Control device for vehicular AC generator

A control voltage is set to an acceleration control voltage which is higher than a battery voltage V by a predetermined voltage difference DELTA V1 within a range and delayed by a predetermined time DELTA T1 during acceleration at low speeds. During acceleration at low speeds, the rotational speed is less than a predetermined value and the rate of increase in rotational speed is equal to or greater than another predetermined value. The range of voltage is higher than battery voltage V and lower than the steady state control voltage of 14.5V.