JPH07254520A - Three-phase on-load voltage and phase adjusting transformer - Google Patents

Abstract

PURPOSE:To obtain the three-phase on-load voltage phase compensating transformer which is small, lightweight and low-cost by a method wherein a three-phase-type on-load tap changer can be used as both on-load tap changers for voltage adjustment and for phase adjustment. CONSTITUTION:A main transformer is provided with a primary main winding 3, with a tap winding 4 for voltage adjustment, with a secondary winding 5 and with a delta- connection tertiary winding 6. A phase shifter is provided with a delta-connection exciting winding 10, with a tap winding 15 for phase adjustment and with a delta- connection stabilizing winding 9. The tap winding 4 for voltage adjustment is connected in series with the neutral-point side of the primary main winding 3 so as to become the same phase, and a delta connection is constituted. A three-phase-type on-load tap changer 13 for voltage adjustment is attached to the neutral-point part. In addition, the tap winding 15 for phase adjustment is connected to a terminal used to release the neutral point of the secondary winding 5 so as to obtain a phase difference of 90 deg. from the secondary winding 5, and a delta connection which is provided with a phase-shifting winding is constituted. A three-phase-type on-load tap changer 16 for phase adjustment is attached to the tap winding 15 for phase adjustment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase load voltage phase adjustment transformer for electric power, which can perform voltage adjustment and phase adjustment under load.

[0002]

2. Description of the Related Art Among electric power equipment, a three-phase load voltage phase adjustment transformer is an equipment that performs voltage adjustment and phase adjustment during load. FIG. 2 is a connection diagram showing an example of a conventional three-phase load voltage phase adjustment transformer for electric power. This three-phase load voltage phase adjustment transformer includes a main transformer 1 and a phase adjuster 2. It is configured.

As shown in FIG. 2, the main transformer 1 comprises a primary main winding 3, a voltage adjustment tap winding 4, a star-shaped secondary winding 5, and a triangular tertiary winding 6. ing. On the neutral point side of the primary main winding 3, a voltage adjusting tap winding 4 and a voltage adjusting single-phase load tap changer 7 are connected in series so as to be in phase with each other, and the terminals are connected in series. X, Y,
An open star connection with Z is constructed.

Further, the phase adjuster 2 is provided with a phase adjusting tap winding 8, a triangular connecting stable winding 9, and a star connecting exciting winding 10. Of these, the phase adjusting tap winding 8 is provided with a phase adjusting three-phase load tap changer 11. The phase adjusting tap winding 8 has a phase difference of 90 degrees with the primary main winding 3 of the main transformer 1, and the neutral point open terminal X,
It is connected to Y and Z, and is configured such that the primary side is a star connection with a phase shift winding. Furthermore, the main transformer 1
Side-sided tertiary winding 6 and phase-adjuster 2-side star-shaped excitation winding 10 are connected in parallel.

The operation of the conventional three-phase load voltage phase adjustment transformer having the above structure is as follows. First,
In the main transformer 1, the voltage adjustment single-phase load tap changer 7 changes the number of turns of the voltage adjustment tap winding 4 which is a part of the primary winding and the direction of the induced voltage thereof, thereby The magnitude of the voltage is adjusted by changing the turn ratio between the primary winding and the secondary winding 5 and the tertiary winding 6.

Next, in the phase adjuster 2, the star-shaped excitation winding 10 is connected to the triangular winding tertiary winding 6 on the main transformer 1 side, and the primary transformer 1 side primary winding is connected. Winding 3 and 90
A phase adjusting tap winding 8 for inducing voltages whose phases differ by degrees is connected in series to the neutral point side of the primary main winding 3 and the voltage adjusting tap winding 4. Therefore, by changing the number of windings of the phase adjusting tap winding 8 and the direction of the induced voltage thereof by the phase adjusting three-phase load tap changer 11, the voltage induced on the secondary side and the tertiary side is
The phase angle of the voltage induced on the primary side can be adjusted.

The stable winding 9 of the phase adjuster 2 circulates the triple harmonic current generated in the phase adjuster 2 to prevent induced voltage distortion, and also to reduce the zero-phase impedance seen from the primary side. Performs the function of reducing the size.

[0008]

However, the conventional three-phase load voltage phase adjustment transformer having the above structure has the following problems. That is, since the voltage adjustment single-phase load tap changer 7 and the phase adjustment three-phase load tap changer 11 are connected in series in the primary main winding 3, the voltage adjustment single-phase load tap changer The tap changer 7 is connected to the line side of the phase adjusting tap winding 8. Therefore, since the terminal voltage of each phase is different, it is not possible to use a three-phase load tap changer used at the same potential at the neutral point as a load voltage tap changer. It requires three phase-type load tap changers, one for each load, which increases the size and weight of the entire transformer and also increases the cost.

The present invention has been proposed in order to solve the above problems of the prior art, and its purpose is to:
Provide a compact, lightweight, and low-cost three-phase load voltage phase adjustment transformer that can use a three-phase load tap changer for both voltage adjustment and phase adjustment load tap changers. That is.

[0010]

A three-phase load voltage phase adjusting transformer according to the present invention comprises a primary main winding, a voltage adjusting tap winding, a secondary winding, and a triangular winding tertiary winding. In a three-phase voltage phase adjustment transformer with a main transformer, a star-shaped excitation winding, a phase adjustment tap winding, and a phase adjustment equipped with a triangular connection stable winding, for voltage adjustment The tap winding and the three-phase load tap changer for voltage adjustment are installed on either the neutral point side of the primary main winding or the neutral point side of the secondary winding, and The feature is that the three-phase load tap changer for phase adjustment is attached to the remaining one of the neutral point side of the primary main winding and the neutral point side of the secondary winding.

In the three-phase load voltage phase adjustment transformer according to claim 1, a voltage adjusting tap winding and a voltage adjusting three-phase load tap changer are mounted on the neutral point side of the primary main winding.
The secondary winding is characterized in that a phase adjusting tap winding and a phase adjusting three-phase load tap changer are attached to the neutral point side.

The three-phase load voltage phase adjustment transformer according to a second aspect has the following features in addition to the features of the first aspect. That is, first, on the side of the neutral point of the primary main winding, the voltage adjusting tap windings are connected in series so as to have the same phase, and are configured to form a star connection. A three-phase load tap changer for voltage adjustment is attached to. Further, on the side of the neutral point of the secondary winding, the phase adjusting tap windings are respectively connected in series so as to have a phase difference of 90 degrees, and are configured to form a star connection with a phase shift winding. A three-phase load tap changer for phase adjustment is attached to this neutral point. Furthermore, the tertiary winding and the excitation winding are connected in parallel.

In the three-phase load voltage phase adjustment transformer according to the third aspect, the phase adjustment tap winding and the phase adjustment three-phase load tap changer are attached to the neutral point side of the primary main winding.
The secondary winding is characterized in that a tap winding for voltage adjustment and a three-phase load tap changer for voltage adjustment are attached to the neutral point side.

A four-phase load voltage phase adjustment transformer according to a fourth aspect has the following features in addition to the features of the third aspect. That is, first, on the neutral point side of the primary main winding, the phase adjusting tap windings are connected in series so as to have a phase difference of 90 degrees, and a star connection with a phase shift winding is formed. A three-phase load tap changer for phase adjustment is attached to the neutral point. In addition, the voltage adjustment tap windings are connected in series on the neutral point side of the secondary winding so that they are in phase with each other, and are configured to form a star connection. A three-phase load tap changer for adjustment is installed. Furthermore, the tertiary winding and the excitation winding are connected in parallel.

[0015]

In the three-phase load voltage phase adjustment transformer of the present invention having the above-mentioned structure, the following effects can be obtained. That is, with such a configuration, the voltage adjustment and the phase adjustment can be separately performed for one of the primary side and the secondary side and the other.

In the first and second aspects of the invention, the voltage adjustment and the phase adjustment can be performed as follows. That is, the voltage adjustment three-phase load tap changer changes the number of turns of the voltage adjustment tap winding and the direction of its induced voltage, and changes the winding ratio of the secondary winding and the tertiary winding to change the voltage. Adjust the size of. And
The three-phase load tap changer for phase adjustment changes the number of turns of the phase adjustment tap winding and the direction of its induced voltage.
The phase angle of the voltage induced in the secondary winding is adjusted with respect to the voltage induced in the primary winding and the tertiary winding.

In the inventions of claims 3 and 4, voltage adjustment and phase adjustment can be performed as follows. That is, the voltage adjustment three-phase load tap changer changes the number of turns of the voltage adjustment tap winding and the direction of the induced voltage, and changes the turns ratio between the primary winding and the tertiary winding to change the voltage Adjust the size. Then, the three-phase load tap changer for phase adjustment changes the number of turns of the phase adjustment tap winding and the direction of its induced voltage, so that the primary winding with respect to the voltage induced in the secondary winding and the tertiary winding is changed. Adjust the phase angle of the voltage induced in.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a description of one embodiment of the voltage phase adjustment transformer for three-phase load for electric power according to the present invention.
An embodiment of a voltage phase adjustment transformer for three-phase load for electric power, to which the invention of claim 2 is applied, will be specifically described with reference to FIG.

As shown in FIG. 1, the main transformer 1 of the present embodiment.
The reference numeral 2 includes a primary main winding 3, a voltage adjusting tap winding 4, a star-shaped secondary winding 5, and a triangular tertiary winding 6. Of these, the star-shaped secondary winding 5 has terminals X,
It is constructed as a star connection with an open neutral point having Y and Z. Further, on the neutral point side of the primary main winding 3, the voltage adjusting tap windings 4 are connected in series so as to have the same phase, and the primary side is configured to have a star connection. A three-phase load tap changer 13 for voltage adjustment is attached to the neutral point.

Further, the phase adjuster 14 of the present embodiment is provided with a phase adjusting tap winding 15, a triangular connecting stable winding 9, and a star connecting exciting winding 10. Of these, the phase adjustment tap winding 15 is provided with a phase adjustment three-phase load tap changer 16. The tap winding 15 for phase adjustment is used as the secondary winding 5 of the main transformer 12.
And the secondary winding 5 is connected to the terminals X, Y and Z of which the neutral point is opened, and the secondary side is a star connection with a phase shift winding. Is configured. Further, the triangular winding tertiary winding 6 on the main transformer 12 side and the star-shaped excitation winding 10 on the phase adjuster 14 side are connected in parallel as in the conventional example of FIG.

The operation of the three-phase load voltage phase adjustment transformer of the present embodiment having the above-mentioned structure is as follows. First, in the main transformer 12, the voltage adjustment three-phase load tap changer 13 changes the number of turns of the voltage adjustment tap winding 4, which is a part of the primary winding, and the direction of the induced voltage thereof. The magnitude of the voltage is adjusted by changing the turn ratio between the primary winding and the secondary winding 5 and the tertiary winding 6.

Next, in the phase adjuster 14, the main transformer 12
3 side winding 6 of the triangular connection on the side, excitation winding 10 of the star connection
Is connected, and the secondary winding 5 on the main transformer 12 side is connected.
A phase adjusting tap winding 15 that induces voltages having a phase difference of 90 degrees is connected in series to the neutral point side of the secondary winding 5. Therefore, by changing the number of turns of the phase adjusting tap winding 15 and the direction of the induced voltage thereof by the phase adjusting three-phase load tap changer 16, it is possible to prevent the voltage induced on the primary side and the tertiary side from increasing. The phase angle of the voltage induced on the secondary side can be adjusted.

Further, the stable winding 9 of the phase adjuster 14 circulates the triple harmonic current generated in the phase adjuster 14 to prevent induced voltage distortion, and also has a zero phase impedance seen from the secondary side. Fulfills the function of reducing.

Next, the difference between the operation of the three-phase load voltage phase adjustment transformer of this embodiment and the operation of the conventional three-phase load voltage phase adjustment transformer of FIG. There are differences in adjustment. That is, in the conventional example of FIG. 2, the phase adjustment was performed between the primary side, the secondary side, and the tertiary side, but in the present example, the phase adjustment is performed between the secondary side and the primary side and the tertiary side. Done in.

However, such a difference between this embodiment and the conventional example does not correspond to a substantial difference in function. That is, since these three-phase load voltage phase adjustment transformers are used in the power system, the primary side and the secondary side are connected to the system circuit, and the phase angle between the primary side and the secondary side is adjusted. It would be good if I could do it. Since both the present embodiment and the conventional example can adjust the phase angle between the primary side and the secondary side, they can be said to have substantially the same function after all. The tertiary side is connected to a circuit different from the power system to which the primary side and the secondary side are connected, for example, the substation load, and the phase of the substation load and the primary side of the power system or Since the relationship with the phase on the secondary side does not generally pose a problem, the above-mentioned difference in action between the two does not pose any problem in practical use.

Further, the angle of phase adjustment is changed by voltage adjustment in the conventional example of FIG. 2, but has an advantage that it is not changed by voltage adjustment in the embodiment of the present invention.

As described above, in the present embodiment, the load tap changer to be used may be a three-phase load tap changer mounted at the neutral point for both voltage adjustment and phase adjustment. In this way, when one three-phase load tap changer is used, the entire transformer can be made significantly smaller and lighter than when three single-phase load tap changers are used. Also, the cost will be reduced.

Since the load tap changers 13 and 16 for voltage adjustment and phase adjustment are attached to the neutral point, their insulation reliability is determined by the insulation strength of the neutral point. Therefore, in the case of step insulation in which the insulation strength at the neutral point can be reduced, the reduction is advantageous.

In the above embodiment, the invention of claim 1 or 2 is applied, and a tap winding for voltage adjustment and a tap changer at load are attached to the primary side, and phase adjustment is performed on the secondary side. The case where the tap winding and the tap changer during load are attached has been described, but when the invention of claim 3 or 4 is applied, the configuration is reversed.
That is, the phase adjusting tap winding and the load tap changer are attached to the primary side, and the voltage adjusting tap winding and the load tap changer are attached to the secondary side. Even with such a configuration, it is obvious that the same effect as that of the above-described embodiment can be obtained.

[0030]

As described above, in the present invention, the voltage adjusting tap winding and the voltage adjusting three-phase load tap changer are provided in the neutral point side of the primary main winding and in the secondary winding. Installed on either side of the neutral point side, the phase adjustment tap winding and the phase adjustment three-phase load tap changer remain on the neutral point side of the primary main winding and the neutral point side of the secondary winding. It is possible to use only one three-phase load tap changer as load tap changer for both voltage adjustment and phase adjustment. A three-phase load voltage phase adjustment transformer can be provided.

[Brief description of drawings]

FIG. 1 is a connection diagram showing an embodiment of a voltage phase adjustment transformer for three-phase load for electric power according to the present invention.

FIG. 2 is a connection diagram showing an example of a conventional three-phase load voltage phase adjustment transformer for electric power.

[Explanation of symbols]

 1 ... Main transformer 2 ... Phase adjuster 3 ... Primary main winding 4 ... Voltage adjustment tap winding 5 ... Secondary winding 6 ... Tertiary winding 7 ... Voltage adjustment single-phase load tap changer 8 ... Phase Adjustment tap winding 9 ... Stable winding 10 ... Excitation winding 11 ... Phase adjustment three-phase load tap changer 12 ... Main transformer 13 ... Voltage adjustment three-phase load tap changer 14 ... Phase adjuster 15 … Phase adjustment tap winding 16… Phase adjustment three-phase load tap changer

Claims (4)

[Claims] 1. A main transformer having a primary main winding, a voltage adjusting tap winding, a secondary winding, and a triangular winding tertiary winding, and a star connecting excitation winding and a phase adjusting tap winding. In a three-phase load voltage phase adjustment transformer having a wire and a phase adjuster provided with a triangular winding stable winding, the voltage adjustment tap winding and the voltage are provided on a neutral point side of the primary main winding. An adjustment three-phase load tap changer is attached, and the phase adjustment tap winding and the phase adjustment three-phase load tap changer are attached to the neutral point side of the secondary winding. Three-phase load voltage phase adjustment transformer. 2. The voltage adjusting tap windings are respectively connected in series on the neutral point side of the primary main winding so as to have the same phase, and are configured to form a star connection. The voltage adjustment three-phase load tap changer for voltage adjustment is attached to a neutral point portion, and the phase adjustment tap windings are respectively connected in series on the neutral point side of the secondary winding so as to have a phase difference of 90 degrees. The phase-adjusting three-phase load tap changer is attached to the neutral point, and the three-phase winding and the excitation winding are connected. 3. The three-phase load voltage phase adjustment transformer according to claim 1, wherein the two are connected in parallel. 3. A main transformer having a primary main winding, a voltage adjusting tap winding, a secondary winding, and a triangular winding tertiary winding, and a star connecting excitation winding and a phase adjusting tap winding. In a three-phase load voltage phase adjustment transformer having a wire and a phase adjuster provided with a triangular winding stable winding, the phase adjustment tap winding and the phase are provided on the neutral point side of the primary main winding. A three-phase load tap changer for adjustment is attached, and the tap winding for voltage adjustment and a three-phase load tap changer for voltage adjustment are attached to the neutral point side of the secondary winding. Three-phase load voltage phase adjustment transformer. 4. A star-shaped connection with a phase-shift winding, wherein the phase adjustment tap windings are connected in series on the neutral point side of the primary main winding so as to have a phase difference of 90 degrees. The three-phase tap tap changer for phase adjustment is attached to the neutral point portion, and the voltage adjustment tap winding has the same phase on the neutral point side of the secondary winding. Are connected in series so as to form a star connection, and the voltage adjustment three-phase load tap changer is attached to the neutral point, and the tertiary winding and the excitation winding are connected. The three-phase load voltage phase adjustment transformer according to claim 3, wherein the two are connected in parallel.