changer 15 is enhanced by performing this reciprocating operation. In the switching part, the contact group is generally divided into three parts as shown in Figure 8, and the tap winding is divided into two or three parts in parallel, taking into consideration the switching capacity of the tap switching device under load. It is used by dividing the contactor group and arranging each contactor group in two or three parallels to correspond to the tap winding.

[Problem to be solved by the invention]

However, as explained above, this configuration is an extremely large-scale device. This is because the current flowing through the tertiary winding is large, so the switching capacity is large and the voltage fluctuations in the tertiary winding are
This is due to the inability to apply normal on-load tap changers for direct regulation. Therefore, there is no choice but to use an indirect compensation method for the tertiary voltage as shown in FIG. 6(b), which can reduce the switching capacity of the on-load tap switching device. Another method for directly adjusting the tertiary voltage is the no-voltage tap switching method, but in this case, the transformer must be stopped before switching, and then turned on again after switching. is necessary, and is unsuitable if the transformer cannot be easily stopped.

The purpose of the present invention is to provide a streamlined on-load tap switching device that can directly adjust voltage fluctuations in the tertiary winding, and as a ripple effect, it is possible to create an economical large-capacity autotransformer with a smaller overall size. It is to make it.

[Means to solve the problem]

The above purpose is to provide a small number of taps on the tertiary winding, connect the taps to the fixed main contacts of the corresponding switching switches, and then connect a pair of current limiting resistors and fixed resistance contacts connected in series to the fixed main contacts. The movable contacts are connected between the contacts and in parallel with the fixed main contact, and have an arbitrary curved shape, from the first fixed main contact to the next fixed main contact, and from the last fixed main contact. The fixed main contact should be connected to the corresponding fixed energizing contact of the tap selector for energization, and the fixed main contact should be connected to the fixed energizing contact of the tap selector for energization via the movable contact of the tap selector. Terminals of the tertiary winding are formed, and the fixed main contact, current limiting resistor, tap selector movable contact, etc. are all housed in a single cylindrical insulator that is airtight from the outside. It can be achieved with

[Effect]

In the present invention, the current-carrying circuit includes one that connects the tap of the tertiary winding to the terminal via the fixed main contact and the movable contact in the normal position, and the one that connects the tap to the terminal through the fixed main contact and the movable tap selector. It becomes parallel with the circuit connected to the terminal via the contactor.

When changing the tap from this state, the movable contact
Switching occurs from the currently energized fixed main contact to the next fixed main contact while making rolling contact on the fixed resistance contact. Furthermore, the same operation can be repeated when switching to the next tap or returning to the original tap, and by repeating this, it becomes possible to continuously switch to any tap without any trouble.

〔Example〕

Embodiments of the present invention will be explained with reference to FIGS. 1 to 4.

In these figures, the same reference numerals as those in conventional FIGS. 6 to 8 indicate the same or equivalent parts.

FIG. 2 is a wiring diagram of the on-load tap switching device of the present invention,
This corresponds to cross section AA and cross section BB of the structural diagram of the present invention shown in FIG. FIG. 3 is a transformer wiring diagram according to the present invention.

First, in FIG. 3, 40 is a tertiary winding, which has a small number of taps, and a tap switching device 41 on load.
It is drawn out to one terminal 10 via the terminal. The other terminal is 11.

This connection is extremely simple, and when compared with the conventional diagram of FIG. 6, it can be seen that negative and cubic voltage regulators are not required. This on-load tap switching device 41 will be explained with reference to FIG. 2. From the tertiary winding 40 to the taps 64A, 64B, 6
4C are pulled out, and fixed main contacts 54A are each arranged on the circumference of the cylindrical insulator 50 of the switching switch section 51,
54B.

It is connected to 54C. A pair of current limiting resistors 56 and fixed resistance contacts 55A and 55A' are connected between each fixed main contact (between 54A and 54B, between 54B and 54C).
(55B, 55B', 55C.

55C', 55D, 55D') are connected in series, respectively, and the fixed main contacts 54A, 54B as a whole.

It is arranged to be connected in parallel with 54C. Further, inside the cylindrical insulator 50, a movable contact 53 having an arbitrary curved shape is arranged with the switching operation shaft 57 as the center of rotation, and is arranged from the fixed main contact 54A to 54B and from 54B to 54.
It is possible to switch to C and vice versa by continuously rolling contact on each contact. Reference numeral 52 denotes a tap selector section, in which tap selector fixed current-carrying contacts 74A, 74B, and 74C arranged on the circumference of the cylindrical insulator 50 are connected to the fixed main contacts 54A, 54B of the corresponding switching switch section 51. , and 5
Each is connected to 4C. 59 is a tap selector movable contact, which rotates around the switching operation shaft 57';
Tap selector fixed energized contacts 74A, 74B and 74
C can be selectively switched. The rotation center side of the tap selector movable contact 59 and the rotation center side of the movable contact 53 of the switching switch section 51 are connected to each other to form one terminal 10 of the tertiary winding 40.

Here, the operation of this on-load tap switching device 41 is as follows:
This is done according to the switching sequence shown in the figure.

Assuming switching from tap 64A to 64B,
First, the switching operation shafts 57 and 57' begin to rapidly rotate clockwise in the figure due to a spring force (not shown), and the tap selector movable contact 59 and the movable contact 53 of the switching switch section 51 rotate to select the tap. The fixed energizing contact 74A opens. Next, the fixed resistance contact 55A of the switching switch section 51,
After 55A' is closed, fixed main contact 54A is opened.

Further, when the fixed resistance contacts 55B and 55B' are closed and the other fixed resistance contacts 55A and 55A' are opened, the fixed main contact 54B is closed. In the final stage, the fixed resistance contacts 55B, 55B' open and the tap selector fixed energized contact 74B closes and ceases operation, completing the switch to tap 64B. The next switching from tap 64B to 64C and switching in the opposite direction may be performed in the same manner as described above.

By the way, in this switching switch section 51, as shown in FIG. 2, the movable contact 53 is similar to the conventional on-load tap switching device 1 shown in FIG.
5, that is, only the reciprocating movement of the movable contact 33 divided into three parts, for example, from the fixed main contact 54A to 5
It is possible to switch continuously up to 4C, which allows for a large distance between the contacts, making it possible to switch a large capacity. In addition, the current carrying capacity can be easily handled by optimizing the current carrying capacity of the fixed current carrying contacts 74A, 74B, 74C and the movable contact 59 of the tap selector, and with this configuration, the large capacity tap in the tertiary winding Switching becomes possible. Moreover, because of its simple configuration, the switching switch section 51 and tap selector section 52 can be housed in a single airtight cylindrical insulator 50, as shown in FIG. This allows for a compact, simple and economical structure.

Therefore, the autotransformer to which the on-load tap changer 41 is applied can be miniaturized and manufactured in an economical size.

The basic embodiment of the present invention has been described above, and next, another embodiment will be described with reference to FIG. The difference from FIG. 2 is that the movable contact 83 of the switching switch section 51 is made into a roller type, which also makes the fixed main contacts 54A, 54B
, 54C can be switched by rolling contact, and this method can also be applied to the west tap where the number of taps is limited to three as shown. Furthermore, if the arrangement angle of the fixed main contact is considered, five taps or six taps are also possible, allowing for more fine adjustment. The embodiment shown in FIG. 5 also provides the same effect as that shown in FIG. 2.

〔Effect of the invention〕

According to the present invention, it is possible to provide a streamlined on-load tap switching device that can directly adjust the voltage fluctuation of the tertiary winding, and as a ripple effect, it is possible to create an economical large-capacity autotransformer with a smaller overall size. do.

[Brief explanation of drawings]

Figure 1 is a side view of the on-load tap changer, Figure 2 is
A wiring diagram of an on-load tap switching device showing an embodiment of the present invention,
FIG. 3 is a wiring diagram of an autotransformer showing an embodiment of the present invention, FIG. 4 is a switching sequence diagram of the on-load tap switching device of FIG. 1, and FIG. 5 is a diagram. A wiring diagram of an on-load tap changing device showing another embodiment of the present invention, FIG. 6 is a wiring diagram of an autotransformer showing a conventional example, and FIG. 7 is a side view of a conventional on-load tap changing device. , FIG. 8 shows a wiring diagram of the on-load tap changer device, taken at cross section CC in FIG. 7. 1-Series winding, 2--Shunt winding, 3--Tap winding,
10.11 Tertiary winding terminal, 40... Tertiary winding, 41
... Tap switching device on load, 50 ... Cylindrical insulator, 5
3... Movable contact, 54A, 54B, 54C... Fixed main contact, 56... Current limiting resistor, 55A, 55A'5
5B, 55B', 55C, 55C', 55D. 55D' Fixed resistance contact, 59...Tap selector Fig. 2 Fig. 3 Fig. 5 Fig. 6 (b)

Claims (3)

[Claims] 1. In an autotransformer comprising a series winding, a shunt winding, a tap winding connected to these windings, and a tertiary winding magnetically coupled to each of the windings, the tertiary winding In the on-load tap switching device for switching the taps, the taps are respectively connected to fixed main contacts arranged on the circumference of a cylindrical insulator corresponding to the taps, and further , a pair of series-connected current limiting resistors and fixed resistance contacts are arranged between the fixed main contacts, and are connected in parallel with each fixed main contact, with movable contacts having an arbitrary curved shape, Continuous rolling contact is possible from the first fixed main contact to the next fixed main contact and to the last fixed main contact, and the end of the movable contact is used as one terminal of the tertiary winding. An on-load tap switching device characterized by: 2. In claim 1, the fixed main contact is connected to each corresponding tap selector fixed energized contact, and the tap selector fixed energized contact is configured to be selectable by the tap selector movable contact. , and an on-load tap switching device in which the arbitrarily curved movable contact and the end of the tap selector movable contact are connected to serve as one terminal of a tertiary winding. 3. In claim 1 or 2, a set of the fixed main contact, the current limiting resistor, the fixed resistance contact, the tap selector movable contact, and the contact side of the tap selector fixed energizing contact with the movable contact is connected to the outside. A load tap changer housed in a single cylindrical insulator that maintains airtightness.