IMPLEMENTATION OF A BROADBAND DATA COMMUNICATION NETWORK AT THE SATELLITE SUBSTATIONS FOR THE ELECTRICITY DEPARTMENT  OF THE TSHWANE METRO

Index: Introduction, Coverage, Substations, Services, Equipment, Interfaces, Data Networking, Network Management, Technical Characteristics, Planning, Contractors, Costs, Acknowledgements.

INTRODUCTION

The Primary Network Division of the Electricity Department of the City of Tshwane operates an extensive network of 132 kV electricity substations as part of the electrical distrubution network for the City of Tshwane. Connected to these primary substations is an extended network of 11 kV satellite substations to serve the connected customers

Over the years a pilot cable network had been deployed as part of the power line protection scheme.  Initially the pilot cables were used for point-to-point differential protection schemes.

In 2003 the council published a tender requesting proposals to extend the communication network to also include the satellite substations  into the municipal wide data network.  The design contract was awarded to Delport Du Preez and Associates and work started early in  2004.

Index

DESCRIPTION OF THE PROJECT WORKS.

Coverage.

The optical fibre data communication network covers the entire area serviced by the primary substations operated by the Tshwane Metropolitan Municipality. The pilot cable network connects to all the Satellite substations of the municipality

Substations.

Some 20o  substations form part of the network.

Services.

The following services are supported on the data communication network:

• Powerline protection
• SCADA communication
• “Red” telephone service
• Qaulity of Supply monitoring
• Load logging
• Power demand recording
• “Ampacilty” recording
• Data communication
• Micro-scada control and monitoring
• Battery charger monitoring
• Security and Access monitoring.

Index

Equipment.

The fibre Optic communication system is based on the use of multiplexing equipment manufactured and supplied by ABB of Switzerland.  The following units are employed:

• Fox 515 - SDH technology
• Fox U - PDH technology
• Fox U/M - PDH technology

The Fox 515 equipment in the primary network provide carrier signals up to STM 4  level. This is the equivalent of 622 000 kbps data channels.  The Fox U and U/m multiplexers provide an 8 Mbps carrier with the equivalent of 120 * 64 kbps signal channels.

The secondary substations initially communicated on HDSL at E1 level.  This will be gradually replaced by PDH / SDH level as fibre is installed between the primary and secondary stations.

Initially  the data services for the satellite substations for the Electricity Department used the equivalent of one E1 data channel.  The balance of the channels on the multiplexer network was available for other services.  It was anticipated that the extra capaciity could be made available for commercial purposes by either subleasing to the  services to third parties.

Index

Interfaces

The network services connect to the multiplexer network using one or more of the following interface units:

• Optical Interfaces - Tunos / Tunop / Synio / Tupos
• HDSL copper interfaces - Lesa 8
• Unida - 4 * X-2, 4 * RS 232 electrical interfaces
• Megif - 2*E1/ fractiuonal E1 electrical interfaces
• Synam - 34 Mbps electrical interface
• Tebit - Powerline protection interface.
• Subla, Exlan and Ringen - telephone line control
• LAWA 4 - Router / TCP/IP

Index

Data Networking.

The multiplexer network provides the carrier system for a multitude of point -to-point data links, all configurable and managable from the control centre at the Electronic workshops of the Council.  Some services, such as the SCADA system, employ dedicated data links using the X-21 channels.For the bulk of the services a WAN had been created, to allow all these services to share the data network using the Ethernet and TCP/IP protocols.

For this purpose each substation has a router and Ethernet hub, to give access to the required services.  Each station was allocated a block of 64 IP addresses.

The routers are Cisco 2400 and ABB Lawa 4 equipment, furnished with the required interface cards.  Most routers are equipped with E1 wan ports, to give 2Mbps access speed.  In the case of some of the smaller substations equipped with older Fox U/m and Fox 6+ units the wan interface may be limited to one 64kbps channel.

The Electricity WAN is connected to the Corporate WAN via a Cisco PIX firewall.  A security policy was put in place to govern access to the network and services allowed to pass through the firewall.

Index

Network Management.

The following management facilities are employed on this network:

• UNEM and FOXMAN - this is a software manager supplied by ABB that allows for the management of the data channels on the Fox 515 and Fox U multiplexers.  UNEM allows the network administrator to allocate channels to services and to route services between substations.  It further allows for the monitoring of the multiplexer functioning and even alternatve routing of channels in case of a failure.
• CiscoWorks for Windows - this is an SNMP manager for the WAN.  All the routers, hubs, switches, firewalls and Etherpads in the network are SNMP enabled.
• GPGIT and AM/FM - the electricity department of the council operates an extensive database management facility through the GPGIT system.  With this system it is possible to record all the data relevant to a subtation and it’s equipment and to make the information available for operational and management purposes.  For example, it is possible to list all the details of a power transformer at a substation - make, rating, serial numbers, protection system, circuit diagrams, last date serviced, oil analysis reports, etc.  With the data network it is possible to log in to the GPGIT system from the substation and to access diagrams, drawings, data sheets, etc.  It is further possible for the operator to mark changes and submit updated information to the database moderator for revision purposes.

Index

TECHNICAL CHARACTERISTICS OF THE SATELLITE SYSTEM

Index

PROJECT PLANNING AND CO-ORDINATION

The instruction to proceed with the planning of the Works was issued in Oct 2003. The Design report was submitted in August 2004. Tenders for the Phase 4 main contract were received in November 2004 and the contract was awarded to ABB (Pty) Ltd in February 2005. 

Completion of the first station  was planned for 1 September 2005.  Acceptance of the complete installation up to the end of phase 4 was scheduled for September 2006.

The project leader for this project was Mr Wimpie van der Merwe of CTMM.

Index

CONTRACTORS

The contract was awarded to ABB South Africa (Pty) Ltd located in Midrand, Gauteng.

Commissioning and maintenance of the network was the responsibility of ABB South Africa (Pty) Ltd.

Index

PROJECT COSTS

Amount approved for Phase 1:        R 7 870 875

Amount approved for Phase 2:        R 1 558 589

Amount approved for Phase 3:        R 7 123 697

Amount approved for Phase 4:        R 64 000 000

Index

ACKNOWLEDGEMENTS

The Project Engineers wish to extend their appreciation and gratitude to the following persons for their dedicated participation to make this a successfully completed project:

The Staff Members of the City Council of Tshwane:

The Engineers and support staff of DPA responsible for the planning and design.

The Contractor's Project Engineer and support staff for the dedicated work on site:

P. D. Du Preez. Pr. Eng.

Project Engineer

Delport Du Preez and Associates.

5 Setember 2005.

Index

Top

BACK TO HOME PAGE

© - 2005. DPA