This report investigates how the situation has been historically with regards to voltage levels, power flow and shunt connections; how the situation may change in the future and which measures may improve the situation.
Data is gathered from both Ringhals and Svenska kraftnät regarding the reactive resources in the area as well as operational routines. It can be seen in the measurement data that Ringhals’ reactive power capability is used to a high degree during several occasions. During high voltage situations it is observed that, even with all reactors connected, Ringhals absorbs a high value of reactive power. This highlights that, during low load situations, the area has a high demand of reactive power absorption.
On several occasions there has been high reactive power export from Ringhals with nearby reactors connected and vice versa. This indicates that the control of the reactors may be improved with regards to voltage control and reactive power transfer to or from Ringhals. The future commissioning of a STATCOM at Stenkullen and the South-West link will certainly help to improve these aspects. However, due to the complexity of the situation it cannot be concluded in this report if these measures are sufficient to maintain stable and reliable voltage control in the future.