| 摘要 |
PURPOSE:To improve the stability and the reliability of an inverter device without loss of responsiveness by suppressing the output voltage when an operation mode is abruptly varied, thereby suppressing excess current. CONSTITUTION:A polarity discriminator 15 discriminates the polarity of the output of a slip frequency signal amplifier 9, and inputs the output to a voltage correcting circuit 16. The circuit 16 produces an output which is reduced to a value set by the time constant which is determined in advance at the points when the inputs becomes ON and OFF and again reset to the original value at the predetermined time constant. This output is inputted to a voltage instructing circuit 11, and the circuit 11 is varied at the output in proportion to the value of this output. In this manner, the output is suppressed when the operation mode is abruptly altered, for example, from the power drive time of an AC motor 5 to the regenerating time or from the regenerating time to the power drive time. |
