| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power conversion device that improves controllability of an AC motor by expanding a low-rotation speed region without using a special means for varying an output voltage, achieves size reduction, installation space saving, and cost reduction, and allows energy-saving operation of the AC motor. <P>SOLUTION: Resistors (R1, R2, and R3), semiconductor switching elements (Q1, Q2, and Q3) connected to the resistors (R1, R2, and R3) in parallel, and a gate drive circuit 8 for turning on/off the semiconductor switching elements (Q1, Q2, and Q3) are respectively provided between wirings of output terminals (U, V, and W) of an inverter 3 and input terminals (R, S, and T) of an AC motor 4. A control circuit outputs an opening/closing control signal for turning on/off the semiconductor switching elements to the gate drive circuit 8. <P>COPYRIGHT: (C)2010,JPO&INPIT |
