| 摘要 |
PURPOSE:To permit a smooth acceleration without waiting at a constant rate of the frequency of an electric source by a method wherein a temp. detecting means for detecting the temp. of a hysteresis motor or vacuum degree detecting means for detecting the vacuum degree of a centrifugal machine is provided, and the output electric power from an electric power conversion device and an acceleration time gradient control means for controlling output frequency are controlled by a temp. detecting means or vacuum degree detecting means. CONSTITUTION:The temp. of a hysteresis motor 5 is detected by a temp. detector 10 and, when the temp. of a centrifugal machine reaches a predetermined value, an acceleration time gradient adjustment indicating signal is sent from the temp. detector 10 to an acceleration time gradient adjustor 6. Based on this signal, an acceleration time gradient signal from this adjustor 6 is changed. An acceleration rate signal is supplied to a frequency reference generator 7 and a voltage reference generator 9. When the temp. of the centrifugal machine reaches a predetermined value at time t1, the acceleration time gradient adjustment indicating signal is sent from the temp. indicator 10 to the acceleration time gradient adjustor 6. The acceleration time gradient signal from the aforesaid adjustor 6 is lowered in proportion to the acceleration time gradient adjustment signal. |
