| 摘要 |
<p>Method for rotor winding damage detection in rotating alternating machines by differential measurement of magnetic field by using two measuring coils is based on the use of two measuring coils (1) and (2) shown in the drawing 1. The measuring coils (1) and (2) are installed on the stator teeth or the stator wedges that, by absolute value, have the same vector magnetic potential. A mutual distance between the measuring coils (1) and (2) is equal to the pole pitch taurho or to the multiple of the machine pole pitch. The ends of the measuring coils (1) and (2) are connected in series over the executive member (3). By differential measurement of the voltage U that is induced in the measuring coils (1) and (2), connected in series, it is possible to unambiguously detect rotor winding damage in all rotating alternating machines. By connecting the measuring coils (1) and (2) in series, magnetic field present in a properly operating machine is excluded from the measured value without any winding damage so that the measured value depends only on the magnetic field caused by rotor winding damage. An increase of the measured voltage U in relation to a reference voltage, signals the presence of rotor winding damage. The executive member (3) can be used for turning off the machine or for a sound or light damage signalization.</p> |
