METHOD AND DEVICE FOR MEASURING THE ANGLE BETWEEN THE FLUX VECTOR IN THE AIR GAP AND THE VECTOR OF THE STATOR CURRENT OF AN ASYNCHRONOUS MACHINE FED BY A CURRENT INDIRECT CONVERTER

摘要

According to the method, current blocks of the stator currents are transformed into square waves of constant amplitude and the current blocks of the stator currents are extended to 180 DEG el. Fundamental components are filtered out from the stator voltages and the phase of the fundamental components are shifted lagging 90 DEG el. The phase-shifted fundamental components are connected into square waves of constant amplitude, at least one square wave of the currents is multiplied by the square wave of the voltage phase following the current phase, and the mean value thereof is formed. There is also an apparatus for implementing the method.