RU1823933C - Electric power line - Google Patents

Abstract

Usage: in power lines with a device for melting ice. The inventive device for melting ice is made in the form of two three-phase sources of reactive power, one of which is a consumer of reactive energy, and the other a generator connected at the ends of the ice melting section and forming a parallel oscillatory circuit close to resonant currents. A reactive power source, which is a reactive energy generator, can be installed at the receiving end of the ice melting section, and a reactive power source, which is a reactive power consumer, can be installed at the starting end of this section. The device for melting ice can be provided with an additional source of reactive power, the sign of which coincides with the power sign of one of the sources of reactive power, with sources of reactive power of one sign located at the ends of the ice melting section, and a source of reactive power of another sign between them. A source of reactive power common to all sections of ice melting can be installed at the starting end for several sections of ice melting, and the source of reactive power of a different sign is made in the form of several sources of reactive power that are distributed at the ends of the sections of ice melting. Reactive power sources can be made according to the scheme of a triangle or a star with an isolated neutral. 4 c.p.f., 4 ill., 2tab

Description

The invention relates to the electric power industry and can be used for melting ice on wires of overhead power lines (OHL) of power transmission or for their preventive heating without disconnecting consumers.

The purpose of the invention is to simplify and increase the reliability of the gas-discharge unit by enabling the use of simple and reliable standard elements, for example, batteries of static capacitors and reactors, and other sources of reactive power;

increasing the cost of smelting ice by reducing the loss of active power in the device itself and reducing power and voltage losses in the transmission path of active power for melting ice by generating and consuming reactive power in the ice melting sections themselves and maintaining the voltage at the receiving ends of these sections in permissible limits;

increasing the selectivity and efficiency of smelting ice on VL sections that are part of any circuit circuit in a network with both isolated and grounded neutCO

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rails, due to the exclusion of melting on overhead lines parallel to the ice melting section and not requiring this melting, as well as due to localization of reactive power flows during ice melting on radial lines consisting of consecutive sections or departing from the common tires of a substation or power station, realizable (localization) by installing one source of reactive power of one sign common to all ice melting sections and reactive power sources of another sign at the end of each of these sections;

suppression in the power system of odd harmonics that are multiples of the third harmonic and due to possible asymmetry of the output voltage of the power source realized by performing reactive power sources according to the triangle pattern;

elimination of energy losses in the working grounding devices and the costs of their creation and operation, as well as the exclusion of electromagnetic influence on communication channels;

multipurpose use of reactive power sources (for melting ice and maintaining a normal voltage level in the network);

As a result of solving this problem, a technical result is achieved consisting in creating a melting current (substantially exceeding the operating current) only in the ice melting section, while only the load current and the current corresponding to the power consumed in the ice melting flow in the head sections of the power transmission.

The solution of the problem and the receipt of the specified technical result is ensured by the fact that in the power line with a gas generator integrated in the circuit, which covers the ice melting section, the gas generator is made in the form of two three-phase reactive power sources, one of which is a consumer of reactive energy, and the other - its generator, connected at the ends of the ice melting section and forming a parallel oscillatory circuit with it, tuned to a mode close to the current resonance. In this case, the reactive power source, which is a generator of reactive energy, can be installed at the receiving end of the gas-turbine unit, and the reactive power source, which is its consumer. - at the starting end of this section. The UPG can be equipped with an additional source of reactive power, the sign of which coincides with the sign of the power of one of the sources of reactive power, with reactive power sources of one sign located at the ends of the ice melting section, and the reactive power source of another sign

between them. At the starting end for several sections of ice melting, a reactive power source that is common to all sections of ice melting and a reactive power source of another

0 sign can be made in the form of several sources of reactive power, which are distributed at the ends of the ice melting sections.

Figure 1 shows an example of a single-circuit three-phase power transmission circuit, one of the sections of which is equipped with a gas-turbine unit; Fig. 2 is an example of a power transmission circuit comprising parallel sections of overhead lines, one of which is to be heated; on the

0 FIG. 3 is an example of a power transmission circuit containing three heated sections B L; figure 4 - diagram and transmission parameters with a section of melting ice in its middle part, for which the calculations were performed

5 electrical quantities in normal mode and in ice melting modes.

The overhead line, which is part of a power system with transmitting 1 and receiving 2 parts (Fig. 1), contains ice melting section 3, flowed by Inr current. Reactive power sources 4 and 5 are included at the ends of section 3. Reactive power source 4 is in this case a reactive energy consumer, and source 5 is a reactive energy generator. Sources 4 and 5 may be included in a delta or star pattern and constitute the UPG 6.

When the power transmission (figure 2) contains a plot of 3 melting ice and parallel

In addition to sources 4 and 5, section 3 is equipped with a third reactive power source 9, which for this case is a consumer of reactive energy, and sources 4 and 5 are reactive energy generators.

In the case where the power transmission (FIG. 3) contains three heated sections 3, the UPG 6 contains a common for sections 3

0 reactive power source 10, which in this case is a consumer of reactive energy, and reactive power sources 4, 9, 5 of a different sign, which in this example are reactive energy generators 5 and switched on at the receiving ends of heated sections 3. Ice is melted as follows . When deciding on ice melting, taking into account the direction of the flow of active power P from the transmitting 1 part

power systems and, therefore, reduced compared to the voltage at the head node of the voltage section 3 in the final node of this section include sources 5 (e.g. capacitors) and 4 (e.g. reactors) exchanging reactive power in circuit 4-3-5. moreover, the melting current of ice 1Pg in section 3 is determined by the melting conditions of the ice under given atmospheric conditions and should not exceed the largest allowable melting current. Other sections of the power transmission are surrounded by load currents, and active power is also transmitted through the head section of the power transmission, which is used for melting ice (see table).

In the particular case, switching places of reactive power sources 5 and 4 can be justified.

If it is necessary to melt ice on only one of two parallel overhead lines (section 3 in FIG. 2), they include sources 4 and 5 of reactive power of the same sign (for example, capacitors) at its ends and between them - a third source 9 of reactive power, but sign (reactor) and set up two parallel oscillatory circuits - circuits 4-9 and 9-5. With such a scheme, ice smelting is carried out selectively only in section 3, and sections 7 and 8 of parallel OHL are surrounded only by load currents.

If it is necessary to melt ice simultaneously in several sections located consecutively and on different radial overhead lines (Fig. 3), a common reactive power source 10 (reactor) is installed on the substation's tires common to these sections, and at the end of each section - source 4 , 9 and 5 of reactive power of another sign, in power corresponding to the melting current of this particular area. (Such an UPG circuit is rational if the current 1Pg of the subsequent ice melting section does not exceed the current 1Pg of the head section through which the total active ice melting power flows).

The calculation results of the parameters of the normal mode (P1), ice melting modes with one (condenser) (P2) and

two sources (reactor and capacitor) (RE) of reactive power for the power circuit shown in Fig. 2 are shown in the table.

The table also shows the results of the calculation of the normal mode (P4) using part of the power of the reactive power source (capacitors) in node B.

Claims (5)

1. A power line containing an ice melting device included in a circuit having an ice melting section, characterized in that the ice melting device is made in the form of two three-phase reactive power sources, one of which is a consumer of reactive energy, and the other its generator, connected at the ends of the ice melting section and forming with it a parallel oscillatory circuit close to the resonance of the currents. 2. The line according to claim 1. characterized in that the reactive power source, which is a reactive energy generator, is installed at the receiving end of the ice melting section, and the reactive power source, which is a consumer of reactive energy, is installed at the starting end of this section. 3. The line according to claim 1. characterized in that the device for melting ice is provided with an additional source of reactive power, with reactive power sources of one sign located at the ends of the melting section of ice, and a source of reactive power of a different sign installed between them. 4. The line according to claim 1. characterized in that a reactive power source that is common to all ice melting sections is installed at the outlet end for several ice melting sites, and the reactive power source of a different sign is made in the form of several reactive power sources that are distributed at the ends of the ice melting sections. 5. Lines popp.1,3i4, characterized in that the reactive power sources are made according to the scheme of a triangle or a star with an isolated neutral. -tfZhE. 0-gd .HEZH #  . v WC-KDifDKMb-S / IC-Wi 20 KM r b SS-B No. FIG. Z J tone Lij Ifff 3MM Ifr hLS 50; 5km MM Sg-i. G ce FIG. 4