Direct torque control method of common DC bus type open-winding permanent magnet synchronous motor system

Abstract

The invention discloses an improved direct torque control method of a common direct current bus type open winding permanent magnet synchronous motor system. Six voltage vectors which generate a zero sequence voltage of zero are selected as basic voltage vectors, and optimal voltage vectors of each sampling period are determined according to flux linkage and torque errors; meanwhile, a zero voltagevector is introduced, and an action position and action time of the zero voltage vector are determined according to a given zero sequence voltage of a zero sequence circuit loop; and direct torque control on the common direct current bus type open winding permanent magnet synchronous motor is realized. Therefore, the method is simple in control thought, low in implementation difficulty, high in dynamic response speed, capable of effectively inhibiting a zero sequence current, low in calculation amount and small in system burden.

Description

technical field [0001] The invention belongs to the technical field of motor control, and in particular relates to a direct torque control method of a common direct current bus type open-winding permanent magnet synchronous motor system. Background technique [0002] The common DC bus type open-winding permanent magnet synchronous motor is a new type of structure in which the two ends of the stator winding of the traditional Y-connected permanent magnet synchronous motor are opened to form an open winding, and a DC power supply supplies power to both ends at the same time. This motor has a simple structure , which can generate abundant voltage vectors to increase the voltage level and reduce the system fault tolerance. Since the zero-sequence loop is closed, the zero-sequence voltage generated by the voltage vector and the rotor flux harmonics will cause zero-sequence current, and the zero-sequence current will cause current harmonics to increase, motor temperature rise and ...

AI Technical Summary

Problems solved by technology

At present, there is no research on the system strategy of common DC bus type open-winding permanent magnet synchronous motor based on direct torque control. Therefore, in order to suppress the zero-sequence current, it is necessary to make corresponding adjustments on the basis of conventional direct torque control to improve the operating performance of the system.

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