摘要 |
Control means (5) for outputting voltage instructions for drive control of an electric rotating machine (1) adds, by using adders (23u to 23w), position estimation voltage instructions for estimating the rotor position generated by a position estimation voltage generator (12), to drive voltage instructions, and outputs the resultant signals as voltage instructions. Position estimation means (4) include current extractors (6u to 6w) for extracting position estimation currents having the same frequency components as that of the position estimation voltage instructions, from electric rotating machine currents detected by a current detection means (2), a position estimation current amplitude calculation section (7) for calculating position estimation current amplitudes from the position estimation currents; and an estimation position calculation unit (8) for calculating an estimated position of the electric rotating machine (1), based on the position estimation current amplitudes. The position estimation current amplitude calculation section (7) calculates the position estimation current amplitudes, based on an autocorrelation obtained by squaring the position estimation currents. |