RU2316867C1 - Combinatorial ice melting and reactive power correcting installation - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: proposed combinatorial ice melting and reactive power correcting installation that takes more advantage from using its equipment throughout the year, that is uses it to correct reactive power for most part of year and to melt ice during ice formation period on conductors and ground wires running from high-voltage line substation for short time has common rectifier section, disconnecting switches, and reactors which makes it possible to employ this installation in three alternatives of circuit arrangement: as adjustable section of static reactive power corrector with delta-connected thyristor-reactor group and as two ice melting circuits implementing different principle of current regulation. First ice melting circuit is six-phase bridge-type controllable DC current thyristor converter. Second ice melting circuit makes it possible to melt ice on thee conductors of high-voltage line at a time using controllable AC current.

EFFECT: reduced capital outlays due to less number of pieces of equipment installed in substation.

1 cl, 3 dwg

Description

Technical field

The invention relates to the field of electrical engineering and can be used in high-voltage substations, where it is necessary to maintain the voltage level on AC buses and to melt ice on wires and lightning protection cables of overhead power lines (OHL) isolated from supports.

State of the art

As a means of maintaining (regulating) the voltage, static thyristor reactive power compensators are known, consisting of a capacitor bank and a thyristor-reactor group, connected, as a rule, in a “triangle” [1]. The traditional thyristor compensator in the traditional design of the connection of the branches of the thyristor-reactor group in the "triangle" cannot be used for melting ice. For melting ice on wires by controlled rectified current, a well-known device is used - a six-phase bridge thyristor converter [2].

Placing installations for reactive power compensation [1] and ice smelting [2] at the substation leads to inefficient use of equipment, because a six-phase thyristor bridge converter, designed for melting ice on wires and lightning protection cables of overhead lines extending from the substation, is idle most of the time of the year when ice formation is absent.

SUMMARY OF THE INVENTION

The objective of the invention is the creation of a combined installation for melting ice and reactive power compensation, allowing more complete use of the installation equipment during the year, namely, most of the time of the year to use it to compensate for reactive power and for a short time during icing to use the same equipment for melting ice on wires and lightning protection cables extending from the OHL substation. The solution to this problem saves capital costs by reducing the total amount of equipment installed in the substation, and using the same equipment for smelting ice and reactive power compensation.

The essence of the invention lies in the fact that the combined installation for melting ice and reactive power compensation comprises a three-phase transformer, to which, through the first three-phase group of reactors, the first bipolar leads of the first and second three-phase groups of thyristor valves are connected, and through the first three-phase disconnector, the second three-phase group of reactors and the second three-phase disconnector - the second terminals of the first three-phase group of thyristor valves, which are connected through the third three-phase disconnector to the second terminals of the second three-phase group of thyristor valves, connected through the fourth three-phase disconnector with a three-phase output of the installation, intended for melting ice with alternating current, and a control unit, the outputs of which are connected to the control inputs of the first and second three-phase groups of thyristor valves, while the installation is equipped with an output, designed for melting ice with direct current, the fifth three-phase disconnector connected in parallel with the first three-phase group of reactors, the sixth and seventh three-phase disconnectors, which are included with the possibility of switching the second terminals of the first and second three-phase groups of thyristor valves to the poles of the output intended for melting ice with direct current, and the control unit is configured to regulate voltage and reactive power in the mode of static compensator and proportional-integral regulation of the effective value current at the outputs intended for melting ice.

This set of features allows to solve the problem of the invention.

The implementation of the invention

The invention is illustrated by the scheme of a combined installation for melting ice and reactive power compensation, shown in figures 1-3.

The combined installation comprises a three-phase transformer 1, to which are connected: through the first three-phase group of reactors 2, the first bipolar leads of the first and second three-phase groups of thyristor valves 3 and 4, and through the first three-phase disconnector 5, the second three-phase group of reactors 6 and the second three-phase disconnector 7, the second the conclusions of the first three-phase group of thyristor valves 3, which are connected through the third three-phase disconnector 8 to the second terminals of the second three-phase group of thyristor valves 4. The same conclusions four fifth three-phase disconnector 9 connects with the three-phase output Fitting intended for ice melting alternating current. The outputs of the control unit 10 are connected to the control inputs of the first and second three-phase groups of thyristor valves 3, 4. In parallel with the first three-phase group of reactors 2, a fifth three-phase disconnector 11 is connected. Sixth and seventh three-phase disconnectors 12, 13 connected respectively to the second terminals of the first and second three-phase groups of thyristor valves 3 and 4, provide switching with the output of the unit, intended for melting ice with direct current.

The scheme of the adjustable part of the static reactive power compensator (Fig. 1) is formed when the position of the first, second and third three-phase disconnectors 5, 7, 8 and the disconnected position of the fourth, fifth, sixth and seventh three-phase disconnectors 9, 11, 12, 13. Valve groups connected between the two reactors, thus eliminating the rapid increase in current through the valves due to the own capacitance of the transformer inputs and busbars.

The installation circuit for melting ice with controlled direct current (Fig. 2) is formed when the fifth, sixth and seventh disconnectors 11, 12, 13 are turned on and the first, second, third and fourth three-phase disconnectors 5, 7, 8, 9 are turned off. To the poles of the formed the bridge connects the OHL wires to be melted. This installation scheme is proposed to be used for melting ice on long lines connected according to well-known schemes [2]: “two wires-wire”, “wire-wire” and “snake” - “wire-wire-wire”.

The installation diagram of ice melting by controlled alternating current (Fig. 3) is formed when the position of the third and fourth three-phase disconnectors 8, 9 and the disconnected position of the first, second, fifth, sixth and seventh three-phase disconnectors 5, 7, 11, 12, 13. The circuit is proposed use for melting ice on short lines. This method of melting ice is characterized in that it allows the melting of ice on three wires simultaneously controlled by alternating current, which reduces the time of melting ice.

In the control unit 10, when the device is operating in the mode of a static reactive power compensator, known algorithms [2] are used, which are determined by the requirements of the compensator installation conditions. Typically, a voltage regulator and a reactive power regulator are included in the unit.

The control unit 10 when operating in the ice melting mode with direct current uses a constant current regulator of proportional-integral type.

The control unit 10 when operating in the mode of melting ice with alternating current uses a regulator of the effective value of the phase current in the overhead proportional-integral type.

The technical result is:

- to expand the scope of the device for melting ice due to the use of the device as a reactive power compensator;

- in a fuller use of equipment available as part of the installation;

- to reduce the time of melting ice when using the scheme TRG-UPG, as ice is melting at all phases;

- the ability to melt ice at one substation on lines of different sections and lengths thanks to the use of transformable schemes that allow the use of controlled direct or alternating current;

- in the elimination of adverse conditions for thyristor valves when melting ice on short lines due to the use of a circuit for melting ice with alternating current;

- in improving the quality of electricity, i.e. maintaining the required voltage levels in the mode of reactive power compensator.

Information sources

1. Ya.Yu. Soloduho “Static reactive power compensators of leading foreign firms and domestic enterprises” Inform-electro, 1982.

2. L.L. Balyberdin, M.A. Kozlova, Yu.A. Shershnev Managed installations for smelting ice on wires of power lines // New Technologies in Power Engineering, Print Service Group LLC, 2002.

3. Under. ed. P.M. Matura Static reactive power compensators. M .: Energoatomizdat, 1987.

Claims (1)

Combined installation for smelting ice and reactive power compensation, containing a three-phase transformer, to which, through the first three-phase group of reactors, the first bipolar leads of the first and second three-phase groups of thyristor valves are connected, and through the first three-phase disconnector, the second three-phase group of reactors and the second three-phase disconnector, the second leads the first three-phase group of thyristor valves, which are connected through the third three-phase disconnector to the second terminals of the second three-phase group thyristor valves connected through a fourth three-phase disconnector with a three-phase output of the installation, intended for melting ice by alternating current, and a control unit, the outputs of which are connected to the control inputs of the first and second three-phase groups of thyristor valves, while the installation is equipped with an output intended for melting ice current, the fifth three-phase disconnector connected in parallel with the first three-phase group of reactors, the sixth and seventh three-phase disconnectors, which are included in the possibility of switching the second terminals of the first and second three-phase groups of thyristor valves to the poles of the output intended for melting ice with direct current, and the control unit is configured to regulate the voltage and reactive power in the mode of a static compensator and proportionally-integral regulation of the effective value of the current at the outputs intended for melting ice.

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