Pulsed load effects on electrical power distribution systems

The method for analyzing this problem was to obtain an approximate computer modeling of conditions in the distribution system and make recommendations, based on the computer modeling, for network modifications to minimize or isolate the impact of these experiments on the EBT-P experiment through the Y-12 plant electrical distribution system.

A load flow program developed by The University of Tennessee, Knoxville, personnel (under Union Carbide Corporation, Nuclear Division Subcontract No. 7259) was used to model the system during steady state conditions.

A computer program entitled "Electromagnetic Transients Program" or "EMTp" for short was used to model the system during the application of the pulse loads.' The EMTP program was developed by Dr. Herman Dommel and Dr. Scott Meyer of the Bonneville Power Authority in Oregon. . The EMTP consists of simple electrical or power system components which can be connected together to model electrical systems over intervals of time.

After modeling the pulsed loads on the computer a consistent trend emerged. A power system voltage dip occurred during the peak of each pulsed load, proportional to the size of the load.

To eliminate this voltage dip from affecting the entire distribution system, a separate transmission line and transformer were added to the model to supply the pulsed load experiments. A capacitor bank was also added to the model to see if any reduction of the voltage dip occurred.

Conclusions from the computer modeling suggest that a separate transmission line and transformer would reduce the voltage drop due to the pulsed load experiments to less than l percent in the Y-12 distribution system. Little reduction in the voltage drop was seen when a capacitor bank was added to the model.