Specifics of Emergency Operation in Distribution Grid and their Effect on Integration and Functioning of Distributed Generation Facilities
Keywords:Distribution grid, emergency operation, distributed generation facilities, gas-turbine unit, steam-turbine unit, asynchronous operation, resynchronization, self-start, sectionalization
This paper focuses on the characteristic features of distribution grids, which have the greatest impact on the stability of generators and motor loads. It shows that severe accidents in distribution and transmission grids differ in nature, starting with an overload leading to line disconnections and further evolving into a voltage collapse. It appears that where generator capacity is commensurate with the total power of motors in a grid, the motor load has a significant impact on transients. The paper discusses how asynchronous operation is triggered, progresses, and can be addressed in a grid with distributed generation (DG) facilities. It further analyzes the consequences of deep grid sectionalization and proves why grid structure needs to be optimized for further development. The paper also shows how to take into account the specifics of emergency processes (i.e., accident-associated processes) in distribution grids when integrating and operating DG facilities.