| 摘要 |
PURPOSE:To obtain a desired control signal without using the circuit constant of a motor by calculating the phase value of an exciting current from a primary current and the absolute value of the exciting current in a vector controller for an induction motor to be calculated based on a vector control system. CONSTITUTION:A primary current I1 and a command value B of a phase angle difference from an exciting current are added by an adder 32 to obtain the phase angle command value of the primary current as an input signal of a current command value calculator 7. The value 11 of the primary current absolute value is calculated by a root-mean-square calculator 8 similarly as an input signal of the calculator 7. The primary current command values of three phases are compared with primary current momentary values (iU, iV, iW) output from a current detector 2 in which they are input to a current control circuit 6, and a PWM inverter 3 is so controlled that the momentary value becomes the primary current command value. |
