Current control method for double three-phase permanent magnet synchronous motor

Abstract

The invention provides a current control method for a double three-phase permanent magnet synchronous motor. The method is characterized in that a rotor synchronous coordinate system is set for two sets of windings of the double three-phase permanent magnet synchronous motor respectively; the difference between synchronous coordinate systems of the two rotors is 30 degrees; each winding comprisesa d-axis current regulator and a q-axis current regulator; a d-axis current regulator feedback value of the first set of windings is a linear combination of d-axis currents of the two sets of windings; a q-axis current regulator feedback value of the first set of windings is a linear combination of q-axis currents of the two sets of windings; a d-axis current regulator feedback value of the secondset of windings is a linear combination of d-axis currents of the two sets of windings; a q-axis current regulator feedback value of the second set of windings is a linear combination of q-axis currents of the two sets of windings; and a cross-coupling feedback coefficient is set for controlling the cross-coupling degree of the currents of the two sets of windings. According to the invention, thedefects of independent current feedback control strategies are overcome, and the advantages of the two current feedback control strategies are considered.

Description

technical field [0001] The invention belongs to the control technology of a permanent magnet synchronous motor, and in particular relates to a current control method of a double-phase permanent magnet synchronous motor. Background technique [0002] Compared with asynchronous traction motors, permanent magnet synchronous traction motors have the advantages of high power factor, high system efficiency, high torque density, small inverter capacity and strong dynamic response capability. Especially in the past two decades, rare earth permanent magnet materials have developed rapidly. New permanent magnet materials have the characteristics of high remanence density, high magnetic energy product and high coercive force, which have led to the rapid development of permanent magnet synchronous motors. Most of the motors we use on a daily basis are three-phase motors, while dual-phase motors can achieve greater output torque at a smaller winding current, which is beneficial to improv...

AI Technical Summary

Problems solved by technology

for figure 1 With two sets of winding average current feedback control strategies, the influence of the 6th harmonic current on the current loop can be completely eliminated; for figure 2 The control strategy of independent current feedback of the two sets of windings, the impact of the 6th harmonic current is relatively large, which will cause a relatively large current harmonic distortion (THD) in the two sets of windings, which will have an adverse effect on the long-term stable and reliable operation of the motor

[0007] To sum up, for a dual-three-phase permanent magnet synchronous motor with a certain imbalance in the two sets of windings, the average current feedback control strategy may cause the d-axis current and q-axis current of the two sets of windings to be equal to the current given value The difference is large, and the expected control effect cannot be achieved; the current control strategy of the independent current feedback of the two sets of windings may cause the 5th and 7th harmonic current components in the winding current to be relatively large, which is not conducive to the long-term stable and reliable operation of the motor

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