| 摘要 |
PURPOSE:To organize the stop control system of an induction motor at a low cost, by storing a latch circuit additionally, and by providing an unused domain with a storage element to practical use effectively. CONSTITUTION:The control circuit of an inverter controlling the rotational frequency of an induction motor is provided with a voltage command generator 1 generating the output of 6 bit signal, a micro-computer 6 having a frequency command generator 2, a ROM 3, a data selector 4, and a ring counter 5, and the main circuit switching element of the inverter is switched according to a voltage pattern stored in the ROM 3. Then, to a domain with the ROM 3 unused, a voltage pattern exclusive for stop with DC excitation most suitable for the induction motor is added, and a latch 7 is provided. In this manner, on stop through speed reduction, the voltage pattern exclusive for stop which is not selected on acceleration is controlled to be selected for an optional time in no relation to a set sped reduction time. |
