| 摘要 |
PURPOSE:To accurately perform vector control using a resistance using the constant estimating device of an induction electric motor which can accurately calculate and estimate the resistance of a conductor. CONSTITUTION:A temperature estimation means 112 calculates the loss due to present and past copper loss and iron loss using the current and past values of a frequency command output from a vector control operation means 102 and those of a current component value output from a current component output means 108. Then, a final temperature increase is calculated for each loss and each temperature increase is superposed considering the time lag due to a thermal time constant to calculate a present temperature. Using the temperature of resistance output from the temperature estimation means 112, a resistance estimation means 114 outputs resistance based on the correspondence map between temperature and resistance. Then, the resistance output from the resistance estimation mean 114 is inputted to the vector control operation means 102, thus accurately obtaining slip frequency etc. |
