METHOD TO CONTROL PHASE-SHIFTING DEVICE Russian patent published in 2014 - IPC H03H7/18 

FIELD: electricity.

SUBSTANCE: phase-shifting device is controlled by means of stagewise switching of windings of its shunt transformer by thyristor bridges. For this purpose they measure thyristor bridges and voltage on their switched windings. By measured current and voltage values in the initial condition of the phase-shifting device for each thyristor bridge they fix intervals of the first type, starting from shift in polarity of voltage and ending with shift of current direction, and intervals of the second type, starting from the shift of current direction and ending with shift of polarity of voltage. Intervals of the second type are shortened in the start of the interval - by the value exceeding the time of recovery of the control properties of the thyristor, and in the end of the interval - by the value exceeding the sum of time for recovery of control properties of the thyristor and time of current switching in the winding of the shunt transformer. Duration of shortened intervals is compared with duration of the thyristor switching pulse. Sequence of the permitted intervals is generated from intervals of the first type and shortened intervals of the second type, duration of which exceeds the duration of the thyristor switching pulse. The permitted sequence of the stagewise switching of windings is selected, meeting the specified limitations, in accordance with which they perform switching of the windings in the permitted intervals.

EFFECT: improved reliability.

4 cl, 4 dwg