A control method and device for AC-D axis decoupling of permanent magnet synchronous motor

Abstract

The invention discloses a control method and device for AC-D axis decoupling of a permanent magnet synchronous motor. The method includes: performing synchronous rotation coordinate conversion after collecting the three-phase current of the motor stator, and obtaining the synchronous rotation coordinate system of the permanent magnet synchronous motor The d-axis current and q-axis current under the following; take the current loop coupling item as an external factor, construct the nominal model of the permanent magnet synchronous motor current loop; identify the coupling item of the current loop through the inertial link in real time, and design the corresponding feedforward path for compensation. And set the identified coupling item at the output of the current controller for voltage compensation; input the α-axis voltage, β-axis voltage and DC bus voltage of the system after voltage compensation to the space vector pulse width modulation unit, and output according to the calculation The six-way pulse modulation signal drives the power tube of the three-phase inverter to complete the decoupling control. The invention can reduce the influence of motor parameters on the decoupling effect, improve the decoupling efficiency and be applicable to more occasions with complicated working conditions.

Description

technical field [0001] The invention relates to the technical field of permanent magnet synchronous motors, in particular to a control method and device for decoupling the AC-D axis of permanent magnet synchronous motors. Background technique [0002] Due to the advantages of high efficiency and high power density, permanent magnet synchronous motors are widely used in various occasions. In high-performance applications, permanent magnet synchronous motors are generally required to have relatively fast electromagnetic torque response to ensure high efficiency of the entire system. performance. At present, the commonly used decoupling method is to use the internal model principle to perform feedforward decoupling. According to the actual parameters of the motor, use the internal model principle to perform feedforward decoupling, that is, to establish a voltage compensation item through the current feedback value, so that the voltage compensation item and The coupling term of...

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Problems solved by technology

[0003] However, in the process of research and practice of the prior art, the inventors of the present invention found that there are some defects in the feed-forward decoupling using the internal model principle, which not only requires accurate motor resistance, inductance, flux linkage and other parameters to achieve Better decoupling effect; and under complex working conditions, there are interference problems such as parameter changes and sudden loads during the operation of the motor. When the inductance parameters do not match, the control strategy cannot achieve complete decoupling control of the current loop, that is, the solution The coupling term cannot completely offset the coupling effect inside the permanent magnet synchronous motor, thus affecting the decoupling effect and dynamic response of the system, resulting in decoupling effect and motor control performance degradation

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