Fault-tolerant dual-vector prediction control method and apparatus for six-phase permanent magnet motor

Abstract

The invention discloses a fault-tolerant dual-vector prediction control method and apparatus for a six-phase permanent magnet motor. The fault-tolerant dual-vector prediction control method comprisesthe steps of obtaining the rotor position, rotary speed and phase current of the six-phase motor; solving fault phase counter electromotive force according to the rotor position, the rotary speed, thepermanent magnet flux linkage on the rotor and the axial line position of the fault phase, and establishing a motor frequency converter model by considering the fault phase counter electromotive force; establishing a reduced-order motor mathematical model according to the position of the fault phase; establishing a six-phase motor switch meter after fault, obtaining phase voltages corresponding to respective switch vectors, bringing in the reduced-order motor mathematical model, and determining a phase current prediction value of each switch vector after one sampling period is executed; performing evaluation on error between each phase current prediction value of each switch vector and the corresponding phase current instruction value, and selecting the switch vector with the minimum error as the optimal switch vector; and performing modulation on the optimal switch vector and a zero vector in one sampling period to determine the duty ratio of the optimal switch vector. By virtue of the fault-tolerant dual-vector prediction control method, the current harmonic of the faulty motor can be suppressed effectively.

Description

technical field [0001] The invention belongs to the field of electromechanical technology, and more specifically relates to a fault-tolerant double-vector predictive control method and device for a six-phase permanent magnet motor. Background technique [0002] At present, multi-phase motors have been widely used in high-power and high-reliability applications. The high degree of freedom of multi-phase motors enables fault-tolerant control after phase loss. Researchers have proposed many fault-tolerant control methods, such as resonance control, proportional integral control, direct torque control, and model predictive control. Compared with other control methods, model predictive control has the outstanding advantages of high response speed and no need to adjust parameters. Model predictive control realizes the prediction of the state of the motor under the action of different voltage vectors by establishing the mathematical model of the motor and inverter, and then import...

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Problems solved by technology

[0003] Aiming at the defects of the prior art, the purpose of the present invention is to solve the problem that the fault-tolerant predictive control method of the traditional six-phase permanent magnet motor only selects one action vector in each sampling period, and there are low switching frequency and current harmonic content at the same sampling frequency. Big problem; in addition, the number of action vectors that can be selected is limited, and the gap between the target vector and the target vector always exists; to improve the current quality can only be achieved by increasing the sampling frequency, which greatly increases the technical problem of the amount of calculation

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