We consider additive generalizations of matrix differential equations defin
ed by particular representations of a Lie algebra. To the right-hand sides
of such matrix differential equations we add appropriate terms chosen in su
ch a way that it is possible to obtain important information about the dyna
mics without solving the equations. For example, we can write explicitly th
eir first integrals and functions which are linear in time along solutions.
Sometimes we can also predict the asymptotic behaviour of trajectories.