This paper discusses nonlinear proportional-integral (PI) current control with anti-windup of reluctance synchronous machines (RSMs) for which the flux linkage maps are known (e.g. obtained by FEM analysis or measurements). Due to the nonlinear flux linkage, the current dynamics of RSMs are highly nonlinear and, so, to obtain an (almost) identical current closed-loop dynamics over the complete operation range, the controller parameters and the disturbance compensation terms must be adjusted online at each sampling instant. The model-based controller design is derived theoretically in state space. The theoretical results are illustrated and validated by simulation and measurement results.