In this chapter, the research design and methodology will be elaborated upon. Included in the discussions are: introduction, research methodology, sampling strategy, the questionnaire construction, data collection, validity and reliability, limitations of the study, ethical considerations and chapter summary.
1.8.4 Chapter 4: Statement of Results and Discussion
This chapter makes sense of the data through discussion. This involves stating what the theory says and outlines the author’s findings from the case study presented and the integration of the results of the questionnaire survey. The findings are presented and discussed under five sections aligned to both the research questions and objectives.
1.8.5 Chapter 5: Conclusions and Recommendations
Conclusions and recommendations for the study are discussed in this chapter. Key elements raised will be revisited and recommendations will be made not only to mitigate the research problem, but also provide answers to the research questions and the associated investigative questions and case study results. These sections will include: findings from the study and findings from the primary research. This chapter presents the information pertaining to the context of the research. It provides the reasons for the research study with an overview of what the author has concluded in the research topic concerned and highlights the conclusion obtained from the study and recommendations from the research.
T.R Khumalo (Montso) 13
Chapter 2: Literature Review
2.1 Introduction
Reliability is like safety, it is much favored, yet the sustainability of it proves to be a challenge and can’t be overlooked. It’s an important factor when planning, designing and operating a system.
People have always expected trains to be on time, electric power not to fail, telephones and communications lines to be reliable at any instant of time for an effective conversation, and so on (H. P. BLOCH, Janaury 2008) . A reliable electricity delivery system in South Africa has become more important since the stability of the economy relies heavily on it.
Utilities around the world have been taking a fresh, hard look at managing reliability. Since risk management directly affects reliability management, in the process, utilities are redefining the role of reliability management in achieving objectives, and ultimately, increasing shareholder value. The main goal is not to totally eliminate risk, but rather to be proactive in assessing and managing risk for their advantage including the customers concerned (H. P. BLOCH, Janaury 2008). Reliability has over the past few years emerged as a widespread practice in utility organisations and has been increasingly included in regulatory, corporate governance and organisational management blueprints (DHILLON, OCTOBER 1986).
However a question is always asked as to why are utilities/organisations struggling to implement, embed and sustain a pragmatic reliability management system solution that is robust, adds value and creates a balance between cost and reward, if risk management is a well-established philosophy and methodology? What measures need to be considered and implemented in order to optimise a reliable power delivery system?
This study focuses on the evaluation of Eskom’s Reliability Management in one of its divisions (Distribution) and its impact or contribution to the power delivery management system as guided by the above-mentioned arguments. The discussions in this chapter are structured along the issues raised in both the research questions and research objectives. The literature review outlines the
T.R Khumalo (Montso) 14 definitions and explanations of key reliability management terms and concepts whilst highlighting the relevance of risk management to utility organisations and its relationship to strategic objectives.
In addition, this chapter discusses the evolution, trends, principles, frameworks and best practices of international utilities that are widely applied relative to Eskom’s reliability management practices.
2.2 Reliability management definition of terms and concepts
Reliability management has its roots in the military and space technology which keeps on evolving and improving (Utley). It started with few fields such as transportation and medical equipment, where people’s lives are involved and endangered by unreliable equipment. Its influence has been increasing into many other applications, e. g. nuclear and conventional power generation and transmission systems, communication systems, medical equipment and chemical systems (H. P.
BLOCH, Janaury 2008). The assessment of reliability is no longer restricted to military equipment but also, the commercial world. The impact of reliability is becoming greater and greater (H. P. BLOCH, Janaury 2008). The world’s economy changes over time with a high speed and the industry has to keep up to survive. The power distribution system is also part of the applications that are influenced by reliability.
2.2.1 Reliability risk management
Reliability engineering is the application of engineering knowledge to risk management. By increasing the probability that the network will operate or perform when needed by defining strategies to prevent failures, system operators must detect the onset of failures in their earliest stages, and minimize all risks associated with the overall network (DHILLON, OCTOBER 1986) (Utley).
Identifying potential for cost reduction through extended parts life reduced labour cost, and other parts or equipment-related improvement techniques. The Participation in review phases of design of capital changes in network layout is done to ensure full maintainability of equipment and utilities (Cameron, et al., 2012).
T.R Khumalo (Montso) 15 The Initiation of corrective action using the study of corrosion, fatigue, wear, and erosion rates throughout the life cycle of the network reduces the reoccurrence of failures (Brunekreeft, 2015).
Also Alternate solutions to reduce the high costs associated with certain units of equipment. The application of reliability modelling addresses these reliability risks.
2.2.2 Reliability management general considerations
Reliability management considers a number of factors in an electricity delivery system .Factor such as increasing system complexity and size, economics, and competitiveness in the market. South African distribution increases in the number of connections everyday as new residential and commercial dwellings develop daily. Under present environments, neither can overdesigns be permissible nor unreliability be tolerated, as in the case of load shedding. In this respect, management plays an important role by guiding input to the specified reliability and the ways and means to achieve it (Brian Ó Gallachóir, 2012) (Brown, 2008).
In order to have an effective reliability program that will ensure optimisation of a distribution network system, there are various factors in which the responsibilities of management are embedded in, namely:
1) The establishment a program to access in real time, with respect to reliability, the current performance of the utility operations performance;
2) The establishment of certain reliability objectives or goal, in this case, ‘Keeping the lights on’;
3) The establishment of an effective program to fulfil set reliability goals and eradicating current deficiencies. An absolutely effective program should be able to pay in return many times its establishing cost; the public’s corporation plays a role in this regard;
4) Providing necessary program related authority, funds, manpower (qualifies personnel), and time schedule;
5) Monitoring the program -on a regular basis (National Grid performance power alert system and modifying associated- policies, procedures, organization and 'so on, to the most desirable level (Brown, 2008).
T.R Khumalo (Montso) 16 Facts such as the following are a guiding force for the general management to have an effective power delivery reliability program. Changes in maintenance, storage, testing and usage in field of the engineering product tend to lower the reliability of the design. Planned programs are needed for application in design, manufacturing, testing and field phases of the engineering product to control reliability (Arends, et al., 2014). It is during the early phases of the design (planning included) and evaluation testing programs when high levels of reliability can be achieved most economically.
Power distribution performance indicators assist in incorporating reliability in a network.
2.3 Eskom in terms of reliability
Eskom Distribution’s power network has experienced rapid expansion since the early 1990’s in keeping with the government’s policy of extending electricity as a basic service to millions of previously disadvantaged citizens. The power delivery network operates under pressure .Focused initiatives are underway to improve the performance of the MV(medium voltage) network in order to improve Eskom Distribution’s overall network reliability and technical performance (Newbery, 2002). Since the inception of the electrification programme (or universal access) in 1991 Eskom has connected 4.05 million new households to the electricity grid (D GÜTSCHOW, 2013).
The current and past approach to connecting electrification customers did not explicitly consider the impact that such connections (based on current design for such connections) would have on both the national system’s performance and the economic cost implications thereof (Cameron, et al., 2012). Consequently, electrical network infrastructure provision in South Africa has traditionally been based on a least-cost approach for the last 20-plus years.
2.3.1 Distribution Network System: Overview
The Distribution network is made of a number of equipment, namely – power generator, power transformers, overhead line, underground cables, etc. The combination of the equipment allows for power delivery to the customers (Eskom). In order to ensure visible performance of the
T.R Khumalo (Montso) 17 aforementioned equipment, there are electronic devices that are installed at various places of the network being the following:
Automatic reclosers Automatic reclosers are hydraulically or electrically operated devices that can sense over-current (O/C), fault (E/F) or sensitive earth-fault (SE/F) conditions. Under these conditions the recloser will, subject to pre-determined settings, trip and after a time delay re-close automatically. If the fault is not cleared the recloser will go through a fixed sequence of trip and re-close cycles after which it will lock out.
When the recloser is in the lock-out mode the faulted section will be isolated from the supply and human intervention is required to close the recloser. Integrated automatic reclosers have integrated remote terminal units (RTUs) that enable remote control and monitoring.
Automatic sectionalizing devices
Sectionalisers are hydraulically or electronically operated devices that are used in conjunction with an upstream recloser to isolate a fault.
Fuses Expulsion fuses, installed in a fuse cut-out base, are used extensively in Eskom. These fuses provide a relatively inexpensive yet effective method of clearing fault current.
Fault path indicators A fault path indicator (FPI) is a device that provides a visible and/or remote indication that fault current passed through the location at which the FPI is installed. It is thus a very useful fault finding device,
T.R Khumalo (Montso) 18 Remote terminal unit A remote terminal unit (RTU) is an intelligent electronic device that
facilitates remote control and monitoring of electrical equipment by means of a communications network. Through the use of RTUs the control centre has remote visibility and control over substations and switchgear installed on feeders.
Indoor switchgear Indoor switchgear refers to metal-clad switchgear that can be of the fixed pattern or withdrawable type. It excludes gas-insulated switchgear (GIS) as well outdoor switchgear used indoors.
Outdoor switchgear Outdoor switchgear refers to switchgear designed to be used outdoors in combination with air insulated busbars.
Gas insulated switchgear Gas insulated switchgear refers to switchgear assemblies that contain gas-insulated busbars.
These components form part of the power delivery system .The system comprising generation, transmission and/or distribution, are subjected to many adverse events such as accidents, random component failures and weather conditions resulting in power interruptions (Qzobo, et al., 2012).The use of these devices is very crucial because faults, network interruptions and failure maybe caused by different reasons .The causes are mainly due to design and topology of the network, planned operation and maintenance sessions and but not limited to physical infrastructure failures. Major contributors on load planned, unplanned faults and failures that occur on the physical structure of the network of which the typical causes are:
•Incorrect design application (feeders design without contingency)
•Poor construction
•Equipment overloading
•Poor condition due to inadequate maintenance / refurbishment •Environmental factors (lightning, vegetation, pollution).
T.R Khumalo (Montso) 19
2.4 Electricity distribution best practises and lessons from various international utilities.
The reliability challenges that the South African National distribution grid is facing is not entirely new. Utilities internationally have been and some are still having challenges of providing a reliable power system. The international community is vastly growing. The climate is ever changing.
Optimisation of the power distribution system internationally, at least cost to both the supplier and consumer is the solution.
2.4.1 Power distribution reliability challenges: Lesson from Rwanda
Before 1947 electricity was supplied by a private entity called the East Africa Power and Lighting Company (EAPLC), which operated diesel generator stations in Kampala and Ninja. The company had a total installed capacity of 12.1MWand served about 3200 customers in the two towns. Later in that same year the government corporation, Uganda Electricity Board (UEB) was established by an Electricity Ordinance and started operations in June 1948 (Mwaura*, 2012). During the 1970’s to 1980’s the electricity infrastructure suffered neglect in terms of maintenance, then couldn’t perform optimally. A significant proportion of energy produced was lost due to power transmission and distribution system breakdown, and the inability of UEB to bill and collect money from electricity users.
Uganda’s electricity generation potential of 5300 MW including hydro (2000 MW), biomass-cogeneration (1650 MW), peat (800 MW), geothermal (450 MW), mini hydro (200 MW) and solar (200 MW), is poorly developed).There were some low investments. Reasons for low investment in the electricity sub-sector have been identified assets , perceived technical and financial risks by the private sector in Uganda .Although the total electricity demand was estimated at 580 MW by 2005, the country installed capacity is 464 MW with actual power generation ranging from 195 to255 MW.
The situation is aggravated by unpredictable rainfall and is likely to suffer from climate change (Mwaura*, 2012).
T.R Khumalo (Montso) 20 The situation worsened in Rwanda .The country experienced high non-technical energy losses estimated at 18 percent of the total generated power remained a major constraint for Uganda as it pursues transformation to a modern economy. Consensus has been reached among electricity stakeholders on the importance of prioritizing reduction of non-technical energy losses in the subsector. These non-technical losses refer to electrical energy lost through theft, which could be in form of illegal connections, fraud or non-payment of bills. The high energy loss had a disastrous impact on the power sub-sector, both on supply and demand side management. Illegal tapping of power from the distribution lines led to overloading of the power delivery system resulting in intermittent power disruptions (Mwaura*, 2012). Those who pay for power were exorbitantly charged to cover the costs of energy lost (due to illegal connections) as the utility companies pursue cost recovery strategies. Failure to implement energy loss reduction strategies has impacted negatively on government’s efforts to increase connectivity and increase supply to meet the expanding demand effectively and affordably.
The Rwanda utility took relevant intervention to counter-act the effects of energy losses due to lack of reliability management in their power delivery system. Control and preventative failure maintenance was implemented to alleviate the risk of collapsing the power grid. The EPBS (Electricity Pre-Payment Billing System) information technology-based innovation that mostly utilizes a “smart card” was also implemented. This technology requires the customer to make advance payment before electricity can be used. If the available credit is exhausted then the supply of electricity is cut off by a relay. Illegal connections were significantly reduced and utility profits
T.R Khumalo (Montso) 21 increased. The figure5 below indicates Rwanda’s utility increase in system reliability and profits.
Figure 4 : Electricity purchase, sales and percent loss for Umeme between 2005 and 2010.
(Source (Mwaura*, 2012))
Table 3: Total energy losses experience by Electrogaz (Rwanda Utility) between 2004 and July 2009. (Source (Mwaura*, 2012))
The benefits of energy losses reduction in Uganda included reducing cost of thermal generation;
reducing tariff; improving power planning and implementation; improving profitability to power
T.R Khumalo (Montso) 22 utility distributors, manufacturing sector and the entire economy; reducing load shedding; breaking the hindrances to wider and quality distribution (Mwaura*, 2012). These benefits as they harnessed strongly, they would lead to economic growth, environment protection and reduction of incidences of diseases associated with poor energy sources such as the use of paraffin and biomass; poverty reduction; stimulation of investments in the sub-sector; and withdrawal of government subsidy to shield private entities . Rwanda Electrogaz continues currently to implement these reliability management strategies in order to supply electricity reliably to its communities.
2.4.2 Power distribution reliability challenges: Lessons from independent regulation in Indian electricity.
The electricity reliability challenges that were present in the past two decades in India were influenced by the political and economic situation. Many developing countries introduce independent regulation of power distribution as part of a larger program of electricity reform and restructuring (Navroz K. Dubash, 2008).
Dating back to 1989, the Indian national electricity state was operating under huge constraints due to power shortages and uneconomical operations (Navroz K. Dubash, 2008). There were four major regional grids, namely: eastern, northern, western and southern. These regions were managed by five regional electricity boards (REBs), which monitored the interstate (within the region) and inter-regional exchange of power .these board operated differently which contributed to unreliable power supply in the country.
The primary power resources of which were mainly coal accounted for 62% of the total generation and was concentrated in relatively small areas which were in the southern and eastern regions. In order to get the energy resources to these two regions, coal was to be transported over long distances – in some cases in excess of 1000 km (Navroz K. Dubash, 2008). That incurred high cost of transportation which made generation of power expensive for many coal-based plants. Operations in the southern region were highly constrained by the required licences and releases of water for irrigation, which took preference for multi-purpose hydro projects. Projects to build new hdro power stations were delayed .
T.R Khumalo (Montso) 23 In 1995 India power contraints got worse because of the integrated operations of the 5 boards. The power boards needed to overcome serious hurdles which were hampering the development of the country. These hurdles were constraints that were categorised into the following: infrastructural constraints, operational constraints and institutional constraints.
Infrastructural constraints:
There was an overemphasis on goals such as regional self-sufficiency made at the cost of sacrificing the benefits of a total systems approach that would have benefited the country.
There were weak connection links between and within regions of which limited inter-regional power transfers. It was estimated that construction of additional inter-inter-regional links would have led to additional utilization of 6500-6700 GWh.
There was lack of communication facilities amongst the power boards which resulted in a large number of grid collapses, long response and restoration time, and unscheduled power flow among states.
There was lack of metering facilities for power exchanges, real-time monitoring and an efficient accounting system.
The availability of funds for building transmission links and system control facilities, which was l estimated at Rs.500-600 million over the next8-10 years. The economic state of the country was challenged with this constraint.
Operational constraints:
There were technical Large-scale voltage fluctuations (320-430kV on a 400kV bus), frequency deviations (48.0-51.5Hz), and inadequate reactive power compensation at all voltage levels.
The lack of grid, discipline in the system, in terms of penalties for overdrawing and underdrawing by SUs from the scheduled transfer and time-of-use pricing schemes.
Institutional constraints:
T.R Khumalo (Montso) 24 The Lack of commercial agreements between the SUs resulted in energy being traded under ad hoc arrangements which were rarely related to the marginal cost of generation and was without appropriate division of benefits between the importers and exporters.
The unremunerated tariff structure in terms of providing electricity was at a highly subsidized rate to agricultural consumers of which results in poor financial performance of SEBs.
Indian electricity regulators were established explicitly to de-politicize the sector, but little thought was given as to whether devolving legal power to regulatory technocrats was a sufficient way to
Indian electricity regulators were established explicitly to de-politicize the sector, but little thought was given as to whether devolving legal power to regulatory technocrats was a sufficient way to