Netplan Consulting Electrical Engineers were appointed by the Pretoria Electricity Department to investigate, plan, set-up and test the feasibility of a full blown AM/FM system at the Pretoria City Council`s Electrical Department. It was decided that a process of prototyping would be the best way of evaluating and testing the available technology in a real world situation. The final choice of software was Smallworld GIS because it dramatically decreases the time and costs of implementation, it provides the ability to model complex network applications and perform powerful tracing routines, it has a fully customisable interface as well as the functionality to manage the long transaction and the concurrent access of thousands of users.
The use of Pilot Projects is very common for AM/FM conversions. This is due to the complexity of the software and user procedures involved and because it represents a significant change in a company`s way of doing business. It is a means to test and refine the new system with a production database before committing significant financial and human resources to a full-scale conversion. As such, its purpose is to reduce risks and safeguard your company`s assets against inferior solutions.
In business, there is rarely a single task upon which success or failure hinges. Instead the business process is made up of a complex range of interrelationships. In the same way, there is no single IT solution upon which a business can depend. Instead, solutions that perform the tasks critical to business success must be integrated to work together. It is the technology challenge of the 90s to provide integrated solutions which support not only the individual business tasks but which also work together to streamline the business process.
Automated Mapping and Facility Management (AM/FM) is a generic term addressing transmission and distribution facilities management in utilities and telecommunication companies which are have primarily linear networks. AM/FM is a specialisation of Geographic Information Systems (GIS) that historically has been less concerned with area features than with linear and point features. An AM/FM system builds a linear network model that uses topological intelligence to analyse and run applications across linear features such as power lines, cables or pipes. This process includes network traces and load analysis. A network trace is the process of starting at any point in the network, for example a substation, and following the connected network from that point along a certain route, highlighting and act on (for example writing out to analysis programs) the components found along the route whilst taking into account the state of switches and other network components.
The electrical industry in South Africa is going through fast and widespread change due to national and regional restructuring. The increasing rate of change that is occurring necessitates pro-active management and development of an infrastructure that can quickly adapt and consequently prosper.
Similar to other industries quality decisions depend on quality information. The better the information, the better the decisions, thereby providing a better service to the customers. Furthermore, regulatory aspects or queries are far easier to attend to if all the necessary information is readily available. Information Technology is a key business tool that is central to a strategy aimed at improving competitive performance in the electricity supply industry.
Some facts became apparent through the years:
The single largest investment is data
Different departments generate different types of data
Many departments can benefit by using data from other departments
Departments will most likely automate incrementally
A long range implementation plan is necessary
Different users have different skill levels A system offered as a solution to managing one`s facilities must address the above issues.
Deficiencies and lacks of present systems
With the rapid development in the computer industry many commercially available software products, as well as many customer (one of a kind) products, are currently being used to support the management of utility facility records. Each of these products has a unique set of capabilities and product features overlap extensively. In a number of applications information is still managed by a manual system. The diversity of products used and the different approaches within a utility to manage a variety of information typically leads to one or more of the following problems or shortcomings:
Data is maintained in separate and redundant data models. This causes inefficiency due to the duplication of effort and has the added risk that the different data sets do not correspond.
With different map sets, something as simple as adding a transformer may require revision of six different maps.
With an extensive and old map set, more than one person may be needed full time just to maintain the ink work on the maps.
A growing utility can end up with hundred of thousands of maps of various sizes and levels of accuracy. Some may even be piled in cardboard boxes on the floor making them very difficult to identify and use.
An enormous amount of time may be wasted before a job can even be initiated because the information needed is distributed over at least five different locations. Typically it is then discovered that some documents are already in use, so the person who`s using them has to be found.
Performing multiple tasks may involve different computer sessions with logging out and back in or moving to another terminal.
One utility summarised their situation in the following way: "Historically, we`ve been a bunch of islands of automation. Each department stayed confined within its own group and developed its own programs. One department had no idea of what information and resources were available in another department. Going from one department to another was like going to a different company."
Methodology followed
The cadastral background in vector as well as raster format were overlaid with the electrical network digitised from paper maps. The electrical network consisted of the low voltage 220 V, the 11 kV network as well as the 132 kV backbone. The minisubs and substations has separate drawings known as internal worlds. Access to these is by querying the substation yard or minisub symbol on the cadastral map.
Some of the functions now in the pilot project at Pretoria City Council.
Tracing from any customer supply point to find the nearest distribution box, minisub or substation. The electrical distance is also given.
A simple voltage drop calculation routine that shows the stands with undervoltage problems in red, both on a map as well as on a graph.
Generate interruption of supply notices to relevant customers whose electrical supply are going to be affected by maintenance work on a specific part of the network.
Generate files suitable for electrical analysis by tracing out a network. Under development Some of the functions now in the pilot project at Pretoria City Council.
Smaller alternatives: Microstation and Netbase
Netplan Consulting Electrical Engineers in conjunction with Cadnet Information Systems have developed a suit of software called Netbase to address some of the issues mentioned in the previous section.
The classic scenario for consulting engineers was that they design an electrical reticulation project and then supervise its construction. This was fine as long as the high voltage backbone was in place but with the increasing consumption, its related expansion had to be planned as well. These plans are called master plans. Netplan have made increasing use of Microstation to design and plan for such services.
These master plans normally involved inputs from town and regional planners, various figures of resource consumption (the most important being electricity) and finally numerous maps depicting the existing electrical network on the ground. Other maps consisted of backgrounds helping in the planning process of a master plan such as areas where no servitudes are available.
Netplan and Cadnet work together with various town planners to estimate the areas of maximum growth and based on demographic information they create a long-term (20-year) load forecast that is stores the anticipated growth in Microstation Geographics and Access.
Netplan needed a method whereby future infrastructures could be planned and visualised from the current date to say 20 years henceforth. Cadnet thus started with the initial stages of developing software later called Netbase. Microstation was used to represent the current and future network in the form of lines and symbols. Each electrical network component in the Microstation design file is linked to a corresponding database record in Access. The data for each component consists mainly of electrical parameters describing the component as well as the necessary fields for uniquely identifying the component. Two dates were attached to each component: a commissioning date and a de-commissioning date. This allows one to automatically visualise future development by entering the date and executing the relevant mdl program to only show the network at the specified date. One very obvious advantage is that only one design file is necessary to contain all twenty progressively changing future networks. There are about fifteen mdl screens to help in the placing and querying of the components. The same number of Borland C++ forms are used in the population of the database records. The mdl and C++ routines are tightly integrated to enable the user to work with either the C++ database interface, Microstation and the mdl routines or both simultaneously. The database interface contains various error checking functions as well as a very important ability to generate files suitable for analysis by packages such as PSS/E, CYME or PSS/U.
"We use Microstation and Netbase to produce possible future scenario files which are suitable for using in conjunction with our analysis programs, " said Francois Theron, of POWER SYSTEM HOUSE. "When used in conjunction with Netbase, Microstation allows a user with a large network to study smaller isolated portions of the network by fencing off the relevant area and generating an ASCII file to study with the analysis packages. This cannot be accomplished using Netbase alone. Naturally, using Microstation speeds up the process quite substantially".
"In the planning process it is extremely useful to have a geographical map in front of you," he said. " This is where Microstation plays a big role - the electrical data of a network component which lies in Netbase can be reached by querying the corresponding element in the design file." Netplan also uses Microstation Geographics, typically to generate, merge and manage the loadzones in the Microstation files. Recently, in South Africa`s KwaZulu Natal province, Netplan utilised information derived from town planners on an enumerated area basis to calculate electrical consumption. Based on this information they were then able to ascertain the rate of electrical load growth for each load cell. This would then allow the planner to decide whether or not a substation is warranted for a particular area. Prior to using MicroStation Geographics, this process was an absolute nightmare.
On a recent RDP undertaking in the former Transkei, Cadnet utilised Microstation Geographics and Descartes to manage the data capturing for Eskom`s HELP Database to enable planners to determine the necessary locations for electrical substations throughout 6000 small rural villages. They digitised the village shapes from aerial photographs, warped the design files using Microstation Descartes using GPS (global positions system) co-ordinates acquired from the field for each of the villages.
Additionally, Information gathered from certain households through a questionnaire was added to this data to provide a comprehensive profile. The final information was then filtered through Microstation and Netbase to produce a long-term electrical reticulation supply programme.
The two programs Netbase and Smallworld each has its place in the electrical industry. While Netbase is fine for a small planning environment (large projects, few people), Smallworld caters for a company wide solution. With its ability to handle hundreds of people simultaneously connected by either a LAN or even a 64 kB Diginet connection it is the ideal package for multi-disciplinary integration as far as availability of data as well as analysis is concerned.
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