Method of measuring motor constant for induction motor

摘要

A method of measuring a motor constant is provided in a vector control apparatus for an induction motor. A voltage output phase thetav is set at an previously set arbitrary phase. Prior to applying a current, a current command is fed to operate the vector control apparatus with a proportional-plus-integral controller being set operative. After conduction for a predetermined time, the gain of the proportional-plus-integral controller is set to zero to maintain an integrated value constant and accordingly fix a voltage command value. In this state, a current command value and a detected current value are measured. k is measured at two levels of current, and a primary resistance value (or a line-to-line resistance value) is derived from the slope.