| 摘要 |
PURPOSE: To obtain reliable magnetic flux of the rotor for an induction motor, only by computation without requirement for a speed detector by providing a rotor magnetic-flux computer, for computing the magnetic flux of the rotor, based on a deduced equation in the circuit. CONSTITUTION: This method comprises a first process, which computes stator voltages and currents (ixs , iys , vxs and vys ), a second process, which computes the variables (αx and αy ) of expressions I and II, a third process, which estimates ϕxr and ϕyr by expressions III-V, a fourth process, which updates ϕr from an expression VI, and a fifth process, which computes the angular velocity of the rotor by an expression VII. Furthermore, the method consists of a sixth process, which computes the control inputs (u1 and u2 ) by utilizing the expressions VIII and IX (ωr * and ϕr * are the instruction inputs of ωr and ϕr , respectively), and a seventh process, which substitutes the values obtained in the sixth process into the expression X and obtains the current instructions (ixs and iyr ). Thus, the accurate rotor speed can be detected, without the requiring a speed detector. |
