Mms Communication Network Deployment - NR Electric PCS-9611 Instruction Manual

object. When retrieving data from IEDs within the substation, the gateways are considered as
servers whereas transmitting data to control centers, the gateways are considered as clients.
Peer-to-peer
This is a non-connection-oriented, high speed type of communication usually between substation
equipment, such as protection relays. GOOSE is the method of peer-to-peer communication.
Substation configuration language (SCL)
A substation configuration language is the number of files used to describe IED configurations and
communication systems according to IEC61850-5 and IEC61850-7. Each configured device has
an IED Capability Description (ICD) file and a Configured IED Description (CID) file. The
substation single line information is stored in a System Specification Description (SSD) file. The
entire substation configuration is stored in a Substation Configuration Description (SCD) file. The
SCD file is the combination of the following items: individual ICD files, SSD file, communication
system parameters (MMS, GOOSE control block, SV control block), as well as GOOSE/SV
connection relationship amongst IEDs.

10.4.3 MMS Communication Network Deployment

To enhance the stability and reliability of SAS, dual-MMS Ethernet is widely adopted. This section
is applied to introduce the details of dual-MMS Ethernet technology. Generally, single-MMS
Ethernet is recommended to be adopted in the SAS of 110kV and lower voltage levels, while
dual-MMS Ethernet is recommended to be adopted in the SAS of voltage levels above 110kV.
Client-server mode is adopted: clients (SCADA, control center and etc.) communicate with the
IEDs via MMS communication network, and the IEDs operate as the servers. IEDs are connected
to clients passively, and they can interact with the clients according to the configuration and the
issued command of the clients.
Three modes for dual-MMS Ethernet (abbreviated as dual-net) are provided as below.
NOTE! Hereinafter, the normal operation status of net means the physical link and TCP
link are both ok. The abnormal operation status of net means physical link or TCP link is
broken.
1. Mode 1: Dual-net full duplex mode sharing the same RCB instance
Net A and Net B share the same report control block (abbreviated as RCB) enabled by the client.
IED sends undifferentiated date through dual-net to the clients. If one net is physically
disconnected, the flag of RCB instance (i.e.: "RptEna" in above figure) is still "true". Only when
both Net A and Net B are disconnected, the flag of the RCB instance will automatically change to
"false".
In normal operation status of mode 1, IED provides the same MMS service for Net A and Net B. If
one net is physically disconnected (i.e.: "Abnormal operation status" in above figure), the working
mode will switch to single-net mode seamlessly and immediately. Network communication
supervision is unnecessary here, and Buffered Report Control Block (abbreviated as BRCB) need
PCS-9611 Feeder Relay
Date: 2014-04-08
10 Communication
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