| 摘要 |
PROBLEM TO BE SOLVED: To obtain an alternating current detection and control system which is constituted of the small number of components, and detects and controls the current of a motor with a high degree of accuracy without being influenced by the residual flux of a core or magnetic saturation. SOLUTION: The alternating current detection and control system comprises: an inverter; the motor which is connected with the inverter and is rotated according to the output voltage or the inverter; a current transformer which is placed between the motor and the inverter, and detects the current of the motor; and a microcomputer which is connected with the secondary side of the current transformer, estimates the primary current thereof from the secondary current thereof, and controls the above output voltage based on the result of the estimation. When the microcomputer estimates the primary current, the microcomputer operates as follows: based on a current value for determining the rotational position of the motor from the inverter and a reference current value at the waveform inflection points in the waveform supplied to the motor, the microcomputer corrects the secondary current and estimates the primary current based on the result of the correction. |
