JPH01307209A - Variable capacitance phase adjusting equipment - Google Patents

Abstract

PURPOSE:To reduce sharing voltage of a tap winding for surge, and realize a small-sized and light-weight winding by installing arresters between each tap of the tap windings of an auto-transformer. CONSTITUTION:Arresters 33 are connected between each tap 13. The equivalent circuit of this constitution for surge is shared by the arrester 33 and an earth capacity 32. The voltage shared by the arrester 33 becomes lower than or equal to the limiting voltage of the arrester 33, and similarly the voltage between the taps 13 also becomes lower than of equal to said limiting voltage. As a result, an excessive voltage as in the conventional case is not applied between the taps 13, and the small-sized and light-weight tap winding 12 can be realized.

Description

[Detailed description of the invention] (Industrial application field) This invention relates to variable capacity conditioning equipment.

(Prior art) When using capacitor equipment in variable capacitance conditioning equipment, for example, the capacitance of the capacitor changes in proportion to the square of the applied voltage, so in order to adjust the capacitance of the capacitor, it is necessary to vary the applied voltage. It is already well known that the required harmonization is achieved by this method.

Figure 4 shows its conventional configuration, where L is a power supply line.

1 is an autotransformer, which is composed of a main winding LA11 and a tap winding 1ll12 connected in series, and the main winding 1
1 is connected to the neutral point Nt side, and the tap winding 12 is connected to the power line 1 side. 13 is a tap drawn out from the tap winding 12, and 14 is a tap changer.

Reference numeral 2 denotes a harmonic capacitor facility, which is constructed by connecting a capacitor 21 and a series reactor 22 in series. 2
3 to 25 are the capacitances to the ground, and Nc is the neutral point.

Here, when the tap 13 is switched by the tap changer 14, the voltage applied to the capacitor equipment 2 is adjusted,
The capacitance of capacitor 21 changes.

This allows the capacity of the phase adjustment equipment to be made variable.

(Problems to be Solved by the Invention) An equivalent circuit for surges in such a configuration is shown in FIG. In the figure, 31 is the self-inductance at the tap portion of the tap winding 12, and 32
is the ground capacitance of capacitor setup @2.

Since this ground capacitance 132 has a small impedance with respect to surges, most of the surge voltage is shared by the self-inductance 31.

In this case, there is no particular problem when the tap changer 14 selects the tap 13 located closest to the power line side.

However, if a tap 13 closer to the main winding 11 is selected than this, the entire voltage will have to be shared between that tap and the tap closest to the track side. Therefore, the tap winding 12 must be provided with insulation capable of withstanding this voltage.

If such insulation were to be applied, the tap winding 12 would be so large that it would be virtually impossible to manufacture it. For these reasons, large-scale variable capacity phase adjustment equipment has not been realized to date.

This invention is a variable capacity conditioning equipment in which the capacity is 11J.
The purpose of this invention is to reduce the voltage shared by the tap winding of the No. 11 autotransformer against surges, and to make it smaller and lighter.

(Means for Solving the Problems) The present invention is characterized in that an arrester is provided between each tap of the tap winding of an autotransformer.

(Function) When a surge enters, the voltage shared between the taps will be below the arrester's limit voltage.

As a result, the insulation between the taps can be reduced, making it possible to significantly reduce the size and weight of the tap winding.

(Example) An embodiment of the invention will be explained with reference to FIG.

Note that the parts with the same reference numerals as in FIG. FIG. 2 shows an equivalent circuit for surges in this configuration.

According to the above configuration, the voltage between the taps 13 is shared between the arrester 33 and the ground capacitor 32, as shown in the equivalent circuit of FIG. The voltage shared by the arrester 33 is below the limit voltage of the arrester 33, and therefore the voltage between the taps 13 is also below this limit voltage.

Therefore, an excessive voltage is not applied between the taps 13 as in the conventional case. Therefore, the tap winding 12 can be made smaller and lighter.

Further, in this case, the arrester 33 is used for bypassing between the taps 13, not between the arrester 33 and the ground, and behind it there is an impedance such as the ground capacitance 32, which determines the current value. Therefore, the processing energy of the arrester 33 is small.

Therefore, it is also possible to use an arrester 33 having a multi-stage structure as shown in FIG. In FIG. 3, numeral 34 is an arrester element stacked in multiple stages, and a terminal 35 is interposed between the plurality of tubes. The terminal 35 may be connected to the tap 13, and 36 is an insulating stud for tightening.

Although the above example was an example in which the present invention was applied to a harmonizing facility using a capacitor, the present invention is also applicable to a phase adjusting facility that uses a shunt reactor instead.

(Effects of the Invention) As detailed above, according to the present invention, when adjusting the voltage applied to the phase modulating equipment and making the phase modulating capacity variable by using an autotransformer equipped with a tap winding, it is possible to make the phase modulating capacity variable. This has the effect of making it possible to significantly reduce the size and weight of the tap winding compared to the configuration.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the present invention, and Fig. 2 is a circuit diagram showing an embodiment of the present invention.
Equivalent circuit diagrams 1 and 3 are sectional views showing an example of an arrester, FIG. 4 is a circuit diagram of a conventional example, and FIG. 5 is an equivalent circuit diagram of FIG. 4.

Claims (1)

[Claims] In variable capacitance phase adjustment equipment in which the output voltage from an autotransformer consisting of a main winding and a tap winding is applied and the phase adjustment capacity is made variable, between each tap of the tap winding,
Variable capacity phase adjustment equipment connected to an arrester.