METHOD OF ELECTRODYNAMIC TESTS OF POWER TRANSFORMERS Russian patent published in 2020 - IPC G01R31/62 

FIELD: electric power engineering.

SUBSTANCE: invention relates to electric power engineering and can be used in creation of network test benches for testing of power transformers for resistance to short circuit currents. Phase output of the high-voltage winding of the transformer through the in-series connected high-voltage thyristor switch and the capacitor bank is connected to buses of the electric mains, and the neutral and the shorted low-voltage winding are grounded. Capacitor bank is divided into N sections with ratio of capacities of sections 2⁰:2¹:2²:…:2^N-1. Current-free switching of separate sections is provided. Capacitive bank capacitance is set equal to the inductance component of the short-circuit impedance of the power transformer. Preliminary charging of capacitor bank from buses of electric mains is carried out along high-voltage circuit, galvanically isolated from short circuit current flow circuit, during M periods of electric circuit voltage, number of which is selected depending on rated power S_nom of tested power transformer by criterion S_nom/M=const for whole range of tested power transformers. Creasing signal of conductivity interval of high-voltage thyristor switch equal to duration of short-circuit test with equal number of positive and negative half-waves of short-circuit current is generated. Master signal is synchronized with voltage of electric mains and supplied to high-voltage thyristor switch. Short-circuit test is started at the moment of voltage maximum at the buses of the electric circuit, which is opposite in sign to direction of voltage of preliminary charging of the capacitor bank.

EFFECT: expanded range of tested power transformers.

1 cl, 1 dwg, 2 tbl