中医推拿家庭保健问答.pdf

华中科技大学硕士学位论文
Abstract
Speed sensorless vector control not only maintains the excellent performance of
vector control, but also es the adverse effects of speed sensor, so it is a
promising way to realize low-cost, high reliability and high performance AC speed
regulation system, due to which it es a research focus of electric drives at home
and abroad. In this thesis, theories and related issues of induction motor speed sensorless
vector control are researched in depth. Speed estimation theories, motor parameters
off-line identification methods, and inverter nonlinearity pensation strategies
are analyzed, and also verified by simulations and experiments.
Vector control theory and the speed estimation principle are two theoretical bases of
speed sensorless vector control. In this thesis, vector control theory is described, on the
basis of which an induction motor slip vector control system structure is designed out.
Adaptive state observer is the selected scheme for speed estimation, and a full-order
adaptive flux observer model of induction motor is built. On the basis of Lyapunov
stability theorem, speed adaptive law is derived as the adaptive institution. Then an
induction motor speed sensorless slip vector control system structure is designed out, the
correctness and effectiveness of which is verified by simulations. Simulation of
parameter sensitivity is also done with stator resistance as the deviation parameter, on the
basis of which system robustness to parameter changes is analyzed.
An off-line motor parameters identification method is given, which can effectively
eliminate the effect of dead time on the accuracy of identification for stator resistance.
During the process of identification, the current of motor is controlled to ensure security
of the system. And by simulations and experiments, the identification method proves
high accuracy. Nonlinear error of inverter output voltage can affect estimation for