  We describe the Lie group and the group representations associated to the
nonlinear Thermodynamic Coordinate Transformations (TCT). The TCT guarantee the
validity of the Thermodynamic Covariance Principle (TCP) : {\it The nonlinear
closure equations, i.e. the flux-force relations, everywhere and in particular
outside the Onsager region, must be covariant under TCT}. In other terms, the
fundamental laws of thermodynamics should be manifestly covariant under
transformations between the admissible thermodynamic forces, i.e. under TCT.
The TCP ensures the validity of the fundamental theorems for systems far from
equilibrium. The symmetry properties of a physical system are intimately
related to the conservation laws characterizing that system. Noether's theorem
gives a precise description of this relation. We derive the conserved
(thermodynamic) currents and, as an example of calculation, a simple system out
of equilibrium where the validity of TCP is imposed at the level of the kinetic
equations is also analyzed.
