The derivation of accurate dynamic average-value models for synchronous machine-rectifier systems is challenging.. proposed parametric approach uses a computer-aided A recently procedure for constructing the required averaged models, wherein the key nonlinear functions are extracted from a detailed (valve-by-valve) simulation. This letter shows that by using a judicious selection of parametric functions, a model obtained at a fixed generator speed is also valid for variable speeds. This is an important feature that makes this approach applicable to systems where electromechanical dynamics and variable speed operation is required.