RU2088997C1 - Electroinductive apparatus used for control of reactive power - Google Patents

Abstract

FIELD: electroinductive apparatus for control of reactive power with a linear flux-current characteristic is intended for power supply systems of industrial enterprises. SUBSTANCE: the apparatus uses high-voltage supply-line winding 1, which accommodates ferromagnetic rod 2; low-voltage control windings 3 are symmetrically arranged along the rod relative to the ends, each control winding is connected to switching device 4 of its own and grounded. The control windings may have a single turn (all of them) or have a different number of turns (a to 3), the number of turns in the windings increases from the rod end to its middle. The control windings may be made of sheet conductor or multicore cable. EFFECT: reduced cost and enhanced reliability due to the use of cheap low-voltage switching devices. 5 cl, 2 dwg

Description

 The invention relates to the field of electrical engineering and energy, to reactive power controllers, in particular to adjustable arc quenching and compensating reactors with a linear Weber-ampere characteristic for power supply systems of industrial enterprises.

 A feature of regulated reactors with a linearly Weber-ampere characteristic is the absence of higher harmonics in their current and voltage, in contrast to controlled reactors with a non-linear Weber-ampere characteristic (magnetized reactors), therefore, the use of such reactors does not require additional installation in networks of expensive higher harmonic filters .

 Known electric induction apparatus for regulating reactive power, an adjustable reactor with a linear weber-ampere characteristic, containing an armored magnetic circuit and a winding located on a plunger rod, in which the inductance is controlled by changing the magnitude of the non-magnetic gap by moving the movable part of the rod using an electric drive [1] analogue.

 Due to the presence in the magnetic system of an adjustable air gap, the weber-ampere characteristic of such a reactor is linear.

 The power of plunger reactors usually does not exceed 2 mVA. Such a design becomes economically disadvantageous for high power, since with increasing reactor power the mobility of the rod part increases, and the “magnetic traction” forces between the movable and fixed parts of the rod become so large that the dimensions and power of the electric drive become comparable with the dimensions and power of the reactor itself . Also known is an electric induction apparatus for controlling reactive power with a linear Weber-ampere characteristic, comprising a high-voltage network winding and switching devices [2] analogue.

 Such electro-induction apparatuses are used in reactive static compressors (STK).

 The inductance in them is controlled by switching devices based on thyristor switches, connected in series with the high-voltage network winding of a dry reactor without steel, by changing the ignition angles of the thyristors and thereby the current in the reactor winding.

 The weber-ampere characteristic of such an electric induction apparatus is linear, since it uses a steel-free reactor.

 Thyristor-controlled electro-induction apparatus for controlling reactive power does not contain bulky moving parts of the rod; their power is much higher than plunger reactors; they are used for voltages up to 35 kV.

 The disadvantage of these reactive power controllers is that in them thyristor switches, connected in series with the high-voltage network winding of the reactor, are energized and must be rated for the corresponding high voltage.

 In networks with voltages exceeding 35 kV, reactive power controllers of a known design are not used, since their switching devices become very expensive and bulky due to the complexity of the control system, the reliability of its operation, and therefore the electro-induction apparatus for regulating reactive power as a whole, is reduced.

 The aim of this proposal is to create an electric induction apparatus for regulating reactive power with a linear weber-ampere characteristic, used both at voltages of 6, 10, 35 kV, and at voltages of 110 and 220 kV with cheap and reliable low-voltage switching devices.

 To this end, in an electric induction apparatus for regulating reactive power with a linear Weber-ampere characteristic containing a high-voltage network winding and switching devices, the high-voltage network winding is equipped with a ferromagnetic rod located inside it, on which there is a set of low-voltage regulation windings distributed symmetrically relative to its ends along the rod , and each regulation winding is connected to its own switching device and is grounded.

 In this case, the low-voltage control windings can be made single-turn or with a different number of turns, and the number of turns in the windings increases from the ends of the rod to its center.

 Low voltage windings can be made of sheet conductor or multi-core cable.

 In FIG. 1 schematically shows an electric induction apparatus for controlling reactive power; figure 2 embodiment of the windings of regulation of the electric induction apparatus.

 The electric induction apparatus for regulating reactive power contains a high-voltage network winding 1, inside which a ferromagnetic rod 2 is placed, along the rod symmetrically relative to the ends are regulation windings 3, each of which is connected to its own switching device 4 and is grounded.

 The control windings are made of low voltage. They can be all single-turn or contain a different number of turns (from one to three - Fig. 2).

 The control windings can be made of sheet conductor or multi-core cable.

 As switching devices, thyristor switches can be used, as in the well-known design of a reactive power regulator, or low-voltage switches.

 The regulation of inductance in this induction apparatus is carried out by sequentially shorting the control windings with switching devices, from the ends of the rod to its middle.

 In this case, short-circuited circuits are formed in which magnetic fluxes are induced, compensating for the main stream of the network winding of the apparatus, changing its inductance.

 The flow of the control windings with the magnetic flux of the network winding at the ends and in the middle part of the rod is not the same, therefore, if there is a need to equalize currents in short-circuited circuits, the control windings are performed with a different number of turns, while the number of turns in the windings increases from the end of the rod to its middle.

 The magnetic fluxes of the short-circuited loops of the control windings compensate for the main flow of the rod when the windings are short-circuited sequentially, which is equivalent to a change in the height of the rod and, therefore, inductance of the apparatus.

 In reactive power controllers with voltages up to 35 kV, the inductance can be regulated stepwise by both switches and thyristor switches. In reactive power controllers with a voltage of 110 kV and higher, in order to equalize the voltage of the network winding along the height of the rod, it is preferable to regulate smoothly with the ignition angles of the thyristors.

 The weber-ampere characteristic of this electric induction apparatus is linear, since its magnetic system is open.

 In the proposed electro-induction apparatus for controlling reactive power, the switching devices are not energized by the network, as in the known construction, but under the voltage of the EMF induced in the regulation windings, which does not exceed 1 kV, which allows the use of cheap and reliable switching devices, reducing cost and increasing reliability the operation of the entire electric induction apparatus.

 Electric induction apparatuses for regulating reactive power with a linear weber-ampere characteristic of the proposed design can be used in static thyristor compensators and as adjustable arc suppression and compensating reactors at voltages up to 220 kV.

 For networks with voltages up to 35 kV, the electric induction apparatus can be made with a "dry" version (Fig. 1,2), at voltages of 110-220 kV the apparatus is placed in a tank with oil (not shown in the drawing).

Claims (5)

 1. Electro-induction apparatus for regulating reactive power with a linear Weber-ampere characteristic, comprising a high-voltage network winding and switching devices, characterized in that the high-voltage network winding is equipped with a ferromagnetic rod placed inside it, on which a set of low-voltage regulation windings are distributed symmetrically distributed along it relative to its ends, with each regulation winding connected to its own switching device and grounded.  2. The apparatus according to claim 1, characterized in that the low-voltage regulation windings are single-turn.  3. The apparatus according to claim 1, characterized in that the low-voltage regulation windings are made with different numbers of turns, and the number of turns in the windings increases from the ends of the rod to its center.  4. The apparatus according to any one of paragraphs. 1 to 3, characterized in that the low-voltage regulation windings are made of sheet conductor.  5. The apparatus according to any one of paragraphs. 1 to 3, characterized in that the low voltage control windings are made of multi-core cable.

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