Considerations in Scheduling and Maintaining Power Flows in Distribution Grids of Large Cities and Metropolitan Areas

The study examines the root causes of disruptions of normal operation of power distribution grids in large cities and metropolitan areas, as well as the factors that have a significant impact on the severity of the consequences of accidents. We analyze existing principles of scheduling and maintaining power flows in power distribution grids as well as ways of ensuring the reliability of their operation. We also discuss the considerations in application of automatic emergency control systems to bringing power flows back to the allowable range. The authors propose to use the upward margin when planning power flows, taking into account sudden load increases, for example, in the event of a sharp decrease (increase) in the ambient air temperature. We establish evaluation criteria and provide upward margin values to determine the acceptability of the planned power flows. The study reveals general patterns in the calculation of the upward margin for power distribution grids of large cities and metropolitan areas. Test power flow analysis is performed for a real-world segment of a metropolitan area power distribution grid to identify possible overloads of power grid equipment and compile a list of measures to bring the power flow within the allowable range. The proposed approach makes it possible to minimize load shedding or rule out load shedding altogether, ensuring reliable power supply to consumers in large cities and metropolitan areas.