A Linear Field Weakening Control System for Embedded Permanent Magnet Synchronous Motor

Abstract

The invention discloses a linear field weakening control system of an embedded permanent magnet synchronous motor, and belongs to the technical field of motors. The linear field weakening control system comprises the embedded permanent magnet synchronous motor, a linear field weakening controller, an inverter and a rotating speed detection module. The linear field weakening controller is provided with a first linear field weakening control area, a second linear field weakening control area and a third linear field weakening control area. The rotating speed of the embedded permanent magnet synchronous motor is detected through the rotating speed detection module and sent into the linear field weakening controller, the corresponding linear field weakening control area is selected by the linear field weakening controller according to the target rotating speed, the linear field weakening controller controls the inverter to conduct power amplification an output current control signal according to the current control signal output by the corresponding linear field weakening control area, and the embedded permanent magnet synchronous motor is driven to rotate. The linear field weakening control system is simple, high in control speed and high in reliability, constant torque output is achieved when the speed is low, constant power output is achieved when the speed is high, the output torque is large when the speed is low, the speed adjustment range is wide, and the linear field weakening control system has the good application prospects in the fields such as electric vehicles.

Description

technical field [0001] The invention relates to a motor control system, more specifically, to a linear field-weakening control system for an embedded permanent magnet synchronous motor. Background technique [0002] The embedded permanent magnet synchronous motor has the characteristics of high power density, small air gap magnetic circuit, and is suitable for high-speed operation. This type of motor can use the reluctance torque component to improve speed regulation performance and improve motor efficiency. Applications in higher speed adjustable drive systems are becoming more and more widespread. When the ordinary permanent magnet synchronous motor runs above the base speed, its back electromotive force is proportional to the speed, and increases with the increase of the motor speed, and is limited by the limit circle of the voltage and the limit circle of the current, which will restrict its speed range further. broaden. Although the conventional field-weakening contro...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the disadvantages of traditional permanent magnet synchronous motors that are difficult to effectively decouple the direct axis current and the quadrature axis current at the operating point of the field weakening control, the current is easy to get out of control, and the constant voltage frequency ratio control cannot realize the field weakening control. The linear flux-weakening control system of the embedded permanent magnet synchronous motor adopts the technical scheme of the present invention, and through the segmental linearization of the field-weakening control area of ​​the embedded permanent magnet synchronous motor, the direct axis current and the quadrature axis current of the working point can be realized. Linear control avoids the coupling of direct-axis current and quadrature-axis current at the working point. It has the advantages of simple system, fast control and high reliability. It can realize constant torque output at low speed, constant power output at high speed, and large output torque at low speed. , wide speed adjustment range and other characteristics, it has good application prospects in electric vehicles and other fields

Images