III Improvement of Reliability

5. Recommendation to Improve the Distribution Operation System of PT PLN

5-1 Distribution Feeder Configuration

5-1-1 Distribution Feeder Interconnection and Division

It is most critical to prevent faults to improve power system reliability. However, power system reliability can still be improved as long as faults are identified, fault section isolated and wholesome section supplied with power as quickly as possible to minimize fault duration & fault-impacted customers. In the same vein, installing section switches adequately along distribution lines and interconnecting distribution lines or substations is the most cost-effective alternative to reduce fault section and outage duration, which helps improve operational efficiency of distribution line, depending on line division and interconnection configurations.

PT PLN interconnects its distribution lines to reduce fault section and shorten outage duration. However, even if a lot of distribution line are interconnected with each other, not many of the distribution lines drawn from different substations are interconnected and distribution lines are splitted or interconnected simply by rule of thumb without sufficient consideration of power interchange needs, resulting in less return on investment. Therefore, we introduce the following concept of distribution line division and interconnection in an effort to help minimize fault section and fault recovery time by division and interconnecting distribution lines effectively.

(1) Concept of Interconnection and Division of Distribution Line

Distribution system configuration can be broken down to radial, loop and network type, depending on line configuration and more than 80% of the distribution circuits around the world are radial type. Substation and customer is connected by a single path in radial model. Most of distribution systems are configured as networks physically but operated as radial models by opening switches in critical points. Radial circuit is the most cost-effective and easiest to analyze and operate distribution system model. Radial model is also advantageous as additional loads can be connected to radial branch lines with ease. However, its disadvantage is such that once exposed to fault, all the customers connected to load side of fault point are interrupted.

Therefore, scope of interruption is extensive and reliability of power supply becomes quite low.

On the other hand, loop type distribution system consists of a ring circuit and electric power is supplied to one end of the line and transmitted to customers. As electric power can be supplied either end of the line any time, it is more reliable than radial circuit. However, it is more cost-intensive and difficult to analyze and operate than radial model. Loop system is operated as an open loop with opened switch in the middle of feeder and the same as radial model in that case basically.

Network model is composed of feeder groups crossed to keep more than one path available between two certain points all the time. If line capacity is sufficient and protective arrangement across the system is well-coordinated, network feeder ensures very high reliability. Although some section or source side is tripped, electricity keeps flowing to customer and even multiple contingency events may result in no or few interruptions if any. However, it is costlier than radial model or loop circuit and highly complicated to analyze and operate.

Radial & Open loop systems divide sections in each line and interconnect with nearby lines to switch some loads so that interruptions can be confined when main line is tripped, hence, reliability is enhanced.

Multi-section and multi-interconnection configuration divides distribution line into adequate number of section by installing switches along main distribution line. Section switches may divide circuit further into sub-sections to reduce scope of interruption during fault recovery or scheduled interruption but such sub-sections are not included in the concept of sectional division considering interconnection. Also, interconnection switches are installed in each section for interconnection with nearby distribution line.

In that case, it is more effective to interconnect with distribution line of other transformer bank or substation in consideration of bank or substation failure.

If line length is relatively short, one zone is interconnected to nearby line by a single interconnection path and, if it is long, load in one section may be interconnected by two paths, depending on site conditions.

If faults take place in some sections at the system, after confirming fault, turn off the switch at source side and restore power of substation and turn on the switch interconnected to other feeder, leaving interrupted section without power while supplying electricity to other sections.

In order to transfer load from sound section, neighboring feeder should have capacity to supply both its own feeder and sound part of interrupted feeder. In other words, current of load accepting feeder increases and influence utilization ratio of conductor because the feeder should cover loads not only itself but also transferred load. For this reason, the level of restoration capacity should be determined regarding various types of contingency faults including fault of single distribution line, fault of main transformer, accident at substation level, and faults of nearby lines.

(2) Distribution Feeder Section Switch

At present, Semarang APJ uses LBS (Load Break Switch), South Surabaya APJ uses LBS (Load Break Switch), and RMU (Ring Main Unit), and South Denpasar AJ uses LBS (Load Break Switch), RMU (Ring Main Unit), and remotely-controlled SF6 gas switch for Distribution feeder section switch.

The initial construction cost of LBS which uses contact blade is reasonable, however maintenance is difficult; overhead feeders are established along the road, unbalance between blade holder and blade by vibration from vehicles and corrosion shorten life span of the switch and sometimes operation itself is not easy.

These days, a switch using SF6 gas, which shows excellency in arc suppressing, and polymeric switch, which is eco-friendly and is being insulation reinforcement, are available at cheaper price, therefore, it is strongly recommended to use this gas switch in areas including locations with saltly wind or contamination damage, industrial complex with heavy dust and hazardous material, loop trunk line with frequent switching of load in downtown, and ally arm assembling spot where side clearance is difficult to be secured. Switches should be installed at locations with easy access and poles in good condition.

(3) Recommendation

Overhead lines that have radial type distribution lines where load cannot be transferred in response to fault occurrence should be extended to be interconnected with adjacent lines and several section switches installed. To be noted, interconnections should be made and section switches installed for lines that supply power to critical customers or have significant impact on power system operation.

The foremost consideration to be made regarding sectionalizing and interconnection configuration is such that normal and emergency operation capacity needs to be determined in consideration of allowable current of distribution line and main transformer capacity.

Normal operation capacity should be determined with specific margin considering load to be transferred from interconnected lines during emergency. When emergency operation capacity is determined, sum of aggregate loads during emergency should not exceed allowable capacity of distribution line.

When distribution lines are interconnected, interconnection system should be configured to ensure that a feeder from tripped substation is transferred to the feeder of other substation and energy is supplied to the transferred load.

5-1-2 Examples of Improving Distribution Feeder Configuration

1. Semarang branch office
   The total number of distribution feeders in Central Java district office is 386 and the length of 20kV midium voltage line is 42,897C-km (including 29,918C-km of single phase line), whose average length of distribution feeder is 111.1C-km. The average length of Semarang Branch office with high load density is 47.6C-km. Central Java district office faces a lot of difficulties in the interconnection of distribution feeders because length of distribution feeders is longer and the number of single phase lines is larger than those of other branches. Most of the switches for distribution feeder division and interconnection are air insulated load break switches (IS). In this regard, malfunction or inactivation are likely to take place and it would be difficult to switch heavy load distribution feeders, if the air insulated load break switches is obsolete.
   If section division switch is installed in or places where it takes a lot of time to go to the site from Distribution operation Center (DOC), installation of Distribution Atomization System (DAS) would be effective in improving the reliability.
2. South Surabaya branch office
   The total number of distribution feeders in East Java District office is 806 and the length of 20kV medium voltage line is 28,924C-km, total transformer capacity is 6,665MVA, average length by distribution feeder is 35.9C-km, the aggregate amount of transformer capacity by distribution feeder is 8.2MVA. In the South Surabaya Branch office where loads are concentrated, the average length by distribution feeder is 5.3C-km and the aggregate amount of transformer capacity by circuit is 9.1MVA. In addition, there are already many switches built to divide circuit and interconnection with other distribution feeders is established very well.
   However, the switches are not properly managed, some of which are not working. In this regard, maintenance works for switches are necessary. When interruption happens, it is necessary to use the lines as thick as those of outgoing line of substation, given the load transfer.
3. South Bali branch office
   Since there located many key customers including Hyatt Hotel in Semawang region of South Bali Branch office, distribution feeder interconnection between substation and switching station is well established and express feeder and RMU (Ring Main Unit) which is enable a remote control of switch from APD are built. Line utilization rate goes down because it can’t be used in express feeder for load transfer in case interruption happens. Although feeder division is greatly done, only 50% of maximum feeder capacity can be used in the distribution feeders which have no express feeder because interconnection between feeders are based on 2-interconnection. In this regard, multi-interconnection should be implemented to increase line utilization rate, and maximize load transfer capacity in case interruption happens.
   The total number of distribution feeders in Bali district office is 132 and the length of 20kV medium voltage line is 4,946C-km and the aggregate amount of transformer capacity by circuit is 821MVA. The average length by feeder is 37.5C-Km and the aggregate capacity of transformer by feeder is 6.2MVA. Except for Denpasar and Kuta where loads are concentrated, most of the regions have longer average length by feeder and lower average load density.
   Outside the downtown, there adopt open loop circuit or radial system circuit. Therefore, they need to do as much as feeder division and interconnections by installing a switch in order to increase load transfer capacity and minimize fault section in case interruption happens.
4. Loop scheme
   Central Java district office and Bali district office have adopted Loop scheme and have plans to expand it. Twenty years ago, KEPCO also had adopted the same loop scheme with PT PLN.
   However, it does not use the loop scheme any more because customers don’t want to tolerate even a short interruption. Due to the characteristics of loop scheme, it is inevitable to stop the power supply even to sound section to confirm the sound section from the fault section. For this reason, there were a lot of customer’s complaints. In addition, the distribution line of loop scheme must have enough supply capacity for loop load in case of an interruption. Given all the factors, it would be desirable for PT PLN to reconsider the plan to establish loop scheme.

5-2 Implement Distribution Automation System (DAS)

In order to improve the reliability, the Distribution Automation System (DAS) should be introduced. It is possible to reduce the range of interruption through the division and interconnection of distribution lines, however it has limits to decrease the time necessary to separate the fault section and repair the fault. Meanwhile, Distribution Automation System (DAS) can make it possible to quickly identify the fault section and separate the fault section without visiting the site. By establishing Distribution Automation System (DAS), KEPCO could dramatically cut the average repair time from 53.8 minutes/case to 3.3 minutes/case.

Distribution automation system refers to a system that can operate switches installed in distribution lines, locate interrupted sections and collect line operation data such as voltage or current, etc. from a remote office automatically thanks to IT technologies, which can minimize number of interrupted sections and duration of interruptions.

5-3 Improvement of operation scheme for Distribution Information System (DIS)

5-3-1 Facility Information and Data Management

(1) Computerization of Facility Management

Facility management is a critical element of asset management, maintenance planning and aging factor management to prevent interruption. It is also critical to distribution expansion plan and design. Currently, the facility statistics and facility history management of PT PLN is conducted both by manual work and computerized method. The history of each equipment is managed with the own card of each equipment or input into computerized device. If there are only a few facilities to be managed, they may be manageable manually. But, as load and electrical facilities increase in response to economic growth, it becomes increasingly difficult to manage facility statistics and history manually. Therefore, facility management schemes needs to be planned in advance to increase in loads to be supplied and electrical facilities.

Computerization of facility management is required to manage increasing number of facilities effectively. Computerization of distribution facility management can expedite facility data search and enhance efficiency in facility management. However, computerized facility management system requires lots of investment in terms of H/W and S/W procurement, data migration and system maintenance. However, given the potential increase in loads and facilities to be managed in the future, computerization of facility management system is imperative.

(2) System Integration

Since PT PLN has a massive power facility, it is recommended that in the long run, it should swiftly build an integrated Distribution Information System (DIS) which combines all information systems into a single system.

Such a system will integrate all functionalities from the drawing of the distribution system to facility record management, construction and materials management and computerized work processing. In building this system, irrational and problematic processes is improved and unnecessary elements is removed to improve work efficiency.

This system will simplify work processes, render them paperless and automatic as well as improving procedures to enhance efficiency and reaffirm customer-orientation. The end result will be informatized, scientific management framework and a more efficient and economic system.

The Distribution Information System (DIS) is designed to standardize the overall distribution operation from the designing phase to construction phase, to systematically manage it in an integrated manner and makes it easy to check operational progress and manage operation by utilizing WFM (Work Flow Management) function. In addition, it eliminates the needs to do additional works that is needed for unit operations, including manual input of various data.

Other advantages of Distribution Information System (DIS) include synchronization with customer information at Customer Information System (CIS), automatic synchronization with financial information such as budget planning and asset acquisition, synchronization with material procurement system including request of materials, cancellation of request and return of materials and synchronization with loads and feeder operation information such as Distribution Automation System (DAS) and SCADA. If the above functions are organically associated to provide the necessary functions, the effect of system integration could be maximized.

5-3-2 Drawing Management

Drawing is one of the most instrumental tools for facility management. Drawing can be broken down to distribution planning drawings, system operation drawings and design drawings by usage.

PT PLN has established distribution facility drawing management system by using Geographic Information System (GIS). However, some of the regions with no GIS in place are still using rayon card.

However, GIS Map and data which have required a lot of efforts to implement do not seem to be utilized as actively as they can be. It is used in a limited manner such as detecting the locations of customer and distribution facility. Such GIS Map do not provide data on sections and interconnection points of distribution lines and hard copy system drawings should be referenced to identify system operation status. Facility route map and data are managed in soft copy format. But, as system drawings are maintained manually in hard copy, the well-implemented drawing data on the basis of GIS is not utilized to its full potential. To facilitate utilization of soft copy drawings, system diagrams need to be computerized as well. If route map, system drawing and facility data are integrated, facility drawings can be managed much more effectively and synergy effect may be achieved. Therefore, it is desirable to implement an integrated drawing management system involving system drawings based on as-is GIS Map. Furthermore, the reliability and accuracy of the input data related to facility and customer information should be continuously upgraded. One way to enhance accuracy and reliability is that the PT PLN head quarter conducts sampling of DB on a regular basis for field research.

5-4 Recommendation to Reduce Scheduled Interruption

Scheduled interruption means that distribution circuit is interrupted in whole or in part to allow for expansion, maintenance of distribution circuit or pole relocation in the wake of road expansion. Beyond using indirect hotline method, PT PLN is currently in the process of introducing direct hotline method.

5-4-1 Hot Line Work

Hot line work refers to work conducted without interruption by qualified hot line crews on hot lines energized at more than midium voltage using hot line work tools such as hot stick, insulated boom truck or rubber gloves. It can contribute significantly to reducing aggregate scheduled interruption duration. Hot line work is divided into indirect hot line work using hot stick and direct hot line work using insulated boom truck.

(1) Indirect Hot Line Work

Indirect hot line work was originated when disconnection stick was used to make/break charged disconnector switch in 1913 and used up to 1980s. But, given extensive manpower requirement and difficulty with using hot line stick, indirect hot line work method has been substituted by direct hot line work using insulated bucket truck in most countries around the world. However, as indirect hot line work tools are less costly and safety can be ensured as long as sufficient clearance is secured, it still warrants consideration depending on specific needs of each electrical utility.

As hot line work is a very dangerous task, hot line work tool must be fabricated in conformance to strict requirements and extreme care must be taken to ensure required insulation and strength. Hot line work tool is manufactured under three principles of maximum insulation, maximum strength and minimum weight and should be easy to manipulate and adaptable to needs of various hot lines. Internal arrangement of metal part should be inspected by X-ray test and pass various tests. Epoxy glass hot stick widely used is made of glass fiber coated over mono cell plastic resin filled with inactivated gas.

(2) Direct Hot Line Work Tools

Introduction of rubber glove live line work method in the early 1990s marked a turning point to reduce duration of scheduled interruption which accounted for 85% of aggregate interruption duration. The method allows workers wearing protective gear to contact live part and requires insulated bucket truck. The rubber glove live line work method can reduce interruption duration drastically as it overcomes limitation of existing hot stick method and provides more convenience. Notably regarding installation of new circuit parts, simply connecting existing line and jumper wire following completion of pole and line installation or installing branch hooks required for transformer installation without interruption is simply to enforce, yet effective greatly in reducing interruption duration.

Direct hot line work requires several special equipment in addition to indirect hot line work tools.

Hot line bucket truck is a specialty multi purpose hot line work vehicle equipped with insulated upper boom, lower boom and basket. It is mounted with various work safety arrangements and gears and hydraulic cylinders for bucket control.

5-4-2 Non-Interruption Work Method

Non-interruption work allows for no interruption and is performed by movable transformer vehicle, by-pass cable or construction switch methods. Brief concept of each work method and work sequence is as follows.

(1) Movable Transformer Vehicle Method

Movable transformer vehicle supplies low voltage load while pole-mounted transformer is replaced without interruption.

(2) By-Pass Cable Method

If branch line, high voltage customer or bank pole is located within construction section, by-pass cable provides temporary connection between power source and load in construction section and jumper wire in the construction section is removed and installed by hot line work method.

(3) Construction Switch Method

If there is no work underway in construction section and load downstream construction section can be transferred to other line, construction switches can be installed to allow jumper wires on both sides of construction section to be disconnected using hot line method.

5-4-3 Recommendations for Reducing Scheduled Interruption

Customers feel inconvenient whether interruption is forced or scheduled and reducing frequency and duration of scheduled interruptions is of foremost priority and notifying interruptions sufficiently in advance is also important to improve customer convenience. To that end, repetition of scheduled interruption in the same section during a short period of time should be prevented and work should be completed as soon as possible by mobilizing much equipment and resource. Planned and systematic management of scheduled interruption may be highly conducive to reducing interruption duration but limited in reducing interruption frequency. To reduce interruption frequency, direct hot line & non-interrupted working method not involving interruption needs to be considered.

PT PLN already tried to introduce direct hotline method, however the process is delayed in some degree due to difficulties in educating the hotline crew and budget issues such as buying bucket truck. Compared to indirect hotline method, direct hotline method makes it possible to reduce scheduled interruption for the operation speed is faster. However, the possibility of safety accident is higher if safety rules and guidance are not complied. In this sense, it is important to train well-educated hotline crews. Until now, PT. PLN could conduct hotline operation by its own because there have been not many demands for hotline work. However, the demand for hotline work will grow to reduce scheduled interruptions as customer’s complaints about interruption increase. In this case, the resources in PT PLN will be not sufficient to take care of all the demands. As a result, they need to gradually transfer hotline work technology to outside contractors. Establishing a special course in the training center or outsourcing the training session to outside experts would be a good idea to secure qualified hotline crews.

Although hot-line construction must be performed by qualified technicians, in-house employees are generally reluctant to take up the task for safety concerns, and there are likelihood that mutual supervision among peers and safety management system will not be performed and observed well. Moreover, expensive equipments may not be so much of use for them. Through outsourcing, PT PLN does not have to purchase such high-cost equipments.

Also, applying Rubber Glove Live Line Work Method to simple works including cutting and connecting jumper and connecting stirrup for transformer will make more sense from an economic standpoint. Better yet, it can be effective for preventing safety-related accidents via stringent safety management by the PT PLN itself and keeping employees from refraining from performing the method.

In addition, since hot-line construction requires expensive equipments and highly trained technicians, a group of several areas will have to be allotted to a single contractor. In the meantime, if profits of the provider can be guaranteed by extending the contract period to a long-term one for two or more years, unless there is any major defects, raising utilization factor of the equipments as well as cost saving will be achieved at the same time.

In a long run, a large amount of costs will be incurred by introducing non-interruption method. Thus, it is better to introduce the method when hours of forced interruption significantly drops to the same level as that of scheduled interruption.

5-5 Security of Maintenance Budget for Distribution Facility Maintenance

Distribution budget can be largely divided into construction and maintenance budgets. New construction can be regarded as an asset increase in that new facility is acquired after construction. But, maintenance budget can not create assets, rather, can be regarded as only cost. Therefore, two budgets should be clearly divided and handled for transparent accounting management.

Every economic units from a country to a household budget because they should prioritize and coordinate expenditure to effectively utilize limited resources. Therefore, detailed budget plan is required for facility maintenance and operation. If a budget for a business should be transferred for another purpose, rigid approval process should throughly review the transfer not to let a critical business delayed or cancelled.

Power industry is based on facilities. How the power company does facility investment and maintenance work can make a big difference in its reliability. The reliability will significantly improve, if the company continuously makes efforts in facility investment and maintenance.

Otherwise, facilities will become obsolete, which will lead to more interruptions and faults. In a nutshell, improvement in reliability requires continuous facility investment and maintenance in a timely manner, which is possibly if it is backed by sufficient amount of budget.

If comparing Semarang Branch office, South Surabaya Branch office and South Bali Branch office to one of the KEPCO branch offices with similar environment and similar length of line, the PT PLN’s budget for maintenance is significantly lower. As seen as the table below, the maintenance budget of Semarang, South Surabaya and South Bali branch offices are only 1/5~1/10 of that of KEPCO’s branch offices with a similar size. In many cases, PT PLN must not be able to replace facilities or perform maintenance operation even through it knew it had to, because of lack of budget. In fact, a large amount of power supply facilities are outdated. If it wants to improve reliability, we recommend PT PLN secure enough amount of budget for facility investment and maintenance operation. To do so, PT PLN should seek to receive more government’s subsidies or normalize electricity fee.

5-6 Improve Efficiency Distribution Planning

Distribution planning refers to the plan that is established to build a more efficient distribution system while satisfying the load requirement of a given year by identifying system problem areas and forecasting future load demand. There are two types of distribution planning: short term plan and long term plan. Short term plan refers generally to 3-5 year plan; and here, we deal primarily with overload alleviation of feeder, new feeder construction by new/expanded substations, reduce loss and interruptions by sectionalize/interconnection of distribution system.

On the other hand, long term plan generally looks forward 10 years or more into the future, and addresses such issues as forecasting long-term demand, deciding the construction time, location, capacity of new substations, and optimizing the coverage for each substation as well as the number of circuits and shortest route.

5-7 Reliability Improvement through Improving the Quality of Materials and Equipment

5-7-1 Material Procurement in Indonesia

As a facility-based business, the reliability of facilities is of paramount importance in the electric business. The reliability of facilities can only be guaranteed with high quality raw materials and manufacturing, reliable transport and storage, high quality installation and construction as well as regular maintenance, inspection and timely replacement. High quality materials and equipments used in electricity generation and deliver could only lead to high quality electricity supply. In this sense, the quality of material and equipment is critical to the improvement of reliability.

5-7-2 Reliability Improvement through Improving the Quality of Materials and Equipments

Weak material and equipment manufacturing industry is considered the biggest problem for distribution electric power industry in Indonesia. Domestic material and equipment industry could be the base to provide high quality materials and equipments at relatively low price on a timely manner. The followings are suggestions to improve reliability by improving the quality of materials and equipments.

(1) Using Highly Reliable Materials and Equipments

According to interruption statistics of PT PLN, many of them are occurred because of poor material or equipments including CSP transformer, insulator and lighting arrester. The poor quality of materials and equipments are directly connected to the depreciation of reliability.

Using unreliable materials and equipments just because they are cheap would only lead to increasing possibilities of interruption. Some of materials or equipments have no problems at the initial stage but show some defects as time elapses. This is because the quality of the product has not been guaranteed against long-time elapse. To improve supply reliability, highly reliable materials and equipments with no problems only at the initial stage but also at long-time elapse should be used. The below table provides the list of highly reliable materials and equipments. Polymer insulator was adopted to reduce interruptions occurred by porcelain insulators which are highly susceptive to contamination and degradation of quality. Polymer insulator shows high level of performance and even its price is low. Particularly, it is very effective in preventing flashbacks in contaminated region. This means polymer insulators would be highly effective in south Surabaya with a lot of contamination. KEPCO has used polymer insulators for around 15 years and currently, around 10 million polymer insulators are installed in distribution lines. Currently, polymer insulator accounts for 90% of insulator purchase budget.

In addition, there developed and used various materials and equipments which adopt polymers which is effective in insulation, such as lighting arrester, line post insulator, bushing, circuit breaker and switch. The initial construction cost of air insulated load break switch (IS, Interrupt Switch) which uses contact blade is reasonable, however maintenance is difficult; overhead feeders are established along the road, unbalance between blade holder and blade by vibration from vehicles and corrosion shorten life span of the switch and sometimes operation itself is not easy. It is strongly recommended to use these gas switch and polymeric switch in areas including locations with saltly wind or contamination damage, industrial complex with heavy dust and hazardous material, loop trunk line with frequent switching of load in downtown.

(2) Promotion of Domestic Materials/Devices Manufacturers

Purchasing most distribution materials/devices in the Indonesia itself enables the timely supply of low-price goods and thus offers many benefits. But a high R&D budget is required for developing electric equipment and extensive capital expenditure is needed for mass production; also, the first few years of operations, many defectives are produced due to errors in design and manufacturing process. Given such conditions, the domestic industry cannot be expected to compete with foreign players without any support. As a strong domestic industry is a prerequisite for the future of the power industry, the electric companies and the government must supply their support by offering facilities and funds, cooperating in joint initiatives to reduce defects, and conducting joint R&D to develop new products. This support will ultimately benefit the distribution companies and the people by bringing down prices and stimulating the local economy.

As the power business is facilities-based, the price and quality of materials and devices is directly linked to a power company’s competitive power. Thus, the government should take the lead in protecting and fostering the domestic industry for the production of distribution equipment, which is relatively easy to develop and requires smaller-scale manufacturing facilities. Such initiatives will contribute to stimulating the domestic economy, creating new jobs and the supply of high quality power.

(3) Strengthening Performance Testing for Materials and Equipments

If the highly reliable supply of power is the responsibility of a power company, then another important task would be thorough inspection and testing of the quality of purchased materials and devices in order to supply reliable power. There are two ways to ensure such quality: one is for the power company to have its own testing equipment and persons to conduct tests according to various inspection criteria to pass or fail the purchased materials/devices; the second is for the company to recognize the manufacturer’s own test results and accept the supplied goods based on the manufacturer’s high credibility and a stringent testing agreement.

Of course, the latter option has the distinct advantage of saving on high testing facilities purchase and operation costs but it does require some preconditions such as stringent quality management and reliability on the manufacturer’s part as well as a long-term supply contract between the manufacturer and power company. The first option requires investment in large-scale testing facilities, testing personnel and time, but is the appropriate method if the equipment supply base is poor or the manufacturer/suppliers’ reliability is low.

In order to secure quality of materials and equipments, PT PLN’s affiliate, ‘PT PLN Certification Service’, takes part in performance testing for materials and equipments. If we analyze interruption statistics of PT PLN, we realize that many of interruptions are caused by defective materials and equipments. In this regard, it is necessary to strengthen the performance testing for materials and equipments and actively perform the approval of domestically produced materials and equipments. In this way, it cannot only upgrade the quality of materials and equipments purchased but also contribute to the establishment of better production facilities of domestic material and equipment industry.

(4) Procurement System by Headquarter and Supply to District Offices

Currently, the most serious weakness in material and equipment procurement system is that each district office puts its respective buying order to purchase a small amount of materials and equipments. It is necessary for the HQ of PT PLN to directly purchase materials and request “PT PLN Certification Service” to conduct testing on the materials and then supply them to each district office. If materials and equipments have a reported defect, then HQ should notify this to all branch offices to prevent the same material from being supplied again. If the HQ becomes the centralized purchasing body, then it will buy a large amount of materials, reducing the unit price of supply and secure high quality materials. Until the quality materials and equipments made in Indonesia reaches a certain level, centralized purchase system by the HQ would be effective.

(5) Introduction of Long-Term Contracts

Another option is for the distribution companies to directly sign long-term supply contracts with domestic or foreign manufacturers with no wholesaler or retailer in the chain so as to cut prices, guarantee high-quality and ensure better after-sales service.

(6) Strong Policy Support from the Government

Along with water and air, electricity is a common resource of people and a precious energy source for a nation’s future. A power company’s owners and employees must be aware of this responsibility and make all efforts to provide inexpensive and abundant power and the nation’s people must also conserve this precious resource. Thus far, this report has stated many items for improvements of power companies to make enhanced work process efficiency and preparation that must be made from now for a brighter future for the Indonesia. However, as electric energy belongs not to the company but to the people, the supply of electricity must be uninterrupted regardless of the fate of the individual power companies. In this respect, the government, electric companies and the people must all cooperate to ensure the continuous supply of inexpensive, high-quality electricity. If electricity charges go up or reliability falls due to insufficient cooperation by the government and the public, any resulting inconveniences will be felt by the people; and if cooperation goes well, the benefits will also go to the people.

Therefore, the government and regulatory authorities should lift social, structural obstacles and provide a stable environment for power companies to do business so that they can focus on long-term facility investment, quality enhancement and cost reduction. To this end, systems should be fixed and maintained with the aim of minimizing the total social cost of supply a nation’s common asset-electricity.

(7) Building an Industrial Cluster of Electricity Material and Equipment

As seen in the KEPCO’s experience, it is required to organically combine all the players related to the power generation and consumption, including the government, material and equipment manufacturers and electric power company as in [Fig 3-96] in order to improve the reliability of the power supply.

It is necessary to establish an industrial cluster between the government, electric power company and equipment and material manufacturers. In order to build the industrial cluster, all the players including electric power company, the government and the manufacturers should mutually cooperate with each other and play the role of their own. The government must strongly implement the policies to promote and support domestically produced electrical materials and equipments. PT PLN should implement various policies which KEPCO is already adopted to lead electrical technology of manufacturers. Material and equipment manufacturers should try harder to be more active in R&D and to produce quality products. Electric power company should play a critical role in this part and in order to do this, it needs the government’s strong determination to implement policy. This is a key factor that makes or breaks the establishment of the industrial cluster. Through the cluster, a fundamental to not only the develop material and equipment industry but also improve the reliability of power supply can be built.

5-8 Construction Underground Distribution Feeder

Underground line requires more cost than overhead line. But, it is less prone to fault and advantageous aesthetically since they are not exposed to the elements. However, such merits of underground line cannot be utilized fully if not maintained adequately. They are not as prone to fault as overhead lines as they are not exposed. But, once a fault occurs in underground line, it is hard to locate such a fault and takes long time to fix it. Therefore, preventative maintenance of underground line is extremely critical.

KEPCO established ‘Underground Construction Operation Procedure’ to implement ‘automatic approval system’ for the underground construction business requested by municipal governments. According to the automatic approval system, the underground construction business is immediately embarked on, if the municipal government pays 1/2 of the total construction cost. If the municipal government pays 1/3 of the total construction cost, then it is reflected in the long and short term underground plans for further implementation.

PT PLN also needs to introduce ‘Underground Construction Operation Procedure’ to proactively respond to the growing demand for underground electric facility by the municipal governments and the demand to improve environment from the general public. Since the cost of building underground lines is 5 times more expensive than that of building overhead lines, it is impossible to even start the business if the budget for construction is not set aside. According to the newly introduced ‘Underground Construction Operation Procedure’, the underground construction business can start if the municipal government pays part of the construction cost and prepare the space to install electrical facilities including switch and transformer. However, ratio of the capital paid by the municipal government should be adjusted to the specific situation of Indonesia. Given the Indonesian condition that the sidewalks are narrow and other underground facilities including telecom and water supply and drainage are already established, large obstacles of pursuing underground construction can be easily removed if it is possible to obtain support from the municipal government in securing space to establish electric facilities such as switch.

5-9 Building Up Distribution Department and Hiring New Employees

In order to improve customer service by providing high quality electricity, systematic planned maintenance, repair and technical review are required. However, only one distribution department out of 5 departments is in charge of technological operations in Semarang and South Surabaya Branch office. The department has a responsibility for whole distribution from planning to maintenance such as distribution planning, new power supply, distribution O&M, interior wiring & meter. In KEPCO, distribution operations of the branch office which is bigger than a certain size are shared by two departments. In general, one department is in charge of distribution planning and new supply while other is in charge of distribution operation and maintenance. It is recommended that PT PLN divides distribution operations into two parts as seen in the case of KEPCO to expand distribution department. In this way, it can supply high quality electricity and improve the reliability of energy supply.

40% of employees in PT PLN are in their 50′s or older. The company is aging. Given that the retirement age is 56, a large number of employees are expected to retire within a couple of years if the trend of aging continues. In this case, a big confusion can occur because of operation vacancy. In addition, aged organization has a risk of becoming conservative and inflexible. For the reasons, PT PLN should continuously hire new employees and provide them with training and education to prepare for the time when skillful employees retire.