A high efficiency control strategy for synchronous reluctance generator including saturation

Abstract

In this paper, a high energy efficiency control strategy for electric power generation with synchronous reluctance machine (SynRM) is proposed. This kind of machine is gaining attraction in various fields of application due to its high efficiency, compactness and the capability of operating over a wide speed range. These features are highly desirable for generators especially those that operate from energy sources with variable speed. Performance of SynRM is mostly dependent on machine inductances, which are not constants due to magnetic saturation and effects of cross magnetization. State of the art control methods usually assume parameters with constant value neglecting saturation, leading to possible under-use of the machine. A control strategy to operate a SynRM as a generator, in an extended speed range, with high energy efficiency and considering magnetic saturation is proposed in this paper. Finite element analysis is used to establish the reference current vector trajectory to take full advantage of the machine. The control strategy is evaluated via numerical simulation of the machine operating under an actual wind profile demonstrating the higher efficiency and higher power conversion achieved with the proposed strategy.