| 摘要 |
PROBLEM TO BE SOLVED: To easily provide a measure for over-voltage due to non-load induction voltage of a motor and restart of inverter, by inserting in series a parallel connecting circuit of a one-way conducive means and a switching means between the power supply of inverter and inventor arm. SOLUTION: For example, in the case of restarting inverter operation during rotation of a PM motor 5, the inverter operation is restarted while a switching means 7 is kept open with a control device 40. In this case, while a torque current element is maintained at zero, only the energizing current element is controlled to set a terminal voltage of the PM motor to the predetermined value. As a result, a magnetic flux of the PM motor 5 is lowered, thereby lowering an inducted voltage. Charges accumulated in the capacitors 31 to 33 are lowered due to the switching loss of the inverter operation during this period and consumption by copper loss of a coil of the PM motor 5. In this case, when loss exceeds an extra element of the charging voltage of the capacitors 31 to 33 for the power supply voltage, the power is supplied from the power supply side 1 via the one-way conductor means 8. |
