The invention belongs to the technical field of safety guarantee of extra-high-
voltage alternating-current
power grid electrical equipment, and particularly to a direct-current magnetic bias real-timecalculation method for extra-
high voltage transformer parallel winding series resistance compensation. The method comprises the following steps: constructing three-dimensional geometric models of three transformers and a direct-current magnetic bias calculation
magnetic field model according to actual structural parameters of a main
transformer, a
voltage regulation
transformer and a compensationtransformer of the extra-
high voltage transformer; calculating a self-
inductance value when different currents flow through each transformer winding and a mutual
inductance value between the windings; in combination with an
electrical connection relationship among the three transformers, establishing an overall direct-current magnetic bias
equivalent circuit calculation model of the three transformers through series resistance compensation
voltage; solving the direct-current magnetic bias circuit model by using a fourth-order Runge-Kutta method of
inductance parameters; multiplying the instantaneous current value of the
branch where the series
resistor is located by the increased series
resistor to perform
voltage compensation; and calculating the voltage and current values of each transformer and carrying out FFT (
Fast Fourier Transform) to obtain the voltage and current
harmonic condition of each transformer under the
direct current magnetic bias of the extra-
high voltage transformer.