Reduced magnetohydrodynamics of a toroidal plasma with flows

A simplified system of MHD equations describing the nonlinear dynamics of a toroidal plasma in a high magnetic field is obtained by correct elimination of the fast magnetosonic oscillations. In contrast to earlier analogs (Kadomtsev-Pogutse, Strauss, and other equations), the symmetries and the corresponding conservation laws characteristic of the initial complete system of MHD equations are preserved in the system of equations obtained here. This makes it possible to use the system obtained here to analyze the dynamics of plasma with flow and to avoid error accumulation in the analysis of the long-time evolution of disturbances.