| 摘要 |
<p>The method of determining the magnetic properties of the rotor of a hysteresis motor by measuring the current in the stator windings when the rotor is held stationary is characterised in that the stator is energised at a frequency (50c/s) considerably lower than the frequency (1,000 c/s) at which it is designed to be energised when the motor is in use. With this method (which clearly also requires that the stator energising voltage be reduced in magnitude by the same proportion as its frequency is reduced) the rotor is still driven completely round its hysteresis loop but eddy currents and reactive loses are reduced. The stator current is therefore more representative of the rotor's hysteresis losses. As shown the stator 4 is energized by a three-phase supply with the rotor 3 held stationary and the average values of the active currents and the voltages are evaluated and displayed. <IMAGE></p> |
