| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve operator's comfort in operation and simplify control by minimizing a torque limitation amount for preventing an increase in temperature of a switching element and by increasing the power density of an inverter by improving the conducting capability. <P>SOLUTION: A torque limiting section for limiting a torque command value of a motor so that the temperature of the switching element may be suppressed to the upper limit value of the element or below includes a torque suppression means for determining a torque suppression value for suppressing the torque of the motor based on the temperature of the switching element; a torque suppression relaxation means for determining a torque suppression relaxation value for relaxing the torque suppression value based on an integral value of a deviation of the temperature of the switching element from the upper limit temperature of the element; a first subtractor for determining a torque limitation value by subtracting the torque suppression relaxation value from the torque suppression value; and a second subtractor for determining a limit torque command value by subtracting the torque limitation value from the torque command value and outputting the limit torque command value to a gate generating section. <P>COPYRIGHT: (C)2009,JPO&INPIT |
