CN-114629085-B - Method for protecting and controlling multiplexing of communication channels between stations of multi-terminal direct current transmission system

CN114629085BCN 114629085 BCN114629085 BCN 114629085BCN-114629085-B

Abstract

The invention discloses a method for protecting and multiplexing control communication channels among stations of a multi-terminal direct current transmission system, which comprises n converter stations S1, S2, and S.C., wherein each converter station is internally provided with a control unit and a protection unit, the protection units of different converter stations realize the transmission of protection signals through the protection communication channels among the two stations, the control units of different converter stations realize the transmission of control signals through the control communication channels among the two stations, the inter-station protection communication channels and the control communication channels are mutually multiplexed and redundant, when the protection communication channels fail, the protection signals are transmitted through the control communication channels, and when the control communication channels fail, the control signals are transmitted through the protection communication channels. The invention further improves the reliability of communication between stations of the multi-terminal direct current transmission system, does not change the hardware architecture of the direct current control protection system and does not need additional investment.

Inventors

WANG DAQUAN
YANG HAO
YANG JIANMING
ZHAO JIANHUA
ZHANG XIONG

Assignees

南京南瑞继保电气有限公司
南京南瑞继保工程技术有限公司

Dates

Publication Date: 20260505
Application Date: 20201210

Claims (2)

1. A method for protecting and multiplexing control communication channels between stations of a multi-terminal direct current transmission system comprises n convertor stations S1, S2, and Sn, wherein each convertor station is internally provided with a control unit and a protection unit, the protection units of different convertor stations realize the transmission of protection signals through the protection communication channels between every two convertor stations, and the control units of different convertor stations realize the transmission of control signals through the control communication channels between every two convertor stations. There are two path options for the station-to-station protection communication of the converter station Si and the converter station Sj, where 1≤i < j≤n: A path (1) for protecting a direct communication channel between the stations of the converter station Si and the converter station Sj or for protecting a communication channel between the stations of the converter station Si and the converter station Sj, which is detoured by a third station; The protection action signal of the converter station Si is firstly transmitted to the control unit of the self-station, and then the protection action signal is transmitted to the converter station Sj through a direct connection control communication channel Si-Sj from the converter station Si to the converter station Sj or a station-to-station control communication channel detoured by a third station; path (1) and path (2) take or logic; when a junction converter station Sj generates a bus protection action, a control unit of the junction converter station Sj is used for locking a converter valve of the junction converter station and tripping an alternating current breaker of the junction converter station, protection action signals are transmitted to other converter stations Si connected with the bus, and a communication path (1) or a path (2) is selected to realize transmission of the inter-station protection action signals.
2. The method for multiplexing the protection and control communication channels between stations of the multi-terminal direct current transmission system according to claim 1, wherein the control communication between the stations of the converter station Si and the converter station Sj has two path selections, wherein i < j < n: a path (a) of an inter-station control communication direct channel between the converter station Si and the converter station Sj, or an inter-station control communication channel between the converter station Si and the converter station Sj which is detoured by a third station; the control signal of the converter station Si is firstly transmitted to the self-station protection unit, and then the control signal is transmitted to the converter station Sj through a direct connection protection communication channel Si-Sj from the converter station Si to the converter station Sj or a station-to-station protection communication channel detoured by a third station; path (a) and path (b) take or logic.

Description

Method for protecting and controlling multiplexing of communication channels between stations of multi-terminal direct current transmission system Technical Field The invention relates to a method for protecting and controlling multiplexing of communication channels between stations, in particular to a method for protecting and controlling multiplexing of communication channels between stations of a multi-terminal direct current transmission system. Background In the conventional design of control protection inter-station communication of the existing multi-terminal direct current transmission system, an inter-station protection communication channel and an inter-station control communication channel are mutually independent in actual use of the channels although the inter-station protection communication channel and the inter-station control communication channel are physically connected. When the junction station of the multi-terminal direct current transmission system generates a bus protection action, the control device of the junction station is used for locking the current conversion valve of the junction station and the alternating current breaker of the junction station, and an action signal is transmitted to other stations connected with the bus and locking the current conversion valves of the other stations. In the prior art, for the inter-station protection communication channel, the transmission of the bus protection action signal is realized only through the inter-station protection communication channel, if all the inter-station protection communication channels associated with the hub station are failed or stopped, the protection action signal of the hub station cannot be transmitted to other stations, for the inter-station control communication channel, the transmission of the control signal is realized only through the inter-station control communication channel, and if all the inter-station control communication channels associated with the signal sending station are failed or stopped, the signal cannot be transmitted to other stations, so that the reliability of the correct transmission of the protection communication and the control communication between the stations of the multi-terminal direct current transmission system is lower. Disclosure of Invention The invention aims to provide a method for protecting and controlling multiplexing of communication channels between stations of a multi-terminal direct current transmission system, which realizes cross detour transmission of signals and has high transmission reliability. The multi-terminal direct current transmission system comprises n converter stations S1, S2, and Sn, wherein the converter stations are connected through a bus bar, a control unit and a protection unit are arranged in each converter station, the protection units of different converter stations realize transmission of protection signals through protection communication channels between every two stations, the control units of different converter stations realize transmission of control signals through control communication channels between every two stations, the protection communication channels between the stations and the control communication channels between the stations are mutually multiplexed and redundant, when the protection communication channels fail, the protection signals are transmitted through the control communication channels, and when the control communication channels fail, the control signals are transmitted through the protection communication channels. There are two path options for the station-to-station protection communication of the converter station Si and the converter station Sj, where 1≤i < j≤n: The protection action signals of the converter station Si are firstly transmitted to the control unit of the station, then are transmitted to the converter station Sj through the direct connection control communication channel Si-Sj of the converter station Si or the inter-station control communication channel of the third station detour, and the protection action signals are transmitted to the converter station Sj through the path (1) and the path (2) to get OR logic. When a bus bar protection action occurs to a certain hub converter station Sj, a control device of the station is used for locking a converter valve of the station and tripping an alternating current breaker of the station, protection action signals are transmitted to other converter stations Si connected with the bus bar, and a communication path (1) or a path (2) is selected to realize transmission of the inter-station protection action signals. There are two path options for control communication between the converter station Si and the converter station Sj, where 1≤i < j≤n: The control signal of the converter station Si is firstly transmitted to the protection unit of the station, and then is transmitted to the converter station Sj through the direct connection protection commun