Arbitrary double vector model predictive thrust control method for linear induction motor and drive system

Patent metadata

Field	Value
Publication number	US-11228269-B2
Application number	US-201916640723-A
Country	US
Kind code	B2
Filing date	Aug 29, 2019
Priority date	Feb 28, 2019
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

The present disclosure provides an arbitrary double vector and model prediction thrust control method and system, which belongs to the technical field of linear induction motor control. The present disclosure combines a double vector modulation algorithm to improve the modulation accuracy, in which two voltage vectors are used in one cycle, so that the amplitude of the fluctuation can be reduced, thereby improving the running performance of the motor. The addition of the double vector modulation strategy increases the complexity of the algorithm, and the calculation process is too complicated. The present disclosure further proposes a simplified search process instead of the traditional repeated calculation and comparison method, which eliminates the need for a complex online calculation process, thereby simplifying the implementation process of the algorithm in the actual system.

First claim

What is claimed is:

1. An arbitrary double vector and model prediction thrust control method for a linear induction motor, adapted to an arbitrary double vector and model prediction thrust control system for the linear induction motor, wherein the arbitrary double vector and model prediction thrust control system for the linear induction motor comprising a speed loop PI regulator, a flux linkage loop PI regulator and a controller, wherein the speed loop PI regulator is configured to generate a thrust reference value, the flux linkage loop PI regulator and the controller are configured to generate a conjugate thrust reference value, and the controller is configured to perform the method, the method comprising following steps:
(1) sampling a current and a running linear velocity of the linear induction motor at a current timing k;
(2) predicting a thrust and a conjugate thrust of the linear induction motor at a current timing k+1 according to the sampled values at the current timing k;
(3) solving an optimal voltage vector combination at the current timing k+1 by taking the predicted thrust and conjugate thrust of the linear induction motor at the current timing k as target values; and
(4) calculating an optimal duty cycle for the optimal voltage vector combination, and allocating pulses of three-phase bridge arms,
wherein an equation for calculating the thrust and conjugate thrust of the linear induction motor is expressed as:

{

F

(

k
+
1

)

=

3
⁢
π

2
⁢
τ

⁢

(

ψ

α
⁢

⁢
1
⁢

(

k
+
1

)

⁢

i

β
⁢

⁢
1
⁢

(

k
+
1

)

-

ψ

β
⁢

⁢
1
⁢

(

k
+
1

)

⁢

i

α
⁢

⁢
1
⁢

(

k
+
1

)

)

F

(

k
+
1

)

_

Assignees

• Univ Huazhong Science Tech

Inventors

• Xu Wei
• Zou Jianqiao
• Liu Yi
• Dong Dinghao

Classifications

• H02P21/13 Primary

  Observer control, e.g. using Luenberger observers or Kalman filters · CPC title

• H02P25/062 Primary

  of the induction type · CPC title

• H02P21/16

  Estimation of constants, e.g. the rotor time constant · CPC title

• H02P21/05

  specially adapted for damping motor oscillations, e.g. for reducing hunting · CPC title

• H02P21/14

  Estimation or adaptation of machine parameters, e.g. flux, current or voltage · CPC title