Unlock instant, AI-driven research and patent intelligence for your innovation.

Bipolar balance control method and device for three-terminal DC power transmission system and medium

A DC transmission system and balance control technology, which is applied to emergency protection circuit devices, electrical components, power transmission AC networks, etc., can solve the problems of reducing the minimum operating current and the inoperability of DC transmission systems

Active Publication Date: 2020-09-22
ELECTRIC POWER RESEARCH INSTITUTE, CHINA SOUTHERN POWER GRID CO LTD +1
View PDF5 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the process of implementing the present invention, the inventors found that the prior art has at least the following problems: when performing bipolar balance operation, the current of station C pole 2 is reduced to be equal to the current value of station C pole 1 to eliminate undesired balance current
But because pole 2 is in the three-terminal operation mode, station A and station B are limited by the conventional DC minimum operating current, the minimum current value of station C pole 2 can only be reduced to the sum of the minimum operating currents of station A and station B
If the sum of the minimum operating currents of stations A and B is still greater than the current value of pole 1 of station C after performing the bipolar balancing operation, the bipolar balancing fails, and the DC transmission system will implement bipolar blocking of the three stations, and the DC transmission system cannot run

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Bipolar balance control method and device for three-terminal DC power transmission system and medium
  • Bipolar balance control method and device for three-terminal DC power transmission system and medium
  • Bipolar balance control method and device for three-terminal DC power transmission system and medium

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] A multi-terminal DC transmission system refers to a DC transmission system that contains multiple rectifier stations or / and multiple inverter stations. Its most notable feature is that it can realize multi-power supply, multi-drop power receiving, provide a more flexible power transmission mode, and have various operation modes. In Embodiment 1 of the present invention, see figure 2 , is a schematic structural diagram of a three-terminal bipolar direct current transmission system in Embodiment 1 of the present invention. When the three-terminal direct current transmission system is in the bipolar operation mode of two sending-end converter stations and one receiving-end converter station, the three-terminal direct current transmission system includes sending-end converter station A, sending-end converter station B and receiving end converter station C, station B is an intermediate converter station, and the three stations are connected by overhead lines. Each station...

Embodiment 2

[0062] In Embodiment 2 of the present invention, when the three-terminal direct current transmission system is in a bipolar operation mode with one sending-end converter station and two receiving-end converter stations, the three-terminal direct current transmission system includes a sending-end converter station Station A, receiving-end converter station B, and receiving-end converter station C. When the single pole of a receiving-end converter station is out of operation, the system enters the 2+3 operation mode from the 3+3 operation mode. At this time, part of the operating current of the local pole of the sending-end converter station A will be transferred to the opposite pole. Or it will be lost, which will eventually lead to a large unbalanced current in the bipolar area of ​​the sending end converter station.

[0063] see Figure 4 , is a schematic flowchart of the steps of a bipolar balance control method for a three-terminal direct current transmission system provid...

Embodiment 3

[0072] see Figure 4 , is a schematic structural diagram of a bipolar balance control device for a three-terminal direct current transmission system provided in Embodiment 3 of the present invention. The bipolar balance control device 30 of the three-terminal direct current transmission system described in the embodiment of the present invention includes: an operating current judgment module 31, an operating current boost module 32 and a bipolar balance control module 33; wherein,

[0073] The operating current judging module 31 is configured to, when the three-terminal direct current transmission system is in the bipolar operation mode of two sending-end converter stations and one receiving-end converter station, if any sending-end converter station's own If a pole is out of operation, and a bipolar area fault occurs in the receiving-end converter station, it is judged whether the operating current of the local pole of the other sending-end converter station is less than the ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a bipolar balance control method for a three-terminal DC power transmission system. The method comprises the following steps: when the three-terminal DC power transmission system is in a bipolar operation mode of two sending-terminal converter stations and one receiving-terminal converter station, if the local pole of any one sending-terminal converter station exits operation and a bipolar region fault occurs in the receiving-terminal converter station, judging whether the operation current of the local pole of the other sending-terminal converter station is less than afirst preset current threshold value or not; when the operation current of the local pole of the other sending end converter station is less than a first preset current threshold value, increasing the operation current of the local pole of the other sending end converter station to be equal to the first preset current threshold value, and then controlling the three-end DC power transmission system to execute bipolar balance operation. The invention further discloses a corresponding device and a medium; by adopting the embodiment of the invention, the situation that the three-terminal DC powertransmission system fails to execute the bipolar balance operation can be effectively avoided, and the safe and stable operation of the three-terminal DC power transmission system is improved.

Description

technical field [0001] The invention relates to the technical field of DC engineering control and protection, in particular to a bipolar balance control method, device and medium for a three-terminal DC transmission system. Background technique [0002] The three-terminal conventional HVDC transmission system includes three converter stations, Station A, Station B and Station C. The converter stations have two working modes: rectification mode and inverter mode. Due to the one-way conduction of the thyristor current, the direction of the DC current of the conventional DC converter is fixed. In the system, station A is used as a rectifier station, and station C is used as an inverter station. By adding switches to change the physical connection between the converter and the DC line, the control station B acts as a rectification station or an inverter station, so that the three-terminal DC transmission system forms two different operating modes. The three stations are connect...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H02J3/36H02J3/26H02H7/26
CPCH02H7/268H02J3/26H02J3/36Y02E40/50Y02E60/60
Inventor 郭铸黄伟煌刘涛李桂源彭发喜李岩许树楷
Owner ELECTRIC POWER RESEARCH INSTITUTE, CHINA SOUTHERN POWER GRID CO LTD