| 摘要 |
PROBLEM TO BE SOLVED: To attain good speed and torque characteristics over the entire frequency region by a constitution wherein a dead time correction amount operating unit, receiving a set dead time correction amount, corresponds to the current amplification amount. SOLUTION: The PWM inverter comprises a gain operating unit 6, a multiplier 7, and a dead time correction amount operating unit 42 for receiving a set dead time correction amount K and a current amplification amount X from the multiplier 7 to generate a dead time correction amount A'. The multiplier 7 receives a voltage command V* and the dead time correction amount A' and delivers a corrected voltage command SW' to an inverter 2. When the operating parameter has intermediate value, the amplitude of product of output from the gain operating unit 6 and motor current I is increased and the dead time correction amount A' varies abruptly before and after the polarity of current is switched. Consequently, a substantially stepwise dead time correction amount A' is obtained and the speed and torque characteristics are improved. |
