Permanent magnet synchronous motor model prediction control method for discrete space vector modulation

Abstract

The invention relates to a model prediction control method for discrete space vector modulation, and aims to improve the current, torque and rotating speed control performance of a permanent magnet synchronous motor. According to the method, a discrete space vector modulation method is adopted, a large number of discrete voltage vectors are synthesized through basic voltage vectors, however, the calculated amount and the calculation complexity can be obviously increased due to increase of the number of the voltage vectors, and therefore the calculated amount is reduced through a sector division method. According to the method, a model prediction control method and a discrete space vector modulation method are combined, the advantages of the two methods are integrated, the steady-state performance is improved, nonlinear constraint conditions are embedded, the number of voltage vectors is increased, and the calculation amount is reduced by adopting a sector division method; and the current, torque and rotating speed control performance of the permanent magnet synchronous motor is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of permanent magnet synchronous motor control, and in particular relates to a model predictive control method of discrete space vector modulation to improve the performance of current, torque and speed control of permanent magnet synchronous motors. Background technique [0002] The permanent magnet synchronous motor uses permanent magnets as the rotor, eliminating the need for collector rings and brushes that are prone to problems, improving the reliability and stability of the motor operation, and because it does not need to apply excitation current, there is no excitation loss, which improves the efficiency and power density of the motor. Due to the above advantages, permanent magnet synchronous motors are widely used in high-precision speed and position drives. In high-precision speed drive systems, permanent magnet synchronous motors are required to have low speed error, low torque ripple, low current h...

AI Technical Summary

Problems solved by technology

The first method is field oriented control, which realizes the decoupling of the stator current torque component and the excitation component in the rotating coordinate system, and has good static performance, but the torque response speed is slow

The second method is direct torque control, which selects the appropriate switch state from the switch table according to the torque and flux linkage, which has a simple structure and fast response speed, but the torque ripple is large and the switching frequency is not fixed

The third method is model predictive control, which predicts the current, torque or flux linkage at the next moment according to the discrete mathematical model of the permanent magnet synchronous motor, and selects the optimal voltage vector by minimizing the error between the expected value and the predicted value , the method has good steady-state performance, simple structure and easy to embed nonlinear constraint conditions, but the calculation amount is large

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