RU2070745C1 - Adjustable air-core reactor - Google Patents

Abstract

FIELD: electrical engineering; reactive power correction in high- and superhigh-voltage power transmission lines. SUBSTANCE: reactor phase is built up of several air-core coils connected in series and mounted on insulating supports one on top of other. Each coil is built up of series-connected main and adjusting sections with taps and switching device. All coils are built as separate modules, each provided with separate switching device connected in parallel with adjusting section of coil. EFFECT: provision for across-the-line connection without using special high-voltage oil-immersed transformers. 4 cl, 6 dwg

Description

 The invention relates to the field of electrical engineering and energy, in particular, to dry adjustable electric reactors of reactive power compensation devices in high and ultra-high voltage power transmission systems.

 Dry single-phase and three-phase adjustable transformers are known in which the reactor phase comprises a coreless (steel) coil mounted on supporting insulators and consisting of a main and adjustable parts that are switched between themselves by a device connected in series with the adjustable part of the coil.

 Switching is performed either when the reactor is switched off by reconnecting the taps on the outer layer of the adjustable part of the coil by means of jumpers (Canadian patent N 1114465, MKL H 01 F 29/02, 1981), or under load using a switching device (Canadian patent N 1065028, KMI H 01 F 29/02, 1979).

 Known designs of controlled reactors relate to low-voltage reactors and cannot be directly connected to power lines with voltages exceeding 110 kV, since they would cause unacceptable overvoltages in the regulated part of the coil on de-energized sections due to the high inductive EMF from the mutual induction flow.

 In addition, in the case of regulating the inductance under load, switching devices connected in series with the adjustment part of the coil allow operation at voltages up to 35 kV, otherwise the switching device must be made to a higher voltage class, while its dimensions become comparable with the dimensions the reactor itself, which is practically impracticable, since it is economically disadvantageous.

 Also known is an adjustable reactor containing in phase several coils without a core (without steel), connected in series and mounted on top of each other on insulating supports (support insulators), each of which consists of series-connected main and control parts with taps on the outer layer, and switching devices (Romanian patent N 73218, MKI H 01 F 37/00, 1980). The inductance in this reactor is controlled by reconnecting (switching) the taps of the various coils with two jumpers with the reactor turned off. Jumpers are made in the form of half rings and are connected in series with the adjusting parts of the individual coils. In this reactor, due to the presence of several control sections, a wider range of inductance control is possible. However, this reactor, as described above, refers to low-voltage reactors, since if it were used in networks with voltages above 110 kV, unacceptable voltages would arise in the regulating parts of the reactor windings in de-energized areas due to the induction emf from the mutual induction flow. All the regulated reactors described above are included in high-voltage power lines through a high-voltage oil transformer by connecting the reactors to the low-voltage winding of the transformer, which ensures the operation of powerful regulated reactors of class 6-35 kV networks with a direction above 110 kV.

 However, the presence of a high voltage oil transformer in the known inductance control systems for high voltage power lines makes such systems fire hazardous, bulky in size and uneconomical.

 The aim of this invention is the creation of a dry powerful high-voltage regulated reactor without steel (core) of an outdoor installation, connected directly to the transmission line voltage of 110-1150 kV without using a high-voltage transformer.

 To achieve the specified technical result in a dry controlled reactor containing in phase several coils without a core, connected in series and mounted on top of each other on insulating supports, each of which consists of a series of main and control parts with taps and switching devices; all coils are made in the form of identical modules, each of which is equipped with its own separate switching device, connected in parallel to its adjustment part. At the same time, switching devices can be made in the form of high-voltage switches, or thyristor switches, or automatic multi-stage tap switches.

 In FIG. 1 shows a wiring diagram of this phase of the proposed reactor (for power transmission voltage of 500 kV).

 In FIG. 2-4 shows a circuit diagram with various options for switching devices.

 In FIG. 5, 6 schematically depict design options for one reactor module with a connected switching device.

 The proposed controlled reactor contains in phase several series-connected identical modules 1 (for the 500 kV line, four). Each module is a dry layer coreless coil, the winding of which consists of a series 2 main and 3 adjustment parts with taps. The winding is made of aluminum multicore cable and fixed in structural rails made of fiberglass with a moisture-resistant coating. The main part of the module windings is located inside the adjustment part (Fig. 5) or on the same axis with it (Fig. 6). In parallel with the adjustment part of the winding, a switching device, for example, a high-voltage switch 4, is connected. All reactor modules are mounted vertically on top of each other on insulating supports made in the form of a "shelf", consisting of supporting insulators 5 and supporting beams 6. On the supporting beams of the "shelf" the modules are installed using the supporting insulators 7. Serial electrical connection of the modules is carried out using the jumper 8.

 The support beams are made of concrete (reinforced with a bar of non-magnetic steel), or of wooden beams impregnated with a water-repellent composition, or consoles of non-magnetic steel.

 In each module, the switching device can be either a high-voltage switch 4 (Fig. 2), or an automatic switch under voltage 9 (Fig. 3), or a controlled thyristor switch 10 (Fig. 4). The switching device operates in the "on", "off" mode, which provides the adjustment part of the winding in two modes - sequential switching with the main part of the winding (the switching device is open), or short-circuiting the adjustment part of the winding (the switching device is closed), which ensures automatic regulation of reactor inductance without breaking its power circuit.

 The switching device is controlled “from the ground” using an optical fiber cable or through a low-power isolation transformer. Reactors for power lines from 11 to 1150 kV, both single-phase and three-phase, are based on a single module design. The number of modules in the reactor depends on the power line voltage; each of the modules is installed on top of each other at a higher potential relative to the "ground". So, for a 110 kV power transmission line, a single-phase reactor is made of one module, for a 220 kV power transmission line of two modules, a 500 kV power transmission line of four modules, a 750 kV power transmission line of six modules, 1150 kV power transmission line of eight modules. The switching devices of all modules can be switched on and off either simultaneously or sequentially in accordance with the requirements for the magnitude of the reactor inductance regulation stage.

 Despite the fact that the potential of the switching device of each module relative to the ground increases with the installation height of the module, the voltage drop across all the regulating windings of the modules and their switching devices does not exceed 20 kV, due to the high regulatory effect provided by shorting the turns of the regulating winding relative to the main winding, and the opposite direction of their mutual induction flows.

 The proposed design of an adjustable high-voltage reactor allows for the regulation of reactive power in ultra-high voltage power lines using single-phase and three-phase "air" reactors without the use of oil high-voltage transformers, which are bulky, labor-consuming to manufacture, fire hazardous, do not meet environmental requirements, and therefore, obtain significant economic effect. Moreover, all reactors for power lines from 110 to 1150 kV are based on a single module design, which ensures maximum unification of the design and manufacturing technology of the reactors, reduces labor and labor costs, and reduces the manufacturing time of the reactors.

Claims (4)

 1. Dry adjustable reactor containing in phase several coils without a core, connected in series and mounted one above the other on insulating supports, each of which consists of parts connected in series with the base and adjusting with taps, and switching devices, characterized in that all the coils are made in the form of identical modules, each of which is equipped with a separate switching device connected in parallel with the adjustment part of the coil.  2. The reactor according to claim 1, characterized in that the switching device is made in the form of a high-voltage switch.  3. The reactor according to claim 1, characterized in that the switching device is made in the form of controlled thyristor keys.  4. The reactor according to claim 1, characterized in that the switching device is made in the form of an automatic multi-stage tap changer.

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