JPS5845243B2 - Mitsupei Gatachiyokuriyu Henkanshiyo - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a closed type DC power converter that has a configuration that facilitates maintenance, inspection, and replacement in the event of an accident. Concerning conversion stations.

Recently, DC power transmission systems, which have various features compared to AC power transmission systems, are being put into practical use.

Among the equipment in DC converter stations using this power transmission method, thyristor valves have traditionally been indoor, air-insulated, and air-cooled, and in many cases, thyristor valves and their associated control equipment are housed inside buildings. .

On the other hand, in response to demands for larger capacity or higher voltage equipment, oil-insulated and oil-cooled thyristor valves have recently been put into practical use and are being put into commercial operation.

However, the connections between each device in the converter station, namely thyristor valves, DC voltage transformers, DC voltage transformers, transformers, reactors, lightning arresters, disconnectors, etc., are connected to busbars supported by insulator insulation in the air. Or by bushing.

On the other hand, in substations for AC power transmission, SF6 gas-insulated sealed and reduced-sized substations, known as reduced-sized substation equipment, are adopted in order to deal with land shortages, pollution, pollution, earthquakes, etc. There is.

From this point of view, there is a strong demand for SF6 gas insulation of the air insulating portions of the support insulators and bushings, even in DC converter stations.

Particularly regarding pollution, as shown in FIG. 1, the DC pollution flashover voltage a is lower than the AC pollution flashover voltage, so it is important enough to determine the success or failure of DC power transmission.

On the other hand, in an AC substation, the equipment is arranged around the circuit breaker, which is the most important equipment in the substation and therefore requires regular inspection and maintenance, to make it compact and functional.

From this point of view, even in a DC converter station, consideration should be given to the arrangement of each device, focusing on the convenience of the thyristor valve, which is the most important equipment in the converter station and therefore requires regular inspection and maintenance.

At this time, in the DC converter station, DC buses and AC three-phase buses coexist, and in order to increase the voltage, thyristor valves are connected in series, so the arrangement of the buses and equipment must naturally be different. No.

In view of this point, the present invention provides connections between each component device using SF technology.
6. It is an object of the present invention to provide a closed type DC converter station which has a gas insulated pipeline busbar and an arrangement of equipment that allows for easy maintenance, inspection, and replacement in the event of an accident, especially for thyristor valves.

An embodiment of the present invention will be described below with reference to the drawings.

The following embodiments will be explained by taking as an example the main circuit on the positive polarity side of the most common DC converter station shown in FIG.

In this figure 2, TR1 and TR2 are converter transformers, TV
G 1 and TVG 2 are respectively ±125 kV thyristor valve groups assuming that the conversion station is ±250 kV, ■1 to V12 are the thyristor valves that constitute these thyristor valve groups, and the group TVG
1 and TVG2 are connected in series.

LA1 to LA12 are lightning arresters for protecting each thyristor valve V1 to V12 from overvoltage, DCR is a smoothing reactor, and LAl 3. LAl 4 is a reactor DCR, a lightning arrester at the output terminal, DCL is a +250 kV transmission line, and DSl is a disconnector.

Incidentally, on the negative polarity side, the wires are connected in exactly the same way except that the direction of the thyristor is reversed.

FIG. 3 shows a wiring diagram when the devices shown in FIG. 2 are arranged according to the present invention.

Three-phase buses 3φ5US1 and 3φ5US2 connected to converter transformers TR1 and TR2 are arranged in a straight line in the center, and thyristor valves V1. V3
．． V5 and V2. V4. V6 is also the 3-phase bus 3φBUS
2 Thyristor valve group TVG2 on both sides of
Thyristor valve V7°V9. Vl 1 and V8. Vl
0. Vl 2 are arranged respectively.

The three-phase bus lines 3φBUS1 and 3φBUS2 connect the phase rotation busbars at two locations each, so that connections with the thyristor valves disposed on the left and right sides can be easily made.

The positive side single-phase bus 1φBUS 1 of the thyristor valve group TVG1 is connected to the negative electrode of the thyristor valve TVG1 along the three-phase bus 3φBUS 1 , and the negative side bus 1φBUS3 of the thyristor valve group 'I'VG2 is connected to the negative electrode of the thyristor valve TVG1 along the three-phase bus 3φBUS2. The bus line 1φBUS2, which shares the side and the positive side of the thyristor valve group TVG2, is the 3-phase bus line 3φBUS1゜3φBUS
2 are arranged in a straight line, respectively.

The power transmission line DCL is drawn out from the end of the single-phase bus 1φBUS3 near the thyristor valve group TVGZ through the smoothing reactor DCR, and is also connected to the single-phase bus 1φBUS3.
1 is connected to the negative polarity side via a disconnector DS1.

LAI to LA12 and LA13 to LA14 are lightning arresters.

The specific configuration will be explained with reference to FIGS. 4a, b, and c.

3-phase bus 3φBUS1.3φBUS2 and single-phase bus 1φ
BUS2 and 1φBUS3 are SF6 gas insulated conduit busbars, and these are connected to the three-phase busbar 3φBUS by the support frame 11.
1,3φBUS2 is on the lower stage, single phase bus 1φBUS2.1
The φBUS3 is arranged in a substantially horizontal straight line in the upper stage.

The 3-phase bus lines 3φBUS1 and 3φBUS2 are not electrically connected, but they are connected as a conduit and are integrated into one button, and converter transformers TR1 and TR2 are connected from near the center of the line.
3-phase cable line 3φCBI as a connection line to.

3φCB2 is drawn out airtight.

As will be described later, the single-phase bus 1φBUS 1 is air-insulated and I~.

Thyristor valves v1~ arranged on both sides of the busbar group
The V12 has an oil-insulated, oil-cooled, hermetically sealed unit structure, and is movable by being placed on rails 12 laid on the ground.

The housing and smoothing reactor DCR are also sealed and unitized, and can be moved on the rail 12 like the thyristor valve unit.

Management bus group and thyristor valve unit v1 to V1:1
．． - and the smoothing reactor unit 1 - are connected to the DCR by an SF6 gas insulated conduit connection line 13.

That is, the connection points of each pipe bus group, the thyristor valve unit V1 to V12 buttons, and the smoothing reactor unit 1-D.
Short branch pipes 14 and 15 for connection are provided on the connection surfaces of the CRs, respectively, and the short branch pipes 14 and 15 are connected to each other through flexible pipes 16 and 17 for separating the pipeline connection line 13. It is connected by.

The smoothing reactor unit DCR has a short branch pipe 18 for connection on the output side, and this branch pipe 18 is connected to the power transmission line DCL via a flexible pipe 19 for separation and a conduit connection line 20.
It is connected by connecting to the bushing Bg at the end.

Each conduit connection line 13 and 20 is equipped with a protective lightning arrester LAl.
~LA12. LAI 3 and LAI 4 are installed and sealed.

(See Figure 4 b + c) Therefore, thyristor valve unit) V1 to ■12, smoothing reactor unit DCR
The lightning arresters LA1 to LA12 and LA13. L.A.
I4 is the separation flexible tube 16, 17 and 19
By separating the pipes from each other, it is possible to separate them from each other by a distance from the conduit busbar group.

Further, as described above, the positive side single-phase bus IBUs1 of the thyristor valve group TVGI is connected to the thyristor valve unit V2°V4. A bushing 21 provided on the conduit connection line 13 of V6 provides air insulation and is connected to the grounding disconnector DS1.

The negative polarity thyristor valve conversion station also has a completely similar closed configuration.

The single-phase bus 1φBUS1 is normally grounded via the switch DS1, so it is air-insulated, but it may be a sealed bus in consideration of reverse polarity operation.

In this case, the single-phase bus 1φBUS 2 will be grounded via the switch.

Further, when a failure occurs in either the thyristor valve groups TVG1 or TVG2, the failed thyristor valve group of TVGl or TVG2 may be short-circuited to transmit power at half the voltage.

In preparation for this case, install a sealed switch on the single-phase bus 1φB.
Between US1 and 1φBUS2 or between 1φBUS2 and 1φBUS
It may be provided between 3.

As described above, in the present invention, a three-phase AC bus bar and a single-phase DC bus bar are arranged as a linear gas-insulated pipeline bus bar, and sealed movable thyristor valve units are installed on both sides of these bus bar groups. The thyristor valve units are arranged separately according to their polarity, and the thyristor valve units are separably connected using a gas-insulated conduit connection line incorporating a protective lightning arrester, making it easier to maintain regular maintenance of the thyristor valves, which are the most important equipment. Inspection, repair in the event of an accident, or replacement with a spare thyristor valve can be easily performed.

Moreover, one thyristor valve group and one transformer
One sealed three-phase busbar and two sealed single-phase busbars can be connected, and one of the single-phase busbars can be shared when there are multiple thyristor valve groups, which has the advantage of saving installation space. be.

[Brief explanation of drawings]

Figure 1 is a comparison diagram of AC pollution floodover characteristics and DC pollution floodover characteristics, Figure 2 is a positive polarity main circuit connection diagram of a DC converter station, and Figure 3 is an implementation of the present invention corresponding to Figure 2. Wiring diagram based on sealed equipment arrangement as an example, Part 4
Figure a is a plan layout configuration diagram of Figure 3, and the same figure is A-A in Figure a.
Figure C is a view taken along the line B--B of figure a. TR1, TR2; Converter transformer, TVGl. TVG2; Thyristor valve group, ■1 to V12;
Thyristor valve unit, LA1 to LA14; Lightning arrester, DCR; Smoothing reactor, DCL; DC transmission line, DSl; Disconnector, 3φBUS1.3φBUS2; 3-phase AC bus, 1φBUS1 to 1φBUS3; DC single-phase bus, 11; Support frame , 12; Rail, 13, 20; Gas insulated pipe connection line, 14, 15, 18; Short branch pipe, 16゜1
7.19; Flexible tube.

Claims (1)

[Claims] The 13-phase AC bus and the output side DC single-phase bus are each a straight gas-insulated conduit bus, and the ground-side DC single-phase bus is a straight gas-insulated conduit bus or air insulation. thyristor valve units sealed on both sides of the busbar group and movable so as to be separated from the busbar group are arranged separated by polarity, and a sealed thyristor valve unit that is arranged in line with the thyristor valve unit and connected to the DC power transmission line. A thyristor valve group is provided, in which a smoothing reactor unit is disposed, and the smoothing reactor unit button and each of the thyristor valve units are separably connected by a connection line of a gas insulated conduit provided with a protective sealed lightning arrester. Closed DC converter station. 2. When the thyristor valve groups mentioned in item 1 are connected in series, the gas insulated pipes of the three-phase busses of these groups should be connected in a straight line, and the output side single-phase bus of the low-potential group and the high-potential A closed DC converter station with a common single-phase bus on the input side of the side groups and arranged in a straight line.