Vector reduction model predictive control method for permanent magnet motor

Abstract

The invention discloses a vector reduction model prediction control method for a permanent magnet motor. The method comprises the following steps: establishing a discretization mathematical model of a permanent magnet motor driving system; predicting the stator voltage of the motor at the next moment; converting the motor stator voltage into a three-phase stator voltage in a static coordinate system, and judging the voltage polarity; constructing an available voltage vector set of the current control period, and predicting the current magnitude of the corresponding switching state at the next moment; establishing a direct current bus side capacitance prediction model of the inverter, and establishing a switch penalty function model at the same time; and establishing a cost function according to the tracking current error, the neutral-point voltage deviation and the switching frequency tracking error, determining a switching state, and outputting and controlling the on and off of an inverter switching tube. The three-level active neutral-point clamped inverter topology is decoupled into a high-frequency part and a low-frequency part, operation under different frequencies and different operation modes are achieved, and the complexity of a control algorithm and the loss of the inverter are effectively reduced.

Description

technical field [0001] The invention relates to the technical field of drive control of permanent magnet motors, in particular to a model predictive control method for reducing vector of permanent magnet motors. Background technique [0002] In recent years, permanent magnet synchronous motor (Permanent Magnet Synchronize Motor, PMSM) has received a lot of research and gradually applied to the high-power traction system of rail vehicles due to its advantages of high efficiency, high power density, large starting torque and strong overload capacity. Permanent magnet traction is considered to be one of the main development directions for the development of next-generation train traction technology, and has broad application prospects. As a device that directly drives the permanent magnet motor, the traction inverter's control performance and reliability are crucial to ensure the safe and efficient operation of the traction motor. [0003] Existing traction inverters mainly ad...

AI Technical Summary

Problems solved by technology

However, there are two problems in the traditional MPC method used in ANPC inverters: one is the high computational complexity, which makes it difficult for the controller to adopt a higher sampling rate, and it is difficult to implement multi-step prediction; the other is the inverter's The commutation path and voltage vector are relatively chaotic, and it is difficult to predict the loss of switching devices, which brings difficulties to the heat dissipation design of high-power motor drive systems

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