Forecasting data for load flow

In order to achieve a more secure and economic operation of a power system its state should be known not only in the present but some time ahead. Transmission system operators do not have the same security margins like they had in the past. Most of the tools of security assessment operate on-line and provide valuable input to the system operators. Security assessment uses load flow calculation to provide results. If it could be possible to compute load flow several hours ahead it would also be possible to provide security assessment. In this paper a load flow calculation several hours in the future is discussed so developed and tested on-line methods for security assessment can be utilized.