CURRENT VECTOR CONTROL METHOD FOR AC MOTOR AND AC MOTOR DRIVE DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a current vector control method using a weak magnetic flux control section for AC motor, which can generate a rotary magnetic flux command current which does not rely upon the temperature-sensitive parameter fluctuation of an AC motor and can reduce the quantity of arithmetic operation in comparison to the conventional method. ;SOLUTION: A weak magnetic flux control section 30 incorporated in a current vector controller for AC motor computes (308) a voltage error ΔVq*, by inputting a q-shaft command voltage Vq* and calculating an absolute q-shaft command voltage value |Vq*|, and then, subtracting the absolute value |Vq*| from the maximum q-shaft voltage value Vq Limit. Then the control section 30 calculates a new d-shaft command current I_d* by computing (309) a magnetic flux command current I_df* through proportionally integrating the voltage error ΔVq* and performing the computation (310) for limiting the command current I_df* to a preset lower limit magnetic flux current value, and then adding the command value I_df* to a d-shaft command current Idx* (104).;COPYRIGHT: (C)1999,JPO