EXPERIENCE IN 500 kV & TRANSMISSION

The first 500 kV system on Java (and the first in Southeast Asia) was put into service in 1985. This system provided the first interconnection between west, central and east Java. The interconnection linked together the major cities in the northern half of Java and was known by PLN as the ‘North Coast Interconnection’. Within a relatively short period thereafter increasing load demand and new load centres necessitated major reinforcements to this North Coast Interconnection. These reinforcements, under a single project funded by ADB, took place between 1992 and 1998. CONNUSA was the local Consultant providing services for these reinforcements.

Further major reinforcements have taken place during the past decade, including the construction of a ‘South Coast Interconnection’. CONNUSA has provided consultancy services for virtually all of the reinforcements to the original 500 kV development. No other Indonesian Consultant Company can match this experience.

ACHIEVEMENTS: 500 kV TRANSMISSION PROJECTS

In the past twenty years, CONNUSA in association with International Consultants has completed Feasibility Studies, Engineering Design and Supervision of Construction and Commissioning of: Some 1940 km of 500 kV single and double circuit HVAC overhead lines Some 730 km of 500 kV HVDC overhead lines Construction of 3 new 500 kV substations Extensions to 5 existing 500 kV substations and Construction of 2 new 500 kV HVDC convertor stations

The most recent major reinforcement to the 500 kV system involves the interconnection of Sumatra and Java. This entails 500 kV HVAC and +/- 500 kV HVDC developments on both Islands and a +/- 500 kV HVDC submarine cable interconnecting the two Islands. CONNUSA was involved in the original Feasibility Study for this interconnection and is now part of the team providing Consultancy Services for its implementation. This will be the first use of 500 kV HVDC cables in Southeast Asia and one of a very limited number throughout the world. More details of this development are given below.

In the short to medium term PLN has plans for further significant reinforcements to the Java-Bali 500 kV system. On Sumatra plans are in hand for a 500 kV interconnection linking the north and south of the island.

Major 500 kV projects for which CONNUSA has provided Consulting Services include:

Cirata - Cibatu; Ungaran – Krian – Bandung:
500 kV Transmission Interconnection, 646 KM

The 500 kV interconnections between these Cities formed the first major reinforcement to the ‘North Coast Interconnection’. The scope of work included for

• 50 km of double circuit overhead lines
• 596 km of single circuit overhead lines
• Extensions to 3 open terminal 500 kV substations
• Extensions to 1 GIS 500 kV substation

The substations are of the ‘one and a half’ circuit breaker arrangement. The new diameter bays included all associated circuit breakers, isolators, earth switches, current transformers, voltage transformers and arrestors. Also included were all associated panels for protection, control and communications. Civil works included for all plant foundations and building extensions.

Paiton – Kediri – Klaten :
500 kV Transmission Interconnection, 415 KM

The 500 kV transmission interconnections between these Cities formed part of the ‘South Coast Interconnection’. The scope of work included for :

• 415 km of double circuit overhead lines
• Extensions to 1 open terminal 500 kV substation
• 2x 100 MVA, 500 kV shunt reactors

The substations are of the ‘one and a half’ circuit breaker arrangement. The new diameter bays included all associated circuit breakers, isolators, earth switches, current transformers, voltage transformers and arrestors. Also included were all associated panels for protection, control and communications. Civil works included for all plant foundations and building extensions.

Klaten–Rawalo Baru–Tasikmalaya–Depok :
500 kV Transmission Interconnection, 579 KM

The 500 kV transmission interconnections between these Cities formed a further part of the ‘South Coast Interconnection’. The scope of work included for :

• 579 km double circuit 500 kV overhead lines
• 1 new open terminal 500 kV substation
• 1x 500/150 kV, 500 MVA transformer
• 2x 100 MVA, 500 kV shunt reactors.

The new substation at Depok is a ‘one and a half’ circuit breaker arrangement. The new diameter bays included all associated circuit breakers, isolators, earth switches, current transformers, voltage transformers and arrestors. Also included were all associated panels for protection, control and communications. Civil works included for site layout, all cable trenches and earthing, all plant foundations and new buildings.

For the three transmission interconnection projects described above CONNUSA provided the following services:

• Review and comment as necessary on overall programme for manufacture, factory testing, shipping, delivery to site, construction, commissioning tests and system tests
• Review of overhead line routing, tower locations and profiling
• Review of site preparation for substation sites
• Review results of soils investigations to be used in calculations for tower foundations, plant civil foundation and structural designs
• Design audit of contractor’s calculations and designs for all equipment and civil works
• Review and approve all contractor’s drawings for plant, plant layouts, site layouts and all civil works
• Review the Contractor’s Quality Assurance and Quality Control documents for compliance with the contract documents as well as applicable Codes and Standards
• Witness and report on factory tests and inspections
• Review arrangements for delivery of equipment to site with particular emphasis on heavy loads and bridge crossings
• Review arrangement for storage of equipment at the different sites
• Supervise all construction activities for plant and civil works
• Agree as necessary to changes to civil works in accordance with actual site conditions
• Witness Commissioning Tests and System Acceptance Tests
• Assist in final preparation of ‘as-installed’ drawings
• Review of Site Health and Safety procedures
• Project Management:
  • Contract administration
  • Assist Client with contractual matters
  • Monitoring of the implementation time schedule
  • Issue provisional Taking Over Certificates
  • Review Operations and Maintenance manuals
  • Preparation of reports
• Transfer of Technology and Training on Design, Construction, Operation, Maintenance and Test of Equipment.

Java–Sumatra :
500 kV Transmission HVDC Interconnection, 1,070 KM

Notable Achievement: This interconnection is the first use of 500 kV HVDC technology in Southeast Asia. The purpose is to transmit from Sumatra some 3,600 MW generated at a Mine Mouth Coal fired Power Plant. CONNUSA provided services in connection with the Feasibility Study for this Project.

The scope of work for this transmission interconnection includes the following:

• A 300 km 500 kV HVAC double circuit overhead line on Sumatra
• New 500 kV HVAC substations on Java and Sumatra
• New 500 kV HVDC convertor stations on Java and Sumatra
• A 450 km +/- 500 kV HVDC overhead line on Sumatra and a 280 km +/- 500 kV overhead line on Java
• A 40 km +/- 500 kV submarine cable connecting Java and Sumatra
• A new HVDC laboratory
• New 500/275 kV transformers on Sumatra and 500/150 kV transformers on Java

In addition to the activities associated with Supervision of Construction and Commissioning (described in detail above) the services offered by CONNUSA for this project also included:

• Review and update of Basic Design
• Study and design for the new HVDC laboratory
• Preparation of Bid Documents and assistance to PLN during the Bid Process
• Bid evaluation
• Assistance in Contract negotiations
• Preparation of Contract Document

EXPERIENCE IN POWER SYSTEM PLANNING & ANALYSIS

CONNUSA has been involved in power system studies for over a decade and has an experienced staff of system planners, computer programmers, and financial analysts to carry out extensive assignments.

Technical Studies : 500 kV Transmission System

CONNUSA has provided services to PLN in connection with the following Technical Studies:

• Power system stabiliser performance
• Determination of insulation levels for GIS and conventional open terminal equipment
• A review of PLN’s specifications for primary 500 kV equipment
• A review of existing practices for transmission line earthling
• Design of Protection Scheme for the 500 kV system
• Power system fast transient studies