OPEN SUBSTATION AUTOMATION SYSTEM (OSAS)
Prepared By: Shamsheer.T Electrical Engineer Energy & Power Contracting Co. Ltd. Al khobar-KSA
Contents
Introduction
Substation Automation Objective
Traditional SCDA System
OSAS Concept & Components
OSAS Overview & Architecture
OSAS Applications
OSAS Implementation
Merits of OSAS
Introduction
Substation automation was introduced over the last 30years
More than 4000 systems have been installed word wide.
This was based on proprietary serial communication with conventional copper wiring.
With advent of IEC61850 there is a comprehensive global standard for all communication needs in the sub station being introduced now.
IEC 61850
Very big commercial impact “saving “saving millions of dollars”
Substation Automation Objective of automation: automation :
Control
Monitor &
Protect ion
substation equipment must be monitored and controlled for increased reliability, reduced fault restoration times, and balanced electrical demand with available generation Protects high voltage equipments from faults, disturbances, and overloading on the power grid, and optimizes power to utility customers.
Traditional SCADA System Components: Master station, RTUs, IEDs, transducers & sensors. Master Station: Provides the primary operator interface and manages overall system functions, collecting and analyzing data from RTUs, as well as initiating control actions. RTUs: Detects timestamps, and and logs set-point and and I/O events. IEDs, transducers & sensors: measure power, energy, voltage, current, etc.
Traditional SCADA System
Traditional SCADA System Drawback:
Expensive
Master station hardware & software are designed using expensive proprietary systems.
Additional investment for training and maintenance
As the RTU is the central device, many features are to be added to improve reliability
RTU enhancements are very expensive
Open Substation Automation System Concept System comprised of Web enabled software and intelligent IEDs & control devices.
Monitor, record calculate & analyze hundreds of data points in real time
Provide status monitoring
Automatic control, alarm and advanced power quality analysis with OSAS IED.
Open System: A computer system
Open Substation Automation System (OSAS) Components:
Software Applications
Network Communications
Intelligent Electronic Devices (IED)
Gateways/Servers
OSAS (Compnents…) Software Applications: A powerful suite of flexible, user friendly software applications and graphical user-interface modules are available. These advanced user interfaces and easy to configure tools enable improved date reporting and database configuration management. Network Communications: A range of network components are available to tie new and legacy equipment into one unified system. Provide secure and reliable communications media based on experience and expertise in numerous network systems. IEDs:: IEDs
Any device that incorporates one or more processors
Receive or send data/control from or to an external source
OSAS IEDs can be programmed to perform automatic control, alarm and power quality analysis
OSAS Components Gateways/Servers: Robust system for monitoring and controlling devices as well as for performance automation, IED gateways and host communication functions Monitors & Sensors: Remote monitoring monitoring and critical critical fault detection is achieved. Feeder Automation:
Distribution automation remote terminals equipped with autosectionalising and automation restoration
Software can dramatically reduce a customer’s outage frequency.
OSAS Overview System with conventional equipments
Use conventional wiring to the process
OSAS Overview System with non conventional c onventional instrument transformers and modern switchgear Serial point-to-point connections (IEC 61850-9) from primary equipments to the relays
IEC 61850 Substation Architecture
Substation Automation using OSAS Radio Communications Control Center
Ethernet Substation A
HUB
Se rvi ce Entra nce Status input
Se rvi ce Entra nce
Brea ke r
Status input
Brea ke r
Radio Modem Tap Control
OSAS Advanced IED Gateway Modbus Master
Transformer
Tap Control Status input
PT CT RS-485
RS-485
Transformer
RS-485
PT CT RS-485
Breaker OSAS Basic IED OSAS Master Station
RS-485
OSAS Basic IED Breaker
Sta tus i nput RS-485
Modem
Brea ke r
Sta tus i nput
Feeder A
Rela y
Status input
Feede r B
Brea ke r
RS-485 Rela y
Rela y
Feede r C
Telephone System Substation B
Brea ke r
Status input RS-485
RS-485
Relay
OSAS Basic IED
OSAS Basic IED
Feede r D
Radio Communications Substation C
Service Entrance Entrance Modem
Servi ce Entrance Entrance
Radio Modem
OSAS Advanced IED Gateway
OSAS Advanced IED Gateway
RS-485
RS-485
OSAS Basic IED
OSAS Basic IED
Feeder A
Feeder B
Feeder C
Feeder D
Feeder A
Feeder B
Feeder C
Feeder D
Application1:Substation Automation using OSAS
Control Center: Center: master station runs operations software on a PC-based windows xp/2000 server OSAS software communicates to
Substation A via an Ethernet link
Substation B via a telephone modem
Substation C has a wireless radio link to the control center
Substation Automation using OSAS Advanced OSAS IED:
Highly accurate revenue billing
Communication mastering functionality
Control and equipment monitoring functionality
OSAS Basic IED:
Monitor each feeder
Provide real time power and energy, power quality, I/O and alarm information
Feeder information is sent back to the master station through Ethernet gateway located in OSAS advanced IED
Application 2: OSAS System to supplement RTUBased SCADA System Control Center
OSAS Master Station
Ethernet
Power Quality Monitoring
Master SCADA
Ethe rne t
Substation A
Ethe rne t HUB
RS-485 Breaker Remote Terminal Unit
Ethernet
Modbus or DNP
Transformer PT
OSAS Advanced IED
CT
Modbus or DNP
PT CT
Breaker
PT
Modbus or DNP OSAS Basic IED
OSAS Basic IED
CT
Breaker
OSAS System to su supplem pplement ent RTURTU- Based SCADA SCADA System
Traditional SCADA system communicate with RTU
OSAS operations software station station ( in master station) communicate directly with the OSAS IEDs
OSAS IEDs Within the substation:
Provide information to multiple destinations
Provide real-time data to RTU then back to SCADA master station
Replace several legacy transducers
Provide real-time data to the OSAS master station through on-board Ethernet port
OSAS Implementa Implementation tion Implemented in three levels
Level 1: Networks within switchgear
Level 2: Networks within individual S/S
Level 3: Network located in the control center
Level 1: IEDs networked within switchgear or a group of switchgears E.g. low voltage switchgear networked to a common PLC/gateway by the switchgear manufacturer
OSAS Implementa Implementation tion Level 2: OSAS scope starts at level 2 IEDs connected via fiber optic cables to Ethernet switches The Ethernet switches connected by fiber optic cables in parallel redundant topology or bus-ring topology Each substation shall have: Operator Automation Station (OAS), data acquisition server and database, substation annunciator, engineering automation station (EAS), event and alarm printer, GPS clock and SNTP server
OSAS Implementa Implementation tion Level 3: Interconnect the individual SA systems Provide centralized monitoring and control from the control room Central control room shall have: Operator automation station (OAS), dual redundant data acquisition server, historical data server, engineering automation station (EAS),event and alarm printer, hard copier, training simulator, GPS clock and SNTP server
OSAS Substation Architecture
OSAS CCR Architecture
OSAS Block Diagram
OSAS Block Diagram
OSAS Block Diagram
Merits
Lower substation cost
Reduced downtime
Lower equipment maintenance cost
Reduce SCADA system cost
Low initial investment that can meet future needs
