GB2112581A - Three-phase compensating choking coil - Google Patents

Abstract

A three-phase compensating choking coil of delta configuration has return limbs 5, formed as a complete lambination packet, arranged between the coil limbs 1. The number of return limbs 5 can vary and, according to requirements, one to three thereof can be inserted. <IMAGE>

Description

SPECIFICATION Three-phase compensating choking coil The invention relates to a three-phase compensating choking coil of delta configuration, comprising limbs of radially laminated column stumps, distributed air gaps comprising ceramic spacers, and wound yokes.

Compensating choking coils are used to compensate for the capacitive idle power of unloaded or lightly loaded high-voltage lines and to limit switching surges.

The limbs of three-phase compensating choking coils of delta configuration are arranged at the corner points of a triangle between the yokes.

Owing to the increasingly complex design of high-voltage networks and the new network operating methods which this entails, the equipment, such as compensating choking coils, also has to meet new requirements as regards quality. It is inconvenient, for example, for a voltage to be induced in the disconnected winding of a three-phase compensating choking coil in the case of a singlepole momentary break, perhaps due to a temporary short-circuit to which the circuit breaker temporarily responds.

A three-phase compensating choking coil of delta configuration is known which has return limbs arranged parallel to the winding axes on the outside of the compensating choking coil and connected to the upper and lower yoke by way of additional connecting bars. This arrangement of the return limbs requires a relatively large space and is very expensive on account of the relatively complicated construction.

The object of the invention is to improve the arrangement of return limbs in threephase compensating choking coils of delta configuration while avoiding the above-mentioned disadvantages.

This object is solved according to the invention in that return limbs, formed as a complete lamination packet, are arranged between the limbs. An advantageous feature of the invention is that the return limbs can be inserted between the limbs in a variable manner.

The advantages obtained with the invention lie particularly in the fact that the return limbs, which are prefabricated as a complete lamination packet, only have to be inserted and fixed between the limbs and the yokes of the compensating choking coil. Furthermore, the return limbs are thus also arranged in a space-saving manner.

An embodiment of the invention is shown in the accompanying drawings and will be described in detail in the following.

In the drawings: Figure 1 is a plan view of a three-phase compensating choking coil of delta configuration with return limbs; Figure 2 is a plan view of a prefabricated return limb; Figure 3 is a detailed view on section line A-A of a return limb according to Fig. 2 inserted in a compensating choking coil.

Fig. 1 is a plan view of a three-phase compensating choking coil of delta configuration, i.e. the three limbs 1, with the windings 2 disposed concentrically thereon, are arranged at the corner points of an equilateral triangle. The ends of the limbs are connected by wound yokes 3, in which sickle-shaped openings 4 are formed for the guidance of tie bolts which hold the limbs 1 and the yokes 3 together.

Figs. 2 and 3 show a prefabricated return limb 5 which comprises layers of individual laminations arranged to form a compact lamination stack which is held together at both sides by clamping plates 7 and clamping bolts 8 at right angles to the direction of the laminations.

The return limb 5 is then simply inserted between two limbs 1 and the two yokes 3 of the compensating choking coil, while maintaining a respective air gap 9 at the top and at the bottom, and secured to the yokes 3 by means of mounting straps 10, 11. Ceramic spacers 1 2 are arranged in the air gap 9 and are provided at their upper and lower side with an epoxy resin 1 3 as an adhesive coat.

1. A three-phase compensating choking coil of delta configuration, with limbs comprising radially laminated column stumps, distributed air gaps comprising ceramic spacers, wound yokes, and at least one return limb, formed as a complete lamination packet, arranged between the limbs.

2. A three-phase compensating choking coil according to claim 1, characterised in that the return limbs can be inserted between the limbs in a variable manner.

3. A three-phase compensating choking coil substantially as herein described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Three-phase compensating choking coil The invention relates to a three-phase compensating choking coil of delta configuration, comprising limbs of radially laminated column stumps, distributed air gaps comprising ceramic spacers, and wound yokes. Compensating choking coils are used to compensate for the capacitive idle power of unloaded or lightly loaded high-voltage lines and to limit switching surges. The limbs of three-phase compensating choking coils of delta configuration are arranged at the corner points of a triangle between the yokes. Owing to the increasingly complex design of high-voltage networks and the new network operating methods which this entails, the equipment, such as compensating choking coils, also has to meet new requirements as regards quality. It is inconvenient, for example, for a voltage to be induced in the disconnected winding of a three-phase compensating choking coil in the case of a singlepole momentary break, perhaps due to a temporary short-circuit to which the circuit breaker temporarily responds. A three-phase compensating choking coil of delta configuration is known which has return limbs arranged parallel to the winding axes on the outside of the compensating choking coil and connected to the upper and lower yoke by way of additional connecting bars. This arrangement of the return limbs requires a relatively large space and is very expensive on account of the relatively complicated construction. The object of the invention is to improve the arrangement of return limbs in threephase compensating choking coils of delta configuration while avoiding the above-mentioned disadvantages. This object is solved according to the invention in that return limbs, formed as a complete lamination packet, are arranged between the limbs. An advantageous feature of the invention is that the return limbs can be inserted between the limbs in a variable manner. The advantages obtained with the invention lie particularly in the fact that the return limbs, which are prefabricated as a complete lamination packet, only have to be inserted and fixed between the limbs and the yokes of the compensating choking coil. Furthermore, the return limbs are thus also arranged in a space-saving manner. An embodiment of the invention is shown in the accompanying drawings and will be described in detail in the following. In the drawings: Figure 1 is a plan view of a three-phase compensating choking coil of delta configuration with return limbs; Figure 2 is a plan view of a prefabricated return limb; Figure 3 is a detailed view on section line A-A of a return limb according to Fig. 2 inserted in a compensating choking coil. Fig. 1 is a plan view of a three-phase compensating choking coil of delta configuration, i.e. the three limbs 1, with the windings 2 disposed concentrically thereon, are arranged at the corner points of an equilateral triangle. The ends of the limbs are connected by wound yokes 3, in which sickle-shaped openings 4 are formed for the guidance of tie bolts which hold the limbs 1 and the yokes 3 together. Figs. 2 and 3 show a prefabricated return limb 5 which comprises layers of individual laminations arranged to form a compact lamination stack which is held together at both sides by clamping plates 7 and clamping bolts 8 at right angles to the direction of the laminations. The return limb 5 is then simply inserted between two limbs 1 and the two yokes 3 of the compensating choking coil, while maintaining a respective air gap 9 at the top and at the bottom, and secured to the yokes 3 by means of mounting straps 10, 11. Ceramic spacers 1 2 are arranged in the air gap 9 and are provided at their upper and lower side with an epoxy resin 1 3 as an adhesive coat. CLAIMS

1. A three-phase compensating choking coil of delta configuration, with limbs comprising radially laminated column stumps, distributed air gaps comprising ceramic spacers, wound yokes, and at least one return limb, formed as a complete lamination packet, arranged between the limbs.

2. A three-phase compensating choking coil according to claim 1, characterised in that the return limbs can be inserted between the limbs in a variable manner.

3. A three-phase compensating choking coil substantially as herein described with reference to the accompanying drawings.