CN106532754A - Voltage selection equipment of inverter station in high-voltage DC power transmission system and operation method of voltage selection equipment - Google Patents

Abstract

A voltage selection device for an inverter station in a high-voltage direct current transmission system, including a circuit breaker assembly and an isolating switch assembly. The first group of circuit breakers and the third group of circuit breakers in the circuit breaker assembly are installed on the first busbar, and the second group of circuit breakers is disconnected The circuit breaker and the fourth group of circuit breakers are installed on the second busbar, the first group of circuit breakers and the second group of circuit breakers are installed between pole 1 and pole 2, the third group of circuit breakers are installed on the first group of circuit breakers and address 2, the fourth set of circuit breakers is installed between the second set of circuit breakers and address 2, and each isolating switch in the isolating switch assembly is installed on the outgoing line of address 1 on the pole 1 side. The invention ensures that the voltage control of the inverter station can operate reliably under different operating modes.

Description

Inverter station voltage selection equipment and its operation method in HVDC transmission system

technical field

The invention relates to a voltage selection device of an inverter station in a high-voltage direct current transmission system and an operation method thereof.

Background technique

Long-distance transmission problems will be encountered when electric energy is transmitted from large-scale thermal power, hydropower and other power plants to remote load center areas. To achieve long-distance high-power transmission, ultra-high voltage or ultra-high voltage transmission technology is required. UHV AC transmission is currently the most basic long-distance power transmission method at home and abroad, while UHV DC transmission does not have synchronization stability problems, and is an ideal way for large-area grid interconnection.

Compared with AC transmission, the advantages of DC transmission are: long-distance high-power transmission, DC transmission is not restricted by the stability of synchronous operation, and plays a great role in ensuring the stable operation of the AC grid at both ends; the use of DC transmission can achieve The asynchronous interconnection of the domestic regional network or the international network divides the large system into several AC systems that can obtain networking benefits and be relatively independent, avoiding the problems caused by the AC power system with excessive total capacity; AC power When the system is interconnected or the capacity of the distribution network is increased, the DC transmission control system has the characteristics of fast adjustment and good control performance, which can effectively limit the short-circuit current and keep it basically stable. It can be used as a measure to limit the short-circuit current; When the power supply distance reaches a certain level, it is more economical to use high-voltage DC cables. At the same time, the DC transmission method can also be used as a measure to limit the increase in the short-circuit current of the urban power supply grid.

Therefore, UHV DC transmission not only has the characteristics of conventional DC transmission, but also can well solve some existing problems in our country: the distribution of primary energy in China is very uneven, 2/3 of water resources are distributed in the southwest region, and 2/3 of coal mine resources Distributed in Shaanxi, Shanxi and the west of Inner Mongolia, and the demand for electricity is relatively concentrated in the eastern, central and southern regions with better and faster economic development. The distance between the energy production area and the demand area is 1000~2500km. East-to-East power transmission, realize north-south mutual supply, national networking, UHV DC transmission is more economical in long-distance power transmission, and the control and protection are flexible and fast, which is a better way to realize north-south mutual supply; the eastern, central and southern regions of China are the economic In developed areas, there is a large demand for electricity and a relatively high growth rate of electricity load. UHV DC transmission can achieve large-capacity transmission. The planned UHV DC transmission project has a power transmission capacity of up to 5GW and 6.4GW. It will reach 3125A and 4000A, which can better meet the needs of west-to-east power transmission; due to the pressure of China's land and environmental protection, large-capacity and long-distance power transmission can be realized through UHV DC, which can save line corridors and alleviate the impact caused by the development of electric power. shortage of land resources.

Different from the conventional EHVDC power transmission project, after the DC power transmission is completed from the rectifier station to the inverter station, the inverter station needs to supply electricity to different places. According to actual needs, it may all be sent to one place (address 1), Either send it all to another place (address 2), or send it to both places at the same time.

Contents of the invention

The invention provides a voltage selection device for an inverter station in a high-voltage direct current transmission system and an operation method thereof, which ensures reliable operation of the voltage control of the inverter station in different operating modes.

In order to achieve the above purpose, the present invention provides a voltage selection device for an inverter station in a HVDC power transmission system, comprising:

Circuit breaker assembly, which includes four groups of circuit breakers, the first group of circuit breakers and the third group of circuit breakers are installed on the first busbar, the second group of circuit breakers and the fourth group of circuit breakers are installed on the second busbar, the first group of circuit breakers Both circuit breakers and the second group of circuit breakers are installed between pole 1 and pole 2, the third group of circuit breakers are installed between the first group of circuit breakers and address 2, and the fourth group of circuit breakers are installed between the second group of circuit breakers and pole 2 between address 2;

The isolating switch assembly includes a plurality of isolating switches, and each isolating switch is respectively installed on the outgoing line of address 1 on the pole 1 side.

The first group of circuit breakers includes n circuit breakers connected in series, and the value of n is greater than or equal to 1.

The second group of circuit breakers includes n circuit breakers connected in series, and the value of n is greater than or equal to 1.

The third group of circuit breakers includes n circuit breakers connected in series, and the value of n is greater than or equal to 1.

The fourth group of circuit breakers includes n circuit breakers connected in series, and the value of n is greater than or equal to 1.

The voltage selection device further includes: a high-voltage voltage transformer assembly, which includes two high-voltage voltage transformers, the first high-voltage voltage transformer is installed on the busbar on the pole 1 side, and the second high-voltage voltage transformer is installed on the pole 2 side on the bus.

The present invention also provides an operating method of a voltage selection device, which uses the voltage selection device to select voltages for different operating modes:

When the inverter station needs to deliver all the power of pole 1 and pole 2 to address 1, close the first circuit breaker and the second circuit breaker, open the third circuit breaker and the fourth circuit breaker, and close all the isolation switches , so that all circuit breakers in the inverter station are closed;

When the inverter station needs to transmit all the power of pole 1 and pole 2 to address 2, the first circuit breaker, the second circuit breaker, the third circuit breaker and the fourth circuit breaker are all turned off, and all the isolating switches are turned off. Open, so that all the circuit breakers connected on both sides of the outlet point of address 1 are all disconnected, and the rest of the circuit breakers in the inverter station are kept closed;

When the inverter station needs to transmit the power of pole 1 to address 1 and the power of pole 2 to address 2, the first circuit breaker and the second circuit breaker are opened, and the third circuit breaker and the fourth circuit breaker are closed. , so that all disconnectors are closed and all circuit breakers in the inverter station are closed.

The present invention adopts the circuit breaker assembly and the isolating switch assembly to realize that all the voltage of the inverter station is sent to address 1, or all the voltage is sent to address 2, or part of the voltage is sent to address, and part of the voltage is sent to address 2, ensuring This ensures that the voltage control of the inverter station in different operating modes can operate reliably.

Description of drawings

Fig. 1 is a schematic diagram of an inverter station voltage selection device in a HVDC power transmission system provided by the present invention.

2 to 4 are schematic diagrams of the voltage selection device working in different working modes.

detailed description

A preferred embodiment of the present invention will be specifically described below with reference to FIGS. 1 to 4 .

As shown in Figure 1, in a preferred embodiment of the present invention, the present invention provides a voltage selection device for an inverter station in a HVDC power transmission system, including:

The circuit breaker assembly includes four circuit breakers, the first circuit breaker 201 and the third circuit breaker 203 are installed on the first bus 11, the second circuit breaker 202 and the fourth circuit breaker 204 are installed on the second bus 22, the second A circuit breaker 201 and a second circuit breaker 202 are installed between pole 1 and pole 2, a third circuit breaker 203 is installed between the first circuit breaker 201 and address 2, and a fourth circuit breaker 204 is installed in the second circuit breaker Between 202 and address 2;

A high-voltage voltage transformer PT assembly, which includes two high-voltage voltage transformers, the first high-voltage voltage transformer 301 is installed on the busbar on the pole 1 side, and the second high-voltage voltage transformer 302 is installed on the busbar on the pole 2 side;

The isolating switch assembly includes a plurality of isolating switches 401, and each isolating switch 401 is respectively installed on the outgoing line of address 1 on the pole 1 side.

Voltage selection for different operating modes using a voltage selection device:

As shown in Figure 2, when the inverter station needs to deliver all the power of pole 1 and pole 2 to address 1, the first circuit breaker 201 and the second circuit breaker 202 are closed, and the third circuit breaker 203 and the fourth circuit breaker 204 is turned off, so that all the isolating switches 401 are closed, so that all the circuit breakers 5 in the inverter station are closed.

As shown in Figure 3, when the inverter station needs to deliver all the power of pole 1 and pole 2 to address 2, the first circuit breaker 201, the second circuit breaker 202, the third circuit breaker 203 and the fourth circuit breaker 204 All disconnection, so that all isolating switches 401 are disconnected, all circuit breakers 5 connected to both sides of the outlet point of address 1 are all disconnected, and the remaining circuit breakers 5 in the inverter station are kept closed.

As shown in Figure 4, when the inverter station needs to transmit the power of pole 1 to address 1 and the power of pole 2 to address 2, the first circuit breaker 201 and the second circuit breaker 202 are turned off, and the second circuit breaker 201 is opened. The third circuit breaker 203 and the fourth circuit breaker 204 are closed, so that all the isolation switches 401 are closed, so that all the circuit breakers 5 in the inverter station are closed.

The present invention adopts the circuit breaker assembly and the isolating switch assembly to realize that all the voltage of the inverter station is sent to address 1, or all the voltage is sent to address 2, or part of the voltage is sent to address, and part of the voltage is sent to address 2, ensuring This ensures that the voltage control of the inverter station in different operating modes can operate reliably.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the above disclosure. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims (7)

1. Inverter Station voltage selection device in a kind of HVDC transmission system, it is characterised in that include：

Breaker assembly, which includes four groups of breakers, and first group of breaker and the 3rd group of breaker are arranged on the first bus（11） On, second group of breaker and the 4th group of breaker are arranged on the second bus（22）On, first group of breaker and second group of breaker All it is arranged between pole 1 and pole 2, the 3rd group of breaker is arranged between first group of breaker and address 2, the 4th group of breaker peace It is mounted between second group of breaker and address 2；

Switch component, which includes multiple disconnecting switch（401）, each disconnecting switch（401）It is separately mounted to 1 side of pole ground In the outlet of location 1.

2. Inverter Station voltage selection device in HVDC transmission system as claimed in claim 1, it is characterised in that described Breaker of first group of breaker comprising n series connection, the value of n are more than or equal to 1.

3. Inverter Station voltage selection device in HVDC transmission system as claimed in claim 1, it is characterised in that described Breaker of second group of breaker comprising n series connection, the value of n are more than or equal to 1.

4. Inverter Station voltage selection device in HVDC transmission system as claimed in claim 1, it is characterised in that described Breaker of the 3rd group of breaker comprising n series connection, the value of n are more than or equal to 1.

5. Inverter Station voltage selection device in HVDC transmission system as claimed in claim 1, it is characterised in that described Breaker of the 4th group of breaker comprising n series connection, the value of n are more than or equal to 1.

6. Inverter Station voltage selection device in the HVDC transmission system as described in any one in claim 1-5, which is special Levy and be, described voltage selection device is also included：High voltage potential transformer component, which includes two high voltage potential transformers, First high voltage potential transformer（301）On the bus of 1 side of pole, the second high voltage potential transformer（302）Installed in 2 side of pole Bus on.

7. a kind of operation method of voltage selection device as claimed in claim 6, it is characterised in that adopt voltage selection device Voltage selection is carried out to different operational modes：

When Inverter Station needs for the power of pole 1 and pole 2 to be all delivered to address 1, the first breaker is made（201）It is breaking with second Device（202）Closure, the 3rd breaker（203）With the 4th breaker（204）Disconnect, make all of disconnecting switch（401）Closure, makes All breakers in Inverter Station（5）All close；

When Inverter Station needs for the power of pole 1 and pole 2 to be all delivered to address 2, the first breaker is made（201）, it is second breaking Device（202）, the 3rd breaker（203）With the 4th breaker（204）It is all off, make all of disconnecting switch（401）Disconnect, make It is connected to all breakers of the outlet point both sides of address 1（5）It is all off, make remaining breaker in Inverter Station（5）Keep Closure；

When Inverter Station needs the power of pole 1 is delivered to address 1 respectively, when the power of pole 2 is delivered to address 2, first is made to break Road device（201）With the second breaker（202）Disconnect, the 3rd breaker（203）With the 4th breaker（204）Closure, makes all of Disconnecting switch（401）Closure, makes all breakers in Inverter Station（5）All close.