Method for determining the current-dependent and / or rotation angle position dependent parameters of an electrical machine and the frequency converter

摘要

Method for determining current-dependent and/or rotational angle position-dependent characteristic variables of an electrical machine, in particular for performance by an inverter has the steps of: setting a rotational angle position of a rotor of the electrical machine and then blocking the rotor, forming a series current desired value by adding a series current desired value operating point and a series current desired value alternating signal, wherein the series current desired value alternating signal changes periodically with a series current desired value frequency, and/or forming a parallel current desired value by adding a parallel current desired value operating point and a parallel current desired value alternating signal, wherein the parallel current desired value alternating signal changes periodically with a parallel current desired value frequency, regulating a series current to the series current desired value and/or regulating a parallel current to the parallel current desired value, wherein, for the purpose of regulation, manipulated variables in the form of a series setting voltage and/or a parallel setting voltage are produced and are injected into motor phases of the electrical machine, measuring phase currents of the electrical machine and determining an established series current and/or an established parallel current from the measured phase currents, applying a discrete Fourier transform algorithm to the series setting voltage and to the determined series current in order to produce series setting voltage coefficients and series current coefficients and/or applying the DFT algorithm to the parallel setting voltage and to the determined parallel current in order to produce parallel setting voltage coefficients and parallel current coefficients, and calculating the characteristic variables on the basis of the series setting voltage coefficients and the series current coefficients and/or the parallel setting voltage coefficients and the parallel current coefficients.