Nowadays the substations are upgraded with SAS and substations become unmanned.
SAS is the internal Network made inside the Substation. All Protection relays and Bay control units are connected in that network through Industrial Ethernet . This network is controlled and monitor by Station master computers and also this network connected with Station Operator PCs, Station Engineering PCs, GATE WAY computers to control and monitor the substation activities from remote end by SCADA system.
Network
First the network is made section vice according to voltage level. For example all 380kv all protection Relays and Bay control units are connected consider as one group and its connected with two network.
One is main and other one is backup. All relays and BCUs are connected with Industrial Ethernet Switch with fiber optic cable. All Ethernet switches are connected each other in the network.
There are two net work formed for each voltage level . One is main and other one is standby. First network is connected with Station level computer -1 , Gate way computer -1 , Operator work station -1,Engg Station computer , and GPS. Second network is connected Station level computer -2 , Operator work station -2, Gate way computer -2 and GPS.
Protection relays
All numerical relays can connect with SAS network through fiber optic connection. Set-1 Relays ( ABB relays) are grouped for one Ethernet and backup SET-2 relays ( AREVA relays ) are grouped in other Ethernet. All relays should have two fiber connections, one is main and other one is back up ( REDUNDANT PRP).
Non numerical relays are connected with SAS network through RTU.
Bay control units
Bay Control Units is Numerical relay. Fixed in GIS bay Local control panel ( LCC ) .
BCUs are used for Bay equipment operations, Monitor the bay events and Measurement monitor.
a. Bay equipment operations
Bay equipment CB, Disconnectors , Earth switches can Open close according to its Soft and hard wire logic.
Soft logic made inside the BCU. So all open & close status of all equipments in the particular bay should give to BCU. For example to close the breaker in double bus scheme in service condition needs DS status. and for close the DS needs ES status.
Each and every bays can share the status each other through GOOSE signal. This status can monitor in SCADA and SOE.
b. Measurement Monitor
CT,VT inputs can connect with BCU for Current and Voltage monitoring and Synchro Check.
For double bus scheme Bus voltage and line voltage should given to BCU for synchro check function
All voltage related to the bus should give to BCU.
Station master computers
Station master computer is loaded with SAS software Ex.Micro SCADA - ABB. This software is used to connect all IEDs ( Relays ) BCUs and make a way to communicate each other.
SAS engineers download all configuration files from all protection Relays.
ABB relays - PCM -I file for individual relays or PCM - P file for all relays in one project. ( No need *. ICD files)
AREVA relays - *.PLC file ( No need *.SCT file for SAS configuration)
Siemens relays - Device file ( No need Variant file)
SAS engineers will add ( Engineering ) the SAS communication function block in that configurations.All function block in the relay configuration will connected with SAS communication function block. Now this file is called System Configuration Description file ( SCD file).
This SCD files again will uploaded in all protection relays.
Micro SCADA will communicate the relays through this SAS communication function block and get the all Status, Events and voltage current measurement of the relays.
This Events displayed as Alarm list,Event List in the Operator work station PC.
Protection relays can't triggered by using Micro SCADA.
BCUs and Auto Re close RTCC relays configurations allows to receive the command from SAS.
BCUs - Open / Close command
Auto Re close - IN / OUT command
RTCC - Rise / Lower
Station Operator PCs
Station Operator PCs are connected with SAS network for Station equipment operations. The Micro SCADA allows Station operators to Open and Close the Station equipments and monitors Events, Alarms, Measurements through this PC.Station Engineering PCs
Station Engineering PCs are connected with SAS network for Station Protection relays communications. The Micro SCADA allows Station operators to Monitor and upload and download the relay configurations.GATE WAY computers
Station Engineering PCs are connected with SAS network for substation remote Remote access. The Micro SCADA allows Station operators to Open and Close the Station equipments and monitors Events, Alarms, Measurements through this PC in Remote places. SCADA and SOE points are send to NCC through gate way.RTU ( Remote Terminal Unit)
All non numerical relays are communicating with SAS network through RTU.
SAS Photos
