Method for solving phase current reconstruction dead zone of permanent magnet synchronous motor

Abstract

The present invention provides a method for solving the phase current reconstruction dead zone of a permanent magnet synchronous motor. In the method, the current predicted by the model prediction module is adopted to replace the reconstruction current for feedback when the dead zone is reconstructed, and a good control effect is achieved. No extra voltage vector is injected, the stability of thesystem is guaranteed, the single current sensor is used for reconstructing the phase current, the cost of the control system is reduced, the size of the control system is reduced, and the measurementerror caused by the difference between the current sensors is avoided.

Description

technical field [0001] The invention relates to the technical field of permanent magnet synchronous motor control technology, in particular to a solution to a phase current reconstruction blind zone based on a bus current sensor. Background technique [0002] At present, the relatively mature methods of permanent magnet synchronous motor control are vector control and direct torque control. These control methods all rely on collecting the three-phase current of the motor for feedback to form a closed loop. Therefore, the accurate collection of three-phase current is very important for these control strategies. Particularly important. The traditional three-phase current information acquisition is mainly completed through 2 to 4 current sensors, which directly collect the two-phase or three-phase current of the stator to realize control. However, most of the high-precision current sensors that realize the above-mentioned current information collection are relatively expensive...

AI Technical Summary

Problems solved by technology

However, most of the high-precision current sensors that realize the above-mentioned current information collection are relatively expensive, which greatly increases the cost of the motor control system and the volume of the electronic control system, and the difference in DC bias or current gain between different sensors , also brings the increase of torque fluctuation to the whole system, which further limits the improvement of system performance

These problems can be effectively avoided by using a single current sensor, but since there will be blind spots when the single current sensor performs phase current reconstruction, in the initial phase current reconstruction technology, when the output voltage vector amplitude is too low or close to the sector boundary, Refactoring is not possible

At present, some methods to solve the blind area have been proposed, such as measurement vector insertion method, pulse shift method, three-state pulse width modulation technology and hybrid pulse width modulation technology, but there are still more complicated steps such as additional voltage vector injection, which cannot Ensure system stability

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