Control of IPM Synchronous Generator for Maximum Wind Power Generation Considering Magnetic Saturation

Permanent-magnet synchronous generators (PMSGs) are commonly used for small variable-speed wind turbines to produce high efficiency, high reliability, and low cost wind power generation. This paper proposes a novel control scheme for an interior PMSG (IPMSG) driven by a wind turbine to achieve the maximum wind power generation and loss minimization. The effect of magnetic saturation, which causes the highly nonlinear characteristics of the IPMSG, is considered in the control scheme design procedure. The optimal d-axis and q- axis stator current commands are obtained as functions of the generator speed by solving a constrained nonlinear optimization problem that minimizes the copper and core losses in the IPMSG while considering the voltage and current limits of the IPMSG. To eliminate the effects of nonlinearity caused by magnetic saturation, an input-output feedback linearization (IOL) technique is applied to design the high-performance nonlinear current controllers. Implementation results show that the proposed control scheme provides the wind generation system with the maximum efficiency and high dynamic performance.