Variable carrier frequency motor controller

Abstract

The invention relates to a variable carrier frequency motor controller. The variable carrier frequency motor controller comprises a motor vector control module, an analog-digital conversion module, a closed loop PI speed-regulating module, a space vector pulse width modulation module and a three-phase inverter, wherein the motor vector control module, the analog-digital conversion module, the closed loop PI speed-regulating module, the space vector pulse width modulation module and the three-phase inverter are electrically connected in sequence. A coordinate transformation module is arranged between the analog-digital conversion module and the closed loop PI speed-regulating module, and an inverse coordinate transformation module is arranged between the closed loop PI speed-regulating module and the space vector pulse width modulation module. The variable carrier frequency motor controller further comprises a random carrier frequency generating module, and the output end of the random carrier frequency generating module is respectively connected with the space vector pulse width modulation module and the motor vector control module electrically. By changing the motor carrier wave frequency in real time, the signal interference brought by turning on or turning off a driving module in a fixed period is reduced, and the motor control quality is improved.

Description

technical field [0001] The invention is a controller based on the vector control of a permanent magnet synchronous motor to realize the control of a variable carrier frequency motor, and belongs to the technical field of electric drive control equipment. Background technique [0002] At present, AC motors have replaced DC motors and become the mainstream direction of modern power electronics development. AC motors are divided into two categories: synchronous motors and asynchronous motors. The asynchronous motor generates the air gap magnetic field through the excitation component of the stator current, while the permanent magnet synchronous motor generates the air gap magnetic field through the rotor permanent magnet. Compared with the asynchronous motor, the permanent magnet synchronous motor has simple structure, high power density, no Excitation loss, high operating efficiency and other advantages. Therefore, there are more and more applications of permanent magnet syn...

AI Technical Summary

Problems solved by technology

The existing vector control technology is to complete all vector calculations through a timer interrupt in the microcontroller program, such as image 3 As shown, since the interrupt period of the timer is a fixed value, the pulse width modulation control period of multiple transistors in the three-phase power converter is also a fixed value, which leads to the same carrier frequency of the motor speed control system, resulting in a fixed Frequency harmonic interference affects motor control quality

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