Multi-step model forecast control method of linear induction motor

Abstract

The invention discloses a multi-step model forecast control method of a linear induction motor. The forecast control method comprises the following steps of (1) acquiring a state variable and an angular speed of the linear induction motor; (2) solving an optimal value of an input voltage vector of the motor under a non-constraint condition; (3) judging whether the optimal value conforms to a voltage constraint condition or not, if yes, entering step (5), otherwise entering step (4); (4) updating the optimal value by conforming to the voltage constraint condition as a target; (5) judging whether the optimal value conforms to a current constraint condition or not, if yes, entering step (7), otherwise entering step (6); (6 ) updating the optimal value by conforming to the current constraint condition as a target; and (7) calculating a duty ratio of a three-phase bridge arm according to the optimal value of the input voltage vector of the motor, and sending the duty ratio to an inverter to modulate a working condition of the motor. A multi-step model forecast control algorithm is applied to the linear induction motor, and the running performance of the linear induction motor is improved.

Description

technical field [0001] The invention belongs to the technical field of linear induction motor control, and more specifically relates to a multi-step model predictive control method for a linear induction motor. Background technique [0002] Linear induction motors can directly generate linear mechanical motion without intermediate transmission conversion devices, so they are widely used in industrial production, transportation and other departments. At the same time, due to the advantages of low operating noise, small initial investment, and economical applicability, linear induction motors have been widely used in rail transit in recent years, and they are a promising urban transportation mode. However, due to the special structure of the linear motor, there is an edge effect, which has a great influence on the air gap flux and the excitation inductance. The mathematical model of the motor will become more complex than that of a rotating induction motor. [0003] At prese...

AI Technical Summary

Problems solved by technology

Due to the edge effect, the motor parameters change drastically, which will make the magnetic field orientation and thrust calculation inaccurate

At the same time, the PI parameter setting of the current inner loop is closely related to the motor parameters, and drastic changes in the parameters will make the PI parameter setting process more cumbersome

Therefore, the use of traditional control strategies to control linear induction motors cannot achieve good control effects.

Images