| 摘要 |
PURPOSE:To stably operate a current type inverter even under low speed operating condition by rectifying the output voltage of an inverter circuit by an amplifier having an absolute value converting function and producing an output of a voltage detector through a gate which is opened or closed in synchronization with a commutation control signal. CONSTITUTION:The output voltage of an inverter 15 is detected by a voltage detector 27, compared by a comparator 25 with a reference signal of an input limiter 26, and supplied to a voltage controller 20. The output of the controller 20 is compared by a comparator 21 with the output of a current detector 17, and a power reactor rectifier 13 is phase-controlled. The detector 27 has rectifiers 61-63 having absolute value converting function, and can effectively detect the output voltage even when the operating speed is low. The outputs VF of the rectifiers 61-63 are driven by the rectifying frequency 6f, and a pass signal TF corresponding to the commutation superposition time can be obtained from the output of one short multivibrator 65 driven by the frequency 6f, and outputted through a gate 66 by a signal TF. In this manner, the output signal VF1, from which commutation surge voltage is removed, can be obtained. |
