| 摘要 |
PROBLEM TO BE SOLVED: To reduce acceleration and deceleration time by individually setting the ratio pattern between power and frequency being outputted by a voltage-type inverter among acceleration operation, low-speed operation, and deceleration operation and switching the ratio pattern according to the change in an operation state. SOLUTION: A voltage-type inverter 4 is provided with a converter 11, a capacitor 12, an inverter 13, frequency-commanding equipment 14, an acceleration/deceleration computing element 15, and an inverter control circuit 17, and at the same time, either of V/F switchers 21 and 22. With the relationship between a frequency setting value (F*) and a voltage (V*) while a synchronous motor 3 is being accelerated, V*/F* is increased. On the other hand, when the synchronous motor 3 is being decelerated, the V*/F* is reduced, thus switching the ratio pattern between power and frequency being outputted from the voltage type inverter according to the change in the operation state of the synchronous motor and hence reducing acceleration/deceleration time. |
