| 摘要 |
PROBLEM TO BE SOLVED: To estimate a.c. voltage in general-purpose manner by, obtaining an a.c. voltage estimated value according to a specified expression using a d.c. voltage value detected from a PWM converter, an a.c. current value, a d.c. voltage value, an a.c. control voltage value obtained from a generation pattern of a switching bridge, an a.c. reactor value and an a.c. basic frequency value. SOLUTION: An a.c. control voltage Vc is obtained by a d.c. current voltage value VD which is detected by a first means 1, an a.c. current value IA by a second means 2, a d.c. voltage value VD detected by a third means 3 and switching pattern of the control device output. Next, an a.c. voltage estimated value VAK is obtained according to an expression using the a.c. control voltage VC, the a.c. current value IA, an a.c. control voltage value VC, an a.c. reactor value L and an a.c. basic frequency numerical value ω0, where in the expression, (a), (b), (c) are positive constants, K means K-th phase, and S represents Laplacium operator. |
