POWER SUPPLY DEVICE FOR AC POWERED DC TRAIN ENGINES

The power supply device according to the invention contains an adjustable autotransformer (3) and a train transformer (6) to which are connected a thyristor converter (7), an inductor (8) and a drive motor (9). The driving switch (11) is connected to an information-processing block (12) whose second and third inputs are connected to the train transformer (6) and the drive motor (9). One output from the information-processing block (12) leads to a delay angle determination block (13) for determining the delay angle on the front and rear faces of the voltage. The delay angle determination block (13) is connected to a delay angle change-preset block (14) whose outputs are supplied to a buffer distributor (15) and to a delay angle delimiter (16). The two outputs of the latter are supplied to the preset block (14) and to the buffer distributor (15), to whose third input a second output of the information processing block (12) is supplied. The outputs of the buffer distributor (15) are connected to the position selector (5) and to the control unit (17) for the thyristors of the converter (7) and of a forced-commutation block (10). The power supply device according to the invention facilitates control at high power factor levels. The cos phi can be controlled continuously at a value near unity on the basis of the first harmonic of the current; in addition, the arrangement allows a flat phase control, resulting in favourable values of the curvature coefficient.