| 摘要 |
PROBLEM TO BE SOLVED: To provide a current detection method for a three-phase inverter of a resistance-element voltage step-down type that can by far improve current detection accuracy than usual. SOLUTION: Current values of phases of the three-phase inverter 2 are detected based on voltage decreases of current-detection resistance elements 27, 28 and 29 that are connected in series to lower arm elements 22, 24 and 26, respectively, at lower arm sides of the phases of the PWM-controlled three- phase inverter. A reverse signal value of the sum of current values of two phases of the three-phase inverter is employed as a current of the phase of one lower arm element, among the lower arm elements 22, 24 and 26, of which the on-period is short, thus improving the current detection accuracy. COPYRIGHT: (C)2003,JPO
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