Variable Flux Machines for High Performance Drives: Technology Assessment The global shift toward sustainable mobility and energy systems has increased the demand for electric machines that can combine high efficiency, a wide operating range, and flexible flux control. Traditional permanent magnet synchronous machines provide high torque density and compact size, but they have a fixed air-gap flux that limits their performance when operating in flux-weakening mode. Variable flux memory machines (VFMM) represent a promising alternative. They exploit the advantages of the efficiency of permanent magnet machines and the possibility of actively changing and maintaining different magnetization states using low coercivity magnets eventually combined with high coercivity rare earth-based materials in hybrid configurations.