Variable-frequency signal injection embedded permanent magnet synchronous motor maximum torque current ratio control method

Abstract

The invention discloses a variable-frequency signal injection embedded permanent magnet synchronous motor maximum torque current ratio control method which comprises the following steps: in a space vector pulse width modulation algorithm, increasing or decreasing the action time of each medium vector in ten sectors to enable a reference voltage vector to generate phase lead or lag during synthesis; the disturbance signal is directly injected into the motor, the disturbance signal enables the flux linkage vector amplitude and the current vector amplitude to generate disturbance with the same frequency, and the d-axis current and the q-axis current of the motor are determined through the maximum torque current ratio point and the rotating speed closed loop; the d-axis voltage and q-axis voltage of the motor are obtained through the rotating speed closed loop, alpha-axis voltage and beta-axis voltage are obtained through Park inverse transformation, and voltage vector synthesis is carriedout in an SVPWM algorithm. The method can improve the frequency of the injection signal in a multiple form along with the increase of the motor speed and the fundamental frequency, so that the injection signal frequency and the motor fundamental frequency do not interfere with each other.

Description

technical field [0001] The invention relates to the technical field of multi-phase motor maximum torque current ratio (MTPA) control, in particular to a method for implementing MTPA by injecting a variable frequency signal into an embedded permanent magnet synchronous motor based on a space vector pulse width modulation (SVPWM) algorithm. MTPA control is realized by injecting disturbance signals of different frequencies at different speeds of the motor. It is suitable for occasions that have high requirements on the performance and efficiency of motors such as aerospace, electric vehicles, and ship propulsion systems. Background technique [0002] Due to the advantages of high torque density and high efficiency factor, the embedded permanent magnet synchronous motor has gradually replaced a series of motors such as induction motors, and has become more and more important in military, aviation and household fields. Nowadays, energy saving and emission reduction have also bec...

AI Technical Summary

Problems solved by technology

Although the look-up table method is relatively simple, its disadvantages are obvious, such as taking up a large amount of storage space, not being robust to motor parameters, etc.; the extreme value search method is more robust to motor parameters and is easier to implement , but the convergence time of the algorithm is long; and in the most widely used methods of signal injection, it is necessary to artificially inject a high-frequency and small-amplitude disturbance signal to track the MTPA point, which makes the high-frequency Noise is more obvious

At the same time, most signal injection methods inject the signal at the front end of the PI controller, and the frequency of the injected signal will be limited by the PI bandwidth.

Although the space vector signal injection method is to inject the signal into the inverter, the frequency of the injected signal is fixed. When the speed of the motor continues to increase and the fundamental frequency continues to rise, the frequency of the injected model may be different from that of the motor. Fundamental frequency mutual interference

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