Influência da não representação de dispositivos lentos de controle nas análises de segurança de tensão

Abstract

Traditionally, Power Systems capacity has been determined by angular stability or thermal capacity of their elements. But factors like intense load growth, system expansion, and systems interconnections, through long transmission lines, have caused problems related to voltage instability and many voltage collapse events have been verified all over the world. As the majority of voltage collapse events are related to equipments that have a slow dynamic behavior, studies of long term voltage control are significantly affected due to the difficulty of representing these equipments in the process of load and generation variation in the system. The automatic and discrete switching of these equipments generate significant impacts on system voltage control and need to be represented accurately to perform more precise, and less conservative, load margin calculus than the ones that are traditionally performed with the majority of static analysis tools available. The present study used a simulation tool capable of implementing a control logic of these slow dynamic behavior equipments based on the bus to be controlled and on suitable voltage control ranges that were established from the experience of operating the studied system, trying to identify, through comparative studies, the impacts of these equipments on voltage security analysis. The studies were made under a wide range of generation dispatches that were applied in some specific areas of the system. It was verified that representing these slow dynamic behavior equipments using voltage control range brought significant benefits on load margins of the analyzed system.