From GridLAB-D Wiki
deltamode_forced_always - Once delta mode is entered, prevents a return to EVENT driven mode (QSTS)
Synopsis
#set deltamode_forced_always = FALSE
Remarks
If set to TRUE, once delta mode is entered, it will remain in that mode until the simulation end. Defaults to FALSE so normal DELTA and EVENT transitions occur.
This functionality is mainly to test longer-term dynamic behaviors, and to help debug DELTA to EVENT transitions. It is not recommended to use this feature regularly.
Version
This capability is introduced in Lugo (Version 4.1).