Five-phase permanent magnet fault-tolerant motor direct torque control method based on novel pulse width modulation

Abstract

The invention discloses a five-phase permanent magnet fault-tolerant motor direct torque control method based on novel pulse width modulation. The method comprises the following main steps: current and voltage components in a two-phase stationary coordinate system are obtained through coordinate transformation; through a PI regulator, given torque is obtained or the torque is directly given through an initial positioning method brought forward by the invention; an improved voltage method is used for estimating flux linkage, a voltage modulation ratio is obtained through a zero-sequence voltage harmonic injection-type pulse width modulation module, five-phase PWM waves are sent, and more accurate and smoother control is realized on the motor torque and the flux linkage. Compared with the traditional DTC, in the condition of keeping the dynamic response performance unchanged, the motor torque and the flux linkage pulsation can be effectively reduced, and the third harmonic content of phase current can be greatly reduced; and compared with SVM-DTC by adopting the SVPWM technology, sector judgment and voltage vector angle trigonometric function operation are not needed, the operation process is simplified greatly, and operation errors caused by trigonometric function operation are eliminated.

Description

technical field [0001] The invention relates to a five-phase permanent magnet motor control technology, in particular to a zero-sequence voltage harmonic injection pulse width modulation (no position sensor) direct torque control (ZVI-CPWMDTC) method for a five-phase permanent magnet fault-tolerant motor , suitable for high-performance servo control of permanent magnet brushless motors. Background technique [0002] Direct torque control (DTC) is a new generation of high-performance control strategy developed after vector control. It has the advantages of good dynamic response, simple structure, strong robustness, and no need for rotor information and rotation coordinate transformation. attention, and achieved certain results. [0003] In traditional DTC, the hysteresis controller of torque and flux linkage is used, and it is controlled by a pre-established off-line switching table, but there are problems such as large torque and flux linkage, and the switching frequency of...

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Problems solved by technology

[0008] The purpose of the present invention is to provide a direct torque control strategy suitable for five-phase permanent magnet fault-tolerant motors (FT-PMM) and simpler equivalent space vector modulation (no position sensor), in order to solve five-phase permanent magnet fault-tolerant The torque and flux linkage pulsation in the traditional DTC in the motor system is relatively large, and the third harmonic content of the phase current is relatively high. The derivation and implementation of SVM-DTC using SVPWM technology is more complicated, and the current position sensorless technology is more complicated to realize. question

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