Full speed domain torque maximizing vector control current distribution method for induction motor

Abstract

The invention discloses a full speed domain torque maximizing vector control current distribution method for an induction motor. In the method, voltage limitation, current limitation and physical characteristic limitation of the motor are comprehensively considered, and a given torque maximizing exciting current vector value and a given maximum torque current vector value are obtained by deriving in different speed domains. Due to the adoption of the method, the current utilization ratio and efficiency of an induction motor driving system can be greatly increased, and the full speed domain torque output capability of is enhanced.

Description

technical field [0001] The invention belongs to the technical field of AC induction motors and their control, and in particular relates to a vector control current distribution method for induction motors under multi-condition constraints and torque maximization in the full speed domain. Background technique [0002] AC motor frequency conversion speed regulation methods mainly include open-loop V / f speed regulation and closed-loop speed regulation. Closed-loop speed regulation is also called vector control method, which specifically includes indirect rotor field orientation, direct rotor field orientation, and direct stator field orientation. Among them, the indirect rotor field orientation is widely used because it needs less hardware and has high control performance. [0003] The principle of indirect rotor field-oriented vector control of induction motor is: establish the rotating coordinate system on the direction of the rotor magnetic field, and through this coordinate...

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Problems solved by technology

[0005] Generally, the induction motor vector control system sets the excitation current relatively roughly. In the constant torque area, it is generally set to about 30% of the rated current. In the field weakening area, the excitation current is set to be inversely proportional to the speed. The maximum value of the torque current It is set to the maximum current limit; in recent years, a voltage control method has appeared, which adds two new regulators, the algorithm is complex, the parameter selection is difficult, and it will reduce the rapidity of acceleration and deceleration

Therefore, the current vector control current distribution method has low current utilization rate, difficulty in achieving maximum torque output, or difficulty in realization, poor reliability, and reduced speed. These problems make it difficult for the current vector control current distribution method to meet high performance. Application requirements

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