Predictive control method for alternating current permanent magnet synchronous motor

Abstract

The invention relates to a predictive control method for an alternating-current permanent magnet synchronous motor. The method starts from a q-axis current obtained by performing d-q coordinate transformation on a three-phase winding inductive current of a permanent magnet synchronous motor, and predicts the inductance q-axis current at the following several moments by traversing and optimizing the control quantity Uq of the permanent magnet synchronous motor so as to achieve a predictive control effect. According to a predictive control strategy, the excellent dynamic response characteristics and high robustness in traditional predictive control are reserved, meanwhile, the characteristic of tedious operation of a traditional predictive control strategy is avoided, the operation difficulty of a predictive model is reduced, the problem that the switching frequency of the traditional traversal optimization predictive control is not fixed is solved, and meanwhile, the problem that the operand is too large due to the fact that the number of the on-off state combinations of the switch tubes is too large in a power electronic conversion device with the more switch tubes can be solved.

Description

technical field [0001] The invention belongs to the field of motor control, in particular to a predictive control method for an AC permanent magnet synchronous motor. Background technique [0002] Permanent magnet synchronous motors have been widely used in aerospace, automotive, manufacturing and other fields due to their significant advantages such as simple mechanical structure, high energy density, and high torque inertia. With the continuous development of the above fields, higher requirements are put forward for the control effect of the permanent magnet synchronous motor. The traditional PI control strategy will make the motor system have good robustness, but due to its inherent hysteresis characteristics, the dynamic characteristics of the system are poor, while the model predictive control (Model Predictive Control, MPC) has better dynamic response than PI control. Better results. [0003] The existing predictive control of permanent magnet synchronous motors is g...

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Problems solved by technology

The traditional PI control strategy will make the motor system have good robustness, but due to its inherent hysteresis characteristics, the dynamic characteristics of the system are poor, while the model predictive control (Model Predictive Control, MPC) has better dynamic response than PI control. better effect

[0003] The existing predictive control of permanent magnet synchronous motors is generally divided into two directions. One direction is the traditional model predictive control. The predictive control model is brought into the corresponding state vector matrix to solve the most used control variables, but the optimal control matrix is ​​generally Multi-dimensional matrix, the solution is very complicated. It is difficult for the common controller in the pre-industrial control to complete the corresponding solution work, which greatly restricts the application of predictive control in actual production and life; the other direction introduces the idea of ​​traversal optimization, That is, each control cycle calculates the output state of the motor at the next moment under different switching states of the switching tube, selects the optimal switching tube switching state according to these output states, and continuously updates the switching tube state of the converter according to the above method to achieve the control effect. Although this method has a simple and fast control strategy, adjacent control cycles are independent of each other and require a high control frequency.

It will bring problems such as the converter operating frequency jump, the switching state of the switch tube is irregular, etc.

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