| 摘要 |
PURPOSE:To widen the range of acceleration/deceleration command by receiving a command frequency from a CPU, stepping up the frequency at a frequency control section, and bringing the frequency close to the command frequency. CONSTITUTION:An inverter 3 drives a motor 2 with variable frequency. A CPU 5 provides an external command of rotational speed of the motor 2. A pulse signal generating section 6 generates pulse signals with a timing shorter than that of the external command. A frequency control section 7 receives a frequency command fs from the CPU 5. The frequency control section 7 steps up the output frequency f0 so that the current value of the switching element in the inverter 3 will be lower than a rating current and the output frequency f0 will follow the command frequency fs. By such arrangement, speed command can be provided over a wide range and acceleration/deceleration range of the motor 2 can be widened. |
