The influence of power system dynamic regimes on high voltage distribution networks

This article presents an approach for estimating the permissible ratio between reactive power consumption by rapid variable loads, such as electric arc furnaces and rolling mills, and short-circuit power of power supply networks from the standpoint of errors in calculation of the voltage fluctuation values. The appearance of errors caused by electromagnetic rapid and significant changes in magnitude of reactive power consumption of the above mentioned loads and the corresponding voltage fluctuations at different points in the power system. The transients of a turbogenerator with a typical diagram of its excitation control system and various mathematical models of generators were analyzed. The limiting ratio between the standard deviations of the reactive power consumption variations by the rapid variable loads and the power network parameter was evaluated. This value corresponds to the conditions, when it is possible to neglect the appearance of the electromagnetic transients in the power supply system generators during voltage fluctuation calculations at the connection point to the power network of the aforementioned loads.