We analyze a functioning of the thermodynamically motivated Helmholtz extremum principle in the Schr\"{o}dinger picture quantum evolution. The inferred dynamics of the Helmholtz free energy and other entropic functionals quantifies nontrivial power transfer processes in the mean, running even if the quantum system is regarded as "thermodynamically isolated" and kept in a stationary state. Direct analogs of the first and second laws of thermodynamics are obeyed in the course of quantum motion.