JPS5895807A - Autotransformer with phase-shifting winding - Google Patents

Abstract

PURPOSE:To reduce the dimensions of an autotransformer with a phase-shifting winding relatively and to unify the specifications of said transformer and additional transformers for rectifiers so as to simplify the specifications, by installing the autotransformer with the phase-shifting winding on the power source side, by installing the transformers for rectifiers in series to said transformer, and by dispensing thereby with tap windings and phase-shifting windings which are attached usually to said transformer. CONSTITUTION:In the figure, a transformer 2 has an input connection, and phase-shifting windings 3a, 3a', 3b, 3b' and 3c, 3c' for taking out voltages in the phases of 0 degree + alpha degree, and of 0 degree - alpha degree are arranged on an iron core of each phase, while taps 4a, 4b and 4c are provided on a serial winding. When a supply voltage changes in this constitution, a voltage having a constant phase angle can be supplied stably to each transformer on the secondary side by varying the taps fitted to the serial winding without providing each phase-shifting winding with a tap as is the case in a conventional transformer with phase-shifting winding for a rectifier, since a voltage per one turn (volt/ turn) is always constant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an autotransformer with a phase-shifting winding, and particularly to an autotransformer with a phase-shifting winding suitable for use in rectification equipment in which a plurality of transformers for multi-phase rectification are installed. Concerning winding transformers.

An embodiment of the present invention will be described below based on the drawings. In conventional rectifier equipment for multiphase rectification, a plurality of transformers 11, 12, and 13 are installed in a system, as shown in FIG.

Incidentally, in recent years, rectifier equipment has been trending toward larger capacity, and as a result, the problem of harmonics has come into focus. To deal with this, 12-phase and 24-phase.

There is a trend to increase the number of rectification phases to 36 phases. Therefore, in order to increase the number of rectification phases in this way, each transformer for multiphase rectification has Oo, +α0. Alternatively, a phase shift winding is attached to take out a voltage with a phase shift of -α0. Furthermore, each transformer requires a tap winding in order to supply a constant voltage to the load despite fluctuations in the power supply voltage.

Next, FIG. 2 shows the connection state of the primary winding of a conventional transformer with a phase shift winding. Here, the phase shift winding refers to a winding wound around the iron core for phase shift adjustment. In these conventional transformers, the main coils 5a, 5
A method is used to keep the secondary voltage constant by moving the taps 4a, 4b, and 4c attached to the terminals b and 5c, but the drawback is that the phase shift angle changes for each tap because the taps are changed at this time. was there. Therefore, conventionally, phase shift windings 7a and 7b were used to solve this problem.

Taps 6a, 5b, 6c"t' were installed on 7C.

For this reason, the specifications of each rectifying transformer become complicated, the winding configuration becomes complicated, and it is necessary to increase the number of coolers due to resistance loss and stray loss in the phase shift winding. was forced to increase its size.

SUMMARY OF THE INVENTION An object of the present invention is to provide an autotransformer with a phase shift winding for simplifying the specifications and downsizing of various transformers for rectifiers connected to a power system.

The feature of the present invention is that instead of the phase-shifting windings attached to each rectifier transformer of the rectifier equipment, an autotransformer with a phase-shifting winding is installed on the power supply side of these systems, and from this the rectifier transformer is connected in series. By installing a transformer and omitting the tap winding and phase shift winding that were conventionally attached to the transformer, the dimensions of the transformer can be relatively reduced, and the specifications of these transformers can be unified to improve the specifications. The point is that it is simplified.

Next, FIG. 3 shows an embodiment of a main part of a rectifying equipment to which the present invention is applied. In this embodiment, one autotransformer 2 with a phase shift winding is arranged on the power supply side of each transformer instead of the phase shift winding of the transformer for polyphase rectifier equipment.

This transformer 2 transforms each transformer 11', 12', 13'
This is to supply a voltage with a phase shift angle (-α0, 0°, +α0) as required. FIG. 4 shows the connection between an autotransformer with a phase shift winding and a rectifier transformer. This embodiment shows a case where a voltage having a phase shift of -♂ with respect to the power supply voltage is supplied.

Furthermore, FIG. 5 shows the configuration of an embodiment of the autotransformer 2 according to the present invention. In the figure, the transformer 2 is connected in a large scale, and the iron core of each phase has phase shift windings 3a, 3a', 3b for extracting voltages with phase shifts of 0°, +α0, and -α0.

3b', 3c, 3c' are arranged, and the series windings are provided with taps 4a, 4b, 4C.

In the above configuration, if the power supply voltage changes, changing the tap attached to the series winding will increase the voltage per turn (
Volt/turn) is always constant, so even if there is no tap in each phase shift winding like in conventional rectifier transformers with phase shift windings, each transformer on the secondary side always has a constant phase shift angle. It becomes possible to stably supply a voltage having .

Further, the rectifier transformer connected in series to this autotransformer is connected to the secondary terminal of the autotransformer with phase shift winding at 06, -α0.
By fully receiving the voltage of any phase shift angle among the phase shifts of +α0, it becomes possible to supply the voltage of any stable phase shift to the rectifier. By installing an autotransformer with a phase-shifting winding in this way, it becomes unnecessary to provide a phase-shifting winding and a tap winding in each rectifier transformer, and these rectifier transformers can be manufactured with the same specifications. Moreover, since the specifications are simplified, the overall cost can be reduced. Furthermore, since phase shift windings and tap windings are not required, the rectifier transformer can be made smaller.

Next, FIG. 6 shows the connection state of the U phase of the autotransformer with phase shift winding according to the present invention. In the figure, if the primary voltage is VH and the secondary voltage is VL, the self-capacitance P8 of the autotransformer can be expressed by the following equation, where the line capacitance is PL.

Therefore, the smaller the voltage difference between the primary voltage and the secondary voltage, the more the self-capacitance Ps can be reduced, making it possible to manufacture an economical autotransformer with a phase shift winding.

Since the voltage difference between the primary voltage and the secondary voltage of the autotransformer with a phase shift winding according to the present invention is only about the tap voltage, the difference between the primary voltage and the secondary voltage is small, and therefore, the difference between the primary voltage and the secondary voltage is small. Since the features can be fully utilized, weight can be reduced and losses can also be reduced.

Therefore, according to this embodiment, the entire transformer can be manufactured economically.

Next, a specific structure of the autotransformer with phase shift winding according to the present invention is shown in FIG. In the figure, a series winding 3a is connected to the tripod core.
, Bb, 8c and shunt winding 9a.

9b and 9C are wound. However, in this figure, the left half of the winding wound around each leg is omitted. Phase shift windings 3a, 3a', 3b, 3b', 3C.

3C' is arranged concentrically with both the series and shunt windings. To explain using the U leg, a voltage with a phase shift of 0°' is applied to the terminal U directly drawn out from the shunt winding 9a of the U leg.
→0. Similarly, a voltage with a phase shift of +α0 is induced at the terminal u″ connected to the W-phase phase shift winding and drawn out.

FIG. 8 shows another embodiment in which phase shift windings are arranged coaxially and the purpose is to match the output impedance of each phase.

As described above, according to the present invention, the specifications of a transformer for rectifier equipment can be simplified, and the transformer can be made smaller.

[Brief explanation of drawings]

Figure 1 is a wiring diagram showing the configuration of the main parts of conventional rectifier equipment, Figure 2 is a diagram showing the connection state of the primary winding of a conventional transformer with phase shift winding, and Figure 3 is a diagram to which the present invention is applied. FIG. 4 is a wiring diagram showing the configuration of the main parts of the rectifier equipment, and FIG.
The figure is a wiring diagram showing an embodiment of an autotransformer according to the present invention,
6 is a diagram showing the connection state of the U phase of the autotransformer with a phase shift winding shown in FIG. 5, and FIG. 7 is a diagram showing a specific example of the autotransformer with a phase shift winding according to the present invention. FIG. 8 is a diagram showing the specific structure of another embodiment of the autotransformer with phase shift winding according to the present invention. 2...Autotransformer with phase shift winding, 11.11', 12
゜12', 13.13'... Rectifier transformer. Figure U Figure 6 Figure 9 Figure 8

Claims (1)

[Claims] 1. Winding a series winding and a shunt winding on each of the multi-legged cores,
In an autotransformer in which these windings are connected in a polyphase manner, a phase shift winding is wound concentrically with the winding wound around each leg, and the phase shift winding is wound around the ground. An autotransformer with a phase shift winding, characterized in that phase shift adjustment is performed by connecting to a turned shunt winding.