| 摘要 |
PURPOSE:To efficiently control a voltage and to enhance the efficiency of operating characteristic by detecting a component corresponding to the secondary current from the specific phase of the primary current, and obtaining a voltage command value by considering the variation in the input voltage of an inverter. CONSTITUTION:Blocks 100, 101 for controlling the voltage of a PWM inverter to obtain a voltage command calculating coefficient corresponding to a load, blocks 103, 104 for correcting a voltage set value VR by considering the variation in the input voltage Ed of an inverter to obtain an actual voltage set value VR', and a block 102 for obtaining an actual voltage command VR' are provided. Thus, when the input voltage Ed increases from a rated voltage Ed0, a deviation Ed becomes negative. Accordingly, a coefficient (r) for correcting a voltage command VR' decreases to correct to reduce the set value of the voltage. When the input voltage Ed decreases, it is corrected to increase the set value contrary to the above to stably drive a motor. |
