Geographic Information System (GIS) and Their Role in Power Utility Industry

Contributor identification Contribution identification Name Biljana Stojkovska Session 6 Company Korona d.d Block 4 Address Cesta v Mestni Log 88 A Question n° 24 Language used on the floor english Phone Accompanying visuals on file ? yes e-mail [email protected]

Geographic information system (GIS) and their role in power utility industry

GIS – Geographic Information System is complex computer packages designed to efficiently capture, store, retrieve, update, manipulate, analyze, and present every kind of geographically referenced data DLE- Distribution Load Estimation – is a method to combine load research data and the utility’s own measurement data from the distribution automation system At the end we have combination between GIS and DLE – as a combination using a GIS we achieved a more detailed representation of the input data for DLE algorithm so the power traders or retailers should have a reliable and accurate estimates for hourly demands of their customers.

Why the GIS technology was accepted in many electric power distribution utilities. There are various reasons, let us mentioned the most important:  The customer data is geographically related. The billing data is closely associated with the name of the customer, his ID, address, and ID of the measurement units. When the trouble- call appears, it is practically impossible to locate the customer in a short time, as well to trace the rout of related power supply.  The low voltage (LV) network is widely spread. It is very difficult to keep the record on its data, especially to update the database and map drawings with respect to the recent enforcement, or reconfigurations.  To keep an accurate record on the medium voltage (MV) network, as well as the updated record on one-line diagram (with respect to the status of the reclosers) of transformer stations MV/LV especially in a dense urban areas.  The maps are outdated (especially maps with LV network), inaccurate and incomplete, and most of all there exist many copies of the same map with different information. As a result, the network inspection as well the map redrawing must be done on a regular basis.

Some of the load data will be available after a delay because it must first be calculated from the customers of different suppliers. The load must therefore be estimated from various data sources.  SCADA - (acquiring a data about events, status of switches and measurements)  Corporate business database (commercial relational database, file-based data, project documentation, daily reports, executive summaries, displays and various records kept and managed by different systems)  CIS (billing information, annual demands, customer profiles, outages, trouble calls, new customer-focused services)  GIS geographical database (object-oriented database of the distribution network, geographical maps)

Some of the customer loads are metered in real time, at every 15 minutes. The rest of customers have not the metering in real time. Their hourly loads will be known later on, several days after the energy consumption. However, on-line (one hour ahead) forecasts of loads of not metered customers is needed for the trader’s estimate of power generation and electricity purchase. We could to count up one of the main reasons why we need estimation of load:

• Energy purchase optimization • To cut the metering costs • Because of the great number of load points scattered in the whole area supplied by distribution system, it is unrealistic to measure the load and to get the load profile of each load point (transformer MV/LV). • On the other hand the load of the transformers MV/LV is build by the load of each customer which is supplied by that transformer. • The price of hour based meters is too high for the smallest customers

In order to manage a great amount of data of the power distribution system, starting a year ago we explored the tools and capabilities of a GIS system. • It is much easier to utilize GIS for MV network in comparison with LV network. The huge amount of data of LV network, the missing data and a lot of personnel resources are very specific restrictions. • It is difficult to keep the records of network disconectors, fusses, and the topology of the LV network, • The development of metering and data transfer system in integration with distribution network • It is difficult to check the route connection of the customers to the transformer by appropriate object-oriented network presentation without assistance of GIS tools.

The main point of estimation process is the data of energy consumption! The estimation of MV/LV secondary substation’s class of load curves is realized by the state estimation for historic data of substations measurements of feeder currents and busbar voltages. The obtained estimation of load curves of each class is used to obtain the hourly loads of each customer group (residential, industrial and commercial customers) with respect to its energy consumption. The energy consumption of the load point consists of energy consumption of all customers supplied by that transformer.

GIS technology is accepted by many electric power distribution utilities not only to fulfill the corporate business needs, but also as a tool for improvement of the distribution system daily work-process. With the radical changes that the electric utility industry is facing customer choice has become the buzzword for the entire country. The GIS industry will feel the impact of these activities since each new entrant in the energy business, in the form of a broker or marketer, increases the need and utilization of GIS tools, data and products by viewing customers and infrastructure data. The game for retailers will be to capture market share, creating portfolios of customers to diversify and minimize market risk The power exchange set up to price electricity on an hourly basis, a potential problem exists since the bulk of electricity usage is measured only once a month. So GIS in combination with DLE real-time estimates of customer load demands, which are currently unable to be obtained as a results of many limitations at distribution system level.