New system for power transfer between two asynchronous grids using twin stator induction machine

Many systems are provided to transfer the power between two grids, such as FACT, HVDC and VFT. This paper proposes a new link to transfer the power between two AC grids. The link is based on a twin-stator induction machine that acts as a power transformer. This system does not require slip-rings. The electric connection is made between the two rotors directly. The twin-stator machine is driven at a predetermined operating speed. The new system works with no restriction on the grids' frequencies. The system's construction, the simulation and the results are provided. The theory behind the selection of the operating speed is discussed.