| 摘要 |
<p>PURPOSE:To achieve a test without removing an electric motor which is incorporated into a system by short-circuiting either two phases of the three phases of the electric motor, applying a single-phase voltage to the remaining phase, and then at least measuring current in that state. CONSTITUTION:Voltage supply terminals u, v, and w of a three-phase AC electric motor 21 are connected to a short circuiter 25 via feeder lines 22. 23, and 24. The short circuiter 25 short-circuits, for example, the terminals v and w. A test current in a single-phase voltage is allowed to flow from a single-phase power supply 28 to the electric motor 21 via feeder lines 26 and 27. The potential between the terminals v and w is equal to 0, thus preventing the electric motor 21 from rotating and applying the single-phase voltage between remaining terminals u and v (w). At this time, current and voltage are measured by a current sensor 29 and a voltage sensor 30. The characteristics of the electric motor 21 are obtained by the circle diagram method etc. using the measurement values. A system controller 31 totally performs the control of the phase to be short-circuited, the control of the level of application voltage and waveform, and the control and test itself of latching and processing of a sensor signal.</p> |
