Five-phase asynchronous motor control strategy based on stator magnetic field orientation

Abstract

The invention relates to a five-phase asynchronous motor control strategy based on stator magnetic field orientation. Considering the characteristics of a five-phase asynchronous motor, the control strategy combines the advantages of vector control and direct torque control. Starting from the torque control effect, on the basis of voltage drop compensation of the stator resistance, the stator fluxlinkage is controlled by the stator straight axis potential. The purpose of controlling the torque is achieved by controlling the current torque component. The continuous control of the torque and the stator flux linkage is realized. The dependence of the system controller on the rotor parameters is avoided. A continuous control method is adopted to overcome torque ripple caused by hysteresis control. The control strategy provided by the invention is suitable for the fields of power electronics and power transmission.

Description

technical field [0001] The invention relates to the field of power electronics and electric drive, in particular to the field of a frequency conversion speed regulation control system of a multi-phase asynchronous motor. Background technique [0002] For the frequency conversion speed regulation system of asynchronous motor, the torque characteristic of the motor is controlled, and the speed of the motor is also controlled. Therefore, the fundamental problem of AC speed control system is torque control. [0003] The torque of the AC motor is generally related to the rotating magnetic field and the angle between the stator and the rotor. Therefore, in a speed regulating system, if you want to control the torque, you must first control the magnetic flux. In field oriented control (or called vector control, FOC), each AC quantity in the static coordinate system is transformed into two mutually perpendicular components in the synchronous coordinate system, namely the excitation...

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Problems solved by technology

From this point of view, DTC has advantages, because the coordinate transformation and magnetic field orientation in the vector control algorithm are relatively complicated, which will greatly increase the burden on the processor, and the rotor field oriented control is greatly affected by the change of rotor parameters

However, in the traditional DTC control, hysteresis loop or double-position bang-bang control is adopted for the adjustment of flux linkage and torque, and the torque ripple is large at low speed, which causes the low-speed performance of the DTC system to deteriorate and the speed regulation range is not wide.

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