One-phase open-circuit fault-tolerant direct thrust control method for five-phase permanent magnet linear motor

Abstract

The invention discloses a one-phase open-circuit fault-tolerant direct thrust control method for a five-phase permanent magnet linear motor. Firstly, a Clark transform matrix and an inverse matrix thereof are derived based on fault-tolerant phase current. On the above basis, a stator flux linkage on alpha-beta is derived, a stator virtual flux linkage is defined according to the requirements of acircular stator flux linkage trajectory, and thus the voltage compensation on alpha-beta is derived. The stator actual voltage on the alpha-beta is derived by a modulation function of a voltage sourceinverter, and voltage is combined with voltage compensation and stator current, and a stator virtual flux linkage and thrust are observed by a stator flux observer and a thrust observer. Then statorvirtual target votlage is calculated according to given thrust, a given stator flux linkage amplitude and the observed stator virtual flux linkage and thrust. Finally, the stator actual voltage is calculated by the voltage and the voltage compensation, and the motor is controlled by the voltage by the voltage source inverter. According to the method, a thrust fluctuation caused by a motor failureis suppressed, and more importantly, the dynamic performance and steady state performance are consistent with that in a normal condition.

Description

technical field [0001] The invention relates to a direct thrust fault-tolerant control method for a one-phase open-circuit fault of a linear motor, especially a direct thrust fault-tolerant control method for a five-phase permanent magnet linear motor, which can be applied in aerospace, electric vehicles, etc., which have strict requirements on the reliability and dynamic performance of the motor. Where required. Background technique [0002] With the progress of the times and the improvement of science and technology and living standards, users have higher and higher requirements for vehicles, especially for the safety, reliability and comfort of driving. The performance of the automobile suspension system is of great significance to the driving performance of the automobile, so the research on the steady-state and dynamic performance of the active suspension system has received more and more attention. The cylindrical linear motor is a key component of the active suspensi...

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Problems solved by technology

[0004] In view of the deficiencies in the existing motor fault-tolerant control technology, as well as the characteristics of the five-phase permanent magnet linear motor controlled by the present invention and the open circuit fault characteristics of this type of motor, the purpose of the present invention is to overcome the existing one-phase open circuit fault of the five-phase linear motor. The fault-tolerant strategy uses methods such as the traditional Clarke transformation matrix, hysteresis comparator, and switch table, resulting in unequal output phase current amplitudes, large thrust / torque ripple, disordered switching frequency of the inverter, poor motor control accuracy, severe noise, and dynamic Due to the shortcomings of poor performance, there is no fault-tolerant direct thrust control strategy suitable for five-phase permanent magnet linear motors at present. The present invention proposes a fault-tolerant direct thrust control method for five-phase permanent magnet linear motors under the condition of one-phase open-circuit fault. It can not only achieve high fault tolerance performance, high dynamic performance, excellent thrust and speed following performance of this type of motor system in the state of one-phase open circuit fault, but also reduce the complexity of the control algorithm and the overhead of the controller CPU, and can also Realize constant inverter switching frequency, equal motor output phase current amplitude, reduce motor noise and simplify electromagnetic compatibility design, and finally achieve high reliability, high steady-state performance and high dynamic performance

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