Distribution load estimation-a function for the electric utility in the de-regulated electricity market

In the de-regulated electricity market the distribution utility is no longer a monopoly supplier of electricity in its operating area. Only transmission of electricity remains as local monopoly and energy sales will be separated from distribution and transmission. In Finland, the de-regulation of electricity market is planned to begin in the middle of 1995. The first phase allows 500 kW and bigger customers a freedom to select their power supplier. Later on this limit will be removed. The energy balance of the energy selling companies will no longer be equal to measurements in primary substations. Energies of different suppliers must be separated from each other according to the customer measurements. The remaining load, that is measured with conventional energy meters, belongs then to the utility, which is obliged to sell electricity in the area. Some of the load data will be available after a delay, because it must first be calculated from the customers of different suppliers. The utility´s online load must therefore be estimated from various data sources. The distribution load estimation (DLE) prototype is implemented in VTT Energy´s Distribution Energy Management (DEM) project