A novel method for identifying large steam turbine-generator parameters by load rejection test

This paper employs a novel method, which is first decomposing the load rejection model and then deriving optimal combination models from the characteristics of the decaying speeds of the subtransient component and transient component of one phase voltage, to directly identify the transient parameters in different regions employing nonlinear least squares regression theory respectively. Employing the load-rejection model constructed with the design values of turbo-generator QFSN-600-2YH to calculate the quantities by the different methods indicates that the parameters-identified errors of applying the optimal models are far less than the errors of directly estimating all the parameters from the model. By the models one can obtain the direct parameters and quadrature parameters through load rejections under special reference, i.e. direct axis and arbitrary reference. The direct parameters of a 600 MW turbine-generator made by Harbin Large Electric Machine Plant China are determined by the method.