Dodecagonal flux linkage self-control direct torque control method for brushless DC motor

Abstract

The invention discloses a dodecagonal flux linkage self-control direct torque control method of a brushless DC motor. A three-phase bridge type circuit composed of 6 power switching tubes is connected with a seventh power switching tube in series, both ends of the seventh power switching tube are connected with a resistor, states of the 7 power switching tubes are represented by 7 digit combinations, so that an inverter has 12 combination methods and 12 voltage space vectors; a flux linkage trajectory is divided into 12 sectors, and phase commutation is conducted at every 30 degrees; and the 12 voltage space vectors and a zero vector are selected according to the states of the 7 power switching tubes and corresponding to the divided sectors, corresponding switching control signals are generated to control the inverter to drive the brushless DC motor, and the achieved flux linkage trajectory is approximately dodecagon. The dodecagonal flux linkage self-control direct torque control method of the brushless DC motor increases selection number of the voltage space vectors, the optimal voltage space vector is selected by combining a position signal, the phenomenon of excessive adjustment of a flux angle when the voltage vectors of the motor are switched can be effectively reduced, and torque pulsation of the motor can be reduced more efficiently.

Description

technical field [0001] The invention relates to a control system of a brushless direct current motor, belonging to the field of speed regulation of a brushless direct current motor, in particular to a direct torque control method of a brushless direct current motor. Background technique [0002] The brushless DC motor is developed on the basis of the traditional DC motor, replacing the mechanical brush and commutator with an electronic commutator, eliminating the electrical sliding contact mechanism, and having both the characteristics of a DC motor and the structure of an AC motor Simple, reliable operation, convenient maintenance and other advantages, it has a wide range of uses, especially suitable for high-tech fields such as aerospace, numerical control devices, robots, medical and chemical industries. The brushless DC motor integrates the electronic commutator and the motor, and applies advanced electronic technology to the motor field. [0003] Direct torque control ...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of excessive adjustment of the flux angle relative to the sine wave brushless DC motor in the previous control scheme when the voltage vector is switched, and to weaken the suppression effect of the commutation torque ripple. A dodecagonal flux self-control direct torque control method for brushless DC motors is proposed to effectively control torque ripple and improve the dynamic response performance of the system

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