JPH09148185A - Capacitor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise, which is generated from a capacitor device, by a method wherein a capacitor is connected in series with a reactor formed by aggregating a plurality of pieces of unit reactors to each other. SOLUTION: A capacitor device 4 is one formed by series-connecting a capacitor 1 with reactors 2 and 3, which are formed by parallel-connecting a plurality of pieces of unit reactors. In this case, as the unit reactors, shell reactors, core reactors or mixed reactors consisting of shell reactors and core reactors can be used. As the capacitor, a group of capacitors formed by aggregating a plurality of pieces of unit capacitors can be used and as the unit capacitors, case type capacitors may be used. Moreover, the capacitor device 4 has a reactor formed by series-connecting groups of reactors formed by aggregating the plurality of pieces of the unit reactors to each other and the capacitor formed by series-connecting groups of capacitors formed by aggregating the plurality of pieces of the unit capacitors to each other. Thereby, a current, which is made to flow through the reactor, is reduced and noise, which is generated from the capacitor device, can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology of a capacitor device such as a low-voltage capacitor device for power factor improvement or electric power, which is installed in a low-voltage distribution line.

[0002]

2. Description of the Related Art A conventional power capacitor device is
For the purpose of improving the power factor of the distribution system, for example,
A series reactor and a capacitor are connected in series (for example, Electrical Engineering Handbook, 698-6).
(See page 99). The series reactor is connected in series on the power supply side, and as the capacitor, an appropriate number of single-phase unit capacitors are connected in parallel according to the equipment capacity.

Even when the series reactors and capacitors are grouped by the same element, by changing the ratio of the series reactors and capacitors,
It can be configured as an AC filter installed to absorb harmonics in the distribution system.

A conventional example in which a power capacitor is installed in a low voltage circuit will be described with reference to the wiring diagram shown in FIG.

In FIG. 5, reference numeral 51 is a high voltage distribution system, and 52
Is a high-voltage switch, 53 is a power receiving transformer, 54 is a low-voltage distribution line, 55 is a low-voltage load, 56 is a capacitor device, and is composed of a three-phase capacitor 57 and a reactor 58. The three-phase capacitor 57 has a configuration in which a plurality of small-capacity case-type capacitor elements are collected in consideration of its capacity, cost, etc., and the reactor 58 is a simple one reactor element in terms of space factor and cost. It is composed.

The capacity of the reactor 58 inserted in series with the three-phase capacitor 57 in order to prevent the expansion of higher harmonics in the power distribution system is usually 6% or 8% of the capacity of the three-phase capacitor 57. % Or 13%, but in most cases it is designed to be 6%.

[0007]

In the conventional capacitor device, since the reactor 58 for flowing a low-voltage large current is composed of one element, the coil wound around the iron core becomes thick and the flowing current becomes large, As a result, there is a problem that noise is increased.

It is considered that this noise is greatly influenced by the magnitude of the flowing current and the holding of the gap in the magnetic path, and the reactor 58 used in the conventional capacitor device 56 is large, Since the gap is held by bolts or fixed metal fittings, there is also a problem that the characteristics of the inductance largely fluctuate and become uneven due to the initial setting and changes over time. As a result, when a three-phase reactor is used as the reactor 58, it is necessary to consider the design margin as much as ± 10%.

Further, the unevenness of the characteristics also affects the function of removing harmonics in the capacitor device, and particularly when the series resonance between the reactor and the capacitor is used as an AC filter, the resonance frequency is increased. There was also a problem that deviation occurred.

Further, when the reactor is composed of one element, there is a problem that if the coil of the winding becomes thick, it becomes unsuitable for automated production. Moreover, in order to correspond to the capacity of the capacitor to be used, the reactor as,
Since it was necessary to prepare a large variety of capacities, mass productivity was poor, and there was a problem in terms of cost.

[0011]

In order to solve the above problems, in the capacitor device of the present invention, a plurality of small capacity unit reactors are assembled to form a reactor, and the plurality of assembled reactors are A capacitor, for example, a case type capacitor such as an integral type capacitor or a collective type capacitor is to be connected.

By using the reactor having such a structure, noise in the capacitor device can be reduced, the unevenness of the characteristics of the inductance can be improved to stabilize the characteristics, and the mass productivity can be improved to reduce the cost. Can be made.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The capacitor device of the present invention as described above can be used, for example, as a power factor improving or AC filter to be installed in a low voltage distribution line, and is implemented in the following forms.

The capacitor device of the present invention comprises a reactor in which a plurality of unit reactors are assembled and a capacitor is connected in series.

In this case, as the unit reactor, an outer iron reactor, an inner iron reactor, or a mixed reactor of an outer iron reactor and an inner iron reactor can be used.

Further, a group of a plurality of unit capacitors may be used as the capacitors, and a case type capacitor may be used as the unit capacitors.

Further, there is provided a reactor in which a reactor group in which a plurality of unit reactors are assembled are connected in series with each other, and a capacitor in which a capacitor group in which a plurality of unit capacitors are assembled is connected in series with each other.

In the above case, it is preferable to set the value of the reactance ratio of the reactor and the capacitor to a predetermined value.

In the capacitor device constructed as described above, since the capacitor current flowing in the low voltage circuit is shunted to the plurality of unit reactors,
The current flowing through each unit reactor is reduced, the noise caused by electromagnetic force is reduced, and the unit reactors that make up the reactor are downsized, and the iron core used for it is also downsized, so the gap adjustment in the process is adjusted. Further, the gap management is facilitated, unevenness of the inductance characteristics is reduced, and the wire diameter of the coil is reduced due to the downsizing of the iron core, which facilitates automation of coil winding.

Next, a specific embodiment will be described with reference to FIGS. 1 to 4.

[0021]

【Example】

(Embodiment 1) Description will be made with reference to FIG. 1 showing a wiring diagram of a capacitor device used in a high-order shunt of an AC filter for absorbing a plurality of high frequencies, and FIGS. 2 and 3 showing configuration diagrams of a reactor.

In FIG. 1, 1 is a capacitor, 2 and 3 are reactors each consisting of a unit reactor group in which a plurality of unit reactors are connected in parallel, and 4 are reactors 2 and 3 connected in parallel and a capacitor 1 is connected in series. It is a condenser device. As the reactors 2 and 3, reactors whose constructions are shown in FIG. 2 or 3 can be used. The ratio between the total reactance value of the reactors 2 and 3 and the reactance value of the capacitor 1 is 6%.

FIG. 2 shows an outer iron type reactor using an EI iron core, 5 is an iron core, 6 is a winding, 7 is a gap portion, and 8 is a welded portion of the iron core 5. Figure 3 shows the case of the inner iron type reactor.
Reference numeral 9 is an iron core, 10 is a welded portion for fixing the iron core 9 and the fixture 11 to each other, 12 is a gap portion inserted in two places, and 13 is a winding. As these unit reactors, reactors used in the field of so-called large-scale home appliances can be used as they are, so the cost is about 1/2 or less compared to a reactor configured with one reactor element. The cost reduction will be significant due to the miniaturization.

The capacity of the reactors 2 and 3 is 6% with respect to the capacity of the capacitor 1, and when the capacitor device 4 has three-phase 220V, 60 Hz and a rated capacity of 50 kvar, the rated current is 75.8A. . On the other hand, as the reactor 2, 2 unit reactors with a rating of 13 A and 3.9 mH are used.
2 reactors are connected in parallel and the reactor 3 is rated 2
When four unit reactors of 0 A and 1.6 mH are connected in parallel, 6 unit reactors per phase and 18 unit reactors per three phases are used.

In this case, the current value of the reactor 2 is 9.1.
A, the current value of the reactor 3 is 13.8 A, so that the current value is reduced to 1/5 to 1/8 as compared with the case where the reactors 2 and 3 are each configured by one reactor element. . Regarding the capacity, when the reactor is composed of one reactor element, the capacity is 3 kvar, but in the case of the reactor 2, it is 120 var, and
In the case of the reactor 3, each can be configured by a set group using a small unit reactor of 181 var.

Next, as a result of measuring the noise, in the case of the rated current, the noise value at the close range is 42 dBA,
The conventional one consisting of one reactor element is 48dbA
However, it can be reduced by 6 dBA.

This noise reduction is largely due to the structure of the reactor as described below. When the reactor has a small capacity of about 100 to 200 var, as shown in FIG. 2 and FIG. 3, a welding structure in which the welding portions 8 and 10 are formed to form the gap portions 7 and 12 for holding the gap is required. Since it can be adopted and fixed, it is easy to suppress unevenness due to variations in inductance value to 2% or less.

(Embodiment 2) The capacitor 1 in FIG. 1 showing the wiring diagram of the capacitor device is composed of two types of case type capacitors, one of which is 109 per phase.
Two μF case type unit capacitors are used, and the other uses six 167 μF case type capacitors per phase, and a capacitor group constituted by connecting these eight capacitors in parallel is used. The wiring configuration was the same as in the above case. The ratio of the total reactance of the reactors 2 and 3 to the total reactance of the capacitors 1 is 6%.

In this case, since the same operation and the same effect as those of the first embodiment are obtained, the unit reactor can be used even if the capacitors constituted by the group consisting of two types of small unit capacitors are used. It can be understood that there is no influence on the operation and effects of the reactor composed of the grouped unit reactor group.

(Embodiment 3) In FIG. 4, which shows a wiring diagram of a capacitor device when a group of capacitors and a group of reactors are used, 14 and 15 are units each having a plurality of unit capacitors connected in parallel. A condenser composed of a condenser group, 16 and 17 are reactors composed of a unit reactor group in which a plurality of unit reactors are connected in parallel, and 18 is a condenser device composed of condensers 14 and 15 and reactors 16 and 17 connected in series, respectively. is there. The reactors 16 and 1
The ratio between the total reactance value of 7 and the total reactance value of the capacitors 14 and 15 is 6%.

Also in this case, since the same operation and the same effect as those of the first embodiment are performed, it can be understood that the effect of the reactor constituted by the unit reactor group in which the unit reactors are assembled is great.

Further, by setting the ratio of the total reactance value of the reactors 16 and 17 to the total reactance value of the capacitors 14 and 15 to a predetermined value, a combined unit in which a unit capacitor and a unit reactor are combined, a so-called reactor built-in capacitor is formed. By preparing several types of capacitors having different reactance ratios, it becomes extremely easy to design the capacitor device.

Furthermore, when such a composite unit is used, it has been confirmed that it can be sufficiently applied to a capacitor device up to about 100 kvar.
It is not necessary to prepare a large number of types of reactors in order to correspond to the capacity of the capacitor used, and the effect is great in terms of practicality, mass productivity, and cost.

[0034]

The present invention is embodied in the form described above and has the following effects.

Since the reactor forming the condenser device is composed of the unit reactor group in which the unit reactors are assembled, the current flowing through the reactor is reduced and the noise can be reduced.

Further, in the capacitor device, the unevenness due to variations in reactor characteristics is eliminated, the performance is stabilized, the design is facilitated, and the mass productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a wiring diagram of a capacitor device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of an outer iron reactor used in the condenser device.

FIG. 3 is a block diagram of an inner iron reactor used in the condenser device.

FIG. 4 is a wiring diagram of a capacitor device according to a third embodiment of the present invention.

FIG. 5 is a wiring diagram of a conventional capacitor device.

[Explanation of symbols]

 1,14,15 capacitors 2,3,16,17 reactors 4,18 capacitor devices

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[Procedure amendment]

[Submission date] April 10, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

It is considered that this noise is greatly influenced by the magnitude of the flowing current and the holding of the gap in the magnetic path, and the reactor 58 used in the conventional capacitor device 56 is large, Since the gap is held by bolts or fixed metal fittings, there is also a problem that the characteristics of the inductance largely fluctuate and become uneven due to the initial setting and changes over time. As a result, when a three-phase reactor is used as the reactor 58, it is necessary to consider the design margin as large as ± 10%.

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Claims (8)

[Claims] 1. A condenser device in which a condenser is connected in series to a reactor formed by assembling a plurality of unit reactors. 2. The capacitor device according to claim 1, wherein the unit reactor is a shell-type reactor. 3. The capacitor device according to claim 1, wherein the unit reactor is an inner iron type reactor. 4. The condenser device according to claim 1, wherein the unit reactor is a mixed reactor of an outer iron reactor and an inner iron reactor. 5. The capacitor device according to claim 1, wherein the capacitor is a capacitor group in which a plurality of unit capacitors are assembled. 6. The capacitor device according to claim 5, wherein the unit capacitor is a case type capacitor. 7. A capacitor device comprising a reactor in which a plurality of unit reactors are connected in series to each other, and a capacitor in which a plurality of unit capacitors are connected in series to each other. 8. The capacitor device according to claim 1, wherein the value of the reactance ratio of the reactor and the capacitor is set to a predetermined value.